325e M20B27 -> M20B25

[Andy348]

Okay, so here's a list of what I think I'll need.

Just a question though - if I save up a bit more $$$, what could I change on this list to give me a bit more HP (if anything)? I was thinking maybe SuperETA pistons or something.

List:

1989 325i Engine Harness -> will anything else work?
"i" AFM, Idle Control Valve, Intake Manifold, Throttle Body, TPS
"i" Injectors - will these work or will I need better than the I ones?
"i" fuel pressure regulator.
"i" speed/crank pully sensor
"i" coolant sensor
"i" o2 sensor
"i" head (885?)
"i" DME 173
"i" engine harness
"i" exhaust
"i" brake booster cables

Anything else?

[Andy348]

I don't think I saw what kind of rods/crank you're using. If it's a stock b27 bottom end, you can use b27 pistons. If it's something different, the answer to your question changes again.

As for buying a head, a new one for $650 isn't bad if it comes with new stuff and a good cam ready to go. For just a head, you can score something used but perfectly good for less than $200.

Sorry, I must have misread your reply. The motor is a bone stock B27, so Ill keep the same pistons.

I'm going to write up a list of what I need when I get home from work, I'd really appreciate if someone could check it. Thanks :)

[lateracer]

I don't think I saw what kind of rods/crank you're using. If it's a stock b27 bottom end, you can use b27 pistons. If it's something different, the answer to your question changes again.

As for buying a head, a new one for $650 isn't bad if it comes with new stuff and a good cam ready to go. For just a head, you can score something used but perfectly good for less than $200.

[Andy348]

What kind of pistons?

Regular B27 - yes, 88 super eta - hell yes, b25 - no (modification required).

I was hoping to keep my stock ones, but I guess not lol. I'm guessing I'll just get b25 pistons.

For a re manufactured 885 head, would I just buy this on eBay? I found one now for $650.

[lateracer]

What kind of pistons?

Regular B27 - yes, 88 super eta - hell yes, b25 - no (modification required).

[Andy348]

Okay, I've searched quite a bit on the subject.

I've gotten some very different answers... can I run an 885 head without altering my pistons/shaving anything? I've heard yes, no, and only if you're going to turbo.

Ideas?

[ForcedFirebird]

Actually CR has less impact than what you think.

I still think the B28 option using M52 84mm crank is better.

THIS!

Think about it for one second. The 2.5i has 8.5:1 and the 2.7i has 8.3:1. It takes several whole points to make a real difference in power, not tenths of a point.

[digger]

Compression ratio has a large impact on power, and a bump is easily achieved by milling as long as you are mindful of piston-valve clearance.

Actually CR has less impact than what you think.

I still think the B28 option using M52 84mm crank is better.

[Andy348]

I might be able to pick up an M20 for $150.

What parts should I inspect specifically if I'm looking to do the 2.7i stroker? Other than the head of course.

Thanks

[e30huh]

pick-a-pull off of Katella ave (Stanton) and there's one off of Beach blvd. GL.

[lateracer]

Pick-A-Part is my friend and Cali is awesome for e30 parts. I agree, i did get lucky, spend the extra money on the internals and a good head.

SoCal is definitely good for parts from people, but all (4) of the yards I've been to (South of OC) have been picked clean for parts...except for fenders and things like that. Where are you finding stuff?

Eventually I stumbled upon a BMW shop that stock piled old parts for pretty cheap, but that was more dumb luck. Would be cool to know where I could score stupid things like check valves and master cylinders on the cheap.

[e30huh]

I wouldn't throw any more money on that idle problem until after doing the Motronic 1.3 swap (if it still exists)

Also don't get your hopes up on cheap parts. Just don't want you to be dissapointed/make a reckless purchase. Sounds like e30huh got lucky, plus living in California probably helps. Not sure how popular they are in Canada.

The biggest thing is to be wary about used parts purchased over the internet at least for the head. Unless you can obtain very good photos it's completely hit or miss because a cylinder head is a high wear item and you generally don't want to take it back apart anytime soon so getting quality parts is important.

Pick-A-Part is my friend and Cali is awesome for e30 parts. I agree, i did get lucky, spend the extra money on the internals and a good head.

[rcfanatic]

I wouldn't throw any more money on that idle problem until after doing the Motronic 1.3 swap (if it still exists)

Also don't get your hopes up on cheap parts. Just don't want you to be dissapointed/make a reckless purchase. Sounds like e30huh got lucky, plus living in California probably helps. Not sure how popular they are in Canada.

The biggest thing is to be wary about used parts purchased over the internet at least for the head. Unless you can obtain very good photos it's completely hit or miss because a cylinder head is a high wear item and you generally don't want to take it back apart anytime soon so getting quality parts is important.

[lateracer]

If money is a concern and it's a street car, my vote is for the 2.7i build. Two reasons:

1) You'll keep the e's low end torque, and torque is what really makes for power on the street. The additional HP on the upper range is fun too. Toss in a chip, some rebuilt injectors and a good exhaust and you're looking at easily noticeable gains.

2) It's a low introductory budget price to going faster, and the motors aren't what slow these cars down. Spending some of your motor money on suspension upgrades and a differential swap will have you going faster as well.

Finally, it's an old car. Stuff breaks...constantly. It won't be long before you find some where else to spend whatever money you've got left. If it's like mine, about 1/3 of the stuff you take off (belts, hoses, seals, gaskets) dies when it's removed.

Let us know how it goes

[e30huh]

i did my 2.7i build on a $250 budget with a used machine head and all fresh internals (Febi). If you have the patient, then troll around for some new parts other don't need or want and you can get it on the cheap. $275.89 is the total i spend on the 2.7i including Goetze HG and VR gaskets for all other. Napa has the Goetze for $27.99 and with your AAA, it's, $22.78. Do it..........................JUST DO IT.

In then long run, it's cheaper to maintain an M20 head then a M/S50 and slap a turbo on there if you want extra HP.