Full "i" head swap or install parts in my current 885?

[phenryiv1]

I have an 88 S-eta (167K) that needs a timing belt replacement. I plan to do the full WP/thermostat/ accessory belt service at the same time. The current motor seems to run really well (after warming up), but I don't want to risk snapping a timing belt.

As this is a "toy" car and not my DD, I have decided to build the 2.7 Seta (with 885 head) into a 2.7i.

To gather my parts, I sourced a top end from an 88 i, including the "i" head with 131K on the clock. I got all of the top/front-end "i" components as well.

Option 1:

Before I bolt the "i" top end onto my Seta bottom end (as I do the full timing belt service) I am considering having the head rebuilt.

The donor head looks pretty clean on the inside, but the valves on the donor have some carbon buildup. I was also told (based on the pictures below) that I may have one or more bent valves.

Pics of donor head:







Option 2 is that I considered just swapping the cam, double valve springs, and intake parts onto my existing 885 head (remember, 167K on my car) and running with it, then selling the spare head off to recoup costs. I could adjust the valves, do the belt service(s), and be up and running in very little time, but I won't know the condition of my valves and chambers.

If I do that, the motronic harness is still in place, and I don't disturb my factory HG. My car could have equal carbon buildup, or it could be better/worse.

Option 3: I can always pull the head off of mine to check, but that means one way or the other, I need to replace the HG and bolts.

Downtime isn't an issue, btu as it is getting colder, I could use the garage space. I leave for work before dawn and don't like parking outside in the Winter (Yes, I AM lazy!). If this is a long project, I will be parking my daily outside, or working on the E30 outside. Lose/lose, there.

Thoughts on my options?

[jlevie]

Since that head came off a JY car, I'd say that it was rebuilt shortly before the car went to the salvage yard. It is way too clean. That probably means that it has new seals and has had a valve job. Turning the cam to open valves for a look at the mating surfaces should reveal whether a valve job was done. If that turns out to be the case, I'd check the head for flatness and use it as-is. It would be less work to swap heads than to swap parts.

[rpm620]

im so confused 88 ETA's had the i setup from the factory.. same TB, intake manifold and head "885" as the 325IS... what are you trying to do here im so lost.

[thereisnoyun]

check compression then determine if you want to keep the bottom end. I wouldnt just slap anything on without checking compression on a engine with considerable miles.

[phenryiv1]

im so confused 88 ETA's had the i setup from the factory.. same TB, intake manifold and head "885" as the 325IS... what are you trying to do here im so lost.

Only the 885 head itself is the same. The pistons are different (they are special to the 88 "nothing" models), and all of the intake parts from the IM and forward are different. The "i" obviously had "i" parts, and the Seta (the "nothing") had eta IM, TB, AFM, etc.

On top of that, while the 885 head casting is the same, the valve springs and cam are different.

[RangerGress]

You need to evaluate the condition of the heads. Otherwise you are just guessing. Do a wet/dry leakdown test on the head that is in place. DIY here: http://www.gress.org/Home/Cars/Track...down%20DIY.htm

Then invert the head that is not installed and do a drip test. Put a spark plug in and tap the rockers to ensure that the valves are fully seated. Then use something like acetone or gas and fill a combustion chamber. Then see how fast the gas leaks out of the combustion chamber past the valves. 3-4 drips per minute is cherry. I've not done this on old heads so I don't know how many drips/min is considered serviceable for an old head, but someone around here knows.

At endstate you'll have good info on the health of the valve grinds on each head and that will help you make the best decision.

[phenryiv1]

You need to evaluate the condition of the heads. Otherwise you are just guessing. Do a wet/dry leakdown test on the head that is in place. DIY here: http://www.gress.org/Home/Cars/Track...down%20DIY.htm

Then invert the head that is not installed and do a drip test. Put a spark plug in and tap the rockers to ensure that the valves are fully seated. Then use something like acetone or gas and fill a combustion chamber. Then see how fast the gas leaks out of the combustion chamber past the valves. 3-4 drips per minute is cherry. I've not done this on old heads so I don't know how many drips/min is considered serviceable for an old head, but someone around here knows.

At endstate you'll have good info on the health of the valve grinds on each head and that will help you make the best decision.

Thanks for the guidance. Being a n00b to cracking open the motor, this stuff is great to see.

[goodm5]

I just did the same the same thing. I took a SETA block and swapped over the guts from my 87 325is head, bolted it back together and took off. I had the head rebuilt so there would be no questions and I had time too as it was not the DD. This project is well worth it, I am so happy with the conversion! IT is a fun car, there is torque all the time. I am waiting on a D'Sylva chip to arrive, but you will not be disappointed.

Steve
87 327is

[phenryiv1]

I FINALLY found a shop (very close to me) who has done head work on European cars, and has done head work on a friend's E36 M44.

As soon as I talked to the guy, he had me convinced that he knows what he is doing, as he knew the motor codes off of the top of his head. That is good for something.

I have an appointment to meet with him on Tuesday to drop the head off at his shop.

[phenryiv1]

Ready to go to the shop...

I spent an hour and stripped most of the head.

[I got it, yes!!]

Trust me, that is not stripped. to machine the head, they will at least need all the valves seated.

[phenryiv1]

Trust me, that is not stripped. to machine the head, they will at least need all the valves seated.

Hence the words "most of" in my post.

[hotballs]

Remove everything, the exhaust manifold at least! But take out the rockers and the shafts, the cam, the valves. etc.. You'll end up paying somebody labor to do something you can do yourself. The machining is where you should spend your money.

[phenryiv1]

I ran it to the shop and they told me the same thing. They wanted $200 to tear it down from there...MAYBE an hour's work!

I plan to do it myself and go from there.

[JJ1]

Have you thought about getting a schrick cam while you have the head stripped? I think you would have to get an "i" ecu to run the higher rpm. You might get alot of performance out of this without much more work and 400-500 bucks. Im not sure what kind of numbers you would get with this but i sure am curious to find out.