Eta 2.7 block with is 885 head question

[Corsair89]

Please don't flame me. I've been looking and I have not found the answer that I am looking for. I have an '84 eta with a rebuilt engine, don't know if it's a seta or just a regular eta. My new e30 is an 1988 IS and the engine sounds weak, I want to swap blocks and then swap heads. So my question is as follows: how do I find out what eta block I have. Also if it is an early block and not a seta will my '88 885 head work? Thanks in advance.


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[modernist]

seta is 1988 only

[Corsair89]

I know about that much but is there any way to tell if the block is seta? All I know is that the engine is a "new" rebuilt block. I've no way to tell, with my limited knowledge, what the block is.


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[efficient]

Look at the numbers on the side of the motor on the drivers side.

[ForcedFirebird]

Pull a spark plug and look at the piston. Easiest way. eta pistons are flat, seta pistons are shaped like the "i" pistons.

Chances are you have a regular eta, as mentioned 88 was the only year of the seta, they are fairly rare.

[Blake B]

where would one go about finding SETA pistons?

[Corsair89]

Ok so will the flat "i" like pistons work with an 885 head?


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[HarteB]

Nrs of the S eta on the block 27 6KB
Nrs of the eta on the block 27 6EA or (B)

this was the nr of my S eat engine



I drove an '84 323i with the S eta engine .. completely rebuild and blueprinted to 204hp and 270nm Torque .. they are great engines

The flat piston will not work with the 885 head .. compression will be to low

[Andy.B]

Nrs of the S eta on the block 27 6KB
Nrs of the eta on the block 27 6EA or (B)

this was the nr of my S eat engine



I drove an '84 323i with the S eta engine .. completely rebuild and blueprinted to 204hp and 270nm Torque .. they are great engines

The flat piston will not work with the 885 head .. compression will be to low

The flat pistons with an 885 head work fine, provided you run a motronic 1.1 or 1.3 setup.
It's known as a 2.7i. Search on r3v for plenty of info.
You will get better results if you get a chip meant for the combination. Sssquid style a range of fantastic 2.7i tunes.

[Corsair89]

Sweet thanks guys! I really appreciate all the help.


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[HarteB]

The flat pistons with an 885 head work fine, provided you run a motronic 1.1 or 1.3 setup.
It's known as a 2.7i. Search on r3v for plenty of info.
You will get better results if you get a chip meant for the combination. Sssquid style a range of fantastic 2.7i tunes.

I know it works but if you want big power output this is not the way to go .. I tried all kinds of setups (with motronic ecu type 173) and the flat piston with the 885 head gives you a comp of 8.3/1 .. you can reach alot more with the S eta piston (this was put in the S eta for a reason) the S eta also has the 885 head but less oil bores less bearings and a smoother cam .. you got to have the "i" 885 head .. if you skim the head like I did the comp ratio is about 10.2/1 .. you need to run premium fuel

check the picture to see the difference in m20 b25 and b27 are both 885 heads (n° of oil bores is different) b20 is the 731 head



Hope this helps

HartgeB

[jeffnhiscars]

731 came on a B23. not sure about the b20

[digger]

To get a 8.5:1 CR SETA to 10.2:1 you need to remove something like 11cc from head which would be like 2.0mm or 0.08” which doesn’t sound like the best idea….

If you’re going to pull the engine might as well do a worthwhile budget stroker, like a 2.8L with OEM bits and if you set that up correctly you will have 10.1 compression.

[digger]

731 came on a B23. not sure about the b20

b20 had the 731 head as well

[modernist]

The flat piston will not work with the 885 head .. compression will be to low

Uhh ... I daily drive this and it's a hoot. People hating on flat top builds have probably never seen a well sorted one. It might lose a couple of hp compared to a higher compression build, but saying it won't work is just blatantly false. If you do it right, you get a smooth, torquey engine that pulls hard to 6k and still gets decent MPG. Ask me how I know.

Also if it is an early block and not a seta will my '88 885 head work?

Yes, absolutely. Even with ~8.3:1 compression it's still an excellent motor. Remember, BMW shipped M30s with 8.0:1 compression from the factory.

Sssquid style a range of fantastic 2.7i tunes.

YES. I'm using an Sssquid tune and it's FANTASTIC. Worth every penny.