Biggest Exhaust valve on stock seat
#3
FormerVendor
iTrader: (13)
Re: Biggest Exhaust valve on stock seat
We like to see .010"-.020" from the edge of the valve to the edge of the seat. That means the seat needs to be 1.620"-1.640" which it is not. You could set the 45 angle way in on the valve but it usually hurts the flow to do so, compared to the 45 being set all the way out to the edge of the valve. We just installed 1.60 valves on two sets of heads (and put in the bigger seats), they did flow more air at .600" but the STOCK 1.55 valve out flowed it from .100"-.550". Bigger stuff that flows no more air is almost always the loser.
We have had a customer pull off a set of ported big valve heads and install our ported stock valve heads and made MORE POWER, 420 RWHP to be exact.
900 HP NHRA Pro Stock truck heads have 1.56 exhaust valves.
Good luck, hope this helps.
We have had a customer pull off a set of ported big valve heads and install our ported stock valve heads and made MORE POWER, 420 RWHP to be exact.
900 HP NHRA Pro Stock truck heads have 1.56 exhaust valves.
Good luck, hope this helps.
#4
Re: Biggest Exhaust valve on stock seat
Thanks for the insight guys. I have another question. What valve seals are you using when going to the dual spring setups? Can you use the factory style seal with the bigger hardened spring seats?