[Tom Cowle's wife]

What kind of flow figures are you guys seeing out of a set of ported stock LS1 heads?

Secondly: What kind of HP are you seeing out of these heads? 620ish? or more?

Thanks
Tom Cowle

 

[LTLHOMER]

Depends on the casting...true stock ls1 heads (241 castings) can get over 300 cfm while the ls6 and truck castings (same port design between the ls6 and truck stuff but slightly different combustion chambers I believe?) can go even better.

Check ETHEads.com and see their flow numbers. They are one of the few companies that doesn't put up bs flow numbers just to attract attention. They are the best for the ls1 stuff from what I've seen. Best with most stuff actually.

I would imagine you could see at least 600 to the crank n/a with a stock worked over ls1 head...but would depend on cubes, compression, yadda yadda.

 

[STENOD]

Tom-

The stock castings can go a long way once you start getting into porting them and changin the valve size. I've seen some ZO6 heads (Casting number 243) flow around 330 @ 650 or so. 500rwhp is not too far off with a cylinder head guy that knows how to manipulate the ports and such. Seems like just a good simple three angle valve job works wonders to a stock head and valves too. The biggest change in a stock car is getting the stock camshaft out of it and replacing it with something way more aggresive. There are guys with LS-1 running mid-low 10's with just a camshaft change and getting some weight out of the car.

When I get back in the shop in the morning i'll post some of the ET cylinder head flow numbers they gave us. Pretty stout from what were seing. Seems like the really payed attention to the mid numbers and not just the high flow numbers.

if your wanting to make SILLY horsepower, talk to the guys at ET Cylinder heads like LTLHOMER said. They have been making HUGE headway with LS1 design. I know they have thier own custom castings as well as many many CNC designs for stock casting. They brought a head over to our shop the other day that looked really neat, It was one of their new 225 castings. Flow numbers in the mid 300 area with just a mild CNC job. I guess there estimating flow number higher than that if some seriuos time is spent on them.

I think there is going to be a lot of sweet aftermarket cylinder heads coming out for these motors soon, I know were a little excited seeing that it's sort of our motor of choice.

Stenod

 

[DERTY]

Also to kick it up a notch, another local shop built a bigger displacement LSx motor for a guy down south. It made north of 800 HP NA and put a car into the 8's on motor. That's a beginners look at how much power the setup can put out. It's a crazy motor to work with coming from the factory.

 

[LTLHOMER]

Also to kick it up a notch, another local shop built a bigger displacement LSx motor for a guy down south. It made north of 800 HP NA and put a car into the 8's on motor. That's a beginners look at how much power the setup can put out. It's a crazy motor to work with coming from the factory.

South as in Illinois? lol

 

[DERTY]

Oh yeah, lol. I was also thinking of the SAM car at the same time.