I just got running a '73 302 that I rebuilt. It has a Performer cam and Comp Cams adjustable roller rockers. The timing is set at 10 degrees BTDC. I adjusted the valves by spinning the pushrods until resistance was felt, and then an additional 1/2 turn.

All of the header tubes have burned the paint off of them except for the number 2 cylinder -- it hasn't even started to burn. When I rev up the motor, it pops thru the carb. If I unplug the #2 wire, it goes away. The motor has no power on acceleration.

Does anyone have any ideas? I have readjusted the #2 valves twice with no change. Should I try adjusting them hot (back off until clatters, tighten till quiets, then 1/2 more)? I have noticed some clacking that appears to be coming from this cylinder -- could the lifter be collapsed?

Chris Seay
Bealeton, VA

 

Have you checked to see if you have the wires on correctly. KInda sounds likeyou have 2 crossed.

 

Have you checked to see if you have the wires on correctly. KInda sounds likeyou have 2 crossed. Or your distributor is off a tooth.

 

Back off the rockers on the dead cylinder and do a leakdown test. Sounds like an intake valve that isn't seating.

 

I have checked and double checked the firing order -- I have also checked the cap for signs of arcing and checked adjacent wires in the firing order to make sure they aren't causing induction firing. I will pop the valve cover off and back the adjustment of on the valves on that cylinder . . . unfortunately I don't have a leakdown tester . . . I am going to try a compression test before and after backing the adjustment off ( I won't back it all the way off -- maybe about 1 1/2 turns). I'll repost with results.

Chris Seay
Bealeton VA

 

If you have a compression tester with the hose as opposed to the type you just hold in the spark plug hole, you have a leakdown tester. All you have to do is take the schraeder valve out of your compression tester and adapt to your air supply. Plug it in your spark plug hole with both valves closed and listen for any leakage. The tricky part is making sure both valves are closed because at BDC one of the valves will be slightly open on both strokes.
Hope this helps.
Greg

 

Problem has been found -- a defective lifter that came with my edelbrock cam kit. The #2 intake lifter was collapsed. The plunger which is supposed to sit up against the retainer is just flopping around. So when i adjusted the valves what was supposed to be zero lash was actually full compression of the lifter. The result was that both the lifter and the cam lobe got chewed up. I lost .080" in lift @ the cam. When I measured that I pulled the lifter and it looked like someone had held it against a grinding wheel for a good minute. SO -- I have ordered ANOTHER edelbrock cam kit . . . and I will check the lifters first before putting them in to make sure the plungers are against the retainers. I know edelbrock will not warranty a performance part -- I'm sure they will tell me I installed it wrong and caused the lifter to collapse . . . but I'm going to ship it back to them anyway and see what happens.

Chris Seay
Bealeton VA

 

my brother built his first performance engine,,set the timing wrong,destroyed the edelbrock heads when the valves were hittin the pistons,they only charged him for shipping the old ones back & new ones to him,maybe they'll do you good too

 

Installed new cam & lifter kit and ran in the motor last night -- runs great!!! hopefully it will stay that way . . . have not sent the "defective" cam kit back to edelbrock yet.

Chris Seay
Bealeton, VA