Thread: Why my car lost 3 tenths last race

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My last race of the year my dragster lost .3 and I finally got around to pulling it apart. Motor still ran before I tore it apart and I hope no bottom end damage was done because there is a lot of metal in the top end.

Hope your pickup screen and filter caught the particles before they got circulated. The 355 Chevy I got in the Camaro had one lobe gone like that and the lifter was destroyed, but the bearings look good, so no pieces got that far. You might have the same luck.

Don

yep i seen that looks like your running comp lifters . i would go thru the engine when you lose a roller lifter lots of junk ends up on the piston skrits and piston walls. look like a small base cam how much lift are you running . some lifters have a short life with big cam s need to keep a eye on spring pressure .if a big cam you may want to think about a 903 or 931 lifter

They are Isky lifters. Going to completely tear it down to replace all bearings and check pistons and skirts like you said. I do not know the lift of the cam so I am going to have it measured a new custom grind done with new springs.
I bought this motor used so my fault for not going through it and freshening it up before racing it.
Pat what is a 903 or 931 lifter?

Originally Posted by burnout1969

They are Isky lifters. Going to completely tear it down to replace all bearings and check pistons and skirts like you said. I do not know the lift of the cam so I am going to have it measured a new custom grind done with new springs.
I bought this motor used so my fault for not going through it and freshening it up before racing it.
Pat what is a 903 or 931 lifter?

thats the size of the lifter body . crowers hippo lifters or PBM /Ersons have pin oiling or the isky red zone

look like a older set of T&D rockers . i hope you did not force that lifter thru the bore that hard on the lifter bore and if bronze bush then you can screw the bore up your better to cut the tie bar or button off lifter and push it down when cam is out .you will need to look at that lifter bore good

Finally getting around to pulling the pan and the heads off. Found some scratches only on the odd side and all were at the six o'clock position of the bore. My fingernail does not get hung on any of the scratches so they are not too deep. Did find some damage on a couple of pistons and rods from the lifter roller. Pulled one connecting rod cap to check bearing. Currently getting a new custom grind done by Erson and they will be supplying me with all my new valve train components (springs, lifters and valves). Off to the machine shop next.

them walls do not look good . thats from junk under the skirts from cam and lifter going a way . that is the load side so thats were bores get cut up .what helps stop some of this is preping the bottom of piston bores breaking the sharp edge at the bottom of bore . making sure the rings when filed that the rings have no burrs . back side of housing bore on rod looks like it should but as allways should be check if still round in the housing bore

I would agree with you, I was not happy to see them. The even side looks perfect just the odd side has these vertical scratches. You think a rebore is in order to clean them up?

Looks like a pretty rough hone job before---you will have to hone it to see where it cleans up before you order pistons for it---

some look like ring end gap cutting in the bore i did add to my last post about ring and bore prep hard to say if it can be clean up would be to do with some things like what the bore are like round tapper weres the piston to wall is at now after clean up its not hard to add .002 to the bore size after clean up .i cleaned up bores that were like this and more .so it gets down to how loose you can run piston to bore . alot of times if a guy wants to save his pistons theres clean up on them as well were your going to get smaller after clean up to as i get the steel out of the skirts with a file and sand paper if pistons are not collapse i use a piston knurler . i done this may time them and and fit them to the new size on the bore .. look at your valve springs shims can cut walls up to any sharp bits that can get in the oil will be seen on the walls

Got my new cam specs in, got a custom grind from Erson since they just a couple of minutes from my work. I had the old cam measured first.
Old and new cam specs

yep Erson grind most all my custom grinds .for customer builds .low lift cam should be EZ on valve train parts

Looks like the cam bearing walked too, what could cause that?

Originally Posted by burnout1969

Looks like the cam bearing walked too, what could cause that?

Nope i would say they cut the block for a thrust bearing