1970camaroRS

iTrader: (8)

Despite the fact that Iron Vortec heads flow almost as well(if not better) than stock ls1 heads?

SMOKIN01TA

iTrader: (10)

the ls1 heads (241's)are one of the best flowing head gm ever put out up to that time. not the vortec. vortecs are know to flow alot worse over time also.
not to mention the intake flows good and stays cool unlike the normal sbc.
better research led do matching parts better to achive max performance.

1970camaroRS

iTrader: (8)

I've just been looking purely at the CFM numbers. They're pretty close. Especially at the lower lifts. Do LS1 heads have better swirl/tumble...or what? Flow on the intake is only 11cfm different at .500, above that, well yeah LS1 is the winner of course. Below .400 Vortecs outflow ls1s. I realize the I/E is about 70-74% on Ls1s and only 62-66% on Vortecs meaning the LS1 trounces the Vortecs in exhaust port flow.

Is it more than just that? LS1s can run cams with a lot more lift for a give durration as compared to a street roller SBC. My cam for my Vortec headed SBC is 218/224@.050 and .495/.503 lift. In comparrison a Comp Cam LS1 cam with 222/224@.050 has .558/.563 lift. Is THAT the bigger difference. Having more lift for a given durration?

jrp

iTrader: (16)

the GEN 3 engine prior to the ls2 was the pinicle in small block engeneering.

read this:

http://www.idavette.net/hib/ls1c.html

jrp

iTrader: (16)

http://ourworld.cs.com/jrpws6/heads+...ckheadflow.jpg

SMOKIN01TA

iTrader: (10)

ok, so i should say the best instead of one of the best. ill go delete those two words.

jrp

iTrader: (16)

i posted the link for the

Brandon Boomhauer

iTrader: (10)

never seen the head comparo before, thanks for the link jrp

1970camaroRS

iTrader: (8)

Now I realize I didn't finnish my thought. I meant that in low and mid lifts Vortecs flow better. That's really important since the valve is open much longer at mid lift than at peak. I guess though that you move what is considered "mid lift" up when you're dealing with LS1s. I consider Mid lift for a vortec head to be .250-.350. With an LS1 maybe I should consider .350-.450 as mid lifts?

jRaskell

iTrader: (1)

Flow isn't the only factor that goes into how much power a set of heads will make. Combustion chamber design is another, but the flow to port ratio is also a not so commonly appreciated factor. Another way of looking at it is the more ambiguous intake charge velocity. Keeping the velocity of the air flowing through the engine high is good for power. I don't know the intake and exhaust port volumes of the LS1 or vortec heads, but I wouldn't be surprised if the vortec heads had larger port volumes. If flow numbers are fairly similar between two sets of heads, the one that gets those numbers with the smaller port volumes will make more power, all else being relatively equal (but even keeping things relatively equal is tough to do).