What's my best approach? e plus i

[mechdonald]

I have a 1986 325e in pretty good shape - I just want some go-faster.
I have access to a complete spare e motor and I can pick up an i motor locally for fairly cheap.

My question is, what is the best combination to do given 2 complete motors?

I have read up a little on making the 2.7i motor but I was wondering if there was another approach given both complete motors.

No turbo.
Goal of 170+ hp.
Motor would be Megasquirted.

Thanks,
Dale

[Mr. Burns]

budget stroker.

e bottom end, plus i top end.

if you can change a headgasket, you can do this 'swap'

[mechdonald]

budget stroker.

e bottom end, plus i top end.

if you can change a headgasket, you can do this 'swap'

What pistons and rods do I use for this? I have no problem tearing the engines apart and mixing parts around if that helps.

I'll do some more googling :)

[ForcedFirebird]

Just use the entire top end and electronics from an "i" car. You will gain about 40% WHP.

[Mr. Burns]

??

as long as your compression is solid on your existing ETA bottom end, don't touch it.
so no need for rods/pistons.

there are plenty of writups on this swap.

I think there is a stick over on maxbimmer (toronto based) on those who've done it before including myself.

plus, unless you're running boost or some other type of F/I you don't need standalone.

[ForcedFirebird]

If you want a little more than the power of a 2.7i, you can use the e rods/crank with i pistons and shave the block down 2mm. Then you have a high compression 2.7

[pantelones]

How much do you want to spend?

The proper way to do the swap is to use the seta pistons with what is stated above. Most people don't really give a fuck and just want "power". The reason you swap pistons is to match the combustion chamber to the piston design, the eta is a flat top and the i has a hemispherical design. An added bonus is a bump in compression when using the seta pistons. (8.7 I believe? not really sure)

Also you are talking 170+whp you definitely are going to need a 272* or up cam, some head work, and a good set of headers/exhaust.

[ForcedFirebird]

How much do you want to spend?

The proper way to do the swap is to use the seta pistons with what is stated above. Most people don't really give a fuck and just want "power". The reason you swap pistons is to match the combustion chamber to the piston design, the eta is a flat top and the i has a hemispherical design. An added bonus is a bump in compression when using the seta pistons. (8.7 I believe? not really sure)

Also you are talking 170+whp you definitely are going to need a 272* or up cam, some head work, and a good set of headers/exhaust.

seta: 8.5:1
"i":8.8:1
2.7i: 8.43:1
combo I posted: 9:1+ pending head/block shaving.

I took 2.6mm off a block and was going to use the -.015" head and .050" gasket (deeper valve notches in the pistons) which would have yielded almost 11:1, but sold the motor after I wrecked my Delphin :(

I had a budget stroker in my car with a .050" head gasket (-.020) and .015" shaved off the head ~8.9:1.

You will need an adjustable cam gear for a ton shaved off the head/block.

[mechdonald]

If you want a little more than the power of a 2.7i, you can use the e rods/crank with i pistons and shave the block down 2mm. Then you have a high compression 2.7

seta: 8.5:1
"i":8.8:1
2.7i: 8.43:1
combo I posted: 9:1+ pending head/block shaving.

I took 2.6mm off a block and was going to use the -.015" head and .050" gasket (deeper valve notches in the pistons) which would have yielded almost 11:1, but sold the motor after I wrecked my Delphin :(

I had a budget stroker in my car with a .050" head gasket (-.020) and .015" shaved off the head ~8.9:1.

You will need an adjustable cam gear for a ton shaved off the head/block.

Great - This is what I'm after:
2.7 bottom end except for putting in the i pistons.
deck the block 2mm (after double checking everything)
i top end
i ECU
new seals/gaskets

What head gasket would I need? Stock e or i or something else?

Would I need the adjustable cam gear for 2mm off the block? I'm guessing it wouldn't hurt.

Would this give me approximately 160 - 170hp?

What changes to the exhaust, if any, are needed to connect the i manifold to the existing e setup?

[mechdonald]

How much do you want to spend?

The proper way to do the swap is to use the seta pistons with what is stated above. Most people don't really give a fuck and just want "power". The reason you swap pistons is to match the combustion chamber to the piston design, the eta is a flat top and the i has a hemispherical design. An added bonus is a bump in compression when using the seta pistons. (8.7 I believe? not really sure)

Also you are talking 170+whp you definitely are going to need a 272* or up cam, some head work, and a good set of headers/exhaust.

I don't really want to buy pistons. I'm thinking the SETA pistons aren't the easiest to find or inexpensive.

I like the idea of the i pistons with the i head for the reason you stated. Decking the block accomplishes basically the same thing, correct?

Stock i is rated at about 160-165. That's good enough for my little car.

[kronus]

seta: 8.5:1
"i":8.8:1
2.7i: 8.43:1
combo I posted: 9:1+ pending head/block shaving.

Any idea what an eta block + 731 head yields?

[ForcedFirebird]

Any idea what an eta block + 731 head yields?

All the blocks are the same except a few early ones had large welsh plugs on the back.

As for CR's:

http://www.scribd.com/doc/12801628/Mahle-Pistons-M20#fullscreen

[pantelones]

I don't really want to buy pistons. I'm thinking the SETA pistons aren't the easiest to find or inexpensive.

I like the idea of the i pistons with the i head for the reason you stated. Decking the block accomplishes basically the same thing, correct?

Stock i is rated at about 160-165. That's good enough for my little car.

Seta pistons aren't that expensive when they do come around. I have seen them usually go for around $100 or less. Though I was unaware that the I pistons do work. I could have sworn that I saw a photo of an I piston in an eta block and it was sticking out like 1/2". I would just listen to John since he has the experience of playing with these combinations. My only suggestion is that if you do start decking, check your valve clearances with putty to prevent a disaster.

On a side note, if a stock I is good enough why don't you just find a healthy low miles motor and throw that in the car?

[mechdonald]

On a side note, if a stock I is good enough why don't you just find a healthy low miles motor and throw that in the car?

That was my original plan... but I have a mechanic friend who insists it is kid's play.
I guess part of it is that we would plan on replacing gaskets and such anyways - may as well mix it up while it is apart.

Also, he is the source of the extra e motor.

[MR 325]

Any idea what an eta block + 731 head yields?

It will be 9:1 just like the Eta.