Pulled the engine again. This time the 944 graphite reinforced cam tower gaskets gave way and started leaking.

I think this was my fault. I used silicone gasket sealer and I think that gave the gasket the lubrication it needed to slip and split and fail.

The 3rd time you pull an old bugger engine, it goes real fast.

Here's some pictures of the back side of the cam towers showing the problems.




sorry about this one's focus...


I hope this doesn't become a regular Spring event for me.

 

Just a comment, but those don't look like they are leaking.

You could put some silcone gaskets on it and they won't leak anymore than you go there, and they should last a while longer.

 

Have you tried the victor reinz gasket maker?

 

The gaskets were broke all to hell. Split apart (as in the pic's) and even ripped along the gasket. Looks like the clamp of the head and tower squeezed them apart. The gasket came right off. No scraping necessary. But it did leave behind the graphite reinforcement.



This time the gaskets went on dry! I cleaned the surfaces like there was no tomorrow. No oily mess to allow any slippage. I used a set of aftermarket gaskets from Greg B.

Got them torqued down at 20nM. Man that doesn't seem like much (hummm?).

I think this will do it this time (knock on wood).

Also, this gives me a good time to replace the cis fuel injectors. So much easier to get the nuts off when the engine is out of the car. I'll order the short Merc injectors.

And I'm putting on the 86.5 tubular exhaust manifolds.

And, what a great time to replace the throttle cable. Man it was ready to let go anytime.

 

I've had multiple failure here before too. I thought that perhaps I should have the mating surfraces on the head and carrier milled. Also, I noticed that it is where the high pressure oil feeds up to the tower that my gaskets have failed. I wonder if something is supposed to limit that pressure and if perhaps that were not working right and the pressure is way too high. Could be either one of the pressure regulation pistons in the block or whatever passege ways in the tower that it works against. I don't think there is anyway to measure the pressure there, but it would be interesting.

 

Let us know how it works!

 

It's all about that gasket and the amount of torque applied.

If you torque my gasket to 14 ft lbs, starting with a clean surface, they will never leak or squish out.

You can actually use that "stock" gaskets...but you are going to need to hop around counterclockwise two revolutions, on one foot, while you torque them, for them to work.

Before I figured out how to make this area work, I thought I was going to have to use metric wing nuts to hold the cam carriers on....I had some off, that many times.

 

Wing nuts. That brings back memories!

Yes Greg, the surfaces were squeeky clean before I put it back together. Used carb cleaner on a rag to get all the oil off.

Torqued it right, like you said.

I couldn't do the 928 Cam Tower Torque Down Dance anymore!!!

 

You won't have to...should have called me first and you would have only had to do it once...I try and share all my lessons.

 

And how could ANYONE get this done right with the engine in the car?

I mean, with the engine on the stand, my heart pounds as I guide in the bolts praying not to lose a washer!!!

And yes Greg, you the Man.

 

Greg, your post makes it sound like you have your own custom gaskets for this application. If that is true, will you sell them?

 

I just had to do this again too. However the reason I had to redo them was because the bolts backed out allowing the gasket to spit out.
They were torqued to factory spec the first time.

 

Yes. Sell them all the time.

 

You must have some really early bolts. The later bolts have the washers captive. I throw the early bolts in the trash can....you have to be a Ninja to use those things.

 

I suspect I have a cam tower leak also. I haven't confirmed this though. I have a small leak on the passenger side to left of the front passenger tire. (at least that's where the drips are falling)
Is this a job that can be done with the engine in, on a MY 85? If so, how difficult a job is it?