Click on image for the lowdown. 
====
| | | Forums66 Topics128,050 Posts1,055,643 Members48,426 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | The problems in threads under the other headings have been fixed (updates coming) Today was the last test drive before arranging delivery. A run at highway speeds. Took it on a stretch of expressway that had some hills (most are flat). It easily got to 65 at about 2600rpms and cruised nicely, but lost speed on the hills. Cycled the A/C on and off and the OD in and out. Made little difference. RPM increased to about 3200 on the hill but speed didn't increase. Anyway on the last hill everything went to hell. Noise ,lost power, vibration. It was firing back through the rear carb. Ducked over to the breakdown lane and it was pretty smooth at idle (with an obvious miss). Oil pressure good, temp good, no smoke, no fluids leaking. Limped it home to find the following Plugs looked good. Comp test 120,120,120,0,0,120. top end of valves looked good. Will take the head off tomorrow. | | | | | Joined: Mar 2016 Posts: 170 'Bolter | | 'Bolter Joined: Mar 2016 Posts: 170 | Sorry to hear about your troubles, Jim. I'm hoping you don't end up with dropped valves like Red63, but it sure seems likely. Maybe you just lost a couple intake pushrods or something...fingers crossed.
On second thought, you did say the top end of the valves looked good. That's strange, isn't it? I would think something amiss would be visible enough with the valve cover off--especially since your compression was at zero. I'd imagine you're looking for a big, obvious problem here. | | | | | Joined: Jun 2012 Posts: 166 'Bolter | | 'Bolter Joined: Jun 2012 Posts: 166 | Sorry your going thru hard times Mr. Sears. For what it's worth, that seems to be ALL that I get with my trucks. I just keep looking for a day to come when things come together. I hope you get better news as you dig a little deeper.
Troy | | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | update; Tore down the top end and removed the head. As I suspected the head gasket was blown between 4 and 5. And I do mean blown. http://s1276.photobucket.com/user/jsdesign2/library/Head was planed when the valves were done, block was checked for flatness, torque procedures normal - cold and cooled after hot. Will check head and block again tomorrow. | | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | Cleaned the head and block. Both are flat (less than .002 anywhere) Can't see any reason for the gasket to have failed. New Fel-Pro gasket set coming today. | | | | | Joined: Nov 2011 Posts: 1,611 'Bolter | | 'Bolter Joined: Nov 2011 Posts: 1,611 | Jim,
Did you use the copper or composition head gasket? I would chase the threads in the block, and look over the head bolts.
I hope it works out for you.
Paul
| | | | | Joined: Dec 2015 Posts: 2,062 Big Bolt Forum Moderator | | Big Bolt Forum Moderator Joined: Dec 2015 Posts: 2,062 | Agree with Paul on the threads, also, did you spray anything on the gasket before installing it? On copper head gaskets, I always spray them with cheap aluminum color spray paint (the kind that is dull and rubs off on your hand when touching it!) It allows the surfaces to slide a hair when torquing the head down and seems to help the gasket seal better. It may be useless but I was taught to do that on copper head gaskets and never had a problem on my old flatheads running them. I also did the same thing on the steel shim head gaskets on the 440 in my Barracuda. | | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | The threads in the block and on the bolts were cleaned. Head / bolt mating surfaces cleaned and the threads were lubricated.
I usually don't coat copper head gaskets, although my old man always coated them with grease. Not chassis grease but long fiber grease, once used in wheel bearings and washing machine wringers. (do I need to explain what a wringer was) | | | | | Joined: Dec 2015 Posts: 2,062 Big Bolt Forum Moderator | | Big Bolt Forum Moderator Joined: Dec 2015 Posts: 2,062 | strange. If those 2 cylinders were running lean, would that cause them to run hotter and do that? | | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | I thought about that but, no, the carbon on the head and the plug tips looked normal. If anything, the front carb seems to be a little leaner. | | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | The engine is back together and run for the first time to get it up to full heat. Let it cool for several hours and retorqued the head. I'll finish the valve adjustment in the morning. This time I used a NOS original steel and asbestos head gasket. Then and Now automotive is a local supplier of antique and vintage parts. Tomorrow it will hit the road after an oil change. | | |
| |