Thread: 390 cam fail

Tweet

I had a cam totally fail in a 390 I have. I spotted a couple scratches in the bores and such. I have the engine out and on a stand...
do I need to re-hone?
should I take it apart farther (intake and heads are off now) and clean and such?
thanks!

I'll let one of our more saavy engine guys address the serious stuff like honing, but when you say the cam failed, I take it at least one lobe rounded off. If so, all that metal went somewhere and unless you take everything apart and clean it completely those pieces may cause further damage in the future.

Was this a new cam that failed shortly after installation or an old cam that just went away? What kind of oil and oil additives were you using?

Don

Originally Posted by Itoldyouso

I'll let one of our more saavy engine guys address the serious stuff like honing, but when you say the cam failed, I take it at least one lobe rounded off. If so, all that metal went somewhere and unless you take everything apart and clean it completely those pieces may cause further damage in the future.

Was this a new cam that failed shortly after installation or an old cam that just went away? What kind of oil and oil additives were you using?

Don

I bought the truck this way. it had one lobe/liftr fail all the way (wore a hole thru it) the rest of the lifters were missing about a 1/8 of an inch off the bottoms. LOTS of metal in the pan. wave a magnet accross the sludge and it jumps out of the pan
Not sure what additives were put in the oil, but the engine had about 5000 miles before it went south.
oh, and the engine was flogged, street raced, drifted at a track and on the street, and taken to redline a lot... and the truck went thru 4 sets of rear tires in that 5000 miles... talking to the PO I was going

Most cams end up with wiped off lobes and hollowed lifter bottoms today because there are no additives in most of the oil for flat tappet cams. There really have not been any flat tappet cams used in modern engines for the past 20 years or so. Give or take a few years for some possible hold outs. The point is every new type of vehicle has a Roller Cam or Overhead Cam these days.

You have to add an additive like Comp Cams part number 159 Cam Break in Lube and we use a lot of Joe Gibbs XP5 Race Oil. We have not had any cam problems since we started using these products in all our Performance and Race Engines. The Comp Cams additive is only $10.00 and the Joe Gibbs XP5 is about $10.99 a Qt. It is a Semi-Synthetic 20-50 Blend. It cost more but you can run it much longer. Most guys run it through 3 oil changes and only change the filter and add a qt. I sell a lot of it to almost all the racers. Cheap protection against camshaft failure. Of course don't forget to properly set the spring pressure and valve lash too. Oil can't fix everything and there are a lot of guys out there working on engines who should have never picked up a tool.. they make it hard for others who come along and buy a project not knowing it was poorly assembled. Let me know if I can offer any help. Mike at, mikesspeedparts@aol.com