advised timing for an A2 or a 234 cam

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bstark
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My Supersprint with 234 cam used to come on cam about 3000rpm, then pull to 6000rpm when the power would start to tail off (that's with an Aldon Ignitor). Now on a Megajolt on a safe map (so not optimised yet) and it pulls from nearer 2000rpm, then hard from 3000-6500rpm plus (probably higher but don't want to push my luck) Suits the car very well, and no problem with it just have the 4 gears. Bob Stark Supersprinter
Richard K
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Hi Eric, My supersprint (1988 vintage) was built by Vulcan Engineering 234 cam that pulls well at low rev's but starts to come on strong at 3,000. This is their website http://www.vulcanengines.com/ If you scroll half way down the 'brochure' page they have some graphs that show the power output of thier engines. Supersprint is the 135 / 145 bhp. By the way - my engine is 'tired' having never been touched and the valve springs have now soffened such that it won't rev over 6,000 but still managed 110 bhp. at a recent rolling road session. Not bad for a 22 year old engine. Go for the 234 you won't regret it. Richard
eric
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I think about it ... but not sure What I can see that there is nobody for the A2, in a way it is normal becouse in fact Caterham sold very little 1600 sprint with an A2 . The best seller was the 1700 supersprint eric
bstark
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Eric, My car was a 1600 Sprint when I first tested it (not that I knew it during the test - long story) and subsequently had a new Steve Parker Racing 1700 engine to Supersprint spec fitted prior to my picking it up. Basically, I found it transformed the car - went from feeling quick-ish and capable but not extending the chassis to simply feeling alive. All things are relative of course (and this was at the time on rock-hard Goodyears, but over the years as I've improved the car I have never once wished I had kept the original engine. Quite the opposite in fact. All I would say is make sure you get it properly set up - mine wasn't initially and it drove horribly off-cam, then came alive all rough and guts. Once it had seen a rolling road and had the timing and carbs properly set up it was as smooth and tractable as you like. With a Megajolt it's almost modern-car like in its tractability but with that lovely twin 40 throttle response and noise. I occasionally wish for more power (who doesn't) but the car is pretty nippy on track (has a local class championship trophy to back that up), great on the road and if something happens to the engine I'd still stick to the 234. Bob Stark Supersprinter
Iamscotticus
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Eric, fellow 1600 Sprint lump here,

you've been out voted.  234.

But, something that isn't being argued here, you never said you intended to upgrade to 1700.

How can anyone claim a 234 will be better in your 1600 when they are happy with it in their 1700s with uprated pistons and springs?

I am not yet convinced a 234 is justified in a 1600. As many have stated, especially Roger King, that the rest of the engine needs to be built up to support the bigger cam.  This is why the A2 was/is a good choice for a low spec engine.  It gives plenty of low end pull in a basic tune that remains a reliable driver.

Im not saying the 234 isn't worth doing, but getting the most out of it, you might as well do the whole race tune, machined pedestals, iron crank, pistons, etc.  Oh, and while you're at it, 1700! The upside of doing all this bottom end work is you will be able to try all the cams you want till you find the one!

What a hole!

I want to pep up my Sprint as well, but I have to be concerned with that Ital rear end and how much it can take.  Perhaps a map is the better route?  The maps seem to help out a lot.  These are really light cars. Throwing more "power" into them change the character of the handling.  I still like the idea of the Super Sprint, but before all that investment, I will try a map on the A2. If that doesn't do it, a 234, map and dual springs that will clear. If I still need pistons, then its full race or back to the A2.  Also, there are other cam profiles like Pipercross that will work in a road engine.

AM95/1246/UC

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With ECU controlling the fueling and ignition you will make significant gains in low end tractability when using wilder cams allied with more power and better economy too.

I would also look to modify the timing cover to enable you ro alter the cam timing whilst on the rollers, and then look at trying different inlet lengths too once you have optimised the cam timing. 

The timing figures some of the cam grinders publish are way out.