Rustywer
Junior Member
- Joined
- Jul 8, 2014
- Posts
- 15
- Reaction score
- 0
- Location
- San Diego, Ca.
- First Name
- Rusty
- Truck Year
- 1977
- Truck Model
- C30
- Engine Size
- 350 CID
Ok, I should be able to figure this out, but after two weeks of screwing around with this, and re-learning evrything I forgot, I'm going to drop ten and punt this to you all.
77 C30 with a 350. It was rebuilt some 60k + miles ago and I'm finding out that it was a half ass job to start with.
The head head gasket blew about two weeks after I purchased it. Pulled it apat and sent the heads to be checked and they were cracked. Got a good set of 822's and had them done right by a very reputable builder in East San Diego County.
Went through and replaced all the external gaskets with a felpro upper and lower set. Put it back together with a new harmonic balancer, reman distributor, all ignition components, and i just can't seem to get this thing to run right.
With the timing at 8 BTDC it pops from the exhaust, to get the popping to stop and to get it to idle smooth i have to advance it way to much. I have the advance on he ported vacuum, no egr, has air injection into the exhaust manifold on ported vacuum, and the charcoal canister and pcv are on true manifold vacuum.
With timing at 8, I'm only getting 12 to 14 inches of vacuum and a high rpm pop back through the carb, if i advance it comes up to 16 to 18 with no carb pop back. Unloaded, I have verified the secondaries are opening and it feels like it has good power. Then i get it on the road and when i get close to WOT in high gear or hit the secondaries hard it feels like someone hit the compression release.
I know i have a slight intake leak but not enough to keep vacuum that low. The valves are at 1/2 to 3/4 of a turn past zero lash.
Im thinking i might have a mild cam in this thing and the pistons are stamped as .030 over.
What am i missing?
77 C30 with a 350. It was rebuilt some 60k + miles ago and I'm finding out that it was a half ass job to start with.
The head head gasket blew about two weeks after I purchased it. Pulled it apat and sent the heads to be checked and they were cracked. Got a good set of 822's and had them done right by a very reputable builder in East San Diego County.
Went through and replaced all the external gaskets with a felpro upper and lower set. Put it back together with a new harmonic balancer, reman distributor, all ignition components, and i just can't seem to get this thing to run right.
With the timing at 8 BTDC it pops from the exhaust, to get the popping to stop and to get it to idle smooth i have to advance it way to much. I have the advance on he ported vacuum, no egr, has air injection into the exhaust manifold on ported vacuum, and the charcoal canister and pcv are on true manifold vacuum.
With timing at 8, I'm only getting 12 to 14 inches of vacuum and a high rpm pop back through the carb, if i advance it comes up to 16 to 18 with no carb pop back. Unloaded, I have verified the secondaries are opening and it feels like it has good power. Then i get it on the road and when i get close to WOT in high gear or hit the secondaries hard it feels like someone hit the compression release.
I know i have a slight intake leak but not enough to keep vacuum that low. The valves are at 1/2 to 3/4 of a turn past zero lash.
Im thinking i might have a mild cam in this thing and the pistons are stamped as .030 over.
What am i missing?
