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Author Topic:   Mr. Pushrod meets Mr. Rocker
teamstertom
Member
posted August 24, 2003 03:07 PM
I will try to make my long story short...
Brand new,0 laps 355 small block Chevy that was built by a leading engine builder in my area.....well...at least I thought that.

We traveled to Fox Ridge Speedway in Arcadia Wisconsin Friday nite with the Wissota legal Super Stocker only to have the pushrods in 4 cylinders go thru the rockers and also the rockers on some cylinders split in half with the ball coming thru the rocker.

The motor never overheated or over revved as the recall said it hit 6400 rpms. I don't have the spec sheet for the cam in front of me,but something tells me that we had a whole lot of valvetrain bind.....

My guess it would be from poor checking of the clearances of the engine builder..but any thoughts?

It was running when it came off the track,all the retainers and valve springs are in place.

I need to go see the engine builder tomorrow after work,a tuff spot to be put into....but as I see it I spent $2800 on a good short block and another $1000 in a set of heads....I think I should be upset about this for a motor that only ran 9 1/2 laps.




outlawstock17
Member
posted August 24, 2003 03:20 PM
it sounds like the camshaft is too big for the springs. you should have at least .050" clearance between maximum lift on the cam and coil bind on the springs. that's what i'd look at first.


teamstertom
Member
posted August 24, 2003 03:27 PM
My first thoughts were to the valve springs. Hopefully I have no damage to the bottom end,like holes in top of a piston. I feel like the damage will be mostly to the valve train......we will pull the motor torrow and do further research. I thought that the engine builder would have checked all the clearances and valve spring rates,but it seems somethings were overlooked.


tilley88
Member
posted August 25, 2003 12:38 AM
Pushrods were too short.


norightturn
Member
posted August 25, 2003 07:27 AM
Have you checked to make sure that he used long slot rockers? I would think this and coil bind would be the prime suspects.


gerald berry jr
Member
posted August 25, 2003 03:31 PM
have to agree that rocker slots caused this gotta hve long slots for any decent lift cam


teamstertom
Member
posted August 25, 2003 04:48 PM
Talked to the engine builder today....weird feeling telling someone that their engine had a parts failure,but this is something that shouldn't be sugar coated.

One thing he said that maybe the current rockers could be 1.6 long slots,which they are,and he set the cam up using 1.5 long slot rockers specs from the cam card. He stated that this could also do the same thing as in causing coil bind. A mistake none the less,something that was overlooked. When you go to a professional,you want and expect professional workmanship...you would think anyway.....right?




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