Cam Lobe And Lifter Destroyed.....

[rritchey]

Hey guys, I'd like some of you other FE gurus to comment on this... I built a 427 center oiler stroker for a guy, ran it on the dyno and sent it out to him. Everything was great on the dyno - normal oil pressure, normal temp, no indications of any problems. The motor consists of the following:

Late model center oiler block .017" over
428 CJ crank
Lemans rods
Arias pistons
edel. heads and RPM intake
Crane hyd. cam .540" lift (the block was already drilled for hyd. when I got it, perhaps from the factory but not sure)
Roller rockers

Anyway, the guy gets it in his car and 20 miles later it starts popping and acting up. turns out one cam lobe and lifter were trashed. I got the motor back and tore it down, no signs of any problems anywhere except the one cam lobe. All other lobes and lifters were perfect and all bearings were perfect. I contributed it to either a bad cam lobe, bad lifter, or maybe I skimped on the lobe grease on that one lobe. I cleaned everything thoroughly, re-assembled with a new Lunati cam (.600" lift) and went back to the dyno. Again, everything was perfect. No indications of problems. But, once again, the guy gets it in his car and now it has a lifter tick again

I have heard that the late model blocks sometimes have problems with thte lifter bores. Could this bore be off center or something to cause it to eat the cams? You can not see anything wrong with it, I lightly hone all of my engine's lifter bores with a ball hone to make sure they are clean and did not see any evidence of a problem with them.

The motor ran real strong while on the dyno (440 HP 535 ft-lbs) and had good oil pressure. I am pretty well convinced it is not an oiling problem. This is the only engine I have ever had this problem with, so any help you guys can offer is appreciated.

[PatBuckley]

Is it for sure a flat lobe again?

Is it the SAME lobe?

[rritchey]

All I have to go by at this point is the owner's description, but it sure sounds like a flat lobe to me from his description of what it is doing. We will have to wait until either he can check it or until I get it back to see if it is the same lobe. At this point I suspect it is the same lobe as before and it must have something to do with the block. I've heard horror stories about the late model blocks, but this is the first time I've had trouble. He said he drained the oil and had "silvery grey goop" on the magnetic plug.... Pretty sure the cam is gone if that is the case. Nothing alarming was in the oil after the dyno pulls.

[Mr.Fixit]

I am guessing that lifter is not spinning in it's bore.

[Ron61]

A guy here had nearly the same problem with his 460. After three repairs and tear downs they decided it was a something ton do with the lifter and the push rod shaft I think it was. Maybe what Fixit said. Anyway the car is running great now and has been for a long time. The first three times he was lucky to get 50 miles before it started doing just what you described.

Ron

[rritchey]

Ron,

I would appreciate it if you could find out what they did to solve the problem. I really need to get this resolved. Thanks for the tips guys!

[cobra427mnsi]

You might want to check to see if the pushrod is contacting the intake manifold. The spot where the pushrod goes through the intake. I know it sounds silly but, if I recall, there was some discussion on this very topic a while back. It was determined that the pushrod was contacting the side of the hole in the manifold and putting lateral stress on the pushrod and consequently the lifter. The lifter failed and the cam lobe was trashed. Couldn't hurt to check.

Just my .02 worth

Paul

[Jon Miller]

Original owner 428 SCJ out of a Torino complete with snake valve covers, rebuilt and put into the "Work" truck.....Fastest contractor ride in Redwood city.

I bought the motor for my Cobra and when I took it apart I found that the cam had an "extra" bearing.......

I just went out and took a look at the old pushrods; they don't show any sign of rubbing on the manifold......The old manifold was cast iron, so I would think that even a hardened pushrod would show some sign of wear.

-Jon

P.S. The truck was still really fast, even if it was only running on seven!

[Ron61]

Rritchey,

I tried to get hold of that guy and he is out of town for the holiday. He should be back next Monday or Tuesday and I will talk to him.

Ron

[rritchey]

Guys,

Thanks for all the good suggestions. I did ask the owner to pull the valve covers and take a look at all the pushrods to see if they are or have been hitting the intake. He did look and found no problems. The best news of all is this: I asked him if they re-adjusted the rockers after the initial 30 min. run-in on the dyno and he said they did not. Even though this motor has juice lifters I would think you still need to re-set the rockers after break-in. I asked him to get somebody local to come and run the valves, perhaps it is just a loose rocker! (I hope, I hope, I hope)

[joea]

Randy,
You might also try posting a question at:

http://www.network54.com/Hide/Forum/74182

...if you haven't already

[rritchey]

Well, for those of you who might be wanting to know...

The problem was nothing more than loose rockers (thank you Lord). As soon as he got his rockers adjusted properly, no more noise and the car is running fine! Thanks for all the suggestions, but I'm sure glad it turned out to be so simple.

[cobra427mnsi]

rritchey

Isn't it great when things work out the easy way once in a while. Glad it was that simple for you.

Paul

[rritchey]

Yeah, sure had me worried there for a while... I still don't have a good answer for the first cam failure though. It was a Crane cam with Crane lifters - I've never had any problems with Crane parts, maybe I just didn't get it lubed enough. Anyway, what matters is it is fixed and they customer is happy!

We also found out the "grey goop" was just moly grease.

[Ron61]

Glad that your problem wasn't serious. Just for your info. I did get hold of the guy here that had a similar problem and he said that they had a bad adjustment nut on one of the rockers and when they replaced it the next one was bad also. After the third one everything is fine and has stayed that way.

Ron

[Michael C Henry]

Last year I removed my intake manifold to have some testing and work done. When i replaced it .the adjustments were all over the place.Valve lash changed again after 20 miles. I found two lifters that I couldnot remove from their bores. I tore car apart to remove the cam. Two flat lobes. I held up those lifters with magnets. I stuck a magnet in cam bore and caught each lifter. they were mushrumed. Had to have engine gone through. All iron had been caught in oil filter. Oil pump drive was beginning to round. So new rings and bearings.new truck oil pump (larger diameter drive shaft) cam , cam drive, chain and lifters.I installed the heads and rockers.Then I found that the center two rocker studs on both heads were pulling ,heali coils and all.I and the machine shop had not detected the studs being pulled.I had to remove the heads again and have the two center rocker studs repaired with inserts machined into both heads.
I have since gone off the original page and started other projects
Like trying to redo the fuel system larger plumbing and return,tank, pumps ,interior ,seats, dash,heater-defroster. Right now I'm stuck on getting the 5/8"alluminum fuel line from under the body up under the footbox heat sheilds(supply and return). I found that the alternater was bad and hardly putting out. Ive resealed the steering rack, had the radiator gone through, had many peices ceramic coated. new moter mounts.It just keeps going on.I don't think this summer is going to happen.

[SCOBRAC]

Parts break.. My buddies C 500 engine broke a cam at 800 miles. The dealer in Sacramento rebuilt the upper end and sent him home. He noticed it started using about a quart of oil every 150 miles.

He took it to a dealer in Concord and they called him the next day. The good news is there is an engine in a DC in Ohio.. The bad news is it might be 10 days before he gets his car back, as they can't ship it by air. The service manager calls him 9 days later, "Mr Bigshot, Your car is ready, we replaced the engine and the catalytic converters. Mercedes is sorry for your inconvienience and would like you to know they are happy to coner all of the $28,437.67. cost. :lol:

true story