1988 325 engine build options?

[threadediron]

You don't need a gates timing belt to turbo an M20. lol. That's rediculous.

So would you say you could run a turbo kit on a stock M20 with no ill side effects? How high of a psi could you run before you start losing reliability?

I mean, of course and psi greater then 0 surely will be less reliable than the stock engine, but basically what Id like to know is what psi should you keep it at to be safe.

[ThatOneEuroE30]

You don't need a gates timing belt to turbo an M20. lol. That's rediculous.

I like to think of it as an insurance policy On the rest of the motor.

[e30strokr]

Ive got a 1988 325 with the 2.7L super eta engine (comes with the 325i cylinder head).

I knew nothing about this engine when I bought the car, I assumed it was a normal 325i engine like all the others.

The car is great but feels a bit slow to me after being spoiled with a 300HP V6. Without machining any parts myself and without breaking the bank, what mods could I do to get more power out of this engine?

I'd like to break 200HP if possible, at least 220 would be ideal.

Ive read that performance chips (such as the tuner motorsport Jim Conforti) can be installed to get an easy 20HP on 93 octane. Would this work on the stock seta internals?

Bleh. I dont know, Ive read too much on this and found conflicting opinions for nearly every mod, what are your guys thoughts?

This'll also be my first "built" engine, as Ive previously kept my vehicles stock, save for maybe an exhaust and CAI.

just to clarify you already have the "I" cam and dual springs?!?? or just the regular 127 hp SETA engine and want to build it up?!?!?

[djjerme]

Are diffs for these cars basically plug n play? Ive been thinking about swapping in an LSD... Its not a bad idea considering it will give me that "seat of the pants pull" as you so eloquently said hahaha

Somewhat. There is a small and medium case, but you can visual tell the difference. You would have the medium case stock, and you would probably see a difference if you went in the lower 3's for a ratio.

Diff ratio is a really cheap way to change the characteristics of the drivetrain. It can really wake a car up around town, or done the opposite way, improve gas mileage. Just look around locally for an LSD and you can probably get something a little steeper for $300-400.

[illmaticD]

I just got finished with the 2.7i conversion a couple weeks ago, with a Super ETA engine. Its probably the most economical choice for you at the moment, and it does give your car a big boost in power compared to stock. I myself am a college student (from Jersey too!) on a limited budget, so I chose to do the 2.7i conversion. And I did the work myself.


I'll break down to you my costs, just to give you an overlook of the price of parts before shop labor:


-$325 for Cylinder head Resurfacing, pressure testing, and 6 exhaust valve guides. Done by Automotive Machining Inc in Hillside, NJ. No need for drilling extra oil passages. You already have the 7 needed in your head.
-Lapped the valves myself for about $18

-Elring head gasket set from ECS Tuning, which includes all the gaskets you will need after dismantling the head: $80

I had a spare M20B25 engine so I already had the top end parts needed for the swap. But for you, I estimate around $200-350 for the following USED parts:

-325i intake plenum w/throttle body
-325i cam
-Dual Valve Springs
-173 or 380 ecu
-3.0 Bar Fuel Pressure Regulator

-You'll need new coolant ($40 for 2 gallons from BMW), and oil/filter ($30-40)

-Timing belt w/ tensioner: $53

-Water Pump: $40

-New Head Bolts: $29 for Geniune BMW bolts

-SSSquid Tuning 2.7i Chip: $200

-Refurbished m20 injectors: $40 (unless you wanna go the junkyard route)

****All of this totals around $1200**** This doesn't factor the cost for things you should get/change, including:

-NEW rocker arms, springs
-new radiator hoses
-3.73 LSD


With that being said, there's S50 e36 m3 motor on craigslist in our area for $1300!!

[threadediron]

just to clarify you already have the "I" cam and dual springs?!?? or just the regular 127 hp SETA engine and want to build it up?!?!?

Im unsure of this myself.

I found this through research

"1988
In order to meet federal emissions standards in it's final year of production, the '88 325 receives a 325i cylinder head, exhaust system, and engine management control with self-diagnostic capabilities (Motronic 1.1) as well as special pistons, (lowering compression slightly to 8.8:1), a slightly larger intake manifold and a revised valve cover. These changes bump up the eta's power rating slightly (to 127) and a 6000 RPM tachometer is fitted."

and

"6.) What about the 88 325/528e "Super Eta"? I hear those are better for the conversion than the 84-87 etas.

That's true because the '88 325's and 528e's already have the 325i cylinder head (though it retains the eta cam and single valve springs), Motronic 1.1, and pistons that will work without any modification. Saves some time and money. "

So, this is the engine I have, I have no idea which it is. I think its the M20B27 motor, but again, Im unsure.

Its extremely frustrating because all the tuning companies that make parts or chips or what have you, say its either for the i engine, or the eta engine, but I have no idea what will or wont fit my car.

[threadediron]

I just got finished with the 2.7i conversion a couple weeks ago, with a Super ETA engine. Its probably the most economical choice for you at the moment, and it does give your car a big boost in power compared to stock. I myself am a college student (from Jersey too!) on a limited budget, so I chose to do the 2.7i conversion. And I did the work myself.


I'll break down to you my costs, just to give you an overlook of the price of parts before shop labor

Much appreciated my friend. Just to clarify, you built the same exact engine I have?

And out of curiosity, have you had it dyno-ed after you built your engine? Im just curious how much of a gain you think you got out of it.

EDIT: I also saw you said you did the work yourself, how did you manage to get this done while attending school? Im guessing you are a commuter student and so you didnt have to work in the schools parking lot hahaha
Approx. how long did swapping all these parts take?
Thanks again for the help, I do appreciate it.

[SkiFree]

Its extremely frustrating because all the tuning companies that make parts or chips or what have you, say its either for the i engine, or the eta engine, but I have no idea what will or wont fit my car.

To be a bit blunt, their job isn't to educate you on what fits, that is up to you to pop open your valve cover and take a look inside.

Both your quotes from earlier are true. Assuming you are correct in that you you have a seta "885" head, it varies in a few ways from the true m20b25 885 head. Namely the cam, oiling holes, and springs.

Sticking to my original parts list would save you a lot of time and trouble while you are still a student.

[e30strokr]

OK so you probably have the original 2.7 engine meaning you got 127hp ...

SETA has the 325 head but not the springs or the camshaft that make it possible to have 160-180 hp (however I have heard that you don't absolutely need to have the dual springs in order to run the 325I am ie 320 engine has single springs and revs higher that an ETA?!?!? somebody confirmed)

you pretty much can use all the 325I performance stuff once you get the
I computer (alpina has a 2.7 stroker chip)
I cam
I intake
3.0 bar fuel pressure reg (like ilmatic said)

takes about one day (3-4 hrs) to do the swap/belt so on...

4.10 LSD differential would help out, however im not fond of 3/4k rpms regular drives thru town

[illmaticD]

Much appreciated my friend. Just to clarify, you built the same exact engine I have?

And out of curiosity, have you had it dyno-ed after you built your engine? Im just curious how much of a gain you think you got out of it.

EDIT: I also saw you said you did the work yourself, how did you manage to get this done while attending school? Im guessing you are a commuter student and so you didn't have to work in the schools parking lot hahaha
Approx. how long did swapping all these parts take?
Thanks again for the help, I do appreciate it.

Same exact engine. Its a 1988 325 with a build date of 10/87. Came with the 885 head and the special pistons.

I haven't dynoed it, but if I were to guess without being too optimistic, its probably around 180 hp give or take. This is with refurbished 19lb Yellow Ford injectors and an M30 AFM (probably about $120 altogether). Definitely more than a stock 325i, but not a whole lot more. The 2.7i engine conversion is really about torque and a broader powerband.

And yes I am a commuter student at Kean University. I spent a little over a year stockpiling parts for my build (including for a manual transmission conversoin) while working part time 20-25 hours a week. I started working full time this summer, and when I finally got around to it, it took me about a little over 2 months of on-and-off work this summer to get the build done.

This was my first real build but I spent the past year researching every step thoroughly. even if i felt confident that i could do it, I still researched each step. and i did it all within my unevenly paved driveway. i've bought multiple sets of tools from harbor freight when necessary. but besides a good metric socket set and breaker bar, the only specialty tools i can recall that you'll need are a E-socket (Torx socket) set, wobble extensions, flat bicycle wrenches for removing your cooling fan, and a torque wrench. if you're close to my area, i'll even let you borrow them.

now i'm not saying that doing it yourself is a walk in the park. i ran into several hiccups. in fact, i completely trashed the head on my spare engine trying to remove the exhaust manifold bolts. they snapped inside the head and i botched completely the procedure to drill them out! and separating the exhaust from the exhaust manifold is a struggle, involving PB Blaster and multiple socket extensions/wobble extensions.

but if you really insist on going to a shop, Guten Parts in South Orange, NJ is the place to go!

[illmaticD]

OK so you probably have the original 2.7 engine meaning you got 127hp ...

SETA has the 325 head but not the springs or the camshaft that make it possible to have 160-180 hp (however I have heard that you don't absolutely need to have the dual springs in order to run the 325I am ie 320 engine has single springs and revs higher that an ETA?!?!? somebody confirmed)

you pretty much can use all the 325I performance stuff once you get the
I computer (alpina has a 2.7 stroker chip)
I cam
I intake
3.0 bar fuel pressure reg (like ilmatic said)

takes about one day (3-4 hrs) to do the swap/belt so on...

4.10 LSD differential would help out, however im not fond of 3/4k rpms regular drives thru town

you need the dual valve springs for when you run the 325i ECU. the single valve springs on the Super ETA are rated for the Super ETA's stock redline (5,500 rpm).

with the 325i ECU and 325i cam, the car will want to rev to 6,500 rpm, but the Super ETA valve springs are too weak to keep the valves closed at those higher RPMs. the resulting issue is known as valve float.

[threadediron]

To be a bit blunt, their job isn't to educate you on what fits, that is up to you to pop open your valve cover and take a look inside.

Both your quotes from earlier are true. Assuming you are correct in that you you have a seta "885" head, it varies in a few ways from the true m20b25 885 head. Namely the cam, oiling holes, and springs.

Sticking to my original parts list would save you a lot of time and trouble while you are still a student.

Does that mean I should swap to a true 885 head instead of keeping my "imposter" 885 head?

[illmaticD]

1988 325 engine build options?

Does that mean I should swap to a true 885 head instead of keeping my "imposter" 885 head?

It is rumored that early model Super ETAs have 4 oil passages in the head. Although all the ones I've seen all have 7, including mine.

It would make sense for them to have 7 because Super ETA's have a camshaft profile that looks similar to 325i camshafts, both of them having 7 main journals on the camshaft.

Regular ETA's ('87 and older) have a different head with 4 oil passages and four main journals on the camshaft.

In the event that such a head exists and that you do only have four oil passages in an 885, you can get the last three passages drilled out by a machine shop for $20-30, and still use the head.


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[SkiFree]

Does that mean I should swap to a true 885 head instead of keeping my "imposter" 885 head?

No, you will be fine. Out of the hundreds of 885 heads I've peered into, a handful of the early seta engines have had fewer oil passages. As has been said, it is something easily checked for and easily remedied.

The outer valve springs are the same, just have them checked (they do fatigue) and order up a new set of inners.

[illmaticD]

1988 325 engine build options?

I would also like to add that you can definitely go with a hotter cam, for example a Schrick or Bimmerheads cam. They'll get you closer to the power you are looking for. But they put stress on the OEM rocker arms. You might snap several rocker arms. And if you buy used 325i valve springs, they might not be strong enough to close at the appropriate time for the hotter cam, again resulting in valve float.

To remedy this, you have to get Heavy Duty rocker arms and heavy duty valve springs. Bimmerheads makes both. (And they have affordable reground camshafts!)

The price of a new cam, plus HD rockers and springs easily adds almost $1k to your build. This puts your total cost in "engine swap territory"


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