Launch

This car is funny, how do the square port haters explain this one..
https://ls1tech.com/forums/carburete...l#post13221158

There's more stock L92 head n/a sbe cars too, that have done similar, it's not just that one above.

bortous

Oh no.
I hate cathedral heads now.
More than what I did before.

Tuskyz28

01CamaroSSTx

iTrader: (3)

And even more gains on a 427 when you move up to LS7 style heads...

Bill00Formula

iTrader: (4)

My car was a 427 w/ tfs 235s w/ a 92 mm fast until it had issues, may have been having issues for a while (LS7 block). Ran it from 2009-2018. Most of it's life it had 4.10s and I was using 28 inch DR tires. I used some of the parts to build another 427 using a dart ls next block (non skirted). It has AI ported LS7 heads and a Race Proven Motorsports B-3 cam.The intake is a mamo ported MSD. It will be interesting to see how the two compare.at the track. Same car, same driver same track. Car has a 6 speed. I may rev it a little higher but not much. Race weight was around 3670 so it will be around 125 pounds heavier. It's really a street car but I really only use it at the track. I'll probably have it back together in a couple of months. It now has my sbe turbo motor (6.0 iron w/ LS3 heads). I am having issues tuning it with the large injectors.

Che70velle

iTrader: (6)

The LME guy must be lying. No way a ls3 head makes more torque than a cathedral. It’s all fake news. You can see his lips weren’t moving with what he was saying...someone dubbed it.
But then again, after I figured out what an LS3 head wants with camshaft and a couple other tricks, I believe him. The last LS3 engine I built, I did for torque and it’s a pulling machine in a big heavy 4x4 ext cab silveraydo. Hopefully you guys can sense the sarcasm of the first part of what I just wrote. I wouldn’t put cathedrals on anything unless a client insists on it. But to each their own...

lumen8

More efficient head = more cylinder fill, at lower RPM, all else being equal.

If you wind the short motor higher, cathedrals will pull more air in compared to themselves at lower rpm.

I think some of the ideas people have about cathedrals vs square ports at lower rpm is actually the other way around.

Just my 2c.

JRFed

I need to start documenting our test and share it here if allowed. For the record the cathedral head has a purpose they will make power and they do bad *** for caveman technology (Being funny) but time after time we have seen similar results on our dyno sessions and our F110 265cc Cat head did give us a surprise when testing it vs other ports just not as good as a square/Rec head.

ddnspider

iTrader: (26)

CoD and rect port talk..

bortous

Seen that video.
It's a good explanation.
There is also another one with an LS 468 comparing 245cc AFR heads vs MAST Large bore LS3 heads and the MAST LS3 heads win of course but only by 20hp.
If the AFR had the same rocker ratio the result would have been even closer.
They did very good for an engine size that they were never designed for.
If a Mamo version of this head was used it may have been neck and neck.

jhshnh

CoD as Richard explains in this video is what’s important. It’s called math and physics, not personal bias.
An engine doesn’t look at its port shape and decide whether or not it’s going to perform... regardless of what some people think. Mamo’s latest 347 proves this with 1.85 hp per c/i.
I guess I don’t understand why some of us on here roll our noses at other’s builds because they don’t use your choice of heads. I thought the purpose of this site was to share information and learn.

bortous

Not only the head and efficiency, but also the total combination plays a a big part in the final result too as evidenced with Mamo's latest post.
His LS7 packages are even more impressive reaching 700rwhp in some cases through a plastic manifold.

rkupon1

iTrader: (3)

More is still more,...20hp more is still alot when your already full tilt and on the hunt. Finding any hp gains NA after a certain point just gets harder and harder, and more expensive.

ddnspider

iTrader: (26)

It's really just each persons taste and use case. 20hp is alot, but when motors are making 5/6/700hp, some are willing to sacrifice 20hp to gain part throttle torque and off idle response.

jhshnh

Did anyone else notice in this video the dyno graph for the AFR 245s said Fast 78?

ez2cdave

Okay, let's talk about my next project . . . 1989 Camaro / 4L85E / 12-Bolt . . . Cam Undecided, Heads Undecided, Torque Converter Undecided ( want Lock-Up ), Gears Undecided.

Engine : 427 Stroker / Dart LS Next SHP Short Block ( Flat-Top pistons -12cc ) . . . Dynamic Compression Ratio 8.5:1, for 91 Octane Pump Gas ( 9:1 for 93 Octane )

https://ls1tech.com/forums/generatio...ification.html

Goals :

( 1 ) Smooth Idle, High Vacuum at Idle, Broad Torque Band . . . ( Fuel Economy, if possible )

( 2 ) Maximum 6000 - 6500 RPM.

( 3 ) Durability / Longevity - Daily-Driver . . . Some Drag Strip.

( 4 ) Camshaft - .595" Max lift ( easier on valvetrain ) . . . Zero or Negative Overlap. Cam Specs - To be determined

( 5 ) Cylinder Heads - Undecided whether Cathedral Port or Square-Port . . . Same for Intake Manifold.

( 6 ) Exhaust will be Headers, High-Flow cats, Crossover, Walker / Dynomax Super Turbo Muffler, Part # 17739 ( I want it "QUIET" ).

So, CATHEDRAL or SQUARE PORT heads & what INTAKE MANIFOLD ?

Thanks !

Corona

Rpm and Cam lift says Cathedral port.
MSD or FAST.

Tuskyz28

Like Corona said RPM says cathedrals with fast intake but your bore is begging for LS7 heads. I would go LS7 heads and a LS7 intake and turn the motor 7000 RPM.

ddnspider

iTrader: (26)

You may be disappointed with how quiet that muffler is. I have a 17744 and it's not as quiet as I wanted.

bortous

I agree with Smokey.
Cathedrals is what you are looking for.
It will give you what you want and be super responsive everywhere.