bridgeport13b

Hi I am getting my heads freshened up and I will be pushing 700hp with pump gas 92 octane and meth. Anyways should I ditch the stock ls3 valves and go with stainless valves?
Thanks
Richard

CI GS

Lots of folks using stock LS3 valves at that power level with no issues, and the stainless valves will actually be heavier than the hollow stem LS3 valves.

bridgeport13b

Forgot to add I have btr dual springs and retainers. Are stainless valves better? I know they weigh more.

Evo_Joe

For your power I would suggest the following:
Exhaust Valve: 12612427 (GM LY6 Inconel)
Intake Valve: 12569427 (GM LS3 Hollow)

If you're getting everything freshened up I'd also look into:
Katech/Hinson C5-R Timing Chain
LS9 Head Gaskets
Straub Tech Rocker Arm Trunion Upgrade w/ Lifters

bridgeport13b

Hi I have bought a iwis chain and straub kit. But when using inconel valves do i need differnt seats?

Evo_Joe

Seals/Valve Seats sizing shouldn't change
Your stock LS3 valves may be ok, and should be ok if you stay around 700rwhp
If they're going to open her up, then maybe get them 'blue checked' and then decide one way or another
If you decide to put new valves in then I would get the pushrod length checked and order a set from Smith Bros or the like

Main Takeaways:
You may or may not need new valves
Get it blue checked, and if you do need new valves, then go stock hollows for the Intake and LY6 Inconel for the Exhaust
If you get new valves then I would get pushrod length checked and order a set (not off the shelf comp 7.4)

bridgeport13b

Hi I do have a push rod checker, smith brothers is only 4 hours away so they ship quick quick, please add more info in if you have any also from the looks of it I am keeping stock seats.

Evo_Joe

Why did you decide to pull heads and refresh, are you doing a cam swap?
LY6 and LS3 exhaust valves are both 1.59 diameter, should be direct swap application wise.
I don't know what mods you're running, but if you're an LS3 w/ that much power I would pin the crank and put in an ATI harmonic balancer w/ Continental Elite V Belts if you haven't already. I'm guessing you've done some research based on the parts you have. Only other advice would probably be to leave the water pump alone on the LS3, not worth messing with it to me. Also get the LS9 head gaskets if you don't already have them, very very important for high powered applications.

bridgeport13b

The reason for the head removal was because one chamber got a little tore up from previous owner of heads, had heads checked for cracks and it came out good and guides are flawless. Heads are cnc ported.
Also I will get ls9 gaskets or cometic depending on piston to valve clearance.

bridgeport13b

Btw when you say pin the crank do you mean pin the crank and harmonic balancer? if so I am getting a key way put on the crank.

Evo_Joe

Read this: (C5 but same logic applies)
https://www.corvetteforum.com/forums...t-the-kit.html

To me the two weakest components on our cars are the clutch hydraulics and the harmonic balancer.
If you pull the steering rack at any point for whatever reason, then swap the harmonic balancer and pin the crank.
As far as the clutch hydraulics go, just make sure you follow the Ranger Protocol/Method and if it goes down pray it's just the Clutch Master Cylinder and that it's still covered under 'Special Coverage 14717' Create an account and then check active warranty to see your expiration mileage/date
https://my.chevrolet.com/warranty
https://www.corvetteforum.com/forums...al-issues.html
http://www.rangeracceleration.com/Clutch_Care.html


I have an LS3 and this is what I run:
(I called ATI & Summit and talked thru my build/didn't want 10% UD)
ATI 917266
ARP 2342503
Continental Elite 4040410
Continental Elite 4060798

Katech_Zach

There is no Katech/Hinson C5-R timing chain. There is only the Katech C5-R timing chain.

Evo_Joe

Right you are, sorry for the confusion.

I know I bought mine from BTR, which I'm assuming isn't one of the knockoffs.

Just out of curiosity, I see Lingenfelter and Hinson sell them listed as C5R timing chains for around the same price, albeit with no reference to Katech, are those not the same?

Katech_Zach

The C5-R chain is exclusive to Katech and GM Racing. Lingenfelter and BTR are Katech dealers who carry our chain.

CI GS

I got mine from Vengeance Racing with my cam kit.
Do you manufacture those yourself, or does GM make them to your specs?

Katech_Zach

IWIS makes them for Katech and GM Racing.