m20 3.0

[e30powerslide]

Hi im new to this forum and i know this subjuect has probably been beaten to death, but anyone have any info on a 3.0 m20? im not just talking either i WILL do i just need some more info. i was told that i could use a s50 crank but can i use the stock rods? are the m20 rods forged or cast? what kinda HP and Trq numbers im i looking at. im planing on getting the head ported also. what kind of cam should i use? bigger valves? thaks for your time

[darien28]

IE sells a 3.0 kit, but 3.0 is stroking it a bit too much imo... gonna have a rough idle going that far. most just go with the 2.8l since there's no major modifications needed for that.

i believe they use a S50 crank and you use the i rods... not sure tho.

[Jordan]

Re: m20 3.0

what kinda HP and Trq numbers im i looking at.

Honestly? Not enough to warrent the cost of building the motor. Dave Length made the most built 3.0L M20 I've ever seen, and the dyno on it was disapointing to say the least.

For half the money Dave spend, he could have had a complete S50 conversion, and had more power then the finised 3.0L M20 from the get go.

[E30godz]

why would it have a lumpy idle? if its built like shit it may have one. but just boring/stroking doesnt just GIVE an engine a lumpy idle.

[Rob]

the aggressive cams that most people use to take advantage of the increased displacement and compression do, however affect idle

[E30godz]

well if we we're going all technical with talk of "cams" and "engines" and "gasoline" then FUCK IT!!!!!!
















asshole. :D

[nando]

dave never really got that engine tuned right though. he had a lot of trouble with detonation and was stuck using the factory chip. He was also still using an AFM, a MAF conversion would have probably helped significantly.

since I have an ix, engine conversions are pretty much out of the question. I'd love to do a 3.0 M20 some day if I ever had the funds..

[Jordan]

dave never really got that engine tuned right though. he had a lot of trouble with detonation and was stuck using the factory chip. He was also still using an AFM, a MAF conversion would have probably helped significantly.

All coulda shoulda woulda's

3.0L M20's are a joke for the money they cost you.

A stock S50 will out perform it, and cost half as much.

Jordan - who sees no merit in going above 2800cc in a m20.

[SlammedE30]

So Jordy, I'm curious. How much power would a 3.0L M20 have to make to get you to shut the fuck up?

[Jon325i]

Powerslide....

Just in case you haven't seen it, here's the link to Dave's site....in particular, his write up on his experience in building a 3.0L M20. Read it all....then draw your own conclusions.

http://www.davelength.net/car/engine.html

And just FYI, the car that Dave put this motor in was recently totaled (rear-ended). Dave has since purchased an E30 M3 and this 3.0L M20 is up for sale.

Hope this helps.

Jon

[Jordan]

How much power would a 3.0L M20 have to make to get you to shut the fuck up?

Stock S50 HP/TQ figures.

Don't bring up the "well s50 has vanos and 4vps etc etc" crap. I know this. My argument is based on HP for the money. Dave spent like 7k on his 3.0L M20, and it didn't come close to the performance of a s50. He could have had a s50 conversion for less money.

[darien28]

where the hell can u get a s50 done for less than 7k... >.>

the s50 alone costs about 5k w/ tranny, then you gotta rebuild teh engine, and all sorts of other things... pistons, head work, exhaust.. etc... just to bring to to the same lvl as dave's stroker...

I can build a 2.8 stroker re-using old parts for about 2.5k... all you'd need is a good conditioned "i" head, wiring harness, ecu, pistons, block bored out, and that's about it... using i rods and the eta crank. now, if you're going to start fixing up the engine internals, that's where the costs come in. replace all maintnance items (all rubber, all pumps, etc) and then get the td crank, e36m3 rods, new valvetrain and valve job, port matching, extrude hones intake, bored out tb, headers... then yeah, all that brings up your costs. it all depends on how far you want to go.

but still, personally I wouldn't go past a 2.8 or maybe 2.9. 3.0 is too much stroke and you end up with efficiency problems in the combustion chamber, stress on the thinner cylinder walls, and other technicalities like that.

then there's always the option of a 2.7 turbo. use a proturbo adapter and stock i manifolds, td crank, super-eta pistons... etc.

[Rob]

I just read that page, interesting stuff. I wonder how the motor would perform with a maf and really tuned? Hopefully better than in did...



the power curve doesnt look bad though

[Jon325i]

I just read that page, interesting stuff. I wonder how the motor would perform with a maf and really tuned? Hopefully better than in did...

the power curve doesnt look bad though

Before Dave's cabrio met its fate, I had a chance to ride in it around SF (sorry...no wheel time). Initial impressions were that there's a lot of low-end grunt. It had recently rained so Dave wasn't putting his foot into to it too much, not to mention SF's streets can be rather crappy in places, but there is no question in my mind the torque down low is nice. This motor had the "Big 6" AFM conversion on it so its breathing was improved some......but I'm sure a MAF set up would increase HP, torque, and resposiveness across the board.

Knowing that the E30 cabrio's have extra weight to lug around, dropping that motor into a lighter steel-top would only improve its performance potential. However, as Jordan has noted, for the amount invested, going the twin-cam route would have resulted in much more bag for the buck. And that is a strong argument no matter how you slice it.

Jon

[Stu]

Properly setup and tuned 3.0L M20's will roll E36 M3's.

We've done it....in a car wtih a 3.25 rear end.