Lifter went bad at the track

Looks like I missed the shift from third to forth and went into second by mistake. Then the care started running really rough. Pulled the valve cover off and looks like the lifter is bad because it won't compress. So we set the back lash loose and gonna drive it home. We thought about leaving the push rod out. It's a 115 miles back to san diego.

 

Was it the same lifter as the one that had the rocker arm come off ? What kind of a shifter are you using ?

Bad things happen in threes so I would say you have had your limit

 

Yeap same one

 

Hmmm, makes you wonder. Was it he cause of rocker coming off or the result of it coming off, probably the result or you would think the pushrod would have bent.

With the rpms you are running it looks like you need to step up to some better parts. Its only money

 

Or at least a rev limiter!

 

Rev limiter is set at 6800. I'm thinking that is just too high for that engine. We're gonna try the rocker girdle and see if that helps. it still was a great time at track.

 

I would upgrade to a link bar style lifter jmho if in fact it's another bad lifter
Your studs shouldn't be flexing at those rpm's I've spun less harder maybe your getting valve float

 

if you went to shift from 3rd to 4th at 6800 and went to 2nd it would have went way past 7k rpm

 

Something like this would fix you right up.

 

Better have some tall valve covers for those babies!

 

Hehehehehehe, yea they need to be a "little" taller than the stock ones. But pushing .624" gross lift on a solid roller they need to be there.

 

So when I drove home from the track about 1-2 miles into the drive there was a loud rattle in the engine. Opened the valve cover and there was another rocker that had some off the stem. I think it was cylinder 7.

 

Time for a serious look into the valve train. Are the rockers touching the studs? What kind of locks are on the rockers? Are the coming loose or breaking?

 

we inspected it last time and this time. there is no signs of the rockers touching the studs. There are polylocks securing the rockers in place that don't seem to have any damage and don't appear to be cracked or failing in any major way.

 

If you have a mechanical roller cam, with 624 lift you need about 250 lbs pressure closed at the seat. You should have 550 lbs or more open pressure. Roller cams have a fast ramp speed and you need these pressures to hold the push rod on thelifter, and the lifter stays on the cam.If the lifter comes off the cam the resulting pressure changes and allows the cam to wack the lifter as it comes back down.THIS IS VERY HARD ON THE VALVE TRAIN.Can cause the rocker arm to have too much valve lash for that split second.Just remember for every action, there is a alternate reaction.jmo