ST170 VCT Delete Kit from the Statessilky16v - 9/10/12 at 12:09 PM
Just incase anyone is interested in wanting to the delete the VCT on the inlet cam on there ST170 engine & doesn't have the correct ECU to
control the PVM solenoid
I was looking to do this as cheap as possible but still retain the ST170 camshafts
You may or may not be aware of this little bit of kit from the states
Hopefully get some feedback on the issue with oil at the camseal
Just need to buy a Zetec Vernier for the inlet and i should be good to go
I emailed Massive Speed on Facebook and they sent me a Paypal invoice with the correct UK postage all in it worked out at £30.13 i probably couldn't get someone in the uk to make it for that
I'm aware that i will loose the low down Torque i get now switching the solenoid on at 2000rpm/20% throttle
I'm using a Omex 600 ECU so don't have PVM control
But the fact the engine in this state doesn't seem willing to rev freely past about 6250rpm, i hope with a fixed cam postion it will more than
make up for the loss of torque low down & the engine will rev far better at top end
once the kit has arrived i will update this post again
mikey p - 9/10/12 at 02:06 PM
yes the PWM signal on the road car is not as simple as full advance through the RPM range as it advances midrange and then retards back to around
110Deg ATDC iirc for peak power. Will defiantly keep it on the boil at high RPM with fix timing around this figure as st170 themselves love to pull
hard all the way to the limiter.
Dusty - 9/10/12 at 07:07 PM
I had a mate machine me up a new centre for a vernier. Cam now timed with the vernier zero set at 20 degrees advance over vvt base position using 20
degree cam bar. Can swing +or- 10 deg (10 to 30 degrees of cam advance) using the vernier adjustment and found 24 degrees seemed best power spread on
rolling road. Bit like a rally cam. Power from 3000 to 7500. No miracles.
I still think the ST170 is a dead end engine. The stock cams are a compromise. Very expensive to fit better.
As the head gasket is blown on mine I'm currently thinking flowed blacktop head with rally cams on the ST bottom end.
[img]
vvt delete 1
[/img]
[img]
VVT delete 2
[/img]
[img]
vvt delete 3
[/img]
[img]
vvt delete 4
[/img]
[Edited on 9/10/12 by Dusty]
silky16v - 9/10/12 at 08:44 PM
quote:Originally posted by Dusty
I had a mate machine me up a new centre for a vernier. Cam now timed with the vernier zero set at 20 degrees advance over vvt base position using 20
degree cam bar. Can swing +or- 10 deg (10 to 30 degrees of cam advance) using the vernier adjustment and found 24 degrees seemed best power spread on
rolling road. Bit like a rally cam. Power from 3000 to 7500. No miracles.
I still think the ST170 is a dead end engine. The stock cams are a compromise. Very expensive to fit better.
As the head gasket is blown on mine I'm currently thinking flowed blacktop head with rally cams on the ST bottom end.
[img]
vvt delete 1
[/img]
[img]
VVT delete 2
[/img]
[img]
vvt delete 3
[/img]
[img]
vvt delete 4
[/img]
[Edited on 9/10/12 by Dusty]
thanks for that if i've read the above right you are running 109 deg of advanced on the inlet? which you found the best compromise
Can is ask what you did to block the oil ways?
What cam position did you use the exhaust vernier?
What power did it make?
Thanks
Rob Allison - 10/10/12 at 12:47 AM
Cam timing on the ST170 inlet is 85deg to 145 deg. I think the normal position on a zetec is about 110 ? Found that piper have most of there cams at
106deg full lift.
So the above figure of 20deg from base would be 104deg, not far off what is normaly set at and another 4deg added as you said making it 108 deg.
I like the machined centre
[Edited on 10/10/12 by Rob Allison]
Dusty - 10/10/12 at 11:28 AM
109 sounds like a conventional figure. I get confused when some of the degrees are cam degrees and some are crank degrees.
It runs. Can be slow to start from cold. Exhaust runs 6 degrees retard. I get a couple more horses with 8 degrees but over a narrower range which
makes it less fun to drive. Using less inlet advance does reduce the intake roar considerably!!!
I did nothing with the oil supply to the vvt. Still get 3.5 bar. When I take the head off I will find a suitable ball bearing and tap it in the oil
feed with some loctite.
Power output depends on the mapping and the optimism of the gauges on the rolling road. Real world it's about 170 at the wheels. All delivered
with very little excitement but perhaps I'm used to it. Passengers usually go very quiet but that could be my driving.
As I said before I don't like the ST engine. With the vvt just switched by omex 600, not PWM, it's all over at 6000 when you only seem to
have come 'on cam' at 3500. As it is now it's gutless below 3000 but pulls all the way to 7500. If I had the cash then keeping the vvt
by fitting an ecu that will properly control them like the DTA S60 and fitting better cams would be the way to go. Modifying the head is good as the
exhaust ports are tiny, same size as the standard zetec. I have read that the head is a bit fragile when skimmed.
I currently have a blown headgasket due to a sudden water pipe failure. Cut by a jubilee clip. I was going some when it happened. Only realised when I
got steam through the bonnet vents when slowing for the next roundabout, by which time the engine was cooked. So I don't know if the head is
genuinely fragile. It was severely abused running hard with no coolant!
I'm still in two minds about fitting a modified blacktop head or sorting the blown head gasket. Blacktop heads and cams are much cheaper.
silky16v - 10/10/12 at 12:22 PM
quote:Originally posted by Dusty
109 sounds like a conventional figure. I get confused when some of the degrees are cam degrees and some are crank degrees.
It runs. Can be slow to start from cold. Exhaust runs 6 degrees retard. I get a couple more horses with 8 degrees but over a narrower range which
makes it less fun to drive. Using less inlet advance does reduce the intake roar considerably!!!
I did nothing with the oil supply to the vvt. Still get 3.5 bar. When I take the head off I will find a suitable ball bearing and tap it in the oil
feed with some loctite.
Power output depends on the mapping and the optimism of the gauges on the rolling road. Real world it's about 170 at the wheels. All delivered
with very little excitement but perhaps I'm used to it. Passengers usually go very quiet but that could be my driving.
As I said before I don't like the ST engine. With the vvt just switched by omex 600, not PWM, it's all over at 6000 when you only seem to
have come 'on cam' at 3500. As it is now it's gutless below 3000 but pulls all the way to 7500. If I had the cash then keeping the vvt
by fitting an ecu that will properly control them like the DTA S60 and fitting better cams would be the way to go. Modifying the head is good as the
exhaust ports are tiny, same size as the standard zetec. I have read that the head is a bit fragile when skimmed.
I currently have a blown headgasket due to a sudden water pipe failure. Cut by a jubilee clip. I was going some when it happened. Only realised when I
got steam through the bonnet vents when slowing for the next roundabout, by which time the engine was cooked. So I don't know if the head is
genuinely fragile. It was severely abused running hard with no coolant!
I'm still in two minds about fitting a modified blacktop head or sorting the blown head gasket. Blacktop heads and cams are much cheaper.
Thanks very much for this info it all helps, am i right in thinking the degrees that are quoted are camshaft degree and NOT crank?
I must admit the sudden power kick i had when the vvt kicked in was great but the fact it wouldn't rev freely past 6250rpm really started to
annoy me, especially as i had an R1 powered MK indy before this so i was use to having to rev the engine to get it to go anywhere.
If i can obtain the same BHP figure as before (178bhp) i'll be more than happy i just want an engine that rev's freely lol!
Rob Allison - 10/10/12 at 09:29 PM
It's crank shaft degs.
Back to cams. I was looking at how it would be possible to fi black top cams into the st head. It looks like I would only need an adapted front cam
bearing, st is bigger.
silky16v - 10/10/12 at 10:21 PM
quote:Originally posted by Rob Allison
It's crank shaft degs.
Back to cams. I was looking at how it would be possible to fi black top cams into the st head. It looks like I would only need an adapted front cam
bearing, st is bigger.
Thanks though it would be crank degrees
To me if you can cheaply make the standard cam fixed and obtain 180bhp+ from a standard engine (abet fitted with some sort of throttle bodies &
after market ECU)
Then I would think the ST170 would be a good choice as its a much stronger bottom end to start with & has a better around head
I'm personally hoping that I can get nearer 190bhp+ without having to think about changing cams or any internal engine items to get a black top
to that level would to me be considerably more money
Back to your head I'd suggest getting the head checked for flatness I'm led to believe that's the heads don't take kindly to
skimming
[Edited on 10/10/12 by silky16v]
Rob Allison - 11/10/12 at 09:55 AM
Thought i would put up a pic of the st and zetec cams.
Aa you can see the st inlet cam has a larger and different drive end bearing for the vvt system. My thought was that a spacer bearing could be
machined to fill the gap from the zetec cam to the st head. As the vvt is not to be used the phase sensor pickups on the other end will not matter.
There is a difference in the base circle from the zetec to st cam lobes but the cam buckets need to be reset even with modified st cams.
quote:Originally posted by Rob Allison
Thought i would put up a pic of the st and zetec cams.
Aa you can see the st inlet cam has a larger and different drive end bearing for the vvt system. My thought was that a spacer bearing could be
machined to fill the gap from the zetec cam to the st head. As the vvt is not to be used the phase sensor pickups on the other end will not matter.
There is a difference in the base circle from the zetec to st cam lobes but the cam buckets need to be reset even with modified st cams.
true but what sort of power would a standard black top engine make with just a set of cams and throttle bodies fitted? 175bhp???
where as if the above can be performed on a standard ST170 motor and obtain 180bhp+ i think it will make the ST motor a more viable option for the
locost builder on a budget maybe?
I can what your saying fitted after market cams to the ST head, but what ever option you use (ST specific cams or Zetec) it is quite an expense due to
having re-shim the buckets, but it all depends on how knowledgable the end user is?
My aim is use a standard ST170 motor fit the VCT delete kit and a Vernier and after market management and throttle bodies (mine are GSXR1000) and
obtain 180bhp & free reving engine that is usable on road and occasional track use.
Considering my engine made 178bhp with the VCT switching on at 3000rpm/20% throttle i'm hoping 190bhp is obtainable.
My main aim is a free reving usable engine not gonna chase BHP figures
let me know which ever way you decide to go with replacing the cylinder head or cams
scutter - 11/10/12 at 12:14 PM
I'm gonna stick my oar in here, I run the St lump on an old Omex 500 ecu, GXR 750 throttle bodies and a 2.5" exhaust.
The VVc is run of the shift light output at 2600 rpm, with out the solenoid connected it made 190 in a very linier fashion, now its much more lively
to drive with a massive increase of tourque to pull the car through the rev range.
They do seem very sensitive to exhausts as I found 10 hp byu going from a 2.25 to 2.5 diameter with a proper merge collector.
Apart from the exernal parts my engine is standard, so no worries if it pops.
I'm gonna stick my oar in here, I run the St lump on an old Omex 500 ecu, GXR 750 throttle bodies and a 2.5" exhaust.
The VVc is run of the shift light output at 2600 rpm, with out the solenoid connected it made 190 in a very linier fashion, now its much more lively
to drive with a massive increase of tourque to pull the car through the rev range.
They do seem very sensitive to exhausts as I found 10 hp byu going from a 2.25 to 2.5 diameter with a proper merge collector.
Apart from the exernal parts my engine is standard, so no worries if it pops.
Just my 2Ps worth. ATB Dan.
very strange as when i switched my VVT output off my engine would rev freely with no load ie. in netural but on the road it wouldn't rev at all
and once up to 3000rpm just wouldn't go any further, switch it back on and all is fine just no rev's at top end
it does seem strange it made 190bhp with no VVT activated as the cam timing would be all wrong to make top-end power
how have you got your cams timed?
scutter - 12/10/12 at 05:12 AM
This I hope is the original plot before the vvc activation and exhaust change.( currently in the UAE, on crappy laptop)
Just remembered, I did fit the vernier on the exhaust and set it to a safe 4 deg.
Granted it doesn't produce power past 7K, but if your after that then maybe a bec would be better as i've never had a problem on road or
track.
ATB Dan.
Rob Allison - 18/10/12 at 12:56 AM
Has the delete kit arrived yet?
silky16v - 18/10/12 at 06:46 AM
quote:Originally posted by Rob Allison
Has the delete kit arrived yet?
Posted out last Friday so hopefully here soon, just need to order another vernier
Jenko - 18/10/12 at 07:53 AM
Interesting topic.....Must admit, it makes no sense that the VVT should strangle and limit revs as per Dusty's post. Possibly worth checking the
cam pulley was set correctly when doing the timing. As I understood it, the VVT would gradually advanced the timing based on revs (and pssobly
throttle position), I didn't think it then started backing it off again as the revs climbed.
Rob Allison - 18/10/12 at 06:41 PM
Thats not how the ST VVT works. Its a pulsed solenoid which is used to alter the oil supply pressure. This then moves the vvt pulley from it none
pressure filled retarded position. Its not related to revs. The ECU uses a closed loop system with a cam phase sensor to check where the cam timing
is in relation to the crank.
If you just put 12volts onto the solenoid it will go from 85degs full lift to 145 degs full lift. The position which gives the best power is inbetween
them. Thats why only correct control of the VVT will allow good power and the benifit of the inlet VVT.
As said above 108 deg seems to be a good setting, you will not get that by switching the vvt "on and off"
scutter - 18/10/12 at 09:28 PM
Rob, that is the technically correct answer so far. To run the VVC correctly you will need a fully controlled PVM.
Every thing else is a compromise.
ATB Dan.
[Edited on 19/10/12 by scutter]
silky16v - 28/10/12 at 09:11 AM
Small update parts have arrived from the USA, just waiting on my zetec vernier to arrive then i can set about setting it up
Here are pictures below is anyone wants diamension of the spacer let me know
Rob Allison - 28/10/12 at 09:27 AM
If you wouldn't mind measuring it please.
I may even order one up.
[Edited on 28/10/12 by Rob Allison]
silky16v - 6/1/13 at 10:42 AM
Right finally an update sorry for the delay
was too busy of xmas and new year to make a start on things, but i've now had the vernier drilled for the VCT delete kit (12mm hole rather than
the 10mm for a Zetec)
I've also got the pictures with measurement for those who wanted them
I bought a pair of turbosport verniers (will have 1 spare if someone is looking for 1) and will be using this on the inlet
my exhaust already has a Piper vernier fitted
I will do another update as i work away in the garage with how i've setting the static timing
Rob Allison - 6/1/13 at 10:58 AM
That's great. I'll try and get a cad drawing done
silky16v - 6/1/13 at 03:29 PM
Further progress today all the pulleys and VCT delete are fitted and timed up
VCT all removed
VCT delete spacer in place
Vernier in place with VCT delete kit
Checking clearance with vernier fitted
Cambelt all in place and tensioned, just setting the pulleys in place and then tensioning the cam bolt pulleys
I set the new vernier to -10 as the 0 point so that i have a full 20deg of advance (40deg@crank)
inlet vernier set to 12deg advance (24deg@crank) thus giving static timing of 109deg
view from other end of camshafts showing the inlet camshaft advanced
Rob Allison - 6/1/13 at 03:46 PM
Very good that
silky16v - 6/1/13 at 05:57 PM
quote:Originally posted by Rob Allison
Very good that
well if it help's anyone else & the fact it can be done for around £100 i think its a good modification, just need to get engine back in car
and get it mapped
Rob Allison - 6/1/13 at 09:32 PM
I will be good to see the dyno results. 200bhp is the target
silky16v - 6/1/13 at 10:52 PM
quote:Originally posted by Rob Allison
I will be good to see the dyno results. 200bhp is the target
For me the target is 180bhp and a free revving engine all the way to 7250rpm
Anything above that will be a bonus fingers crossed it makes a little more though
silky16v - 18/1/13 at 12:32 PM
quote:Originally posted by Rob Allison
That's great. I'll try and get a cad drawing done
Did you manage to get this drawn out?
Rob Allison - 18/1/13 at 04:39 PM
Not yet. Been on to someone who makes the zetec pullys. He said its possible but may not be able to get a new centre bolt. He also asked how many were
wanted. I guess that more would know the price down. Don't think he was interested in making the st pulley one of his normal sale items
silky16v - 18/1/13 at 08:40 PM
quote:Originally posted by Rob Allison
Not yet. Been on to someone who makes the zetec pullys. He said its possible but may not be able to get a new centre bolt. He also asked how many were
wanted. I guess that more would know the price down. Don't think he was interested in making the st pulley one of his normal sale items
the fact the vct delete kit from the states is so cheap, its not worth getting 1 made unless its a batch lot
big_wasa - 18/1/13 at 09:13 PM
So any chance of floging the vtt solenoid for a few beer tokens please, I want one for my project. I would think you will be pluging it up ?
silky16v - 18/1/13 at 10:20 PM
quote:Originally posted by big_wasa
So any chance of floging the vtt solenoid for a few beer tokens please, I want one for my project. I would think you will be pluging it up ?
As soon as i find a plug for the solenoid hole and I've tested my method for fixed timing has worked you can have it nothingmonck - 20/1/13 at 11:42 AM
Has anyone else got one in touch with this company about the delete kit apart from Silky16v i have tried there email 3 times and there Facebook and
had no luck
[Edited on 20/1/13 by monck]
silky16v - 20/1/13 at 12:56 PM
quote:Originally posted by monck
Has anyone else got one in touch with this company about the delete kit apart from Silky16v i have tried there email 3 times and there Facebook and
had no luck
[Edited on 20/1/13 by monck]
Wired i'll see if I can try again for you
[Edited on 20/1/13 by silky16v]
monck - 20/1/13 at 01:36 PM
thanks
Rob Allison - 20/1/13 at 02:14 PM
Read on some US forums they are a bit hit and miss.
They also list on eBay but postage is too much that's on it.
silky16v - 2/2/13 at 06:31 PM
Today's update
Engine all back in and refitted with new mounts and some other little tweaks
Turned the key over a times to prime fuel system and to get oil back up in the engine
Had to adjust tickover alittle higher once engine was warm and the water pipes had been connected, it has more intake noise as well
monck - 2/2/13 at 07:03 PM
Link don't seem to work ?
Good work tho
silky16v - 3/2/13 at 02:17 PM
Here is the video
monck - 3/2/13 at 07:40 PM
That vid works, it sounds well...
I got a delete kit from the states had no issues and was fast to get here once i got in contact so happy about that ..
Im going to copy your timing settings .. Are you planning on having it on the RR anytime soon?
Ryan
silky16v - 3/2/13 at 09:25 PM
quote:Originally posted by monck
That vid works, it sounds well...
I got a delete kit from the states had no issues and was fast to get here once i got in contact so happy about that ..
Im going to copy your timing settings .. Are you planning on having it on the RR anytime soon?
Ryan
Yeah I'm going to take it to EFI parts to have the map altered, but I have innovate LC-1 I can data log with so can do the fuelling myself and I
emailed omex for a base zetec timing map, I just need to compare that with the timing map that is on ECU already
monck - 4/2/13 at 01:23 PM
Just going of topic a second , in the vid i noticed you water temp gauges ect what make are they look like some ive seen on ebay wondered if they
where any good ?
quote:Originally posted by monck
Just going of topic a second , in the vid i noticed you water temp gauges ect what make are they look like some ive seen on ebay wondered if they
where any good ?
Ryan
As per Coozers reply he built the car, but can't fault the gauges I'm about to add an oil pressure gauge as well
monck - 4/2/13 at 06:45 PM
Thanks Coozer , ill let you know when the engine you sold me is in and running
I like the look of them gauges and after my blacktop threw blew id like to add an oil pressure gauge with the st170 engine ..
Thanks again silky16 ill be keeping my eye out for updates
silky16v - 9/2/13 at 05:33 PM
been working on car again today, and it's finally road ready, so took it out for a quick spin
engine is very very revvy, huge difference compared to pre VCT delete, hopefully i'll get some time to do some data logging and get the fueling
adjusted
Rob Allison - 12/2/13 at 11:35 PM
Sounding good for the delete so far then
Rob Allison - 24/2/13 at 02:43 PM
Just ordered up a couple of Delete kits from Massive Speed. Easiest way to get hold of them is Facebook.
Ordered off there site via paypal. They will then send an altered postage amount. $17.95 for postage i think.
silky16v - 7/3/13 at 12:11 PM
Going for mapping this friday will post up results, once complete
monck - 7/3/13 at 02:18 PM
Nice one , Very interested in the results
Rob Allison - 9/3/13 at 08:35 AM
Any good news
silky16v - 10/3/13 at 09:03 AM
Hi, got the car mapped yesterday very happy with the results haven't had time to drive it on road yet due to the rain (going out this morning)
The car made 175bhp@wheels and 148ft-lb torque@wheels
If you factor about 15% on top of those for a estimated Flywheel power so that is just over 200bhp & 170ft-lb Torque, tbh I'm only interested
in the power@wheels and how it drives
I have the fuel pressure set@45psi so the power is just on the limit of the injectors@80%, I plan to go back and alter the cam position to see if
there is further bhp to be extracted, but for the moment I'm just going to enjoy it
Benzo - 10/3/13 at 12:59 PM
Glad someone has had a break through on these ST170 engines..
They are cheap units!
scutter - 10/3/13 at 07:36 PM
Outstanding fella, do you have a copy of the plot or do we have to wait for the tweeks to be completed
ATB Dan.
silky16v - 10/3/13 at 10:10 PM
quote:Originally posted by scutter
Outstanding fella, do you have a copy of the plot or do we have to wait for the tweeks to be completed
ATB Dan.
You mean the RR graph? Yeah I have it, just not scanned it in yet
scutter - 11/3/13 at 11:10 AM
Yes fella sorry, the plotted graph from the rolling road.
Atb Dan.
Rob Allison - 11/3/13 at 05:28 PM
It's looking good for the ST motor at last.
A cheap 200bhp motor
silky16v - 13/3/13 at 12:10 PM
Old graph with estimated Flywheel power, you can clearly see after 4700rpm it stopped making anymore power
New RR Graph with power measured@the wheels the tiny dip@5000rpm is the inlet cam just coming on (the plans is alter the static cam timing to try take
this out)
I'm also planning to increase the exhaust manifold port size up to 2.5" diameter and have the exhaust port flowed to match, this should
hopefully allow the engine to carry on making power right past 7000rpm
But for the moment i'm just going to enjoy as it is, anyone who has this engine and has the setup so it an on/off to control the inlet camshaft,
i would strongly recommend changing it to fixed cam timing.
The Car is so much more enjoyable to drive & usable
coozer - 13/3/13 at 04:02 PM
The mapper has done a good job there Matt, the O2 line looks spot on.
However, you've lost a lot of torque in the mid range, which shows the benefit of the VVT system, with the loss of torque on the top end overlap
showing the downside of a simple 'switch'. But, again at your peak power your only up 5bhp, more torque yes but I think this is better lower
down.
This exercise tells me, as I thought, the next step was a new gearbox with ratios suited to the engine.
It was already a BEC beater on top end so I wouldn't be tempted to push the revs up any higher without any (expensive) engine mods.
silky16v - 13/3/13 at 04:53 PM
quote:Originally posted by coozer
The mapper has done a good job there Matt, the O2 line looks spot on.
However, you've lost a lot of torque in the mid range, which shows the benefit of the VVT system, with the loss of torque on the top end overlap
showing the downside of a simple 'switch'. But, again at your peak power your only up 5bhp, more torque yes but I think this is better lower
down.
This exercise tells me, as I thought, the next step was a new gearbox with ratios suited to the engine.
It was already a BEC beater on top end so I wouldn't be tempted to push the revs up any higher without any (expensive) engine mods.
The loss of torque in the midrange i don't find noticeable, I didn't like the way it was on/off before it felt like driving a diesel with
the narrow power band it had, it is a lot more driver friendly now as its not always trying to break traction in the lower gears
My graph is power@wheels I believe yours was calculated@flywheel? You need to add around 15%+ to my figures to get an estimated Flywheel power of the
engine now
There is still some further changes to be made mainly the exhaust primary's as they aren't big enough
I'm probably going to fit a MX5 gearbox from the mk3 2.0 model with a 5 speed
The difference is night and day in the way it drives you can hang on to gears alot longer which is what is needed where I live lol!
scutter - 13/3/13 at 08:06 PM
Your last sentence is the most true, about where you like to live.
I wnet from a screamer to running the vvc and really enjoy the torque that it releases.
I picked up a spare engine the other day, so I'm going to port that and think about a 285 piper regrind, the cam is quoted as not suitable for
vvc, a quick email provided the answer. They can't garantee the piston to valve clearances so always play it safe. I'll do the head work
first then post the results.
ATB Dan.
ManuFromParis - 11/4/13 at 09:45 AM
This is a very interesting topic !
Thanks guys for posting.
...and obviously the answer was in the programmation of Variable Cams Timing !!!
...so I Wikied it !
Here is a very simple synthesis :
BMW's VANOS :
quote:VANOS operates on the intake camshaft in accordance with engine speed and accelerator pedal position. At the lower end of the engine-speed
scale, the intake valves are opened later, which improves idling quality and smoothness. At moderate engine speeds, the intake valves open much
earlier, which boosts torque and permits exhaust gas re-circulation inside the combustion chambers, reducing fuel consumption and exhaust emissions.
Finally, at high engine speeds, intake valve opening is once again delayed, so that full power can be developed. VANOS significantly enhances emission
management, increases output and torque, and offers better idling quality and fuel economy.
Track-day-guys are in search of high-end power and without an Engine Managing System that can handle the solenoid, you're basically in the same
situation as me, looking for the best timing but as a compromise.
Anyway, for those who have an Emerald K6, there is a VVT output but not really documented
I wonder if the IACV output couldn't be used, as is or with a voltage inverter, to control the ST170 valve Solenoid ?
[Edited on 11/4/2013 by ManuFromParis]
MarcV - 11/4/13 at 10:28 AM
Manu, any updates on your build? (PM or blog update? :-))
VVT control (or VANOS for that matter) is not as simple as just running a PWM signal. It needs feedback from the cam sensor to close the loop.
Just a question for the crowd here. As I seem to read that the ST engine itself is a desirable unit and people are willing to spend some amount to get
the timing fixed, would you guys consider a little controller to set the cam timing based on revs only. This would give the performance (not the
emissions) benefits from the VVT system.
The delete kit price is about GBP 100, correct? What would be a reasonable price for a controller instead?
silky16v - 11/4/13 at 10:29 AM
You need an ECU that can do camshaft position timing to fully use the PWM valve
not just PWM on its own, this is where the ECU's and mapping time gets expensive
I've done 500miles+ in mine now and i can say that for the cost and ease of fitment the Delete VCT is the way forward for ST170 engine owners on
a budget.
I personally love the way the engine pulls up the topend of the RPM, the engine really does like to be up above 5500rpm
i still have the limiter set at 7250rpm and the motor is stock.
There will always be owners who prefer the VCT on/off function, but for me & where i live its exactly how i want it
it never fails to put a smile on my face blasting down a B-road with the engine on song without having to grab the gearstick every 5 secs because it
out of the powerband
silky16v - 11/4/13 at 10:39 AM
quote:Originally posted by MarcV
Manu, any updates on your build? (PM or blog update? :-))
VVT control (or VANOS for that matter) is not as simple as just running a PWM signal. It needs feedback from the cam sensor to close the loop.
Just a question for the crowd here. As I seem to read that the ST engine itself is a desirable unit and people are willing to spend some amount to get
the timing fixed, would you guys consider a little controller to set the cam timing based on revs only. This would give the performance (not the
emissions) benefits from the VVT system.
The delete kit price is about GBP 100, correct? What would be a reasonable price for a controller instead?
it would need to be RPM and TPS to even get anywhere close, and the mapping time would also increase as you would ideally want multiply fuel/ignition
fields to benefit from the above
the Delete VCT kit is a low cost, easy option for fitting a ST170 engine and having up to 180bhp+ from a stock motor
the cost involved to get the Blacktop Zetec this level to me it's just not worth it.
i would be interested in some uprated camshaft for the ST170 that don't use the VCT (like the blacktop) but i don't think they are
interchangeable between the cylinder heads, unless someone knows different
ManuFromParis - 11/4/13 at 10:42 AM
quote:Originally posted by MarcV
Manu, any updates on your build? (PM or blog update? :-))
Hey Marc. No Blog so far as I'm not building anything, just using/tuning the Zetec 1.8 FI Westfield I purchased second hand in UK last Year.
quote:Originally posted by MarcV
As I seem to read that the ST engine itself is a desirable unit and people are willing to spend some amount to get the timing fixed, would you guys
consider a little controller to set the cam timing based on revs only. This would give the performance (not the emissions) benefits from the VVT
system.
That's exactly what I was thinking about, to get the best out of both options with a simple RPM input (and maybe the TPS) !!
I'm pretty sure Emerald guys could instantly provide an output like this, according to a single matrix RPM/TPS map.
[Edited on 11/4/2013 by ManuFromParis]
MarcV - 11/4/13 at 11:16 AM
Aha, clear. Seemed to recall you were in the market for / building a GKD...
I think you should not base it on TPS as this indeed requires more mapping effort. If it were to gradually change camshaft position over the rev
range, it would give the benefits of the system (low overlap at low rev, higher overlap at higher revs) and still be just as easy to map. So for
every rpm a fixed camshaft position.
Surely it won't do the extra overlap for internal EGR or drag torque reduction and all that, but you don't have this with fixed timing nor
would you be interested in it.
silky16v - 11/4/13 at 12:29 PM
quote:Originally posted by MarcV
Aha, clear. Seemed to recall you were in the market for / building a GKD...
I think you should not base it on TPS as this indeed requires more mapping effort. If it were to gradually change camshaft position over the rev
range, it would give the benefits of the system (low overlap at low rev, higher overlap at higher revs) and still be just as easy to map. So for
every rpm a fixed camshaft position.
Surely it won't do the extra overlap for internal EGR or drag torque reduction and all that, but you don't have this with fixed timing nor
would you be interested in it.
you will require an ECU that can do Camshaft position and PWM this is where the cost is & mapping, you couldn't just use a PWM controller as
the solenoid is pulsed not opened a certain amount vs RPM.
If cost wasn't an issue i would fit DTA pro60 ECU and map my car this way, but it would cost nearly £2000 to do so and all it will do is move the
power around not necessary increase the peak power produced.
but if someone can build a controller that will do the above cheaply that can be used on a more entry leave ECU, i'd be very interested in the
results
MarcV - 11/4/13 at 12:36 PM
What would you define as cheaply?
ManuFromParis - 11/4/13 at 12:45 PM
quote:Originally posted by MarcV
Aha, clear. Seemed to recall you were in the market for / building a GKD...
I was and I even purchased a cheap E36-328i that ended up being my daily, coz' it's reliable and convertible...
But I wasn't very impressed with the GKD chassis design and options. On top of that, registration in France for new built is impossible if you
don't use an up-to-date low-emissions engine or try a pre-1993 carbed UK-registered car, not to mention the time and money needed for a built.
That's why last spring I bought this Westfield with loads of engine and chassis options, to enjoy driving instead of building... done 6000 miles
between may and october !
To get back to the subject, I wonder if the TPS input wouldn't make sense to tune a dynamic timing because obviously a low RPM high TPS should
output a slightly different value than a standard low RPM, wouldn't it ?
[Edited on 11/4/2013 by ManuFromParis]
[Edited on 11/4/2013 by ManuFromParis]
ManuFromParis - 11/4/13 at 05:27 PM
I've asked Emerald about that :
quote:
Hello,
I was wondering if the K6 would be able to manage the VCT solenoid from ST170 Ford engine, for example.
Could any of the output be programmed according to RPM and TPS to map the Cam Timing ?
Thanks
Emmanuel
and here is their response :
quote:
Hi,
We have done a lot of these engines and control the cam via a PWM output table, as you say, rpm against TPS. The engine seems to only need the cam
retarding at idle and very light throttle.
Regards,
Dave.
MarcV - 11/4/13 at 05:48 PM
Correct me if I'm wrong, but It seems to me like this will be just full on / off, no specific position. I'm looking into the Ford specifics,
but the system I am familiar with (VANOS) will not work without closed loop control.
Rob Allison - 11/4/13 at 06:11 PM
I have an Emerald K6 and asked before buying it. For cam control you need a close loop control. So you need to use the phase sensor then use other pmw
output to the solenoid. After that get it mapped. Emerald were not interested as they said on engines they had ran it made little difference.
Delete kit is about £30. And if you wanted you can just use a standard zetec pulley instead of a vernier one. I got a pair of pulleys new for £120.
Far cheaper then the DTA ecu, then hours of mapping.
As for cams. I think the blacktop inlet cam could fit. But it will require a new spacer bearing for the number one bearing. I don't have a head
and cam to check, yet.
ManuFromParis - 11/4/13 at 06:16 PM
quote:Originally posted by MarcV
Correct me if I'm wrong, but It seems to me like this will be just full on / off, no specific position. I'm looking into the Ford specifics,
but the system I am familiar with (VANOS) will not work without closed loop control.
I think it's an analog output that you may amplify to your need and program as shown on screenshots below.
I've asked Dave for more information and he might post answers here as I sent him the link to the topic.
Here is the table Dave is talking about :
There are two other outputs available.
Don't know how they work though
VVT and Vtec (on/off)
Rob Allison - 11/4/13 at 08:09 PM
You can use the VTEC switch if you wanted to. But its full closed loop control thats needed. It can't just use PMW output as the oil pressure
changes will alter the cams timing position. The closed loom is needed to ensure the timing is kept where you want it. Much like idle control.
I think the cam runs 4 sensor lobes for this purpose.
There is not a lot of information on the ford system as they like to keep things to themselfs. But a lot of the SVT engine run it now to beat the
emissions
ManuFromParis - 11/4/13 at 10:55 PM
You mean the command to the solenoid is a not a command to set the cams in a specific position but just a command to increase or lower the oil
pressure and the sensor is needed to stop the command when cams are in wanted position ?
If I'm right, it's then a little more complicated than i thought...
Question is : is the mid-revs torque gain worth the trouble when high-revs power is the main purpose ?
I have a question : On this catalog for ST170 cams, the durations for EOM cams are pretty long, compared to those I knew better of the silvertop :
277° for EOM ST170 Vs 262° for Sport-R Silvertop, both @ 0,1mm lift
I'd think that the duration would have been shorter because of the overlap at full advance.
Another question about what was the main subject of this topic : giving up the VCT.
As the VCT EOM pulley seems to have a spring and a locking mecanism to get the intake camshaft back to "full retard" position, which appears
to be 145° @ crankshaft EOM, and considering the optimal "fixed" timing would be around 108-110° @ crankshaft, wouldn't it be much
simplier to rotate the whole thing, introducing an offset at the intake pulley ?
(Solenoid not active, of course)
If I'm not mistaken, the pulley has 40 teeth, so one tooth offset would be 9°, which in cranksaft timing would be 18° because the crank goes
twice faster.
It would mean that introducing a "two teeth" offset would advance the fixed intake camshaft of 36°, the Full lift would then be 145 - 36 =
109° !!!
Am I right ?
[Edited on 12/4/2013 by ManuFromParis]
silky16v - 12/4/13 at 10:08 AM
quote:
As the VCT EOM pulley seems to have a spring and a locking mecanism to get the intake camshaft back to "full retard" position, which appears
to be 145° @ crankshaft EOM, and considering the optimal "fixed" timing would be around 108-110° @ crankshaft, wouldn't it be much
simplier to rotate the whole thing, introducing an offset at the intake pulley ? (Solenoid not active, of course) If I'm not mistaken, the pulley
has 40 teeth, so one tooth offset would be 9°, which in cranksaft timing would be 18° because the crank goes twice faster. It would mean that
introducing a "two teeth" offset would advance the fixed intake camshaft of 36°, the Full lift would then be 145 - 36 = 109° !!! Am I right
?
The VCT pulley doesn't have a locking mechanism, it alters via oil pressure, you need a fixed vernier to set the timing at a static state
The full retard position is 85° when setting the camshaft timing with the timing bar it you altered the timing by 2 teeth this will take you to 85 +
36 = 121° which isn't ideal
you could however use a normal zetec pulley on the inlet (drilled out to 12mm) and the VCT delete spacer and with a cam timing wheel dial in the
correct ° without the need for a Vernier, but for the cost of vernier its just not worth all the hassle in my eyes.
The way i see this whole thread is to have a cheap 180bhp+ engine
1. ST170 engine = £300 - £500 (with injectors and inlet)
2. VCT delete kit & vernier = £100 - £120
3. Bike throttle bodies = £100+
4. 4 branch & exhaust = £350+
5. standard zetec fuel rail = £10+ (as the ST doesn't have a return line)
6. fuel pump & regulator = £100 - £150
7. odd and ends £100+
8. whatever custom ecu your using = £250+
it can be done cheaper if using Carbs, but i prefer injection
The loss of low down torque from removing the VCT just isn't an issue in my eyes, my car is so much nicer to drive now than before, like a kit
car engine should be.
If i was fitting the engine into a non 7 style car i would consider the VCT again, but in something that weights around 500kg it just isn't
needed,
obviously this is my person feeling on the VCT, this just might not be whatever one's else needs might be
best thing is to try both and see what you prefer
ManuFromParis - 12/4/13 at 11:24 AM
quote: The full retard position is 85° when setting the camshaft timing with the timing bar it you altered the timing by 2 teeth this will take you to
85 + 36 = 121° which isn't ideal
Allright, my mistake.
Not such a good idea then, especially if there is no locking mecanism as shown in the 1600 double VCT video.
Thanks for the reply.
Rob Allison - 12/4/13 at 01:18 PM
The problem with the standard vct pulley is that they can fail. They rattle and don't hold a fixed position. Best off they the delete kit and
standard pulley
ManuFromParis - 15/4/13 at 10:07 AM
quote:Originally posted by Rob Allison
Thats not how the ST VVT works. Its a pulsed solenoid which is used to alter the oil supply pressure. This then moves the vvt pulley from it
none pressure filled retarded position. Its not related to revs. The ECU uses a closed loop system with a cam phase sensor to check where the cam
timing is in relation to the crank.
If you just put 12volts onto the solenoid it will go from 85degs full lift to 145 degs full lift. The position which gives the best power is inbetween
them. Thats why only correct control of the VVT will allow good power and the benifit of the inlet VVT.
Hey Rob,
I'm confused with your post and I just to try to understand how it works :
Do you have information about the signal sent to the solenoid and how it works ?
What do you mean by "pulsed solenoid" ?
[Edited on 15/4/2013 by ManuFromParis]
Rob Allison - 15/4/13 at 01:17 PM
It's PMW. Pulse width modulated.
It's a 12volt signal which is switched at a vairing frequency. I don't have any details as there is little info about it. If someone has a
current Autodata It may be listed on there
ManuFromParis - 15/4/13 at 04:55 PM
quote:
The loss of low down torque from removing the VCT just isn't an issue in my eyes, my car is so much nicer to drive now than before, like a kit
car engine should be.
If i was fitting the engine into a non 7 style car i would consider the VCT again, but in something that weights around 500kg it just isn't
needed,
obviously this is my person feeling on the VCT, this just might not be whatever one's else needs might be
best thing is to try both and see what you prefer
I totally agree with you but the more I read about Variable Valves, the more it would make sense (to me) that a road oriented car, even as a Se7en,
should benefit a lot from this feature.
Most of the car builders want their engine tuned for maximum power and setup the engine for this purpose, but eventually the car is mostly used on
roads where the use of the 4500-6500 RPM range is actually pretty occasional.
The car might as well be used on occasional fun track days (no race) where this race engine setup makes a lot of sense, but only with some chassis and
engine racing options to prevent damages and preserve car and engine (Geometry setup, ARB, sport shocks and calipers, oil cooler, race cams, etc...)
that kitcars don't really have, most of the time. So the benefit of the Race Setup is not really enjoyable without risking damages.
What I mean is that the Fixed Cams Timing compromise, which is "High Revs Power Oriented", is in contradiction with a high percentage of the
engine use, in most cases.
I'm not sure I may change the timing setup from my Kent FZ1802R Cams in SilverTop before and after every fun trackday I go to, but actually I
think I might, because I looove torque, more than power for a road use anyway !
So I'm considering advancing the intake a little on the Zetec (10° ?), just to feel the kind of change one could expect with a VCT on that kind
of engine. What do you think ? Should I try to advance a little more ?
[Edited on 15/4/2013 by ManuFromParis]
ManuFromParis - 15/4/13 at 05:03 PM
quote:Originally posted by Rob Allison
It's PMW. Pulse width modulated.
It's a 12volt signal which is switched at a vairing frequency. I don't have any details as there is little info about it. If someone has a
current Autodata It may be listed on there
Reading the TlxTech article mentionned above and watching the Ford video, I wouldn't be surprised it would indeed work that way.
What is weird though, is that very few Engine Management Units have a Variable Valve management feature and when they have, only the Honda Vtec and
the Rover VVC are options.
That said, I asked Emerald if they had plans about the ST170 and here is the (very fresh) answer I got this afternoon :
quote:
Hi Emmanuel,
we are currently looking for an ST170 engine/car that we can run on the dyno/rolling road for a few days.
We may buy an engine/car if necessary.
Best regards, Karl
Rob Allison - 15/4/13 at 05:47 PM
Don't try and adjust the silver or blacktop engines cam timing by much with out checking valve clearance. They don't have the valve pockets
the st has.
ManuFromParis - 15/4/13 at 05:58 PM
Ok, thanks
cjellwood - 16/10/17 at 08:52 PM
Hi,
Recently my VCT solenoid snapped in half while replacing it and the VVT pulley was messing around so I decided to go for a VVT delete. So far I have
deleted the oil flow and running the car like that pending delivery of the new pulleys which arrived today. The car runs like a 1.6 and is very
economical like this running at full retarded I presume?
This week I need to give my mechanic instructions on how to time the new pulleys after fitting but neither of us know a dicky about it. The car is
standard all round , just the new pulleys (oh and a stage 2 head to make things interesting). Since having the engine rebuilt recently I am yet to
see what the new head has to offer due to the VVT issues.
May I ask if there is a good place to start with timing positions other than playing it safe at 0:0 ?
One day I will let the pro's play with it on the rollers to get thebest setting but for now it is a daily use car and I just need a good place to
start. Oh and do we need special tools for this?
In exchange for good info I will come back here with roller data very soon
cheers
Chris
Rob Allison - 22/10/17 at 06:30 PM
If you use the standard setup timing by fitting the bar in the cams on the st170. This will set the inlet cam at 85degs. A standard zetec would be at
110 or 112 dregs.
So the inlet can on the st needs to be advanced by about 25degs. I can't remember is its 1 or 2 teeth on the cam pulley. So zeroing an adjustable
pulley at that timing will allow you to swing it about 15 to 20 degrees either way if your getting it tuned.
cjellwood - 22/10/17 at 06:41 PM
Thanks! I will be taking the car to a professional tuner but likely they will scratch their head about the ST170 like most do so best I go armed
with some info. The part that worries me is the VVT inlet pulley sits fully retarded as default state. Is this why you set zero at -10 I think it
was to make up for that when setting up with the bar?
Rob Allison - 22/10/17 at 10:14 PM
On a zetec the bar will set the cam at 110 or 112 degrees. On the st it will be about 85degrees as the cam is fully retarded.
In normal running the st engine doesn't retard the inlet cam that far retarded apart from when it starts. There is a plot if the cam timing range
against engine load. It surprising how little the cam timing moves against the total it can move
cjellwood - 22/10/17 at 11:26 PM
Thanks again! I get the plot now, brain was ticking slow earlier sorry. Just a couple more points if you dont mind sorry...
In your first set of pics where you fitted the pulleys it shows you inlet set to zero. I presume you were able to slide it round to -10 without moving
the belt or cam prior to fastening because you have your own machined spacer? I would need to set my inlet pulley to -10 before fitting and pinning
because I have the solid spacer built into the pulley (pipercam ?)
Also in a later pic you mention advancing 12 degrees but it looks more like 14 degrees on the marks?
My IMRC needs to go too but cant afford TB's so am looking at fixing it to a fixed position permanently. At this moment it is fixed to just over
half way pulled. Would you recommend it ti be fixed at another position?
cheers
Chris
cjellwood - 22/10/17 at 11:43 PM
pic of my inlet pulley. The marks are reversed so I assume this is -10 how it should be initially fitted. I am wondering why the 2 x pulley delete
kit that is sold contains the exhaust pulley that does not change from original setting?
big_wasa - 23/10/17 at 02:16 PM
I am sure the inlet is two distinct inlet lengths. Long and short. So setting it inbetween is the worst of both.
What ecu are you running ? If oem the ecu will know the imrc andt vvt solenoid are doing nothing and peg the engine back to around that of a blacktop.
cjellwood - 23/10/17 at 02:57 PM
quote:Originally posted by big_wasa
I am sure the inlet is two distinct inlet lengths. Long and short. So setting it inbetween is the worst of both.
What ecu are you running ? If oem the ecu will know the imrc andt vvt solenoid are doing nothing and peg the engine back to around that of a blacktop.
yes just the standard ECU at the moment but I will go aftermarket ECU now if there is a good value box around that is easy to wire up. Having lost
the VCT now I have a redundant VVTPro box if anyone is interested
Rob Allison - 23/10/17 at 08:34 PM
quote:Originally posted by big_wasa
I am sure the inlet is two distinct inlet lengths. Long and short. So setting it inbetween is the worst of both.
What ecu are you running ? If oem the ecu will know the imrc andt vvt solenoid are doing nothing and peg the engine back to around that of a blacktop.
If you are keeping the standard parts inlet and ecu it would be a problem. But as mine is on a k6 ecu with fixed inlet runner length. It fine for
me.
You can't delete the vvt and keep the standard ecu, etc. Or it will hit limp mode
cjellwood - 23/10/17 at 08:48 PM
Prior to getting an ECU could I just plug in a solenoid and tie clip it somewhere to make the ECU think it is working, or is more complicated than
that?
cjellwood - 24/10/17 at 02:15 PM
One more thing, once the pulleys are in and timed up standardly do I really need a special tool to dial the adjustment?
big_wasa - 24/10/17 at 07:10 PM
The ecu will know the vvt is not moving due to the cam trigger. It will give an out of range code.
cjellwood - 24/10/17 at 07:26 PM
whatever happens I will post back here later with confirmation of whatever happens. After a year of trying I have just managed to lose the SRS
warning light from changing the seats. The typical resistor trick does not work on MK1 /MK1.5 Focus but I got there in the end with a capacitor. No
more yellow lights are welcome.
I failed to mention earlier that my ST170 is not standard. The good guys at CTM Dagenham rebuilt the engine with a stage 2 head amongst other things
but I am yet to see what she can do due to the VVT issue.
cjellwood - 26/10/17 at 02:32 AM
Thanks for the help guys! I managed to get them on without too much grief and she is now nice and smooth with a nice poke starting at around 3.5k
rather than waiting for 5k for things to happen. Loss at top end a tad but if I put the foot down hard it compensates thanks to the stage 2 head.
Where to go from here? Can I advance more for starters or is it time for the aftermarket ECU?
cjellwood - 28/10/17 at 04:06 PM
A quick tech question please. When I am a tad confused when folk talk abuot 40 degrees at the crank being 20 degrees at the dial. The ST170 is
described as going to 60 degrees advance from 4-5k rpm which I assume is cam degrees? Am I right in thinking to achieve 60 degrees advance I turn the
pulley to dial setting 30 degrees?
cjellwood - 3/11/17 at 06:25 PM
Things are not going well. The inlet pulley is wiggling and trying to push the belt off. Everything is bolted up fine ? Has anyone had this problem
before? I am wondering if it is a faulty pulley.
Btw I still sent ahead with tuning and found the best spot to be 34 deg advanced on the dial. Does this tally with anyone else findings?
[Edited on 3/11/17 by cjellwood]
[Edited on 3/11/17 by cjellwood]
big_wasa - 16/5/20 at 06:23 PM
I know it’s an old thread but a big thumbs up to silky16v for posting the dimensions for the Vvt delete spacer. I’ve enjoyed a mooch around the
garage this afternoon
cliftyhanger - 20/5/20 at 03:43 PM
quote:Originally posted by big_wasa
I know it’s an old thread but a big thumbs up to silky16v for posting the dimensions for the Vvt delete spacer. I’ve enjoyed a mooch around the
garage this afternoon
Now, you have a reputation for using OEM management... so whats the plan here?? I am wondering about locking the VVT on an st170, I have a weber
ignition-only ecu from a blacktop (should be about right) but und=sure what induction to use. Could just get an aftermarket ECU, or go carb/s?
Ideas in my head while I am going stir crazy....
big_wasa - 20/5/20 at 09:05 PM
Long Story.
I needed some thing to take my mind of stuff and I didn’t want work on car so l just decided to have a crack.
Run out on the Oem pulley at the out side tip is 0.15mm mine is showing 0.34mm so it’s not perfect. Ie it wobbles 0.17mm out of true at the edge of
the pulley. But it probably won’t ever get used. I just wanted to see how tight I could get the tolerance. My lathe is fairly worn but I think I can
get it closer with more carful indexing the bar stock.
But I’ve just about finished my Zetec turbo on Oem management
[Edited on 20/5/20 by big_wasa]
cliftyhanger - 21/5/20 at 07:27 AM
Ah, I was wondering if you had a clever idea about std ecu on an ST engine.
Guess it isn't clever enough to cope with a change of injectors, or indeed to use the blacktop injectors but the ST will just produce more power
anyway.
All stuff in my head, again as a bit of a distraction from other stuff.
And thanks for replying.
big_wasa - 21/5/20 at 08:18 AM
To use the blacktop ECU on the st you would have to modify the exhaust cam phase trigger. It's more like a trigger wheel than the Blacktops
single lobe.
