KsMySS

iTrader: (10)

I've noticed a trend that most of the heavy hitter are switching over to square port (LS7/LS3) style heads over cathedral. Is there any reason for this? Does one have a large advantage over the other?

Brian Tooley Racing

iTrader: (13)

I say smaller valves for turbo's with higher back pressure (1.5:1 or more exhaust to intake), bigger valves for turbo's with less back pressure (ideally 1:1)

Fireball

iTrader: (21)

I'm staying cathedral for next year...

Shawn @ VA Speed

iTrader: (3)

they flow more air which equals more power at lower boost levels.

Lythropus

iTrader: (13)

I can't really see an upside to square ports or a downside to cathedral ports...

Brian Tooley Racing

iTrader: (13)

The fastest hydraulic roller cammed turbo setup had TFS 245 cathedral heads, Mark Koehler running 7.30's @ 192.

One of his Ohio Boys teamates ran about the same times with All Pro square port heads and a solid roller cam.

The three most important things to making anything fast is combination, combination and combination.

Well, there may be a forth thing, COMBINATION!

427

iTrader: (3)

Both cylinder head types work well when boosted. Most times the cylinder head is made much bigger than it needs to be because cylinder heads designed for racing are normally designed around moving the most air in and out of NA engines. Valve size and placement in a turbo engine are different than the NA stuff, but all will produce great power if the head gaskets stay sealed!

Kurt

Jimbo1367

Brian,
So what exactly are you tring to say?


LOL

lt1773

iTrader: (1)

ls3,l92,ls9,ls7 will not stay at level and will cause water push or lifting ,i mean at high boost .I have a set of l92 heads and i switched to Eledrbrock 245cc ported by Wcch

98Z28CobraKiller

iTrader: (17)

Seems that finding a head that delivers sufficient flow to make the power hasn't really been an issue. The issues have more to do with sealing the deck to the heads and the mains moving around.

Mr.Big

Just got some 265 ETP cathedral port heads setup for a solid roller, I believe I'm going solid roller rather than converting these beautiful heads to hydraulic... something different to try, though we won't spin much past 7750...

Shawn @ VA Speed

iTrader: (3)

no you're right making power isn't an issue. We made 1800 with some old ETP 225's. but the better the head flows the easier is it to make power-no matter what anybody says.

head gasket sealing isn't an issue either,even though alot of people seem to have issues. 1800 hp on 4 bolt heads and well over 2000 with 6 bolt with no gasket issues.We actually break the blocks first.

The mains have been an issue in the past, but we've figures out that problem as well.

If we can get some blocks that will hold the power we will be good to go. Hopefully the RHS will handle some power. We'll see shortly.

Fb0dy0nly

iTrader: (10)

Soon everyone making big boy power will be running a billet block...

Seems like the only safe block to run at super high hp levels AND that doesn't cost a few organs is an RHS.

Whats the next thing to let go then after you have the heads, mains, and block at the "best" it could potentially be with what technology is available?

99 Blue Bird

iTrader: (3)

So whats the conclusion? That it does not matter what head you have, they both work great? And whatever combo you go with they will work no better than the other if both head designs are properly matched with a good combo?

427

iTrader: (3)

If you are running 1800hp plus (200mph) in the drag type car the head needs to seal well and be durable. The better it flows the easier it will be to make the power, but most times budget dictates the cylinder heads. We have seen a few sets of canted heads used with no conclusive results, but they will need time to figure out what they want before we see the full potential. Right now in the high power stuff I work with, most of our effort has been durability and consistant performance. Most of my customers are looking to win races rather than set records, that requires many consistant runs that are hopefully fast also!!

Kurt

bullish

bump
was wondering if anything has changed in the last couple years now that more people are running square ports

NemeSS

iTrader: (127)

combo depends on end goal or budget.
either one gets it done, jy build or aftermarket block and heads.
gotta figure out how much you want to drop, usually results how fasr u go.
i have set of lsa heads. that i believe will hold my 800rwhp.goal.reliably.
but current build has been reliable for many years w 317 cathedrals.
rectangle ports are alot more common now and outflow any cathedrals stock to stock as is. i would prolly have to push my engine harder by using stock 317 over the lsa.
its all relative.
im leaning alot more to rectangle ports now.

SMOKNSS

iTrader: (3)

I have always ran cathedral ports in the past and have always been impressed by them but this time around I am going to try the square ports and see what I can do.