I been stroked! Now what's my rev limit?

[sacse30]

I just had a 'e' motor dropped into my 90 325i and had the 'i' head fitted on there. I know she's a good bit slower for now, but this is only the preliminary setup for the motor. Should I expect to have the same rev limit of 4500rpm (correct me if I'm wrong) as you would have with a stock 'e' motor? Or does slapping the 'i' head on there raise it up at all?

Also, I'm in the process of finding a good m52 crankshaft (at a reasonable price) to go in there and swapping the 'i' heads in there. I know this will give me some pretty good gains in power as my new CR should be 9.7:1 (from what I've been told and gathered from the stroker sticky). What kind of rev limit should I expect at that point and what are the guestimations of power I should receive at that point? Thanks all in advance for your input.

[Brandon12V]

On the m20, rev limit is more affected by the top end, not the bottom. New bearings are certainly reccomended on your short block. If you have an 'I' head, you should be running a dual valve spring setup so you should see the 6000 rpm range all day long with the right ECU. I dont understand how you had a rev limit of 4500 to begin with if your car is a 1990 325i.. You should have done everything at once b/c there will be machine work needed on the crank and/or pistons for that setup to work. In my opinion you should just stick with the 'E' crank, knife it, and have custom pistons made to suit the compression ratio you want. Read up on e30 F34R's build thread. He is doing a relatively same build right now.

[jlevie]

The I head allows for a 6500rpm rev limit, but to get there you need to be using the I intake, throttle body, injectors, AFM, engine harness, and DME. Just dropping an I head on an otherwise stock M20B27 doesn't gain much and the engine management system will still limit the engine to a 5400rpm redline.

[devon.818]

what? when i had my eta i would rev it to like 5200...it was chipped.

my 325i revs out to 7000, then i bounce off revlimiter....

what 6500 limit are you talking about?

[dude8383]

what? when i had my eta i would rev it to like 5200...it was chipped.

my 325i revs out to 7000, then i bounce off revlimiter....

what 6500 limit are you talking about?

factory rev limit on m20b25 is 6500rpm (or maybe 6450?)

[nando]

^

stock?

and while you can safely rev a stock head to ~6900, it doesn't mean you're making any power..

anyway I thought stock was 6250?

[Killacortes]

My tach agrees at 6250

[lolcantturn]

6250 it is.

But M20 doesn't make power up there anyway so.

[dude8383]

^

stock?

and while you can safely rev a stock head to ~6900, it doesn't mean you're making any power..

anyway I thought stock was 6250?

http://en.wikipedia.org/wiki/BMW_M20 - granted that it is wikipedia...

http://e30world.com/specifications/BMW-E30-specs-table - 6200 rpm there

LOL

[nando]

6250 it is.

But stock M20 doesn't make power up there anyway so.

fixed for ya ;)

[sacse30]

The I head allows for a 6500rpm rev limit, but to get there you need to be using the I intake, throttle body, injectors, AFM, engine harness, and DME. Just dropping an I head on an otherwise stock M20B27 doesn't gain much and the engine management system will still limit the engine to a 5400rpm redline.

I have all of the above installed on the motor. I had a b25 turbo in there before I did the swap. However, it needed new tuning software and all that jazz which was going to be about $1500 after labor and such. Decided to make a stroker out of a fully rebuilt 'e' motor that I got for $350. Selling the brand new 'e' head for more than I bought the motor for! Not too shabby.

Still have to source out a m52 crankshaft though. Hopefully our local junkyard will get an e36 with one soon! What other models comes with this crankshaft?

With all of the above installed (MINUS the m52 crankshaft) how much power should I expect? Haven't gotten my car back from my guy yet so I have no clue how it drives?