Weird...cam problem maybe?
This morning when I was going to work my truck warmed up just fine but as soon as I backed out of the driveway it started to run like it had a broken valve spring. I didn't have time to mess with it in the dark before work (after I scraped all the ice off the windows) so I just drove it to work without getting on it. During my first 15 min break I went out, checked all the plugs, wires, cap, rotor, pulled the valve cover, checked all the springs (inners and outers, I'm running dual springs) checked the lash and everything is right were it was the last time I checked when it was running fine. At lunch I put the cover back on and checked the carb, rechecked the plug wires and still found nothing. Pulling all the plug wires one by one while the truck was running also had the normal effect. Each wire when held close to the plug or to a ground had a very strong spark (Accell HEI unit with a MSD Blaster 2 coil).
I buttoned her back up and at 2:30 went home. She was still running rough and under powered until half way home (9 1/2 miles) when I was on a steep hill and had to pass a flatbed hauling a backhoe. I just figured to hell with it, if she dies she dies, dropped into 2nd (A745 3 on the tree/3.55) and floored it. There was the expected cloud of smoke and she took off! At the top of the hill she was running normal just like nothing ever happened.
I let it cool off and I just wend out, fired her up and drove around the block with no issue at all.
What the F?
I am pretty sure that I don't have a bent valve that hung open, I checked and double checked all the springs/keepers while it was running and nothing was hanging open or busted, oil pressure is right were it has always been, the bottom end has all new bearings and all the cylinders when checked after I got home were with in 3 lbs of pressure form each other.
The cam is a Delta Cams regrind. I have been buying cams from them for years and years and years and years and never had a problem. This is however the first slant cam I bought from them. Here are the specs off the box...
RV 254 S Mech. Grind
Specs INT EXH
Duration Deg. 254 254
Valve lift .435 .435
Valve Lash .012 .012
The valve lash I called bullshit on after running it for a while, it runs best at around .008 to .009 but is still pretty loud (even for a mech. cam). I took car of most of the noise by installing the double springs that were on another slant I had in the garage.
I thought I read over on .org that there is no problem with the profile of Deltas cam but the issue is with the actual lobe patterns. The lobes were patterned after a Hyd. cam lobe. If this is the case could I just slap on a later Hyd. head and dro in a set of Hyd. lifters? The cam runs great in my truck and I would love to keep it unless the Hyd. lobes and Mech. lifters are causing the problems but I thought there were others on .org (Reed is one I can remember off the top of my head) that had the same cam in a daily driver.
Or is the cam even an issue? I am pretty brain dead at the moment after New Years weekend.
Other info...
Head is ported and gasket matched with stock valves.
Offy intake also hogged out a little and matched to the head.
Carb is off a Buick and is a 400 cfm AFB with electric choke.
This pic is when I had the POS Holley on it. ANd yes the cheap/crappy plastic fuel filter has been changed
This morning when I was going to work my truck warmed up just fine but as soon as I backed out of the driveway it started to run like it had a broken valve spring. I didn't have time to mess with it in the dark before work (after I scraped all the ice off the windows) so I just drove it to work without getting on it. During my first 15 min break I went out, checked all the plugs, wires, cap, rotor, pulled the valve cover, checked all the springs (inners and outers, I'm running dual springs) checked the lash and everything is right were it was the last time I checked when it was running fine. At lunch I put the cover back on and checked the carb, rechecked the plug wires and still found nothing. Pulling all the plug wires one by one while the truck was running also had the normal effect. Each wire when held close to the plug or to a ground had a very strong spark (Accell HEI unit with a MSD Blaster 2 coil).
I buttoned her back up and at 2:30 went home. She was still running rough and under powered until half way home (9 1/2 miles) when I was on a steep hill and had to pass a flatbed hauling a backhoe. I just figured to hell with it, if she dies she dies, dropped into 2nd (A745 3 on the tree/3.55) and floored it. There was the expected cloud of smoke and she took off! At the top of the hill she was running normal just like nothing ever happened.
I let it cool off and I just wend out, fired her up and drove around the block with no issue at all.
What the F?
I am pretty sure that I don't have a bent valve that hung open, I checked and double checked all the springs/keepers while it was running and nothing was hanging open or busted, oil pressure is right were it has always been, the bottom end has all new bearings and all the cylinders when checked after I got home were with in 3 lbs of pressure form each other.
The cam is a Delta Cams regrind. I have been buying cams from them for years and years and years and years and never had a problem. This is however the first slant cam I bought from them. Here are the specs off the box...
RV 254 S Mech. Grind
Specs INT EXH
Duration Deg. 254 254
Valve lift .435 .435
Valve Lash .012 .012
The valve lash I called bullshit on after running it for a while, it runs best at around .008 to .009 but is still pretty loud (even for a mech. cam). I took car of most of the noise by installing the double springs that were on another slant I had in the garage.
I thought I read over on .org that there is no problem with the profile of Deltas cam but the issue is with the actual lobe patterns. The lobes were patterned after a Hyd. cam lobe. If this is the case could I just slap on a later Hyd. head and dro in a set of Hyd. lifters? The cam runs great in my truck and I would love to keep it unless the Hyd. lobes and Mech. lifters are causing the problems but I thought there were others on .org (Reed is one I can remember off the top of my head) that had the same cam in a daily driver.
Or is the cam even an issue? I am pretty brain dead at the moment after New Years weekend.
Other info...
Head is ported and gasket matched with stock valves.
Offy intake also hogged out a little and matched to the head.
Carb is off a Buick and is a 400 cfm AFB with electric choke.
This pic is when I had the POS Holley on it. ANd yes the cheap/crappy plastic fuel filter has been changed
