zrc3john

As the title states,which heads are better? ( loaded question I know)....Recently had a convo with a hot rod enthusiast....He feels the iron heads from some of the SBC motors back in the day will out perform the aluminum heads today .....

He feels that a lot just can't duplicate what once was a better design in the first place....

Any thoughts?

resdoggie

Imo, there is no comparison. Today's heads are superior, period!

HeadsU.P.

Tell your friend to put down the pipe. He has smoked enough.

Camel heads and even Vortec are old school. Sooooooo much better stuff out there now. ALUMINUM;
Weight savings.
Run more Ign timing.
Run more compression
Run cooler
Bigger Valves
Better Flow
Better / bigger springs
Better guides
Better porting
Better chamber design.
And on & on & on.

zrc3john

Figured as much....In today's world technology just has to keep moving forward....Just figured I would put this out there.....👍

gkull

change one item above. Modern fast burn chambers use less degrees of timing advance

cv67

with all the above, some just cant let go of the "old days".
Even comparing cfm is just the tip of the iceberg...get a set of trick flow double humps a can of spray paint, done.

jim2527

L98 aluminum 113's outperform old camel humps. No comparison.

Kacyc3

The only way you can convince those kind of people is to convince them to take their car to the track and race similar equipped cars or a dyno day.

PainfullySlow

Even then I doubt you would get a convert. It has been my experience that people like this rarely let silly things like facts or data analysis get in the way of their opinion.

OP: Back when these cars were built, a 'badass' SBC was pushing 450HP, these days anyone can get 500 out of a very mild build. The vast majority of the improvements in power came from better flowing modern heads.

71 Vert LS1

I agree the new/modern heads will make more power no doubt. But if you are building a new engine the aluminum heads will allow you to run higher compression on pump gas. Also depending on the heads moving the valve placement like Trick Flow. I have used AFR with great results. There are other lower priced heads out there.

Alwyn678

I like my 041 heads

The13Bats

Just lately i took a crash course in bb chevy heads,

I learned a lot and learned that yeah, some will hold on to something maybe out of sentiment,

What i found was really cool was in the day rectangle port heads were a must have for a hot rod bb,

Now with a zillion dyno reports to prove it rectangle ports were good for wide open racers , sucked on the street, even though some guys still swear by them and insist they are a great street head,

But even cooler some modern oval port aftermarket aluminum heads do better than the old rectangle ports, a best of both words i guess,

Dont get mad at me, go cuss out the dynos....

My budget keep me in old iron

Big2Bird

Set of rebuilt BBC heads laying in my garage you can roll golf ***** down the ports.

roscobbc

One only needs to look at some of the very best race spec' heads (heads that are way too radical for street use) and what design of inlet ports to they have? - Oval of course! Even the simplest logic should tell a 'doubter' that flow of liquid, vapour or gas must flow better through a cross sectional area that is as close to circular as possible - anything less than that will hurt flow) The problem once you have as good an inlet flow as possible is that the exhaust flow then becomes the issue............

derekderek

So what shape are the ports in the LS motors?

L88Plus

^ the only shape they could use that fit between the pushrods and provide decent flow.

The cathedral top provided clearance close to the injector. They're superior in part due to the fact that air has a straighter shot at the back of the valve without making such a huge turn down into the cylinder. Of course, a 12 to 15 degree valve angle helps a bit . Some of the better LS7 type heads now have rounded corners, just like a lot of big block heads today that call themselves "oval" but are nothing more than rectangular ports with rounded corners.

cv67

if someone took a traditional set of heads and a cathedral with equal cfm # the cathedral headed car will still be faster. Tech sure has come a long way!
Remember those days, a 12 sec street car was something to brag about, many a 13 sec car was trailered to the track.

Those cars were still fun but dont dare try and run anything on the st with them today youll get smoked.

The13Bats

A rounded rectangle is an oval....

stingr69

Or an Obround.

427Hotrod

Here's my "oval ports"!!

No such thing as a head that's too big...just a case of an engine that's too small!

Aftermarket is usually better...but it depends. You can make outstanding power with a set of GM iron oval port or rectangular ports. They just need to be bolted on the right shortblock and ported/cammed for what they will be doing.

GOOD aftermarket heads just make it easier...a LOT easier. It's been said that most of your power is made within 1" on either side of the valve...and that's true. Getting the mixture into the cylinder and burning it efficiently is what it's all about.

Some aftermarket heads don't really flow that great and use old design chambers etc...so not as much improvement as you would expect. So on a small cube engine, old design ones might move enough air for 'X" power...but as cubes and RPM go up..air demand does also.

JIM