cams for e30m3

cheers sterling,

not trying to sound stupid what is this alpha n system all about. Heard it mentioned on here a few times.  i take it there is no way of telling if the cams have been changed or not in my vehicle. so compared with your car the scricks on top of the 223bhp should see it past the 235 mark.

cheers

What might be a factor is the Bexleys dyno is different to when most of us got or cars dynoed, that the could make a bit of difference.

Those are very good numbers, but I wouldn't be surprised if it's had a intake cam in it.
Still if it's making that with stock cams then it will only get better if you went down the Schrick route.

Don't read too much into a peak bhp figure as that's all it is and doesn't really mean that muchon it's own. You could drive the same type of car with less peak power that would be quicker.

amorgan wrote: cheers sterling, not trying to sound stupid what is this alpha n system all about. Heard it mentioned on here a few times.  i take it there is no way of telling if the cams have been changed or not in my vehicle. so compared with your car the scricks on top of the 223bhp should see it past the 235 mark. cheers

Yes,with a pair of shricks it should put you around the 235bhp ball park.Personally I think £1200 for 10 brake is exspensive.

Cheers Jon

 Very basically,the max alpha n is a piggy back computer that allows you to remove the afm,which is the major constriction on the intake that stops our cars breathing.From what others have said it transforms the car and the gains are throughout the rev band.

Uwe - thanks for the drawing - excellent info.

The critical thing not shown on the drawing (or perhaps I have missed it) is the gudgeon pin to piston crown height.

But what seems to make sense from the drawing is that that that measurement IS different on the 2.5 pistons so that BMW could use the same rods for the bigger engine.

The squish 'height' is different, presumably to allow for the bigger piston to give a similar compression ratio, which means - presumably - that the combustion chamber in the Sport head is the same as the standard head??

If all these suppositions are correct the 2.5 conversion does seem very straightforward if the block will take the bigger bore. There is one point here (and you mentioning your cracked block reminded me) - on Gustave's site he says that he thinks the 2.5 block is the same as standard except for some added strengthening pads, but he doesn't seem to make much of a point about these. But if you look at the following link you can see photos of the webbing on a 2.3 block, a 2.5 block and also on a DTM block. Makes me wonder whether the extra reinforcement is essential on a bigger bore.

Even if it's the top deck that's cracked it can be caused by movemnt of the block in the crank area. Would be interested to hear where yours has cracked and whether you can establish that it happened after the conversion.

Jonners, it has definately not happend after the conversion. I don't know yet which part has failed. Could also be the head. The combustion chamber is different because of the bigger bore. But you can still use the "standard" head.
Brian, my head is slightly ported, but just to port match
all the bits surrounding and some bumps and humps smoothend. Nothing aggresive.
Jonners here is what you want to see:

this is how the 215 head looks with the 2.5 gasket.
Notice the edge from 94mm bore. I was a bit undecided
if I should machine the head to match the gasket and decided against it because of the compression I would loose. Now I know that it can be removed without loosing to much. Jags worked it out to 10.9 with the "small" combustion chamber, so it might just drop down to the 10.5 of the Sport EVO if you machine it matich to 95 bore.



Edited by UweM3

hi weeksy,

so you are the guy kent have done the profiles for.

Those are some good figures i am sure the other guys will agree for the mods. so instead of just cams i should be looking for some head work also. Not to know whether i have a modified inlet cam or not should i go straight to a  ported polished head?

Amorgan,

That's me!!

Cam's aren't worth 700- odd quid for the pair, when the originals are in perfect conditioned and can be reprofiled!!

Speak to Kent Cams and ask them for the Schrick 284 276 profiles.

I believe they also have the profiles to obviously do you a pair of 284's, and if you fancy pulling the rods and pistons out at the same time as sorting your head, and going a bit silly,  then maybe the 292 'hot cam' for the inlet side- as this will definitely need valve pockets in the pistons. I wouldn't recommend this, however.

This will upset the idle and low speed torque, so be warned!! An excellent cam for the track, but not too nice for the road!! 

Definitely go for the head, let me know if you need a contact, as we aren't far away from each other at all! Take the cams out, and pop them down to Kent Cams, and ask them to check the profile, then you will know where you stand on the cam front

Regards

Weeksy

   

So how much is a crank and pistons from BMW?????????

Darran,

I never had the car on the rollers before.

I've had my Cossie on the rollers at PE, and Engine advantages in Essex, anfd they were within 5 or so bhp of each other.

Reasonably consistent for a turbo car taking changes in atmospheric conditions into account??

 

Regards

Weeksy