Am I doing the right thing?

[rs4pro3]

depends on what other items from the I engine are swapped over. If you just take and eta bottom end with super eta pistons and an I head without also adding the I manifolds, and computer and sensors you won't gain much power at all. Most people get 190-205 hp at the crank with the 2.7's so you should deffiantly have more power than the 325i motor.

[ColdAccord]

i have the complete i motor, so the only eta thing i would use is the block. exhaust manifolds for both motors are the same, correct?

[rs4pro3]

the exhuast manifolds depend on the year. I'll post a picture of both types in a minute for you.

[rs4pro3]

Ok here are the differences between an Eta and latter I manifold
Eta I
Down pipe 37.13mm 42.48mm
Head 29.82 32.78mm
Those are the diameter of the runners where they meet the head and meet the downpipes. The I runners are larger.
Plus the Eta runners make a Jog where as the 325i runners run straight till they curve down towards the downpipe.

[ColdAccord]

i'll have to inspect this next time i go to my buddy's garage (the i motor is on a stand, stripped down to just block and head). im gonna try and get the pistons, hopefully do the 2.7i

[rs4pro3]

Ya most people don't realize the manifolds are different. I believe all 88 up e30's got larger manifold. I'm not positive about 87 325i's though.

[ColdAccord]

my eta is from 87. my i motor is from 88 from a 325ix

[rs4pro3]

check the Ix manifolds and I heard they different also

[JPbmw]

so to make a quick list for to do an e to i conversion with super eta pistons would be :

complete i head
i intake manifold
computer
sensors
super eta pistons
umm fell free to add more stuff

btw: would 19lb injectors be necesary?

[rs4pro3]

Basically take everything from a 325i Engine minus the Crank, rods, and pistons and put a 325e crank and Super eta pistons in it. 19lbs are needed if you add a M30 AFM, with just a standard 2.7 the 325i injectors should do.

[ColdAccord]

im gonna use my 325e block. i bought a clutch, but it's for an m20b25. should i/can i buy a 325i flywheel, put that in my setup, with the 325i clutch, or trade in the 325i clutch for a 325e

[rs4pro3]

That sounds like it will have less hassles then using the 325is block. You should be able to use the 325i flywheel, clutch and pressure plate on the Eta crank and engine. Now what tranny will you be running? Me an E9ine have discussed someabout this as he had problems with his car when running the 325i clutch and flywheel on an eta block. I'm planing on ussing an I flywheel, I clutch and I pressure plate with an I tranny. and am hoping for no probs. Just a little note if the 325e clutch is from a single mass flywheel it is the same as the 325i clutch disc.

[ColdAccord]

i thought the flywheels and hence the clutch discs were different?

i have an e tranny, which is why I'm wondering if I should just trade in my i clutch and get an e clutch

[JPbmw]

im sorry if im asking too many dumb questions but im trying to get everything right. :oops:

ok so it would probably easier to buy a m20b25 have it rebuild and then put in the spuer eta pistons and eta crank? but his way would probably be more expensive right?
thanks rs4pro3 for answering my questions ;)

[rs4pro3]

If you go to Bav auto's website thye have the same part number listed for the 88 325i clutch kit and 84 325e clutch kit. my 88 325is right no has an 84 325e clutch disk with a 325i pressure plate. The problem comes up when you use a different flywheel then was origanly with the tranny. Talk to E9nine more about it as he had the problem.
JPbmw-Basicaly yes you cna buy an Eta crank for $50-4100 from almost anywher I've got one I'll sell for $30 but it needs a full regrind and would need all new oversize bearings. the local junkyard here will sell a complete Eta short block for $150-$200.
Also check out this link as it's info I gathered on building up the m20 http://www.r3vlimited.com/phpBB2/vie...=m20+buildinfo