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A few weeks ago I finished rebuilding my Chevy 350 and it ran good through the break-in period but near the end I noticed a slight ticking sound. I decided to pull the valve covers off and noticed one of the rocker arms was loose but the rocker nut was still set correctly. So I pulled the intake manifold off and sure enough, one of the lifters was worn down about 0.075" taking the cam with it. Found a lot of metal in the oil pan when I removed it. I pulled 2 of the main bearing caps and the bearings looked alright for the most part. I have a new cam and lifters coming soon but I was wondering weather or not I should also replace the cam bearings?
Do you have any drops in oil pressure? As in it use to be 35 at idle but now 25 or so on?
if not your cam bearings are probably fine.
when you pull the old cam out you should be able to see how they look.
Everyone is different, if they look fine, I’d personally put it back together and change the oil and filter probably every 100 miles for 2 or 3 times. Goal of getting all the small metal particles out of the valleys and groves and so on.
than just continue to drive it and keep and eye on it, with the understanding that it may have a shorter total life
With the drain plug out you could pour a gallon of diesel fuel in the lifter valley and head(spring) area.
When you pull the cam if you dont see copper showing on the bearings put another cam in and motor on. Youll know if they are fragged or not..
I bet its fine.
You can get a FT kit with their hardening treatment (generic term lol)...dont know why certain companies dont do this before hand
Jones racing cams offers a P55 core & does his thing to the lfiter faces supposedly bulletproof as far as longevity goes.
Thanks for the suggestions.
I will try to get a better look at the cam bearings but, from what I could see, there is no copper showing. The cam and lifters were just some cheap summit racing branded ones (SUM-1788 and SUM-HT817-16). Had good reviews when I purchased them but recently a lot of people seem to be having the same problem I had. I will look into that hardening stuff for the future.
Thanks for the suggestions.
I will try to get a better look at the cam bearings but, from what I could see, there is no copper showing. The cam and lifters were just some cheap summit racing branded ones (SUM-1788 and SUM-HT817-16). Had good reviews when I purchased them but recently a lot of people seem to be having the same problem I had. I will look into that hardening stuff for the future.
Thanks again,
Andrew.
summit flat tappet cams are as good as any flat tappet cam. they are made by one of the big aftermarket cam makers. The flat tappet lifters being made and sold today are a crap shoot regardless of branding. If you really dont want to worry about it a roller setup is the way to go.. typically 25-35 more hp for same size cam as well.
I would like to go with a roller setup but I'm not sure if it would work with the heads/valve springs I have right now. Also any suggestions for oil to use for break in if I stick with the flat tappet?
1) Cam shaft was coated with Driven Assembly Grease during the install, 2) lifters and bores got a light coat of Driven Assembly Grease and a dab of Moroso Moly Paste on the lifter face during install, 3) GM EOS (Engine Oil Supplement) plus Valvoline VR1 Racing Oil, 4) ran engine at 2000-2500 RPM for 20 minutes during break-in, this is not really required on a stock OEM cam, 5) shut engine off and changed the oil filter than topped off oil level with Valvoline VR1 Racing Oil.
Total cost for the above lubrication products was $108.00, now let's talk lifters. I think there is a lot of truth to the whole lifter debate on inferior products regardless of what oil someone uses. I did a lot of internet browsing on the subject for no other reason than I was bored and the general theme seemed to be this whole wiped cam phenomenal gets tied back to the lifters. One could argue it started out with oil properties but I'm not sure that is case in all failures. Anyway, I choose to go with AC Delco Lifters even though they were $11.26 EA vs. the Summit brand that are $4.99.
Also read in my travels that the "good" lifters are the ones with a ring around the bottom. Anyway, all the above worked for me hope this helps in your second cam swap.
The extra hardening process that cv67 mentioned is called Nitriding. It's basically placing several cams in a chamber and removing all the air. The Nitriding fills all voids in the metals and takes 36 hrs to cure. Last I looked Comp Cams was charging $125 extra.
I guess that is cheap insurance compared to a lobe failure. But thousands of customers still opt not to pay extra for the process.
Proper break-in is everything for a new cams survival. That first 30 mins is do or die.
The problem is not often seen to the naked eye. Even with liberal coating of lubes, removal of inner valve spring and priming the oil pump, etc if the lifter does not rotate in its bore, destruction will soon follow. And that's the tough part to monitor during break-in. Is the lifter / pushrod turning?
Last edited by HeadsU.P.; Aug 19, 2022 at 06:22 PM.
1) Cam shaft was coated with Driven Assembly Grease during the install, 2) lifters and bores got a light coat of Driven Assembly Grease and a dab of Moroso Moly Paste on the lifter face during install, 3) GM EOS (Engine Oil Supplement) plus Valvoline VR1 Racing Oil, 4) ran engine at 2000-2500 RPM for 20 minutes during break-in, this is not really required on a stock OEM cam, 5) shut engine off and changed the oil filter than topped off oil level with Valvoline VR1 Racing Oil.
Total cost for the above lubrication products was $108.00, now let's talk lifters. I think there is a lot of truth to the whole lifter debate on inferior products regardless of what oil someone uses. I did a lot of internet browsing on the subject for no other reason than I was bored and the general theme seemed to be this whole wiped cam phenomenal gets tied back to the lifters. One could argue it started out with oil properties but I'm not sure that is case in all failures. Anyway, I choose to go with AC Delco Lifters even though they were $11.26 EA vs. the Summit brand that are $4.99.
Also read in my travels that the "good" lifters are the ones with a ring around the bottom. Anyway, all the above worked for me hope this helps in your second cam swap.
In my opinion it’s the valve spring pressure (lbs) are not correctly matched to the camshaft. An example would be installing a set of aluminum heads on a motor with springs are that rated or set up for a camshaft with lift up to .550”. And then installed a camshaft with a lift of .480” it just as bad to under spring as over. Mr D when you changed your camshaft did you use a stock rated valve spring.
In my opinion it’s the valve spring pressure (lbs) are not correctly matched to the camshaft. An example would be installing a set of aluminum heads on a motor with springs are that rated or set up for a camshaft with lift up to .550”. And then installed a camshaft with a lift of .480” it just as bad to under spring as over. Mr D when you changed your camshaft did you use a stock rated valve spring.
While you're in there, get rid of your oil filter bypass valve its on the filter adapter that bolts up to the block. You can plug the valve hole or get a filter adapter without a bypass valve. Hope there won't be a next time, but if heaven forbid there is, all the metal trash will be kept out of your oil pressure passages.
Had no idea you could still buy a brand new OEM GM L82 cam..but wasnt that one used in thier crate engines?
Elgin makes a duplicate I believe...many overlook that company but a handful of machinists ive spoken to swear by them.
Just an opinion...when putting the lifters in rotate them to make sure there is no burr that binds..put your secret sauce on the bottom but either very light oil or nothing at all in the lifter bores or the lifter body
Anything that could prevent that lifter from starting to spin right away ought to be avoided...Could be mistaken but makes sense to me
Also the very gentle ramps of OEM or older grinds lessens the shearing action those lifters have to endure. OEM cams arent broken in they turn the key and off the lot they go
Kinda why I dont buy into fast ramp stuff esp on FT cams. If you need a little more then just swap cams....put a bigger arm in it, headwork something.
Or at that point just do a roller. Again....just an opinion Im a nobody out there.
Had no idea you could still buy a brand new OEM GM L82 cam..but wasnt that one used in thier crate engines?
Elgin makes a duplicate I believe...many overlook that company but a handful of machinists ive spoken to swear by them.
Just an opinion...when putting the lifters in rotate them to make sure there is no burr that binds..put your secret sauce on the bottom but either very light oil or nothing at all in the lifter bores or the lifter body
Anything that could prevent that lifter from starting to spin right away ought to be avoided...Could be mistaken but makes sense to me
Also the very gentle ramps of OEM or older grinds lessens the shearing action those lifters have to endure. OEM cams arent broken in they turn the key and off the lot they go
Kinda why I dont buy into fast ramp stuff esp on FT cams. If you need a little more then just swap cams....put a bigger arm in it, headwork something.
Or at that point just do a roller. Again....just an opinion Im a nobody out there.
The L46/82 camshaft is used in the 290 hp crate motor.
Chevy350 Lifter Failure
