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I have a 81 that was all original with all the smog equipment and all the standard electrical gremlins that come with these computerized years. About a year ago I said F it and ripped the 4 speed out and took the engine down to the heads and replaced the seals on both the engine and trans. while I was down there i did full clutch assembly.
my issue has come when I FINALLY get her running after all this time, I have an Edlebrock performer cam (previous owner installed it). I installed summit long tubes, smog pump and egr delete, edlebrock performer intake and a 78 pre smog non CCC Qjet and a vacuum advanced HEI. After getting initial timing set I and idle set I started hearing a lifter tick, and then eventually a skip when cranking.
took the covers off to find one rocker on each head to have loosened itself and fallen off the spring snapping one push rod and bending the other.
I need a better upgrade! I want to ask people who know what to buy what I should replace all my terrible locking nuts with and maybe a nicer set of rockers/push rods too. I don’t plan on racing this car I just want to have a fun weekend car.
You don't need an upgrade but you do need to figure out what went wrong. Might have been a cam going flat....might have been a bad adjustment on the rockers....might have been high mileage on the valvetrain?....something caused the failure.
Was the engine running when you bought the car?
Were you confident with how you set the rocker preloads?
Lastly, did you use the nuts intended for rockers? (they should be locking/deformed thread design)
You don't need an upgrade but you do need to figure out what went wrong. Might have been a cam going flat....might have been a bad adjustment on the rockers....might have been high mileage on the valvetrain?....something caused the failure.
the drivetrain has 99k miles, I believe it was a rookie mistake on my adjustments (I hope). I’ve had the car for almost 3 years at this point and it ran like a champ other than the computer hiccups before I tore it apart. Do you know of a way I can check my cam lobe?
Was the engine running when you bought the car?
Were you confident with how you set the rocker preloads?
Lastly, did you use the nuts intended for rockers? (they should be locking/deformed thread design)
I did use the original rocker nuts and I kept all them in order with their original cylinders during the replacement
Those crimped rocker nuts lose their tension, and then they can come loose.
There was a way to test them back in the day, a TQ setting.
A more aggressive cam puts more pressure on them.
I would not re-use 50 year old rocker nuts.
You could run the short crower poly-loks instead, and they'll never loosen.
Those crimped rocker nuts lose their tension, and then they can come loose.
There was a way to test them back in the day, a TQ setting.
A more aggressive cam puts more pressure on them.
I would not re-use 50 year old rocker nuts.
You could run the short crower poly-loks instead, and they'll never loosen.
All good suggestions.
BUT, have you identified 'what went wrong'?
I dunno which E cam P/N you installed; much less, its Valve Lift.
? did you Verify that your valve springs are Not suffering Coil Bind ?
? did you inspect OE valve springs (both its inner flat damper and outer wire) ?
? did you replace or upgrade the OE valve springs ? If Yes, with which springs ?
Broken pushrods commonly indicate some mechanical interference in the valve train. That theoretically could happen from a poor rocker arm adjustment or a cam going flat where the large gap allows the rocker to tip sideways and bends/breaks the pushrods.
All good suggestions.
BUT, have you identified 'what went wrong'?
I dunno which E cam P/N you installed; much less, its Valve Lift.
? did you Verify that your valve springs are Not suffering Coil Bind ?
? did you inspect OE valve springs (both its inner flat damper and outer wire) ?
? did you replace or upgrade the OE valve springs ? If Yes, with which springs ?
i did replace my valve seals, which means I removed and reinstalled the springs. I’ll look into coil bind. I didn’t see anything wrong with the springs in that process but maybe my installations caused an issue?
I do want to add when I first started her up the firing order was grossly advanced and it idled at 3k rpm for a solid 45 seconds before I managed to fix it. During that time and after it ran on all cylinders and healthily until about 10 minutes went by and then the lifter tick started. My theory is the super high idle immediately after my rebuild caused some of the nuts to back off
All good suggestions.
BUT, have you identified 'what went wrong'? I dunno which E cam P/N you installed; much less, its Valve Lift.
? did you Verify that your valve springs are Not suffering Coil Bind ?
? did you inspect OE valve springs (both its inner flat damper and outer wire) ?
? did you replace or upgrade the OE valve springs ? If Yes, with which springs ?
Originally Posted by RedVirtigo
i did replace my valve seals, which means I removed and reinstalled the springs. I’ll look into coil bind. I didn’t see anything wrong with the springs in that process but maybe my installations caused an issue?
? what is part number of edelbrock cam you installed with your OE valve springs ? I can readily find its specs eg Lift.
Firing Order is the Sequence in which the plugs fire. F.O. neither becomes advanced or retarded.
OTOH, Ignition Timing is adjustable; either advanced or retarded or in-between
*I'm attempting to help you determine 'what went wrong'.
I do want to add when I first started her up the firing order was grossly advanced and it idled at 3k rpm for a solid 45 seconds before I managed to fix it. During that time and after it ran on all cylinders and healthily until about 10 minutes went by and then the lifter tick started. My theory is the super high idle immediately after my rebuild caused some of the nuts to back off
Advanced ignition timing alone should not make an engine idle that high, even on high idle. What do you usually have your hot and cold idles set to?
I do want to add when I first started her up the firing order was grossly advanced and it idled at 3k rpm for a solid 45 seconds before I managed to fix it. During that time and after it ran on all cylinders and healthily until about 10 minutes went by and then the lifter tick started. My theory is the super high idle immediately after my rebuild caused some of the nuts to back off
What did you do to fix the high rpm?
As the two above mentioned, timing isn't going to make your engine idle that high. As a matter of fact, an engine will only run in a small window of timing set; too advanced or retarded and the engine stops running.
BTW, 3k is not engine damaging rpm. New hydraulic cams and lifters must operate around 2000-3000 rpm for a good 20-30 minutes on first firing.
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Run short poly locks. Go with 1.6 rockers. The 1.6 will give a little more lift and duration, win win. Hot rodders figured that trick out in the 60s. Chevy runs 1.5, Ford runs 1.6....it was free power.
If you want a little less rocker wear you can go with Scorpian roller rockers, least expensive high quality roller rockers that are not Chinese....but usually need taller covers or spacers
? what is part number of edelbrock cam you installed with your OE valve springs ? I can readily find its specs eg Lift.
Firing Order is the Sequence in which the plugs fire. F.O. neither becomes advanced or retarded.
OTOH, Ignition Timing is adjustable; either advanced or retarded or in-between
*I'm attempting to help you determine 'what went wrong'.
im not 100% sure on the cam part number since the sticker included with my cam includes 3 part numbers for similar cams, I can send a photo of the sticker
Went to the parts store today and bought a couple of the oem style locking nuts since they were 99¢ each and I can tell a clear difference in my originals vs the new ones, the threads looks like they lost their tension. What do you guys think? I see on the new ones they have flat threads to lock into the stud but the old ones look like regular nuts!
Rocker upgrades?
