building a 24v DOHC engine

[e30this]

but for srs bsns, is 413 the ecu i should be looking for to run an obd1 m52? will i need a chip?

The red lle 413 is non EWS and the silver lable is EWS.
From what I understand the 506 ECU is M3 specific.
I read it some place but dont quote me on it, it has been a while.

[z31maniac]

You should be banned for your outright laziness in this endeavor.

[lifeiskaos]

but for srs bsns, is 413 the ecu i should be looking for to run an obd1 m52? will i need a chip?

[lifeiskaos]

ehh i should just start a new thread. plans have changed a bit. i had fun with the turbo m20, im thinking of trying to build a nice NA engine for now. s52 crank with 84mm bore yields 2.97L iirc so i'll reach my 3L goal no problem. s52 cams, and if i decide to turbo later, i'll get low comp pistons and possibly mls headgasket

[nando]

at some point, sure, but it doesn't seem to be a problem for all the turbo M3 guys pushing 1000hp.

[lifeiskaos]

I did, actually. same bore spacing, 91mm, on everything from the M20B20 to the S54B32.

right, but like i said, it's easier to blow a headgasket when there is less material between cylinders. did you guys read AND comprehend my post?

[nando]

why said anything about an s50?

I did, actually. same bore spacing, 91mm, on everything from the M20B20 to the S54B32.

[lifeiskaos]

Time to use our critical thinking cap kids. The bore spacing on all the motors talked about is the same, why would an m5x with an 86mm bore be any more likely to pop a headgasket than an s5x with an 86mm bore.

Did you actually read AND comprehend nando's post?

why said anything about an s50? the point is im not going to bore it to 86mm, or anything like an s5* engine, and i dont know if a standard m52 headgasket is big enough for an 85mm bore. as of now im going to stick with the stock bottom end, get some s52 cams, and work from there

[z31maniac]

thanks for the post nando. from what i've read, the problem with boring out an m50/m52 to 85mm+ is that there wont be much headgasket between the cylinders. seems like it would be quite easy to pop at >1.0 bar of boost

Time to use our critical thinking cap kids. The bore spacing on all the motors talked about is the same, why would an m5x with an 86mm bore be any more likely to pop a headgasket than an s5x with an 86mm bore.

Did you actually read AND comprehend nando's post?

[nando]

a torque plate is a great idea - but if your engine is detonating, you're going to be losing power either way and likely damage something, so you shouldn't be driving around like that anyway.

but then this is r3v, home of putting random engine parts together with an off the shelf chip (if that) and hoping it doesn't blow up..

[e30serg]

You got some female dogs running around your yard?
:)

The reason you don't want to bore out the cylinders out too much is because they can flex when detonation happens and allow compression gases to blow-by the rings. This makes you lose some power and increases your crankcase pressure.

If you're going to bore it out, make sure you use a torque plate to mimic the stresses put on the block by the head bolts.

Good luck!

[jahnaboi]

Good start. Do it!

[lifeiskaos]

bitches... :finger:

[SpecM]

But blowing a hole through the side of the cylinder wall? That's never going to happen. Maybe if you throw a rod through the block, but that's likely from improper assembly or a $shift. If 1 mm less material (on the radius, for 2mm overall) makes the cylinder wall suddenly collapse, I don't think you'd want to use that particular engine for boost in the first place.

Boring it to 86mm isn't going to hurt it for boost if you use the right hardware. the S52 is already larger than that and they're fantastic for boost. Same damn block too, so you aren't going to suddenly punch through the walls because you did a measily 2mm overbore.

truth

[lifeiskaos]

you have no reason to be posting in my thread unless you have knowledge and experience with said situation, and are willing to share in a constructive way, so please stop wasting your time and mine, and gtfo

thanks