93 K2500 Suburban 454 Holley Sniper Upgrade

[Schurkey]

I'm gonna check the lifters can spin freely in the bores.

Just to be redundant, it's not enough that the lifters "can"spin in the bores.

They have to spin in the bores when driven by the cam lobes. The bores could be perfectly sized, but if they're not aligned with the cam lobes as intended, the cam lobe doesn't spin the lifter, and the lifter bottom and cam lobe wear excessively. And, as said, the BBC has a poor reputation for having the lifter bores properly-placed.

That's why I verify the lifters spin before I install the cam chain. I turn the cam by hand, and watch the lifter in each bore.

The ONLY "American" engine with "flat tappets" I know of that isn't designed to spin the lifters is the Buick Nailhead--1951 (?) to 1966. The lifter bores are not offset to the cam lobes, the cam has no taper ground into the lobes, and the lifters aren't crowned on the bottom.

 

[CrustyJunker]

Sorry to hear about the trouble. You'll see how bad it is when you get it all the way apart. Working inside is not a privilege I had until the last few years...Boy is it way better!

If you didn't already invest in your new stuff, it would be nice if it was just a collapsed lifter and made it real cheap!

I'm a little curious in context though. You had to add 45% of fueling in your tuning. Might want to check and make sure you don't have a valve hanging open and causing crazy readings.

Is that a T-Type I spy in the background?

 

[LC2NLS6]

Yeah 87 T.

You must be registered for see images attach

 

[CrustyJunker]

Cool! You got all kinds of cool stuff.

 

[LC2NLS6]

Finally got around to it. Cam was fine, it was 2 pedestals not the same I think. Basically less than 0 preload - same as the clickety clacky clearance when I thought it was a wiped lobe. I bet during breakin it was so hot that it tightened up the clearance. Then cold, was first time you could hear it. I never rotated the engine the first time to check them all the first time - I just wiggled all the ones and called it good. Now, those two with new cam and new lifters installed, no preload at all when off the lobe. Guess I'll get longer rods or get adj rockers. I wonder if those comp ones for the gen v vi will clear the low stock valve cover...

 

[Supercharged111]

Finally got around to it. Cam was fine, it was 2 pedestals not the same I think. Basically less than 0 preload. I never rotated the engine the first time to check them. Now, those two with new cam and new lifters installed, no preload at all. Guess I'll get longer rods or get adj rockers. I wonder if those comp ones for the gen v vi will clear the low stock valve cover...

The Comp studs that reuse stock rockers clear just fine on a Gen V/VI.

 

[LC2NLS6]

Cool, ordering today. I also kept the old lifters in order of lobes with that cam that came out.

https://www.compcams.com/adjusting-kits-late-model-big-block-chevy-7-16-stud.html

 

[Supercharged111]

Cool, ordering today. I also kept the old lifters in order of lobes with that cam that came out.

https://www.compcams.com/adjusting-kits-late-model-big-block-chevy-7-16-stud.html

That's the one. My dad's GenV Monte has them as does my GenVI dually, both with stock valve covers.

 

[LC2NLS6]

These trucks are so easy to work on. Overnighting the adj stud kit. Hope to get it back together Fri night after work.

 

[LC2NLS6]

Intake, cover, pump, fan, radiator, oil/trans lines, and distributor back on. Alternator still off to make it easier to get to driver valve cover on. All that is left, new wires w/plug boot protectors, drop holley efi back on, fill radiator, set lifter preload, install belt. First I need to rotate a couple deg back to 0 (dots at 12 oclock of course) to set dizzy with the plastic tool from Holley at #1 comp and mark terminal on cap, then rotate crank to adjust lifter preload tomorrow, change oil, fire it up to breakin cam, again.