[rothaus]

Went to the AX at the Porschefest this weekend. Was a lot of fun, but my car is sick. When I took it of the trailer it didn't sound right, like running on 5 cylinders. I was OK driving it, but I felt the loss of power and it did not feel right, and did not sound right.

So back home checked a few thinks like the distributor, to make sure I did not loose the belt drive for the second. All OK. Then I put it on the lift and while running I checked the temperature of the exhaust flanges. I found that cyl # 3 is about half the temp compared the the rest. A leak down test showed that there is a leak at the head gasket area.

my first thing was: a head stud again ? When I rebuild the engine I selected to use Supertech studs, which are not supposed to fail.... WTF.

OK, I will drop the engine and see what's going on, I cannot drive it like that.

Another unplanned thing to slow me down on the 1970 911T

Cheers
Engelbert

[Noah]

So you knowingly ran an AX with a dead cylinder?

[joep]

Not only did he run it, he ran it well! Engelbert, I was the guy who gave you and your wife a ride over and back to Summit Main for the BBQ after the autox in my Cayenne.

If you were having any mechanical trouble it wasn't apparent during your runs when I was working heat 1. Your runs were fast and smooth.

[catron1]

Possible thermal expansion and contraction. If studs were replaced you could torque them?, also could it be possible a plug wire is arching?

[rothaus]

So I took the car over to the shop on the lift and did some more checks, before dropping the engine. I torqued the head studs and all looked OK, no loose nuts or pulled head studs. So I did another leak-down test and found the cyl # 2 has a slight leak, I can hear from the cyl/head area, Cyl # 3 heavier.

I took the engine out.

Here is what I found.

Looks like the 3rd cylinder has a leak. The second a bit. Number 1 was all clean.



Here a closeup of # 3


Here are the heads. # 3 is at the left.





Tomorrow I take the cam tower of and bolt the heads on the cylinder and see how they line up. This was enough for today and is was anyway time for a beer.

Cheers
Engelbert

[hoophead]

Looks like you have the early 964s have no head gasket/o-ring, and leakage is a known issue. The real fix is to get later pistons/cylinders with the head gasket groove - $$$.

[rothaus]

Actually I have gaskets, but there are flat SS.

Below is a picture from the rebuild I did 2012



Here with gasket



I got everything cleaned up this morning. Checked the heads for straightless on the cam tower and looks all good. Next, clean all the sealing compound off and bolt the heads to the cyl. and see how it lines up.

Hope to put it back together next weekend and to last for the rest of the season. I will then see if I still can get the head and/or Cyl. machined so the round gaskets can be used.

Cheers
Engelbert

[rothaus]

So the car is back together.

Engine come together


From the stand on the jack


And into the car.


I got it running and drove it around over 40 miles and it feels, sound good, and has the power as it had before. This Sunday I go for the last Shenandoah PCA AX in Verona.

Now it's time to get back at the
1970 911T Project


Cheers
Engelbert

[N0tt0N]

Great to hear! I saw you following Pat on her bicycle at the Autocross but we had to head back to the track before you came back. I would have loved to have met you in person.

[Trak Ratt]

Originally Posted by hoophead

Looks like you have the early 964s have no head gasket/o-ring, and leakage is a known issue. The real fix is to get later pistons/cylinders with the head gasket groove - $$$.

What I'm looking at