MyE28.com

So the car redlines at 4000 and bounces at 5000, if I wanted to add forced induction should I upgrade to some "i" heads or would it matter?



I've never owned a car that reved so low so I'm just wondering if there'll be any negative consequences if I don't, and should I also rebuild the engine if it has 290000km on it? (139000 miles ish)

Your car doesn't have "heads" unless there is one in the trunk. The questions you are asking lead one to believe that you have limited knowledge of this engine and its design. Research M20B27 and learn what they are about. They are a low-revving efficient engine not designed for high rpm or horsepower, and they reach their intended goal quite well. If you want to make power, you need to upgrade the engine with a different cylinder head and camshaft, and probably matching pistons. The bottom end from a Super ETA and the cylinder head setup from an E30 325i is a good start. Do some more research.

Stronger valve springs will help your motor rev higher. I rev my m30 to 6k often, before heavy springs I could barely go over 5k.

Kyle in NO wrote:Your car doesn't have "heads" unless there is one in the trunk. The questions you are asking lead one to believe that you have limited knowledge of this engine and its design. Research M20B27 and learn what they are about. They are a low-revving efficient engine not designed for high rpm or horsepower, and they reach their intended goal quite well. If you want to make power, you need to upgrade the engine with a different cylinder head and camshaft, and probably matching pistons. The bottom end from a Super ETA and the cylinder head setup from an E30 325i is a good start. Do some more research.

When I said heads, cylinder head is what I meant

marc79euro645 wrote:Stronger valve springs will help your motor rev higher. I rev my m30 to 6k often, before heavy springs I could barely go over 5k.

You mean you bent valves or what?

Just bolt a turbo on it and drive it. I'm sure you'll get more than the 100 hp it presently has.

darbyhood wrote:So the car redlines at 4000 and bounces at 5000, if I wanted to add forced induction should I upgrade to some "i" heads or would it matter?



I've never owned a car that reved so low so I'm just wondering if there'll be any negative consequences if I don't, and should I also rebuild the engine if it has 290000km on it? (139000 miles ish)

Okay. NO NEED TO REBUILD. Youre probably a broke kid like me and really, M30s and m20s last forever. my friend dogs the living shit out of his m20 stroker with 270k+ miles and it takes it like a champ. We even pulled the main caps and rod caps. The bearings were excellent, and the cylinder bores still had decent crosshatching...

Doesn't matter if you have a super ETA or regular ETA engine... People will tell you "you MUST have a super ETA lower end to run an m20b25 885 head! It'll be a dog, the compression will be low!!!" Well that's BS. Even if you put the 885 head on the lower compression ETA rotating assembly you'll still make more HP and torque than a stock m20b25 or m20b27 I've built 885 headed ETA engines with friends and they all rip with 3.73 gears... All 3 were done for less than $700.... One we actually did for $250 including the price of gaskets... And if your boosting, the low compression will be on your side.

1. get an m20b25 885 head from an e30 325i or 325is. (I have two if you want one, PM me) slap that bitch on your 2.7 M20b27 lower end. Get all gaskets required.

2. Get a motronic 1.3 wiring harness

3. 325i or 325is intake manifold, ECU and injectors. I would also recommend a cheap set of headers.

----you now have an m20 stroker that will make excellent low end torque and still love rpm.

4. Take it further and slap a snail on dat bitch and boost the snot out of it.




I made that sound too easy. Well, actually, aside from going turbo, it is really easy.


But you probably have no idea what I'm talking about so I just wasted my time...

marc79euro645 wrote:Stronger valve springs will help your motor rev higher. I rev my m30 to 6k often, before heavy springs I could barely go over 5k.

My b34 revs to 7300 rpm

I'm running an m106/745 kkk turbo, considered small, so I don't get that much more, by revving that high. I do enjoy good torque to 6k with 18# boost.

marc79euro645 wrote:I'm running an m106/745 kkk turbo, considered small, so I don't get that much more, by revving that high. I do enjoy good torque to 6k with 18# boost.

Yes! What rear gear? / Thread jack