I don't think this has been posted.
Interesting read if you have a soft spot for the Pontiac OHC 6.
http://www.overheadcammerschapter.150m.com/Index.htm
Nice!
I always thought about building one of those.
Here is a factory QJ
http://www.pbase.com/galleryhost/image/116239857MBHD
Good tech forum here too, lots engine info on the OHC.
http://sohcsix.yuku.com/forums/2/t/Engine.html
I've always thought these were the neatest engines I ever saw when they came out. That's why I put one in my 36 pontiac sedan a couple years ago. Unfortunately it hasn't worked out quite as planned. I have had nothing but trouble with it.
I bought one from a guy in Tennessee who had it in a 66 Tempest convertible. He had it rebuilt by a machine shop there. The cam went flat in a short time and it burned oil. They put a reground cam in it and replaced all the valve guides. They used a reground cam because he could not find a new Sprint cam. Three lobes went flat and he gave up and put a V8 in it. He said he had spent $3000.00 on the motor all told and it had less than 1000 miles on it. I bought it for $1000.00 and got a NEW Sprint cam from Jerry in Utah. I put it and all new followers in and put it in my car. Looked great, but when I got it running all the lifters (lash adjusters) were rattling. I talked to Tom Langdon, Jerry and anyone else I could find who knows anything about these engines. Unfortunately, although I did every thing they told me to do, nothing worked.
After about 3000 miles, the problem solved itself. I was running down the highway when the #2 exhaust valve head decided to part company with the valve stem. It broke the block, head, #2 piston, and bent the rod. No more noisy lifters.
I found another engine in good shape and rebuilt it. My cam, crank, lifters, and followers were still good, so I rebuilt this engine and put it in. The lifters don't rattle, but it has used oil from day one -- a quart every 200 to 500 miles. I thought the rings might seat, but I've got about 4500 miles on it and it hasn't improved any. Now it has developed a dry rod knock when I start it. Lasts anywhere from a few seconds to a couple of minutes. Not lack of oil pressure -- it comes up quickly and is good. I have some new rings and gaskets. I'm trying to decide to try it one more time or just go with a 250 or 292. I have spent about 4 or 5 times as much money on this as I've ever spent on any engine and I've never had trouble like this. That's my sad story.
BTW I have been a mechanic for 42 years, so I do sorta know what i'm doing. Joe
Joe, I know it's frustrating, but if I had all the parts (and the time) I would try it once more, then scrap it if it doesn't cooperate.
Good luck.
Your engine is probably using oil down the valve guides as they tend to wear. Is your top end whisper quiet or a bit noisy sounding? Were your guides replaced when the head was rebuilt? or just knurled? What valve seals are you using? The head should have the guides replaced and PC (positive) valve guide seals on the intake valves. Give us a bit more info.
Thanks,
Rob
The valve guides are tight and in good shape. it has PC seals. I really don't think it's going by the guides, but i can probably tell when I get the intake off. Joe