F110Mech

iTrader: (2)

I'm going to run 317 heads on my 347 and was wondering if anyone was having an issue running 20-23lbs of boost with stock valves.

F110Mech

iTrader: (2)

Anyone?

Sales@Tick

iTrader: (3)

I am using a stock LS3 hollow stem intake valve and stainless exhaust valves in my engine.

No issues so far, but it has only made dyno pulls currently.

F110Mech

iTrader: (2)

I haven't read about anyone replacing them but my builder thinks that it might be a good idea

Sales@Tick

iTrader: (3)

Stainless exhaust valve is a good idea with higher power boosted engines. Inconel exhaust valves as power levels and heat rise higher may be needed even.

F110Mech

iTrader: (2)

Think it's needed with 23psi? Hoping for 800-900rwhp through a 4l80e

Sales@Tick

iTrader: (3)

I think it's a good practice on a higher HP car. I know there are a lot of guys out there running completely stock cylinder heads like 317's with stock valves, but I did it on my engine for the peace of mind.

dezlfrek

iTrader: (1)

I have had a stock valve and last weekend a stainless vavle go away.. I race a lot more than most but I am going to Inconel this time.. I could do ti but no one has said weather they handle heat better or not..

Forcefed86

iTrader: (4)

I've run 25+ lbs on 5.3's and 4.8's with no issues. 706 heads, 317 heads, 243 heads. (running E85, water inj, and an A2A IC as well) Pretty cheap "upgrade" though. If you have a nice motor I'd go with stainless. If your running a JY SBE motor I wouldn't worry about it.

Sales@Tick

iTrader: (3)

Inconel handles heat much better than Ti. I believe it is also recommend by most cylinder head engineers that a copper beryllium seat is needed for exhaust valve duties if Ti is utilized. That can get expensive...
I agree with this statement 100%.

If you're going to slap a 200 dollar motor in your engine bay, don't worry about it. If you're building a nice 8-10k+ motor, upgrade the exhaust valves to stainless.

F110Mech

iTrader: (2)

It's an ls1 with forged rods and pistons but I don't really want to put the money into 317 heads. I'd much rather save it and put it into a set of aftermarket heads down the road.

Forcefed86

iTrader: (4)

Up to you… you know the risks now. Personally I’d just run a “safe” low timing/rich tune until I could afford the new heads. I've seen very few dropped valves on turbo motors that weren't pushing the limits.

F110Mech

iTrader: (2)

I guess that this was the kind of response that I was looking for. Thanks. I asked because I haven't read about people replacing the valves or having issues with them

Sales@Tick

iTrader: (3)

Same here. I've yet to see one under 800-900rwhp.

That's obviously not to say that it cannot happen though!

Good advice in here.

F110Mech

iTrader: (2)

That's right around the range that I'm hoping to be in. Thanks guys!

RonSSNova

iTrader: (3)

From stock, to SS, to Inconel, what is the weight difference?

Might be important if you are turning some rpm.

Ron

Sales@Tick

iTrader: (3)

Heavy, heavier, heaviest....

Normally we don't worry about the exhaust valve weight as the diameter is much smaller than the intake valve, thus the weight is normally much less.

RonSSNova

iTrader: (3)

Good point!
My cyl head guy gave me crap about not putting better exh valves in when he did my valve job.

But then he thinks I'm nuts for putting a big turbo on a stock engine anyway.

:-)

Ron

F110Mech

iTrader: (2)

Idk if i want to put a good set of heads on this motor or do an aluminum 5.3 later so that i can REALLY lean on it and do a set on that. I'm worried about ballooning the Cyls on my LS1 with my boost level. My engine builder said that i might have to worry about it running around 23psi