Freak problem (cam/lifter) related

[Mr. T-Type]

I've posted a few times about one of my lifters dishing. I went to replace it again today and it turns out 3 of them are dished. #2, 4, and 6....all intake lifters.
I go ahead and pull the cam and those 3 lobes are ground to almost nothing.

The exhaust lifters are just fine and everything on bank one is perfect. I'm assuming the wear is from oil loss....but why only the bank 2 intake lobes?

I've been running a Comp 268H (218) with the lifters and springs that came with the kit. Anyone have an idea as to why this would happen? I'm stumped.

 

[Jerryl]

Interesting.
Dumb questions.
Was there a problem with the previous cam that prompted you to change it?
New motor and/or front cover?
Heads recently freshed up or stock?
Lifter preload verified?

 

[Mr. T-Type]

Interesting.
Dumb questions.
Was there a problem with the previous cam that prompted you to change it?
New motor and/or front cover?
Heads recently freshed up or stock?
Lifter preload verified?

Its had the Comp 218 in since the rebuild (7k miles ago). I believe Dusty did the rebuild. Its made MANY MANY MANY 120+mph passes in the last 2 years. After the first lifter went a few months agoand I replaced it, it was still trapping 117+, so I didn't think of it. The problem happened all of a sudden.

 

[Mr. T-Type]

any suggestions would help. i don't want to put it back together and have the exact same thing happen again.

 

[Jerryl]

I am no expert but it looks like the lifter was not spinning. The wear pattern if off center around the second lifter and a spinning lifter would not only have a smooth polished finish but also be even around the OD.
Of course, the worn lobes will no longer give a good representation of what happened.

One strange thing I noticed (Pic 1) is that the grinding marks are still on the outside diameter of the contact area of the lifter. Thought that the bottom would be “polished” after a few hundred miles. With the problem just one bank and only on the intake, it may be the lobes were not ground correctly and the lifters finally wore through the hardened layer of the lobe …… this than caused a severe reduction in lifter preload which accelerated the wear. If you look closely at the cam lobe, you can see a spot on the lobe where the lifter was “pounding” the lobe and no longer “riding” on the lobe. Because of the “lack of” pressure against the lobe.

Just think how fast you would be with a good cam!

 

[suicide six]

Since Comp wont stand behind high performance parts,Id consider a different vendor.Spring pressusre maybe to high,Cam or lifter hardness is too low.It may be the valves too tight in heads?

 

[Mr. T-Type]

I am no expert but it looks like the lifter was not spinning. The wear pattern if off center around the second lifter and a spinning lifter would not only have a smooth polished finish but also be even around the OD.
Of course, the worn lobes will no longer give a good representation of what happened.

One strange thing I noticed (Pic 1) is that the grinding marks are still on the outside diameter of the contact area of the lifter. Thought that the bottom would be “polished” after a few hundred miles. With the problem just one bank and only on the intake, it may be the lobes were not ground correctly and the lifters finally wore through the hardened layer of the lobe …… this than caused a severe reduction in lifter preload which accelerated the wear. If you look closely at the cam lobe, you can see a spot on the lobe where the lifter was “pounding” the lobe and no longer “riding” on the lobe. Because of the “lack of” pressure against the lobe.

Just think how fast you would be with a good cam!

I'd like to go back with a Comp 218 b/c I know it made good power. I also noticed that the lifters aren't comp lifters (no part number on them). Valve springs were ones Comp reccomended for that cam.

 

[Turbo1dr]

Proper cam break-in is vital to their survival unless you have crazy spring pressures. Time for a billet roller cam and never look back at a flat tappet cam.

 

[Turbo1dr]

One strange thing I noticed (Pic 1) is that the grinding marks are still on the outside diameter of the contact area of the lifter.

It looks like when he replaced a lifter earlier that lobe was already ground down. If that's the case then the bottom of the lifter will never see the full contact area of the cam lobe.

 

[bison]

I am assuming you ran a new lifter on the old cam right. And the lifter in the top pic is that lifter right? It was spinning but wasnt contacting the lobe correctly. Too much pressure in a small amount of area, possibly form the worn cam. I have never had success running new lifters on old cams. They just wont spin. As far as springs go, You must check the spring pressures before installing them. Dont go by the numbers on the box. I have seen variance of 30psi@1.75in. Ive seen some as high as 120psi@1.75in. The lobe will s hit the bed with 120psi. I reccomend using a really weak set of springs for a break in on a fast ramp cam like yours. It will add tremendously to the life of the cam if you do so. The faster the lifters spin the longer it will last. I ran a comp 212-212 and made a ton of power with it years ago, but once i got a little water in the oil the cam was toast within a day. Make sure the cam is ground so that the lifters force it toward the rear of the engine. At this point the engine should be disassembled and cleaned in all possible ways. Get a new radiator also because the oil cooler will be full of metal.

 

[bison]

It looks like when he replaced a lifter earlier that lobe was already ground down. If that's the case then the bottom of the lifter will never see the full contact area of the cam lobe.

Nice reply, was typing when you posted.

 

[Mr. T-Type]

Since Comp wont stand behind high performance parts,Id consider a different vendor.Spring pressusre maybe to high,Cam or lifter hardness is too low.It may be the valves too tight in heads?

I'm not exactly blaming it on Comp. The engine has seen a HARD 7k miles. I want to say its an oiling issue. I've always kept the oil full, but I've never monitored the pressure. I figured that maybe an oil galley is restricted, but I have no idea how it is distributed. Seeing as the only problems are the bank 2 intake lobes/lifters.

 

[Mr. T-Type]

It looks like when he replaced a lifter earlier that lobe was already ground down. If that's the case then the bottom of the lifter will never see the full contact area of the cam lobe.

The worst lobe is the where I replaced the lifter the first time. The tapping went away after I replaced it, but it still didn't run as hard as it did before then. The tapping came back a few hundred miles later.