what kind of m20 is this?

[E30 Wagen]

This engine was in a '88 325is. It had an eta cluster. I'm trying to figure out what the hell is going on.

It had a b25 valve cover and intake manifold so naturally i assumed it was a standard b25. but as i was removing the transmission today, i got a look at the cylinder head:

for a second i panicked because i was counting on using the 885 head. Anyway i pulled off the head and found these pistons. Are these super-eta pistons?


here's the numbers on the block. Please tell me it's at least a seta bottom end. I have an eta engine that's in much better shape, but now i don't know what to do with it.







Also, here's what the inside of the head looked like.


Final question: Are the pistons toast?

[acolella76]

those pistons look weird.. dont look like eta or seta pistons. Doesn't look like they have valve reliefs either unless they're just super super dirty. That is a 200 casting head, most likely you have a 2.7 eta motor.

[E30 Wagen]

There are valve reliefs on the pistons, they are just very very dirty. However on one of the pistons it looks like somebody may have ground the top down because the relief is hardly there. I think a major mouthbreather worked on this thing because there were mismatched bolts everywhere, and i even found a screwbit inside the head...

I'm extremely disappointed.

[scottinAZ]

that is just a run of the mill '87 and prior Eta motor. SETA will have pistons similar to the 2.5 engine.

[TimR]

were they running a 027 ETA ECU or a 173 I ECU, single valve springs?? my guess a non BMW mec did a motor swap, ETA clusters end at 5K, super ETA end at 6K I's at 7k, i think those are I exaust manifolds too. Maybe they thought the I intake and exaust would make it run better or non BMW mec installed a eta motor, the cluster could mean nothing if this was the kind of work on the car,

[ForcedFirebird]

It's an eta engine.

Are you sure the car is an "is"? Seems like a lot of trouble to swap and entire eta engine, ecu, cluster, transmission etc due to a blown motor or the like. there should be a sticker on the driver's strut tower letting you know what it is.

I have an eta with the 2.7i swap, am doing one for a customer now, also the race car is a 2.7i and those definitely do not look like eta pistons even - eta's have a slight dish on them with reliefs for the intake valves that you will see even if dirty as they are quite deep.

[e30rapidic]

are you sure its not an 87 325es?

[E30 Wagen]

I'm positive it was a 88 325is. It had the late model tails, valences, arches, a 325i exhaust, and LSD, and the door jam sticker indicated it as 325isa. It also was hooked up to a 153 ECU to a really hacked up wire harness.

I just thought that eta pistons had a more pronounced dish to them. Maybe I'll tear down my other eta next weekend. If only i could afford to get my 731 head machined...

[nando]

with as rusty as those bores are I wouldn't want to use much from that engine. it's definitely an eta in any case, and not a seta either.

[acolella76]

Yeah, I wouldn't use anything from that engine. Those pistons look completely flat.