Flat tappet failure

[Valman]

Good engine building and run in practices were always employed by everyone else. This included proper run in procedure, zero mechanical interferences, correct spring pressures (including removal of inner springs during run in), identifying and correcting lifter rotation issues by the retruing of lifter bores & using the right oils / assembly lubes.

^^ Agree, these are most likely the culprits for wiping out cams/lifters . Quality has gone down with a lot of parts no doubt, so selection and preparation become more important. ‘Small’ things like knocking the burr off around the oil feed annulus around the lifters, often overlooked. I’ve found new hyd.lifters full of gunk left over from machining. If the lifter bleeds down, where does the gunk go? Between the lifter and bore!
Lots of people cheap out on proper oil, too lazy to pull the dual spring on the valves, and on and on..

Edit: Good idea to always use a molybdenum assembly lube on FT cams for break in.

 

[middleagecrisis]

I just checked comps website and the mopar dlc coated lifters are in stock now. I hope these flat tappet lifters are a solution for the problem with flat tappet failures. I have not tried them yet. They are priced reasonable. Comp seems to be all in on these lifters and it looks like they are available for most applications now. If anyone has any experience with the dlc coated lifters let us know please.

TAPPET, DLC HYDRAULIC FLAT TAPPET .904" DIA AMC & CHRYSLER APPLICATIONS SET 8 CYL - Set of 16 - COMP Cams® https://share.google/2awEYj2Af67SovNIC

“tough and high-lubricity surface to reduce friction at the cam lobe/lifter interface, extending lifter and camshaft life significantly” From immediate failure to 1500 miles? Only time and lessened failures on break in will give me confidence in their products. I know millions of people use their cams, and a good argument could be made that their percentage of failures is the same as other competitors, but time and time again it’s comp cams that have the problem. I’ve had my own issues with them and quality control. I personally feel that they should have addressed this years ago instead of coming out with a “new” lifter.

 

[92b]

“tough and high-lubricity surface to reduce friction at the cam lobe/lifter interface, extending lifter and camshaft life significantly” From immediate failure to 1500 miles? Only time and lessened failures on break in will give me confidence in their products. I know millions of people use their cams, and a good argument could be made that their percentage of failures is the same as other competitors, but time and time again it’s comp cams that have the problem. I’ve had my own issues with them and quality control. I personally feel that they should have addressed this years ago instead of coming out with a “new” lifter.

I'm not making any excuses for comp cams but if it helps prevent cam and or lifter failures I'm all for it.

 

[RustyRatRod]

you're the one that put a date on it. so i guess we can add selective memory to your list now too.

as usual, you've got nothing to back up your wild assertations and you fall back on name calling and *waves hands around* whatever this is.

ohhh... i'm lonely because i followed up on your malarkey? ohhh... i'm boring for the lone reason that i want to hold somebody accountable for spreading misinformation?

so again, where's the proof? where's the data? you know those niggling little details like facts and evidence?

what happened did your highlighters dry up?

as always, you never fail to disappoint.

Snarky cat wants to know.

 

[273]

My experience has been its incorrect machining of the lifter faces. I resurface every flat tappet lifter I use, old or new out of the box.

I think your on the right track, I watched a cam grinders video the other day, he measure the new lifters tapper and hardness, hardness was fine but all the tappers were way off and had to resurface them all. I also heard that should make sure the lifter can spin freely in the bore cause that can cause it to fail.

 

[273]

You hear about hydraulic flat tappet having problems, what about solid flat tappets anyone experienced or heard of people having similar problems ?

I imagine the problem still has to be on the relatively low side or they wouldn't be able to sale flat tappet cams if failure rates where overly high.

Hughes has a warranty against wiped out cams might be worth checking out.

 

[MILO]

Some engines and parts are not so good sometimes

 

[LST46]

Just curious, What brand were the cam and lifters? My machine shop who has done thousands of successful flat tappet cam builds over the past 50 years refuses to do them anymore because of too many problems. Even though I’ve only had it happen twice in 40 years am weary of using flat tappets anymore because of seeing so many failures

 

[Killer6]

Some engines and parts are not so good sometimes

View attachment 1716418116

Pshawww,.....it's letting You know it needs more air......

 

[71Demon540]

Just curious, What brand were the cam and lifters? My machine shop who has done thousands of successful flat tappet cam builds over the past 50 years refuses to do them anymore because of too many problems. Even though I’ve only had it happen twice in 40 years am weary of using flat tappets anymore because of seeing so many failures

The ones that failed in this engine were comp cams cam and lifters

 

[Bewy]

I was given some Eaton lifters ~ 1998, brand new, for an engine I was building. Left over from another job. I didn't use them..... They had a huge chamfer & a very rough finish, almost catch your nail on it.

 

[oldkimmer]

I was given some Eaton lifters ~ 1998, brand new, for an engine I was building. Left over from another job. I didn't use them..... They had a huge chamfer & a very rough finish, almost catch your nail on it.

I think it will buff out. Lol