79 sc engine with 91 turbo cylinders oil leaking at cylinder base

[iamchappy]

Should there be any oil leaking at the base of the cylinders on a newly rebuilt engine thats been started and warmed up but not yet driven for the break in. Will they eventually seal up or should they be dry.

[Steve@Rennsport]

They should dry from the beginning.

Theese do not seal up by themselves, especially on a Turbo motor.

[Henry Schmidt]

We always use Curil T to seal this area. Curil T never hardens so it will continue to seal even after the cylinders move. They are constantly moving due to high cylinder pressures and the expansion and uneven contraction of the cylinders, heads and the case. Supertec head studs will reduce this movement by creating a more stable combination of heads and cylinders as it pertains to case connection.
Some after market studs have been known to cause to cylinder base gasket to squeeze out but we have not seen that phenomenon with Supertec studs.

[iamchappy]

Do you think the engine builder omitted using the base and head o rings and didn't use a sealant.

[Henry Schmidt]

It's hard to predict what may or may not have been done by the engine builder.
The book (factory manual) does not call for sealant at the base gasket and if they are not prolific 911 engine builders they may have just gone with the factory procedure. What have they said about your issue? Have you told them of your concerns? Any reputable shop would want to correct the issue whether the problem is deemed their error or not.
BTW: there is no head gasket on the 91-92 C2 turbo cylinder.

[Aurel]

There is a copper gasket at the base of the cylinder. Some builders don`t use sealant at the base, the factory did not. If sealant was used, I imagine some smears would be visible. Best way to find out is to ask the builder.

Aurel

[patkeefe]

This is a bummer to hear...

[iamchappy]

Henry, I thought these things used an o ring of some sort.

After just replacing the oil return tube because of a torn o ring during their build I am concerned about other surprises i may start to encounter. They are trying to sell me on the idea that the leaks are normal and should seal up during break in, I just dont buy it.

[Aurel]

Who are they? Motor Meister

Aurel

[wmunchovie]

Originally Posted by iamchappy

Should there be any oil leaking at the base of the cylinders on a newly rebuilt engine thats been started and warmed up but not yet driven for the break in. Will they eventually seal up or should they be dry.

Did they have to bore the case openings to make the new cyl's fit or were they straight slip-ins?

munchovie.

[Henry Schmidt]

Originally Posted by iamchappy

...............edit..................They are trying to sell me on the idea that the leaks are normal and should seal up during break in, I just dont buy it.

Chappy, I am the last guy to question another shop but that just sounds goofy to me. Oil leaks rarely get better until you run out of oil.

No head gasket or CE ring. They could have a base o-ring rather than a gasket but I can't remember (CRS you know?)

[iamchappy]

No they slip right in.
I know they talked to Henry a few times while they were building it because they had never done an engine with this modification.
They are nice guys and I will talk to them about it. There main business is building engines for race cars and track preparation, they have been at it since the early 70's they spend the racing season doing track support. They have a nice Semi and support vehicles.
http://www.johnsonautosport.com/

I dont mind pulling the engine and bringing it in to them to fix as the roads are way to sloppy to have my car out driving around. The engine needs to get broke in and I dont look forward to undoing everything I just finished but it has to be right.
Here is a link to my progress thread:
http://www.914world.com/bbs2/index.php?showtopic=75381
Here are some pictures of my car (everyone likes to look at pictures) just imagine climbing into this clean like new car with sandy salty slushy boots.

[john walker's workshop]

they should have used the o-ring and copper base gasket together. and some sealer on the gasket too, like curil t or some non-hardening stuff. i've also used K&W spray copper coat and permatex aviation sealer (brown camel snot).

[iamchappy]

When the cars sits overnight there is oil that has filled the seam where they fit together and two of the cylinders have a small drip hanging on. I haven't even restarted the engine since i cleaned it up and replaced the oil return tube.

Maybe when the roads clear I should take it out for a drive and see what happens.

I could make it a daily chore to hose it down with brake cleaner after every use.

[patkeefe]

Chap:
As I said, bummer. As you know, I pulled mine apart after 500 miles cause it wasn't right. Massive PITA, but it had to be done. I suggest you get yours back out and find out what the problems really are. Not that I'm any expert on this, but I have a feeling that those cylinders will never mate to the case without leaking if you don't have a gasket in there. I'm pretty sure I put mine in with no sealant, and I have no leaks, even after running the crap out of it at the Glen for four days.
Pat

[iamchappy]

Pat I could of saved myself some grief had i sent it off for Henry to build, he really wanted to build this engine for me, but at the time i wanted to keep everything close to home, lets hope everything works out with my guys, if not, Henry gets first crack at it. It's full on Winter here right now, but Spring is only a few months away.

[wmunchovie]

munchovie is impressed with the patience you posses to complete a project such as this

[Porschephd]

You have to use the base gasket and the o-ring on the base. If you do one and not the other your sealing surface is so small it is not going to seal. If you use both the o-ring uses the copper base gasket to keep the o-ring stable and sealed against the case

[iamchappy]

The shop is making good on there promise and is going to fix it. They will use Curil this time around.
Thanks for all of your advice.

[911quest]

I clicked on the link you gave for the shop that did the rebuild and they show the local temperature......I don't know which is worse that fact that your motor leaks or that it is -1 degrees there right now. That is cold