TJ

iTrader: (10)

running 140/385 pressures on a stock valve thats had a 5 angle valve job.
the machine shop says the stock valves are too thin to handle the pressures my cam requires..... but everyone and their grandma runs similar setups with stock valves and have had good sucess with them.
ive run the same valves without a valve job for 2 years now on these spring pressures with no issues. street/track driving. im pretty abusive.

any opinions?

John02SS

iTrader: (47)

I'd find another shop TJ, as they may be trying to sell you valves. Lots of guys running stock valves with more pressure than that and I haven't seen a breakage issue arise.

TJ

iTrader: (10)

i dont think he is trying to sell me anything, i just think this guy is a perfectionist.
im just looking to have my heads cleaned up, not a work of art.

machinistone

Well, I would not run stock valves with solid roller cam spring pressures - but 140/385 doesn't have me scared at all...the open pressure does not stress the valve, it's the seated pressure combined with how the cam lobe sets the valve on the seat that determines the possibility of snapping a head off.

I think you have a good machinist who would rather error on the side of caution than have you break parts.