Cam Questions

[rabbitude]

I am cosidering running the IE 272 billet cam, but I have a few questions. How hard is it to install it, could I do it in a day on my driveway or would I need to have it done. Also what type of increase in HP could I expect with a ported head, Miller AFM, headers, 19lb injectors, and exhaust.

[briansjacobs]

to the best of my knowledge the cam is not billet, it is a factory cam that has been reground. I have run their 272 cam (regrind) with their billet rockers and would advise against it. I do not remember what the power claims were as I installed with a brand new engine. I removed and sent back, to their credit they were great to deal with and very nice, but it cost me alot of money to fix the problems caused by a faulty product.

[rabbitude]

They sell 2, a regrind and a billet

[briansjacobs]

good luck.

[ak-]

I haven't read anyone getting noticeable or pleased gains from a more aggressive cam on an m20. I usually read things against it considering the time & money. But then again, I'm not really talking from experience here.

[LowR3V'in]

I haven't read anyone getting noticeable or pleased gains from a more aggressive cam on an m20.

Because those people you've read about used stock replacement like cams (272).

[Adrian_Visser]

Yeah and anything more than a 272 and you should be starting to worry about valve clearance, piston valve reliefs should be increased and stiffer valve spring should be used.

[Wh33lhop]

Yeah, the Schrick 284/272 installed as a stock replacement (stock height head/stock hg/stock cam gear) just barely taps the pistons with the valves--some are able to get away with it, some aren't. However you won't notice much improvement over stock with anything above a 272 and stock compression ratio, as the dynamic compression ratio is lowered, in general, the more aggressive the cam profile becomes. So, the guys without built bottom ends won't see much improvement with cams bigger than 272s.

The 272 and 284/272 can use stock "i" valve springs. Go for a 288 and up and they will require an upgrade.

[nando]

I haven't read anyone getting noticeable or pleased gains from a more aggressive cam on an m20. I usually read things against it considering the time & money. But then again, I'm not really talking from experience here.

M20's are under-cammed from the factory. The BEST way to improve the head is with a cam. actually as far as "bolt ons" go, the only other thing close to a cam for an B25 motor is exhaust.

and yes, you won't want to go too agressive with a totally stock bottom end.

[briansjacobs]

4.10 ftw

[llll1l1ll]

Basically, OP, you will want to remove the head for this job. Yes, you can do it under a shady tree in your driveway, but it will take some time and effort as those exhaust manifold bolts suck. As does the oil tube.

Once you remove the head and you're planning on putting in a new cam, that would be a wise time to re-do your head. In fact, if you're going to do something like this, you might even be better off buying a used head, rebuilding it with the specs you want, and then just swapping it out.

[sohc12vm20]

Turbo... Ftw!

[rabbitude]

So basically you guys are saying it not really worth the bother

[sohc12vm20]

http://www.youtube.com/watch?v=Lik4YPw0JTM:shock:

So basically you guys are saying it not really worth the bother

[ak-]

Yeah, the Schrick 284/272 installed as a stock replacement (stock height head/stock hg/stock cam gear) just barely taps the pistons with the valves--some are able to get away with it, some aren't. However you won't notice much improvement over stock with anything above a 272 and stock compression ratio, as the dynamic compression ratio is lowered, in general, the more aggressive the cam profile becomes. So, the guys without built bottom ends won't see much improvement with cams bigger than 272s.

The 272 and 284/272 can use stock "i" valve springs. Go for a 288 and up and they will require an upgrade.

This is what I meant when I said "what I usually read about".
Thanks.

M20's are under-cammed from the factory. The BEST way to improve the head is with a cam. actually as far as "bolt ons" go, the only other thing close to a cam for an B25 motor is exhaust.

and yes, you won't want to go too agressive with a totally stock bottom end.

I see.