What is the MAX. valve size (intake) that can be used with a stock bore LS1. I have been told that 2.05 is it and that 2.08 could cause some clearance issues with the Cylinder bore itself. I have an all stroke 396 and want to use the biggest valve so help me out here guys!!! The combustion chambers on the HEAD have already been clearanced for the larger valves so I am just concerned with the block side of this for now.

Thanks

 

Not much I can add...

2.02's are fine on a 346 but some run 2.05's

2.02 are a little small for a 382 stroker/Big bore

2.05 is good for a 382 stroker and Big Bore

2.08 big for a 346 or stroker, and good for a Big Bore or super stroker.

I'd rather have the 2.05's in the stroker probably have a little more P to V safety margin than 2.08's

 

88 Blackbird's answer is on the spot. You COULD run 2.08's, but they most likely won't work as well as 2.05's all around because of shrouding and velocity drop.

 

Keep in mind that you are stroking the motor, but you are not boring any. You would run into the same adverse effects of a big valve on a 346 cause you are not changing the bore size. A 2.08 would be to big and most likley send the air directly into the cylinder wall causing turbulence and a loss of HP. I would not go bigger than a 2.05 on the stock bore.

 

How much power are you making SR71BB?

I have a Lunati 395/396 as well and I have 2.02 valves.

Making 480ish hp right now. Anyone think that 2.055 valves will increase peak hp at all?

 

Kumar,
This motor is being assembled now as we speak so I don't have any power figures YET. Hoping for 500+ so that's the reason for the larger valves, more peak power. May have to also go with oval manifold or LSX manifold to get there. IF the heads will flow a LEGITIMATE 320-325 at peak then the 500+ will be possible.

BTW, Thanks guys for the replies, I think we will try the 2.05's.

 

2.08"/1.60" valves WILL fit in a stock bore. My heads were set up with large valve in prep for a future (now aproaching) big bore motor.

 

Thanks Chris. Just talked to Terry @ Patriot and he says that the 2.055 valve is maybe good for 3-4 CFM over the 2.02 valve but no more. The 2.08 valve on a stock bore while it will work would NOT offer any additional air flow with stock bore motor.