mikem350

Use assembly lube, not just oil! AND go thru full break in procedure, make sure you can start the engine on first try!

spinadog

Yep, some digging shows the same procedure as if a new cam. Moly cam lube is on the way, I'll pull them out and do it right. I'm sure she'll start first time, but I will overhaul carb, fuel line etc to make sure. Man, break-in is such an apprehensive time!

GM also states that replacing lifters and not cam is totally acceptable. And, BTW, my old lifters look new, cam has only 3000 miles on it. So, while I would like to do both, I'll take my chances, as I don't have the muscle or resource to pull the engine again.

jersey68l36

Do you have the resources to switch to lighter valve springs on that bank? You did mention they are single coil. Single spring along with a flat surge spring as used by GM on the low perf big blocks?

TimAT

GM Says that because of warranty cost.

spinadog

Unfortunately, I do not. I gather that could help alleviate load during break in?

And yes, single coil with flat surge spring.

ajrothm

I've thrown new lifters on old cams several times through the years, you just have to follow a new cam break in procedure, use the proper additives, it will be fine. They actually seem to break in easier then way then using a new cam honestly. This is assuming the old cam is 100% healthy and in spec.

spinadog

The cam is in unbelievably good shape, only 3000 miles, as stated - the lobes look new. ZDDP oils and additive used 100% all the time. Oil changed each 1000 miles or annually. The lifters all looked excellent, hard to tell they had been running on the cam.

Appreciate the encouragement, cheers.

spinadog

- I could totally believe that, having performed plenty of aftersales analysis for these guys and most other brands....

spinadog

I finally manned up to the start-2000-RPM-30-minute madness with the help of my lovely fiancee. I am happy to report that I have an intact cam, and replacement of either my lifters or fuel pump resolved the problem, including an intermittent tick I have had since my rebuild 8 years ago, so suspect I have had a bum lifter since then.

So, no issues with a used cam and new lifters if you follow due process. One piece of advice that may have helped was to moly lube the foot of the lifter and only oil the body, so the galleries are kept clog-free from the assembly lube.

Phew! Lots of afterwards.

Kirk H

Hi Spinadog-
Congratulations on your success!
I am going through the exact same thing you are and would like to ask you a few questions about your symptoms. I have a cylinder that is ticking and has a lower compression (180 psi as opposed to the others at 210 psi). I have also had a slightly wobbly vacuum needle, not a drastic jump around like a sticky valve would suggest, but within a inch of low and high which could not be corrected by idle mixture screws. After pulling the intake, the pushrods and lifters all look good and do not compress by pushing hard on the pushrod. The lift is close to what it should be with a rough measurement and the camshaft does not appear to be worn in any abnormal way. I broke in my Schneider cam and new lifters with moly about 15,000 miles ago but have not paid attention to the loss of zinc until just recently (so much debate over that in itself).
My question is about any symptoms you may have observed with compression and vacuum when you first started checking into the ticking sound. Mine noise has been fairly slight ticking but clearly associated with #3 cylinder- it never turned into loud clacking.
Thanks for anything else that you might share.
Kirk

spinadog

Hi Kirk, it's odd you mention vacuum. I just checked yesterday and I am pulling a steady 19", compared to a fluttering 18" beforehand. I attribute that to a better sealed intake rather than any lifter replacement.

I had an intermittent ticking somewhere around #6 since my engine rebuild that now appears to have gone - but I can't tell if that was lifter or fuel pump.

One thing I certainly wish I had done first was change the fuel pump first rather than panic and yank the intake. But I think it seems for the better as a result of this recent repair.

If the weather would get better, I may actually drive and see how she's feeling. So far, a little boggy off the line, so accel. pump or more timing tweaks.