Kind of a stroker...

[Bimmerfanatik]

Ok, as some of you have read, I'm embarking on an SETA swap into my 87iC. The SETA engine is the one year bastard child of the M20 family, and it's not quite an ETA, and not quite an i motor. So figuring out what parts to use, and what parts not to use, is hard to do.

So here's what I've got:

87 325i motor/manual tranny
88 SETA motor/auto tranny

I'm using the 325i tranny and the 88 SETA motor.

For the following parts, what do I use?
SETA or 325i?
Plug wires
intake manifold
flywheel
exhaust manifolds
radiator
anything else??

[nando]

plug wires? - whatever is in better shape

intake? - i for sure. yeah, the e manifold *might* make more torque, but that's at the sacrafice of any power up top.

flywheel? - whichever is lighter, the i is a single mass so I'd probably use that.

exhaust manifolds? - I think they might be the same, but use the i if there is any question.

radiator? - shouldn't matter, use whatever is in better shape.

hopefully you are using the i computer and injection system. should be a pretty decent motor!

I keep forgetting, does the seta bottom end use 135mm or 130mm rods?

[Bimmerfanatik]

Where will the sensor wire go from the #6 wire on the SETA engine?

I was talking on the other post about this - I'm building an i head with aftermarket cam and upgraded springs to swap in a month or so - should I just hold off and wait until then to install the i tb, intake mani, and harness?

Flywheel - is the SETA a dual mass?

I'll just unbolt the i manifolds that are in there now and use them on the SETA engine.

Again, is it safe to use the i tb, fuel rail, harness and chipped ecu without the cam and dual springs?

I am almost certain the SETA rods and ETA rods are the same - so 135mm?

plug wires? - whatever is in better shape

intake? - i for sure. yeah, the e manifold *might* make more torque, but that's at the sacrafice of any power up top.

flywheel? - whichever is lighter, the i is a single mass so I'd probably use that.

exhaust manifolds? - I think they might be the same, but use the i if there is any question.

radiator? - shouldn't matter, use whatever is in better shape.

hopefully you are using the i computer and injection system. should be a pretty decent motor!

I keep forgetting, does the seta bottom end use 135mm or 130mm rods?

[nando]

eta rods are 130mm

the impulse sensor would go to the same place it does on an i engine. I don't know if they both use the same connector though, but I suspect they do (I bet the plug wires are the same anyway). isn't the harness the same between the two? only the ECU is different.

you could safely use the i ecu, intake etc. on the stock bottom end, just don't rev past 5k! if you decide to wait until you build your head, keep in mind you will need to use the seta AFM with the seta ECU.

[Bimmerfanatik]

eta rods are 130mm

the impulse sensor would go to the same place it does on an i engine. I don't know if they both use the same connector though, but I suspect they do (I bet the plug wires are the same anyway). isn't the harness the same between the two? only the ECU is different.

you could safely use the i ecu, intake etc. on the stock bottom end, just don't rev past 5k! if you decide to wait until you build your head, keep in mind you will need to use the seta AFM with the seta ECU.

I keep thinking 2.7=longer stroke=longer rods, but it's the crank that makes the longer stroke, oui non?

ooook. I won't be able to resist r3vving past 5k, so I'm going to treat this like a complete SETA swap and hold the i parts for later on - for safety and simplicity's sake.

[nando]

probably not a bad idea, since you seem to be confused as to what parts do what. KISS. ;)

and yeah, the longer stroke comes from the crank. usually you'd want longer rods to go with that, but the e motor didn't rev high enough for R/S to matter.

[Dave]

ooook. I won't be able to resist r3vving past 5k, so I'm going to treat this like a complete SETA swap and hold the i parts for later on - for safety and simplicity's sake.

Good move . . .

[Bimmerfanatik]

probably not a bad idea, since you seem to be confused as to what parts do what. KISS. ;)

and yeah, the longer stroke comes from the crank. usually you'd want longer rods to go with that, but the e motor didn't rev high enough for R/S to matter.

I just know very little about the SETA when it comes to the fine details. I expected the sensor wire on the #6 wire on the SETA, so when I didn't find it, I was a bit confused. I also thought the intake mani was i - again, it's SETA specific.

My thoughts on the SETA were that it was an i motor with eta crank and rods, and single springs and eta cam. All other parts were i parts, in my mind.

Hence the confusion!

[AdamF 88iS]

As far as the long block itself goes, it is an 'i' head casting on an eta bottom end with special pistons to make that work. You will want to use all of the 'i' manifolds, injectors, throttle, etc.

As far as the radiator, depends on which water pump and hose setup you go with. Pre and post 88 have different cooling systems all together. I prefer the later system, but again, which ever is in best condidtion.

For the electronics- They will both be basically the same wiring. The only difference is that the 87 harness will not have seperate fuel injector wiring, it'll be all one piece. This makes it harder to take the head off in the car, but is more reliable. As far as why your plug wires are missing the pulse sender, beats me, but they should both have it.

[Brew]

Word on the street is that the pulse sender on the "i" plug wires does absolutely nothing....

... but, the word on the street is wrong.

[nando]

I always thought it was for the tach? or does that come from the ECU?

[Bimmerfanatik]

Word on the street is that the pulse sender on the "i" plug wires does absolutely nothing. It was used by an older BMW diagnostic computer(that was phased out many, many years ago).

No seriously, it does nothing. Throw it away.

bah - the wire came off Fielding's car when we did the t-belt and it ran terribly - misfiring, etc. Then we put a new set of wires on and it was fine :)

[bmwsmurf]

The 'e' engines have a different harness than the 'i' engines and don't have the impulse sensor. (that's the only difference as far as I know). It's used to sequence the fuel injectors. See this post here:

http://www.e30tech.com/forum/viewtopic.php?p=105765&sid=36638b6cf825e14f0a64a9438085a1dd

So I guess if you are going to use the i motronic computer, you will need it. If not then no.

[arsevader]

Word on the street is that the pulse sender on the "i" plug wires does absolutely nothing. It was used by an older BMW diagnostic computer(that was phased out many, many years ago).

No seriously, it does nothing. Throw it away.

No it's not for that. It's to sequence the injectors in 2 batchs. If you remove it the injectors will fire in 1 batch. The ETA isn't that drastically different that the 'i' suddenly needs a new sensor to run properly.

I don't know why Fielding's car ran like that but it seriously has no real effect on the running of the car mainly just a tiny increase in fuel economy. more likely the wires you were using were fucked and a new set cured it.

I'm currently not using it on my car and it runs fine.

If you don't believe me, read the Bosch manual or ask Brett Anderson.

[Brew]

I apologize, I just looked in the ETM and it that the "cylinder identification sensor", which is on the "i" but not on the "e", is an input to the DME.

I was told that it was only for diagnostic purposes by an older tech whom I trust very much; he must have just been thinking about another motor.