iank
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| posted on 16/1/07 at 10:20 AM |
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Odd question
Idle thinking is dangerous  But strikes me that the perfect engine for a road car is a cross between a BEC and a CEC.
The real downsides of a BEC (for me) are the very high revs required to do anything, the (relatively) poor torque and the high emissions (reverse gear
would be nice, but livable without). Pro's are obviously the light weight, the quality and sophistication of the parts, and the sequential
gearbox.
In the same way a race cam in a CEC will put all the power at the top end in a steep spike. Is it possible to 'detune' a BEC with soft
cams to bring the power down the rev range and spread the torque out? For some reason I've got a niggle that turbo cams in cars tend to be
soft, so would BEC turbo cams work like this? Has anyone tried this?
Something like the torque/power characteristics of the GXR1400 while being easy to get hold of and fit.
Thoughts?
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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BenB
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| posted on 16/1/07 at 10:30 AM |
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Something like a ST1100 
The power band on the ST is pretty broad. I saw a dyno of a ST compared to a Fireblade- quite a difference..... More rolling countryside than cliff
face!!!
Power on the ST was partially a function of long inlet tubes (which I've removed otherwise the bonnet bulge would be even bigger) but also the
fairly relaxed cam timing. Which it is true does make it suitable for forced induction- which I'm now working on along side a dry sump
setup....
I like the fact that I don't need to keep the revs up all the time. I choose to, but thats because at the moment I'm mostly hooning around
getting used to the car (it was flipping freezing last night BTW!!!!)..... The ST has a good power band so it is possible to drive along in relatively
high gears...
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G.Man
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| posted on 16/1/07 at 10:31 AM |
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goldwing engine maybe?
Only around 90bhp, but 110ft/lbs of torque.. probably tuneable as well..
Lovely flat 6 engine for low cog
even has an electric reverse built in
[Edited on 16/1/07 by G.Man]
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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RazMan
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| posted on 16/1/07 at 10:34 AM |
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The common mistake (imo) that most people seem to make is that a screaming bike engine which is great in a bike, is not going to be right for a BEC.
However there are quite a few bike engines which have a much wider torque band and these tend to be the less fashionable tourers. The Triumph 1200
Trophy for example has loads of torque low down in the rev range and is not particularly high revving for a bike engine. I would like to build a BEC
with one of these little beauties.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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iank
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| posted on 16/1/07 at 11:00 AM |
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Thanks gents,
ST1100, ST1300 seem very interesting
ST1100 UK models: 100PS @ 7,500 rpm 79 ft.lb @ 6,000 rpm sounds more like what I'm looking for.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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BenB
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| posted on 16/1/07 at 11:55 AM |
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ST1100 engines are cheap as chips too....
Got the last one with gearbox, carbs etc for £250..... 1997 model to replace the 1990 unit currently in my car in case I blow it up...
Only thing to look out for is the low sump. Ride height is a bit marginal- hence the rather high front end of my motor. Dry sumping it should cure
that- get rid of the mahusive oil pump arrangement in the wet sump and replace the 5-6cm bulged sump for a flat one....
And its got a very accesible crank pulley just asking for a supercharger to be attached to..... (but then it starts getting complicated!!!)...
Other issue with the ST1100 is the emissions testing. You can easily get pre-95 engines (to avoid CAT test) but before 1996 the ST was fitted with a
smaller 28A alternator which can be a bit marginal depending on how many gadgets you're fitting.... There is a swap available for the later 40A
alternator but its not a simple swap- you need to take the alternators apart and modify things slightly. Not a major problem but a bit of hassle worth
knowing about... Of course if you're going to fit a dry sump pump off the crank pulley you can get rid of the Honda alternator completely and
fit something like a Nova alternator which happily gives 90A....
At the moment I'm running a plain vanilla 1990 ST1100 with the 28A alternator and a slightly ride height. Its a laugh- I should really keep it
as it is....
but I've got a BMW mini cooper S supercharger, 90A Nova alternator, spare engine, lots of pulleys, pulley belts etc taking up room in my
garage..... It would seem a shame not to at least try to get it to work And of course the fairly linear power boost of a lag-free Roots type
supercharger would suit the broad power delivery of a ST engine.... Aiming for 150Bhp. Then all I've got to try and do is avoid the temptation
to increase the boost (destruction testing)....
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Winston Todge
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| posted on 16/1/07 at 12:18 PM |
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Sounds like a great project Ben!
I was seriously considering this route for my car, but decided to get it functioning in standard guise to begin with then start playing with NOS and
forced induction...
How are you going to control the ignition map and fuel injection system with a Mini supercharger? Aftermarket ECU's and things?
Increase the CR with a thicker headgasket?
How do you even go about setting it up to begin with after you've fit the charger? Base fuel injection map and timings?
Would you use standard cams?
Thanks for any pointers,
Chris.
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bimbleuk
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| posted on 16/1/07 at 12:35 PM |
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I've thought about the 4AGE 20V blacktop as almost being a hybrid car/bike engine. Obviously since Yamaha designed the head they must have been
influenced somewhat.
Specifically the angle, shape of the inlet ports and the slender valve stems are very similar to modern bike designs. The rods were almost half the
thickness of previous 4AGE rods plus the many other weight saving revisions used.
The tolerances are very tight for a production engine and the cranks rods and pistons are finely balanced. Much better then my flippin Fidanza ally
flywheel anyway!
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Peteff
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| posted on 16/1/07 at 12:56 PM |
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Triumph 1200 Trophy engine
I would like to build a BEC with one of these little beauties.
There's nothing little about them, they are big for a bike engine. The 900 triple is the same engine with a cylinder chopped off the end.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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BenB
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| posted on 16/1/07 at 01:13 PM |
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I'm going for an aftermarket ECU- either Emerald or KMS (accepts the ST trigger wheel as standard but fewer tuning places are used to it)...
CR I'm adjusting by a couple of copper decompression gaskets from Ferriday engineering... Plan is to go down to 9:1.
Standard cams should be very good on the ST. The standard engine is pretty relaxed, so I expect the valve overlap to not be too extreme....
My plan re timing + injection is to go slowly and gradually. First convert to fuel injection using the standard Honda ECU for timing and run like that
for a while. That way I can get used to the software, iron out any sensor bugs or problems with the injectors etc. Then I'll use the aftermarket
ECU for both....
Then I'll attach the blower and take it to Emerald It is a worry though. I've never heard detonation and don't want to. The
Locost nose does offer good opportunities for intercooling so that's my first port of call for detonation prevention (combined with RON98,
sensible timing and lowish CR). I initially wanted to use RON95 but I'd have to lower the CR so much or retard the timing that the power
increase would be small and I'd have just made the car heavier! I'll just have to be careful where I drive (I know on the tour of Ireland
the drivers who *had* to run on RON98 were the ones with the more worried faces when we drove for miles without seeing a petrol station!! ie even if
you do find one it may only have 95).... Perhaps an emergency bottle of octane booster in the boot might calm the worries.....
It is a leap into the unknown..... I'm confident I'll get the fuel injection side of things sorted relatively simply. Going forced
induction is the big leap. But worse case scenario is I flog the mini supercharger, intercooler etc and get left with two nice decompression plates to
hang on the wall... and maybe have to fit a new engine
quote:
Originally posted by Winston Todge
Sounds like a great project Ben!
I was seriously considering this route for my car, but decided to get it functioning in standard guise to begin with then start playing with NOS and
forced induction...
How are you going to control the ignition map and fuel injection system with a Mini supercharger? Aftermarket ECU's and things?
Increase the CR with a thicker headgasket?
How do you even go about setting it up to begin with after you've fit the charger? Base fuel injection map and timings?
Would you use standard cams?
Thanks for any pointers,
Chris.
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froggy
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| posted on 16/1/07 at 05:40 PM |
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the tl is a good lump too , feels much more car like than the 4cyl bec,s ive been in
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jollygreengiant
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| posted on 16/1/07 at 06:15 PM |
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People seem to be forgetting the 1275 Zetec lump from Ford. In its original life it WAS a Japanese Motor bike engine.
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
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ChrisGamlin
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| posted on 16/1/07 at 07:18 PM |
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There are good reasons why most touring engines aren't that popular as BEC engines though.
I think the big sticking point is often gearing. Touring bikes have a lower maximum rpm and generally aren't geared for doing 180-200mph like
the superbikes are, so a combination of lower rpm and/or lower gearing often means you'll struggle to gear it appropriately in a BEC, ie
you'd need something like a 2.9 rear diff to give decent cruising / top speed
They're also generally a bit (if not a lot) heavier than superbike engines but thats probably less of a concern if you're building a car
like that, as you're obviously not after ultimate performance.
Im not saying there aren't exceptions to the rule, but they are generally the performance derived touring engines like CBR1000FF, Fazer etc
which have a lot of traits similar to the superbike engines.
Chris
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DIY Si
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| posted on 16/1/07 at 07:38 PM |
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As a middle ground there is like the cr1100, which is a 5 speed bird engine, with a wider torque spread, but lower power. Having said that, the bird
isn't too bad in itself, the torque is pretty flat from 5k up to about 9k.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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zxrlocost
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| posted on 16/1/07 at 08:01 PM |
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been in all cars give me an r1 engine anyday for the ££
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iiyama
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| posted on 16/1/07 at 08:13 PM |
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what about an FJR1300??
If its broke, fix it. If it aint broke, take it apart and find out how it works!
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Hellfire
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| posted on 16/1/07 at 10:23 PM |
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Excellent choice. The AS version even comes with push button shift. 
FJR 1300AS
Phil
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gttman
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| posted on 16/1/07 at 10:53 PM |
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Ducati 996 engine?????
For some stupid reason I have just bought one of these with the complete wireing loom.
Andygtt
Please redefine your limits
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G.Man
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| posted on 17/1/07 at 07:04 AM |
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quote:
Originally posted by gttman
Ducati 996 engine?????
For some stupid reason I have just bought one of these with the complete wireing loom.
Maybe because its one of the best sounding engines ever made?
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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