GTO30272

I just picked up a set of like new ported/polished 72cc 317 casting heads with 2.02/1.60 manley valves, dual springs, ect. I was recently told that with a turbo setup you need to go with inconel exhaust valves. I am sure they are better, but is it truley necessary for ~700whp at ~11psi. This is on a budget build and spending money on things that arent necessary is not part of the budget. Eventually there will be ETP 245 heads or similiar on there, but they are not in the budget for now. I just want to know if I will be playing with fire if I dont get the inconel valves, which is how it pretty much sounded to me, that I should be expecting failure and they are pretty much required. Thanks in advance.

Ed @ Late Model Speed

iTrader: (4)

I would recommend getting them, it's not a lot of money to add them now while the heads are off, but if you drop a valve, the cost will be a lot more.

Hope this helps,
Ed

Gregory J. Doyle

I have to Agree W/Ed "kind of like buying insurance" You may go with Manley Severe Duty XH428 material used in severe duty, But not like boat racers where your full throttle max boost almost all the time. They use extreme duty inconel and the valves with high spring pressures will beat on your valve seats pretty hard. Severe duty set of 8 is around $200.00 but extreme would be $300.00 for 8 exhausts. And you already have the heads off the car, be a good investment and you can peddle the heads later when you get the heads you really want. I'm Building a twin turbo and I got 317 heads Iwas going to go that route. But looking @ the flows on the new 92 heads, and they are a bargain right from chevy, I might go that route. But I will use Manley severe or Del West has a real good alloy too. Probably$$$ though. Buy the time you work a good set of heads up (porting,Valves, Springs, retainers, Rockers) you spent 2G's. But thats showbiz!! Gotta go - getting way off the subject!!!
Good Night and Happy Holidays
Greg

Fullthrottledan1

We use manley severe duty in our motors and holding ~50psi with more seat pressure than you wanna know. It does beat the crap out of the seats though. Its worth the extra money in my opinion.

Zombie

iTrader: (2)

My car has stock valves

parish8

iTrader: (6)

i have been running around 1000rwhp for a couple of years now with afr heads. i dont think they have special valves in them. 20+psi, 10,000 street miles, probably 150 track passes and 75 dyno runs.

engineermike

AFR heads with stock valves here too. I've been as high as 26 psi boost with no valve issues. On a drag car, we stay at full throttle / full boost for such short periods it doesn't seem to hurt the valves. However, I built a turbo SBC for an alligator harvesting airboat that was run under heavy load for 12 hours a day for 3 months. You bet we used Inconel valves in that one and it was flawless.

Mike

nitrorocket

iTrader: (12)

You should ask this... has anyone seen a stainless valve fail due to heat in a turbo motor? I never have.

Old Geezer

iTrader: (3)

reply. Yes.
Have seen several such failures in turbo BUICKS, including mine. But then we're only making 850FW, from 274CI... Maybe that's the reason????

TwnTrboCE

iTrader: (43)

You'll be fine. Your tune has a lot to do with that also. Most run safe enough that EGT'S aren't that high.
I ran stainless valves into the 8's.

black98ws6ta

iTrader: (77)

My car made 920 rwhp on stock heads with stock valves, but I know im pushing it. The valves lookes fine but the car had like 15 dyno pulls and maybe 25 WOT passes.

engineermike

Yea, 35 psi boost will do that. . .

Tiago

iTrader: (27)

stainless valves that come on the AFR heads here at 1000 rwhp

Pro Stock John

iTrader: (34)

I went with Inconel valves as a precaution with my newish Allpro heads.

kp

iTrader: (34)

Heck I ran stock GM valves all last year and whatever comes in the dart heads this year. My EGTs have never been hot enough to worry about it, if you try hard enough I'm sure you can melt them though. Sure its 'insurance' but you can spend so much money worrying about every little thing that you can give up before you start when you figure the cost of using the 'best' parts for everything.

It all boils down to how many people have melted exh valves out of an LS1, none @ 700hp at as far as I know.

frcefed98

iTrader: (16)

SS valves here, doing just fine

Zombie

iTrader: (2)

Hmm, I guess that's why some people have $15K motors and I have a $3.5K motor.

Country Boy

iTrader: (24)

stock valves in stock heads here too.

NA$TY-TA

iTrader: (21)

SS Valves here also...... maybe one day if i do another set of heads ill do Tit intake and Inconel exhaust Valves.

Kyle

engineermike

This is a pet peeve of mine. I get alot of harrassment over my locally-built TH350, home-built log header, stock ECM, cast iron 3rd member, stock driveshaft, stainless exhaust valves, etc. . . But, I built a fully streetable 9 second, 146 mph car for $25,000 including the car. The only "cheap" part I regretted buying was the SRP pistons.

Mike