Purepower

iTrader: (1)

OOOOOOPPPPPPPPPPPPPSSSSSSSSS Forgot to post these Here !!!
Reved up to around 5800 rpms Bang !! Stock pistons stock cam with 1.7's ???? Ran this set up for years??? No problems With P/V clearance Before ??? Spring was not broken Keepers and valve spring were still attatched to the stem of the valve.

largeman

valve springs wear over time lose the seat pressure at high r.p.m. and the valves float...enough in some instances to slap the psiton...looks like what happend from what i can see

Purepower

iTrader: (1)

OK what ones do you recommend they were the stock ones that came with the TFS heads

largeman

aha ...stock tfs valves are crap....you need ferra's or something good....give boss racing a call brad will set you up right with what you need...tfs great heads...lousy valves...
1-866-913-2677 jay or brad...they know all the parts to push a n/a motor to the limits...

Stang Seller

I thought the problem with the TFS heads were the valve springs, not the valves. But you should upgrade and run a set of Manley Swirl Polished stainless valves with some upgraded valve springs. You may also want to have the guides checked and replaced.......
SS

largeman

both are suspect....hard to tell from the pics...i have heard nothin but not so good things about tfs valves running at high rpm....

Stang Seller

Interesting, If the valves were slapping (which I think would cause just the valve head to snap off) then there would have been some if not considerable valvetrain noise. It's also possible the rockers were out of adjustment, but generally it would be noticeable either in a power loss up top (floating) or valve train noise (rockers slapping the top of the valves). If the rockers were slapping, more often than not the valve would have dropped. In his scenario, the valve head broke off and the stem remained in the head (though its bent). There should be no clearance issues as the exhaust valve remains in the stock location, it's the intake valve that is moved in the TFS TW head. It's possible the valve springs were weak (though Ryan claimed he had them tested), which caused the valve to somehow whack the piston. It's hard to really diagnose what happened, but it has happened and there must be a lesson to be learned here. More research by a professional engine builder is required so that the true cause of this mishap can be determined. There is also the fluke possibility that the valve was faulty or for some other reason, the valve head just broke off. It is very hard to say what exactly the problem was unless you are there during teardown. Either way, there must be some precautionary measures taken to ensure this sort of thing does not happen again. I would contact Paul Silva at PSP 416-285-7285, in my opinion he's the best in the business and would have some knowledge on a problem such as this. If I can help you in any way, Ryan, dont hesitate to call me.
SS

SirChirpAlot

That sucks to see happen but i feel your pain.
How did the block do? i hope it didn't ding up the bore to bad.

As for how or why this happend. I have seen valves thay were floating for a wile and u can see on the cam were roller jumps off the cam and smacks back on it. Check the down side of the lobes and all the lifters as well.
3 years with stock cam and only 5800 RPM i cant see this being a prob.

My old 302 had x303 cam with dubble springs and stock valves locks and retainers,
I got 3 years of banging the gears well into the 7000rpm range to only have one the hold downs snap and have a lifter spin and jam the cam.
Ended up snaping the timing chain and 3 valves got bent when the pistons came up and kissed them. Same heads i have on my motor now i cheaped out and changed 3 valves and called it good. I still have the dubble springs in there too.


I doubt that u floated the valves and smacked the piston.

THREE40SEVEN

stock valve springs with 1.7's WILL float at high rpm. I've seen a before and after dyno test with 1.7's which resulted in a loss of over 10hp by just switching to the cobra rockers on a 80,000mile 302. Stock valve springs only have 75-80 lbs of seat pressure...

Upgrading to a better valve with a stock cam/heads is a waste of money IMO. Unless the valve was stressed, it's not going to fail.
Unless you want to change cylinder heads, use crane #44308-1. She'll give you ~120lbs on the seat, and enough room/spring to go ~.550 lift. The kit includes retainers and locks, and no machining is required.
Good luck,
Matt

Stang Seller

Ummmm, he's using Trick Flow heads with the stock TFS valve springs.
SS