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1.8 zetec head

Dooey99 - 14/2/13 at 09:18 PM

i have just stripped my standard 1.8 zetec blacktop head and plan to rebuild it with the following;

- the head will be skimmed by 1mm
- valves will be re ground into the head
- new stem seals
- original tappets will be used as they have not done a lot of work and still like new
- 2.0L blacktop cam shafts
- 2.0L blacktop cam pulleys possibly using an exhaust cam instead of an inlet cam

it will all be ran on zzr1100 bike carbs which will be balanced and re jetted to suit

any comments or advisories are welcomed.

i will post updates on this thread as and when they happen

Charlie_Zetec - 14/2/13 at 09:40 PM

Couple of questions;

Why are you having the head skimmed by 1mm? Surely you want to have it skimme/planed by a minimal amount, only enough to ensure a flat mating surface?
What is the advantage of using an exhaust cam in lieu of the inlet?
Why th choice of 1100cc bike carbs? I would've thought 900cc ones (ZX9R seem to be popular because of TPS) would be better suited.

Dooey99 - 14/2/13 at 10:57 PM

having the head skimmed increases the compression ratio of the engine therefore squeezing more power so if the heas is skimmed more than the higher the compression ratio will get providing more horsepower but 1mm skim is about the maximum safe amount having much more removed will give to much compression and it wont run properly and will damage the engine

the advantage of using an exhaust cam shaft is that the profile on cams are different, and an exhaust one holds the valves open slightly longer allowing more fuel and air to enter the combustion chamber

i was given my carbs for free and i believe them to be zzr1100 they do have a tps sensor and i rang a kawasaki dealer and gave them the part number and they confirmed them to be zzr1100's have they made a mistake?

Charlie_Zetec - 15/2/13 at 12:06 AM

I understand about changing the CR, but didn't think this was overly beneficial for N/A engines. I'd also be nervous about taking too much off if you're talking about using different cams to hold the inlet valves open for longer - slightest timing issue could lead to valves meeting pistons, surely? No different to an un-modified engine I suppose, just removing more of the safety margin.

Is using an exhaust cam on the inlet side a proven method? Upgrading to 2L cams is a tried and tested path, but this is a new one to me! In principle I see it being no different to changing to a set of Kent or Piper cams, but I'd want to check the throw on the lobes to ensure it didn't affect running/idling of the engine.

As for the carbs, I'm not disputing the model. The fact they have a TPS is good, as it can be used for fuelling with the ECU better/easief than MAP in most sit-ups of this nature. But I do recall reading on here that there was a general rule of thumb that bike carbs from a 900cc engine that revs to 15,000RPM should adequately fuel an 1800cc engine that revs to 7,500RPM. I suppose that most carbs could be used it jetted and set up correctly on a rolling road though.

Not trying to put you off in any way, just trying to understand where you're coming from, what you're trying to achieve, and if there's a better or easier way to get there!

will121 - 15/2/13 at 07:17 AM

I had 0.5mm skimmed of a silvertop head which increased C/R by 0.5, to 10.5. Believe taking off 1mm possible but would calculate cr first and dry build the engine with plastacine on the piston tops to confirm clearance with your chosen cams. Also would wonder if increasing cr alone worth it without ported head etc then others will suggest why not start with a 2litre. As for carbs what size are they? 36/38mm seem to be ok on a 1.8 so would think yours would be fine

whitestu - 15/2/13 at 08:03 AM

Zzr1100 carbs could well be smaller than carbs from the likes of zx6s and R6s.

MikeRJ - 15/2/13 at 10:34 AM

quote:
Originally posted by Charlie_Zetec
I understand about changing the CR, but didn't think this was overly beneficial for N/A engines.

Raising the static CR is a very common modification when tuning a normaly aspirated engine, especially if longer duration cams are used. The higher the CR you can use, the higher the thermal efficiency and the more power you can make.

quote:
Originally posted by Charlie_Zetec
I'd also be nervous about taking too much off if you're talking about using different cams to hold the inlet valves open for longer - slightest timing issue could lead to valves meeting pistons, surely? No different to an un-modified engine I suppose, just removing more of the safety margin.

This is why you do a dummy build and measure the valve to piston clearance. If you are using vernier pulleys then you need to do this over the expected range of adjustment so you don't get a nasty surprise when setting the engine up on a dyno.

quote:
Originally posted by Charlie_Zetec
Is using an exhaust cam on the inlet side a proven method? Upgrading to 2L cams is a tried and tested path, but this is a new one to me! In principle I see it being no different to changing to a set of Kent or Piper cams, but I'd want to check the throw on the lobes to ensure it didn't affect running/idling of the engine.

It's a common modification on many engines where the cams are interchangeable, since the exhaust cam often has more duration.

quote:
Originally posted by Charlie_Zetec
As for the carbs, I'm not disputing the model. The fact they have a TPS is good, as it can be used for fuelling with the ECU better/easief than MAP in most sit-ups of this nature. But I do recall reading on here that there was a general rule of thumb that bike carbs from a 900cc engine that revs to 15,000RPM should adequately fuel an 1800cc engine that revs to 7,500RPM. I suppose that most carbs could be used it jetted and set up correctly on a rolling road though.

Looking at RPM and displacement alone is not very useful, you need to see what sort of power the original engine was producing as this ultimately tells you the airflow the carbs are good for. Both the ZX9R and ZZR1100 make simmilar levels of power, the ZZR1100 having the edge by 5-10bhp depending on who you believe. The ZZR carbs are larger (40mm) but they are restricted on the UK model bike. Fitting the carb tops from a ZXR750 allows them to open fully which gives a little more power on the bike.

The early model ZZR110 definately didn't have a TPS, which is a downside for running a 3D ignition map, but several people have worked around this by adding an extension to the throttle spindle to a drive a TPS. It's possible the later bikes had a revised system that included a TPS, but I've not seen one.

cliftyhanger - 15/2/13 at 12:35 PM

But raising the compression is usually hand in hand with cam changes. Wilder cams drop dynamic CR, so you need to inrease the static to get it back. If that makes sense. Too high a CR without changing cams requires much thought. I would hesitate to do too much, although the mentioned swap may work better with the higher static CR.

But as above, unless there is a good reason, it is best to start with a 2 litre. It is the cheapest way to give higher power and torque, by some margin. The 1800 will always be 10 bhp behind (give or take)

Paul Turner - 15/2/13 at 03:59 PM

Dooey99

You did not answer my last question so here it is again.

Why, when you said in a recent post Thanks mate will give you a shout if I need any help, I have access to a rolling road and I can map ECUs and stuff as I work for a lotus race team and we are currently having bespoke throttle bodies built, I build performance engines weekly but I have never used bike carbs before do you have to keep asking these basis questions.

Surely if you are really "building performance engines weekly" you would know the answer to this and the recent questions regarding fitting cams and raising compression ratios. If not another professional at the "lotus race team" would be able to help you without resorting to us amateurs on the internet.

To prove I am not making this up here is a link http://www.locostbuilders.co.uk/viewthread.php?tid=178214&page=0&contribmessage=none 7th post down.

Why on earth would you want to use the original tappets, they are not bedded in to the cams and will accelerate wear on both components.

Why on earth would you want to use an exhaust cam instead of an inlet cam.

Please answer this time otherwise we will know you are a troll.

Charlie_Zetec - 15/2/13 at 04:32 PM

Thanks for the feedback - I wasn't trying to be picky, just trying to grasp what was being done.

The biggest thing for me was the exhaust cam. I understand the principle behind it all, but never heard of this being done on a blacktop or other zetec before. Whereas the 2l cams drop straight in, I'd not heard or read on here about anyone doing it - and there's plenty of people who have done zetec conversions before.

As someone else has pointed out, the 2l engine is probably a better base to start from overall. Having said that. I've used an 1800 silvertop and spent more money on that than a new crated unit would have cost, so can't really talk!

quote:
Originally posted by Charlie_Zetec
Is using an exhaust cam on the inlet side a proven method? Upgrading to 2L cams is a tried and tested path, but this is a new one to me! In principle I see it being no different to changing to a set of Kent or Piper cams, but I'd want to check the throw on the lobes to ensure it didn't affect running/idling of the engine.

It's a common modification on many engines where the cams are interchangeable, since the exhaust cam often has more duration.

quote:
Originally posted by Charlie_Zetec
As for the carbs, I'm not disputing the model. The fact they have a TPS is good, as it can be used for fuelling with the ECU better/easief than MAP in most sit-ups of this nature. But I do recall reading on here that there was a general rule of thumb that bike carbs from a 900cc engine that revs to 15,000RPM should adequately fuel an 1800cc engine that revs to 7,500RPM. I suppose that most carbs could be used it jetted and set up correctly on a rolling road though.

coozer - 15/2/13 at 05:15 PM

quote:
Originally posted by whitestu
Zzr1100 carbs could well be smaller than carbs from the likes of zx6s and R6s.

They the same size as ZX9R and ZX7R carbs 40mm.

Dooey99 - 17/2/13 at 01:25 PM

PAUL TURNER

have you ever seen a lotus with a zetec engine?

if i was running a rover k series or a toyota vvti engine i could build a faster engine than alot of people on here.

every engine head has an optimum thinkness for producing the power i have dont know this thickness for a zetec head as they are measured to 0.1 of a mm.

an exhaust cam will hold the valves open a little bit more allow a little more fuel and air into the comobustion chamber

the original tappets have not done alot of work and are bedded into the head.

Paul Turner - 17/2/13 at 02:14 PM

quote:
Originally posted by Dooey99
PAUL TURNER

have you ever seen a lotus with a zetec engine?

if i was running a rover k series or a toyota vvti engine i could build a faster engine than alot of people on here.

every engine head has an optimum thinkness for producing the power i have dont know this thickness for a zetec head as they are measured to 0.1 of a mm.

an exhaust cam will hold the valves open a little bit more allow a little more fuel and air into the comobustion chamber

the original tappets have not done alot of work and are bedded into the head.

To answer your questions point by point:

Yes I have seen a Lotus running a Zetec. An Elan ans a Europa. The owners wanted everyday reliability and accepted the fact that fitting a non original engine devalued the cars. Both owners had kept the original twin cams for refitting in the future.

K series, Toyota VVT or any other engine, the same engineering principals apply to most aspects. A good engine builder can easily work on many types of engine.

Zetecs might well be measured (specified) in metric but its easy to convert f you want it in thou. If you were an engine builder you would be able to convert them easily.

An exhaust cam will only hold the valve open longer if the lobe is so designed, do you know for a fact this is the case with a Zetec cam. If you were an engine builder you would have this info to hand.

The original tappets may well be bedded into the head but they are not bedded to the cams. A good engine builder knows this is essential and all the cam manufacturers specify new tappets or no guarantee.

I rest my case.

Dooey99 - 17/2/13 at 02:55 PM

why are you having a go at me? LOL

this is a forum for discussions and to help each other not to put others down.

i work for a race team that race in lotus cup uk and europe and also elise trophy where we build engines all the time but i have never done a zetec engine.

if you have a problem then come and say it to my face dont coward behind your computer screen.

i am 18 and therefore not going to know everything about every engine i can build k series and toyota vvti engines to a very high standard

Paul Turner - 17/2/13 at 06:14 PM

If you built engines you would not have to ask where to buy valves. You would not have to ask about skimming heads. You would not have to ask about camshafts. If you worked in an engine building shop you would know why it is dangerous to skim flywheels.

These are basic questions that anyone working in a race team or engine building shop would know the answers to.

Do I need to go on.

Ask questions by all means but please don't pretend to be what you clearly are not.

Dooey99 - 17/2/13 at 10:57 PM

im not pretending anything mate, i dont source the parts the office staff get all the parts yes i could ask them but why not ask people who use zetec engines as our staff dont use them if you want a fight im right here and stop pussying about

whitestu - 18/2/13 at 08:17 AM

quote:

The original tappets may well be bedded into the head but they are not bedded to the cams. A good engine builder knows this is essential and all the cam manufacturers specify new tappets or no guarantee.

I don't know much about Zetecs, but it that actually right? With many engines the tappets don't bed into the cams at all as the tappets tend to rotate as well as go up and down so they are constantly moving.

r1_pete - 18/2/13 at 08:26 AM

quote:
Originally posted by whitestu

quote:

The original tappets may well be bedded into the head but they are not bedded to the cams. A good engine builder knows this is essential and all the cam manufacturers specify new tappets or no guarantee.

I don't know much about Zetecs, but it that actually right? With many engines the tappets don't bed into the cams at all as the tappets tend to rotate as well as go up and down so they are constantly moving.

Yes, wherever two components are in contact under load an element of bedding in occurs, the special lube used on cams when first installed is to prevent exessive localised wear occuring at first start up.

Davegtst - 18/2/13 at 10:27 AM

quote:
Originally posted by Dooey99
im not pretending anything mate, i dont source the parts the office staff get all the parts yes i could ask them but why not ask people who use zetec engines as our staff dont use them if you want a fight im right here and stop pussying about

Gotta love forums

Paul Turner - 18/2/13 at 11:12 AM

quote:
Originally posted by Dooey99
im not pretending anything mate, i dont source the parts the office staff get all the parts yes i could ask them but why not ask people who use zetec engines as our staff dont use them if you want a fight im right here and stop pussying about

When it gets to forum members using threats of physical violence it gets laughable.

Come on Dooey99, tell us where you work, whose engines you build and what your qualifications are.

If you won't tell us my case is proven and you are not an engine builder.

Dooey99 - 18/2/13 at 12:03 PM

i never said i was an engine builder? i said i can build engines, i am a mechanic and work for ES Motorsport where we build and race lotus's

Dooey99 - 18/2/13 at 12:07 PM

tappets bed into heads and do not bed into cams alot of people say they do but the bedding into to a cam is virtually nothing as the tappets turn in the head so bedding in would do nothing ans the tappets are forever spinning... everyones opinions differ on weather they bed into cams but that is mine.

im not claiming to be a zetec god, i dont know everything about zetec engines but im learning about them quick. best way to learn is to pull it apart and rebuild it and to ask questions

Paul Turner - 18/2/13 at 01:02 PM

quote:
Originally posted by Dooey99
tappets bed into heads and do not bed into cams alot of people say they do but the bedding into to a cam is virtually nothing as the tappets turn in the head so bedding in would do nothing ans the tappets are forever spinning... everyones opinions differ on weather they bed into cams but that is mine.

im not claiming to be a zetec god, i dont know everything about zetec engines but im learning about them quick. best way to learn is to pull it apart and rebuild it and to ask questions

It is and has been standard engineering practice for as long as I have been playing with engines to use new followers with a new or reground cams and the matching followers (if they are servicable) if using a cam from a different engine, if they are severely worn use new ones. To do anything different to this is gauranteed to accelerate cam and follower wear. Piper, Burton and Kent all specify that new followers must be used. That is why when engines are stripped all the components are clearly labled to ensure they are refitted in the original location.

I accept that they spin but that has nothing whatsoever to do with bedding in, its how they are designed to work.

With regards to you now saying you never claimed to be an engine builder you said on another thread I build performance engines weekly , that is very different to what you say now. Here is the link again to remind you of what you said previously http://www.locostbuilders.co.uk/viewthread.php?tid=178214&page=0&contribmessage=none 7th psot down.

Please tell us exactly what your job is a ES Motorsport

whitestu - 18/2/13 at 02:05 PM

quote:

tappets bed into heads and do not bed into cams alot of people say they do but the bedding into to a cam is virtually nothing as the tappets turn in the head so bedding in would do nothing ans the tappets are forever spinning... everyones opinions differ on weather they bed into cams but that is mine.

That's what I understood from years ago when putting togther Alfasud engines. I've mixed and matched used cams and followers with no noticable problems at all. I wasn't building race engines though, just fixing broken road car engines.

[Edited on 18/2/13 by whitestu]