LA 318 Cam / lifter gut check

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mike91188

mike91188

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Hey there! I recently rebuilt my 70s LA 318 and in the motor and in the process of breaking in the new flat tappet cam / hydraulic lifters we ran into an issue and had some coolant make it's way into the oil due to a gasket failure which worried me a bit so I ended up taking the intake off to check the cam and lifters to see if the break-in worked or not. Upon inspection the lifters all seem to still be ok (crown is still present and none of them are flat or ground down ) visually and the cam doesn't seem do you have any extreme wear issues / flat lobes that I can tell, but I'd love to see if anybody can give me any suggestions from these photos.

I did a Little research on the side and there's some information out there that states the irregular wear patterns on my cam can translate to an early indication of a flat cam. Any thoughts on this?

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If they look OK, and with all the troubles lately with cam and lifters, I would just put it together AS IF IT WAS the first time and break it in all over again, just as you were just starting out. Don't forget break in cam lube, Z oil additive, etc.
 
Hopefully you kept the lifters in order.
 
'70s LA 318?
Off the subject, but that looks like a late 80s/early 90s LA roller block to me...
 
Professor Fate said:
'70s LA 318?
Off the subject, but that looks like a late 80s/early 90s LA roller block to me...
Click to expand...
i don't have one sitting right here staring me in the face... but i think you're right.

valley tapped for the lifter spider and those lifer bores say roller motor to me.
 
these three look sus af to me
PXL_20240614_043651907.jpg


how do they look on a completely flat surface? and the corresponding lobes?

the ones to the left of 2 & 3 and the one to the right of 3 look a little interesting as well, but i can't tell if that's just schmutz from the pic.
 
What brand of cam and lifters? I'm with the above post, the lifter labeled as #1 looks like the cam is wiping straight across it with minimal or no rotation and #2 and #3 llok like they're going that way. I'd probably put fresh lifters on those lobes and scheck all lifters to see if they're rotating while the cam is being turned before going back with it.
 
I would be looking at the lifters under magnification.
Specifically looking for any type of chipping or fracturing, especially on or near the outer edge.
 
You have a roller block, if it were me, i’d put oem roller lifters and cam in it and be done. The oem Mellings lifters are not that expensive and the spider and dog bones are still available in salvage yards from any magnum motor.
 
junkyardhero said:
these three look sus af to meView attachment 1716264855

how do they look on a completely flat surface? and the corresponding lobes?

the ones to the left of 2 & 3 and the one to the right of 3 look a little interesting as well, but i can't tell if that's just schmutz from the pic.
Click to expand...
I didn't wipe them off before I took this picture and I probably should have. . All the little highlights that you're seeing are not scratches, but more so just dusts. When I put them in the box it pulled some of the cardboard dust onto the face of the lifters and it's a real pain in the butt to wipe off
 
junkyardhero said:
i don't have one sitting right here staring me in the face... but i think you're right.

valley tapped for the lifter spider and those lifer bores say roller motor to me.
Click to expand...
Interesting - always had a flat tappet since I bought it. I assume the bolt points in the center of the valley are for the spider you are mentioning?
 
Aww manI have a flat tapppet going into a 340 at some point this year all the cam failures git me a worried...I never had one go flat yet ..
 
yeah man, you're kinda in a spot here. i lack the machinist/metallurgy bonafides beyond saying that **** looks fucky, so besides a recommendation of checking the crown of the lifter, the aspect of the cam and rolling it around to make sure the lifters are rotating i don't have much else to offer.

as to the block, it may be a really really late FT block as they were transitioning into the roller stuff, but i would mos def pull the numbers and run 'em to ascertain what you have. incompatibility of parts would eat up some bits right quick.
 
Seeing that's a factory roller cam block, I think the wise move would be to go with a roller cam and factory roller lifters, spider, dog bones and pushrods, assuming the pushrod holes in the cylinder heads are big enough. Also, no special break-in oil or additives will be needed with a roller cam setup.
 
"I think the wise move would be to go with a roller cam and factory roller lifters, spider, dog bones and pushrods, assuming the pushrod holes in the cylinder heads are big enough."

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I would think unless he is using the 302 closed chamber heads with the large pushrod holes to work with the roller lifters, that would do in any idea of going back to the roller cam setup using regular 318 LA heads.

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