e30 eta with m20b25 swap need some help

[2low]

hey guys so iam picking up a m20b25 today and iam swapping it in my 86 eta since i cant boost my eta iam just gonna go with the "i" swap and boost that but the m20 is from a 89 do i need to change anything or it should be a prefect bolt up and crank. i have the ecu and the harness and all that stuff but i think i read some where that the cooling system is diffrent is that true ? do i have to change anything there ?

[Ceeker]

you can use the eta bottom end and bolt on the I head and intake along with the ecu and engine harness. cooling system? engine internals are the same. Might need to change the rad and plumbing. reroute some hoses but aside from this it's only minor. get yourself a bentley service manual or go online and do a search for swap. if you are planning on boost later on. I would strongly suggest rebuilding the head, as the extra power is going to strain the factory components. new cam, heavy duty rockers, and valve springs. head studs instead of the factory bolts and a really good headgasket. that's for starters.

[InfiniteDice]

The cooling components/hoses are different, the 89i has the coolant tank on the other side. Just use the 'e' setup you have you may need to use the 'e' waterpump and thermostat housing, just swap it all from your e engine. The 86 eta will have the sensors on the bell housing of the transmission. the I has them at the front of the engine. If the 'i' enine you have has those sensors then you are good, just remove the 'e' sensors from the tranny and cap the holes with something. The 'e' has a different tach/cluster with a different code pin. The e'e cluster will work but give the wrong engine speed. Your 'e' will have dual fuel pumps but that's not a problem.

None of these are difficult issues but you'll have to work around them.

I had a few more in my head a couple minutes ago, but can't remember them. I'm sure others will chime in.

[InfiniteDice]

Oh you may have differences in the brake booster to throttle body connection.

From what I remember the harness bundle that passes through the firewall is slightly larger, and you'll need to ream that hole out a bit to slip it on in there.

There are 1 or 2 wires that connect under the dash near the ecu box. I can't remember what they are, but there could be a difference in there. They are not essential to the car running but I recall having something not work till I sorted that out.

[The Twin]

When I did this with my 85 eta to 90i swap, there was much ado about a switch at the clutch level and incompatibilities.... Someone might be able to clear that up, but it was the reason my engine wouldn't turn over once swapped...

[InfiniteDice]

What you must be thinking of is the sensor pickups on the 'e' bellhousing. He simply uses the 'i' harness and sensors, and removes the 'e' ones and plugs the holes.

There is also a park safety switch but that should only be an issue for automatic to manual swaps.

[2low]

Originally Posted by InfiniteDice

What you must be thinking of is the sensor pickups on the 'e' bellhousing. He simply uses the 'i' harness and sensors, and removes the 'e' ones and plugs the holes.

There is also a park safety switch but that should only be an issue for automatic to manual swaps.

lol didnt know that thanks
and its not auto