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aa34s
09-14-2007, 06:21 PM
I just bought a 87 325i (won't start) and it came with an extra 325e engine and transmission. What I want to do is combine these two engines and put it in my 86 325es. I did alot of seaching from the net and forums, e block with i head is the way to do. So now I'm going to do these:

e bottom end with i pistons
i head
shave block 2mm
i ecu
i afm
oil cooler from the 325i

The question I wanted to ask is do I have to use the i harness or I can just stay with the e's harness and just plug in the i ecu?

Also, anyone can recommend a good machine shop in GTA?

It sounds like a easy job but I think there should be alot of little things will happen....the wires, sensors...... hope can finish it before the winter then I can start the body work in the winter time.

EMPOWERD
09-14-2007, 06:32 PM
Everything listed should work fine, including the stock "E" harness. I had the same setup with my 1988 car in the sig (later adding 75HP NOS). Pistons are curcial, make sure you swap them. Too many people just slap the "i" head on the 2.7L bottom and wonder why it's slower than before.

Machine shop? Contact Bimmersport, they deal with an excellent machine shop that does mint work on engines.

SamE30e
09-14-2007, 06:39 PM
Everything listed should work fine, including the stock "E" harness. I had the same setup with my 1988 car in the sig (later adding 75HP NOS). Pistons are curcial, make sure you swap them. Too many people just slap the "i" head on the 2.7L bottom and wonder why it's slower than before.

Machine shop? Contact Bimmersport, they deal with an excellent machine shop that does mint work on engines.

But not changing the pistons if you're doing a FI setup is a good idea right?

aa34s
09-14-2007, 06:48 PM
Everything listed should work fine, including the stock "E" harness. I had the same setup with my 1988 car in the sig (later adding 75HP NOS). Pistons are curcial, make sure you swap them. Too many people just slap the "i" head on the 2.7L bottom and wonder why it's slower than before.

Machine shop? Contact Bimmersport, they deal with an excellent machine shop that does mint work on engines.

I know the piston is the point, I would like to keep in low cost so I choose the i piston rather than the custom make piston, but there is another problem pop up, someone said that the skirt for the i piston need to be machine otherwise it will touch the e crank when it's at the bottom point. Is that true??

86coupe30
09-14-2007, 09:20 PM
is the e bottom end just the crank ? or the block cause i pistons will be too small

aa34s
09-17-2007, 02:08 PM
There is a problem for the pistons from the 87 325i, two of them are gone:( , so I need another set of pistions from i/is, if anyone have a set for sale, please let me know.

Thanks alot

craz azn
09-18-2007, 12:32 PM
I just bought a 87 325i (won't start) and it came with an extra 325e engine and transmission. What I want to do is combine these two engines and put it in my 86 325es. I did alot of seaching from the net and forums, e block with i head is the way to do. So now I'm going to do these:

e bottom end with i pistons
i head
shave block 2mm
i ecu
i afm
oil cooler from the 325i

The question I wanted to ask is do I have to use the i harness or I can just stay with the e's harness and just plug in the i ecu?

Also, anyone can recommend a good machine shop in GTA?

It sounds like a easy job but I think there should be alot of little things will happen....the wires, sensors...... hope can finish it before the winter then I can start the body work in the winter time.

You have one BIG problem. If you cut two mm off the block, it will change the timing. You will need to get an adjustable cam gear to make up for the height loss.

aa34s
09-18-2007, 07:02 PM
So, if I just use the e bottom end with i pistons and i head and shave 30 thou from the head will it be ok??

craz azn
09-18-2007, 07:15 PM
No. Then the compression is still way too low. You had it correct the first time by taking 2mm off the block. You should try and stay away from touching the cylinder head height all together. Unfortunately you will still need the adjustable cam gear if you cut the block down. It will run like crap without it.

Edit: I just reread you're original post. Make sure the car starts and runs properly first. Otherwise you may end up chasing an unknown problem down the road that you may never figure out. Could be fuel related, spark, timing etc etc... My advice would be make sure 110% you know everything is in good running shape before starting to tune it.

Aveman
09-19-2007, 04:17 AM
It's really not that bad to run a eta block with a 325i cyl head.

I'm running a diesel crank with eta rods and pistons, with a 325i head with welded coolant channels. It was built to be a turbo motor, I'll be installing my setup for next year. For now I'm running it N/A on megasquirt and it actually surprised me. It's quicker than a stock 325i as per my buddy that ran a stock 325i for a couple years. I'll be taking it to the track this weekend just to see what it can do. Maybe even get a dyno pull in. It's light years ahead of how my eta was stock, would run circles around it.

I had my head resufaced just slightly after getting my coolant channels welded.

From what I've read people had it wrong thinking a eta bottom end with 325i cyl head would net a comp ratio of about 7.8:1, it's more like 8.4:1 and if you take off 10 thou off the head it's close enough to the 325i comp ratio of 8.8:1.

I expected my car to be slow as shit running it N/A I built the motor to be a turbo motor from the get go but it's actually pretty fun to drive like this.

aa34s
09-19-2007, 05:12 PM
No. Then the compression is still way too low. You had it correct the first time by taking 2mm off the block. You should try and stay away from touching the cylinder head height all together. Unfortunately you will still need the adjustable cam gear if you cut the block down. It will run like crap without it.

Edit: I just reread you're original post. Make sure the car starts and runs properly first. Otherwise you may end up chasing an unknown problem down the road that you may never figure out. Could be fuel related, spark, timing etc etc... My advice would be make sure 110% you know everything is in good running shape before starting to tune it.

Thanks for your advices, yup, I will rebuild and replace everything before I put them all together.

aa34s
09-19-2007, 05:24 PM
It's really not that bad to run a eta block with a 325i cyl head.

I'm running a diesel crank with eta rods and pistons, with a 325i head with welded coolant channels. It was built to be a turbo motor, I'll be installing my setup for next year. For now I'm running it N/A on megasquirt and it actually surprised me. It's quicker than a stock 325i as per my buddy that ran a stock 325i for a couple years. I'll be taking it to the track this weekend just to see what it can do. Maybe even get a dyno pull in. It's light years ahead of how my eta was stock, would run circles around it.

I had my head resufaced just slightly after getting my coolant channels welded.

From what I've read people had it wrong thinking a eta bottom end with 325i cyl head would net a comp ratio of about 7.8:1, it's more like 8.4:1 and if you take off 10 thou off the head it's close enough to the 325i comp ratio of 8.8:1.

I expected my car to be slow as shit running it N/A I built the motor to be a turbo motor from the get go but it's actually pretty fun to drive like this.

Is there any huge differences between the eta crank and the diesel crank on the spec? Actually, that's what I want to do as your's engine. But why you welded the coolant channels? Because of the i head and the e block are not match??? I tried to put my stock e on the track and it made me so disappointed...I know it's just an e not for performance but it couldn't be that bad, that's why I want to try that engine up-grade and see it will get any differents or not. Thanks for your sharing*th-up*

Aveman
09-19-2007, 07:07 PM
Is there any huge differences between the eta crank and the diesel crank on the spec? Actually, that's what I want to do as your's engine. But why you welded the coolant channels? Because of the i head and the e block are not match??? I tried to put my stock e on the track and it made me so disappointed...I know it's just an e not for performance but it couldn't be that bad, that's why I want to try that engine up-grade and see it will get any differents or not. Thanks for your sharing*th-up*


The diesel crank is forged but is exactly the same as a eta crank just stronger. I welded the coolant channels on the head for when I'm boosted, it's not necessary but you're less likely to blow a head gasket when you hit 10+ psi.


I'll let you know what the car runs, it may help you decide. I'm guessing low 15s maybe a bit better. I'm running a 3.73 LSD.

aa34s
09-20-2007, 06:15 PM
The diesel crank is forged but is exactly the same as a eta crank just stronger. I welded the coolant channels on the head for when I'm boosted, it's not necessary but you're less likely to blow a head gasket when you hit 10+ psi.


I'll let you know what the car runs, it may help you decide. I'm guessing low 15s maybe a bit better. I'm running a 3.73 LSD.

Thanks for your infos, will you join the AutumnCruise on 30 Sept??? If yes, we can meet there. I and my friend (actually my boss) will be there.