dilavar studs

[oneblueyedog]

Group, (or Gruppe)

I've torn down the engine to reveal the pistons and cylinders. I haven't removed the pistons and cylinders. The tops of the bores are smooth, I guess where they wear most. I can still see cross hatching 1" down the jugs. this is at 215,000. I don't think I really had to rebuild it. The leakdown only gave me 2 cyls below 10%. But heck, it leaked oil badly at the cam housing to chain housing after I used Mobil 1 in an oil change(lesson learned). It also ran hotter than most SCs do. I also found some chain rail bits a long time ago blocked by the sump screen from the pick up, like it's supposed to do.
It also was out of time with bad chain noise at 3K rpm on bank 123.
I'll get peace of mind out of rebuilding it.

Q:It has dilavar studs, but 2 different kinds! On bank 1,2,3, they look the same as the upper ferrous ones. On bank 4,5,6, they are all thread! What does this mean? Did the factory grab a different style off the shelf after running out of the regular kind? The heads look identical to the other bank (not machined or flycut). The same with the cam housing and chain housing.

Not that I'm not going to replace them anyway.

Q: Since I found the bits of chain rail in the sump, would any others have a chance to get into the oil cooler and oilways in the case?

Q: It has Carerra Tensioners. I suspect one is bad. Who rebuilds them or checks them out?

Sorry for the long content.

78SC

[Wayne 962]

It would be obvious to me that someone already replaced studs on one side of the engine. The ones you have sound like the 993 studs...

The chain ramp bits should be okay - you need to make sure that you clean everything when you rebuild...

Carrera chain tensioners rarely go bad, why do you think this one is bad?

-Wayne

[oneblueyedog]

I guess I was in denial about the studs. Wouldn't they have to flycut the heads on account of the head with the broken stud banging on the jug and blow by?

I had cleaned the debris out about 50,000 miles ago. I was always worried about it though. I thought it may have blocked part of the oil cooler.

I took the car in for a problem that I thought I was catastrophic. The car lugged down over 3000 rpm. The chain rattled on 123 alarmingly. They told me it was a timing problem probably due to the chains stretching out or a bad tensioner. The chains are the original chains.
When taking the engine apart compressing the tensioners was difficult but I've read that's good. When I compressed one of the tensioners though, It was very resistent ( I felt like it was jammed). It made a click or snap as I was putting pressure on it and then began to compress very slowly like the other one did. The snapping tensioner was on bank 123.
I just wanted to clear up the doubt.

Thanks Wayne,