[slowbird]

Anyone know of any actually testing of the old chamber vs new cnc chambers? I keep seeing it posted that they are way better. Are they? How do we know that? Lots of things are good/better in theory.
One big down side i see to the new chambers are the seats are small so you can't run big valves in them like the older heads unless you install bigger seats.

[PAUL K]

The new chamber is definitely not "way better" at making power than the old chamber.

[steve25]

The smaller seats are less apt to run too hot and distort in the middle of the chamber, no less burn out that beak of chamber floor between the valves.

I have seen many Aluminum heads pulled down after just one full season of racing where you could not get the seat of each valve to lap in at the junction of the Intake and Exh seats even though the rest of the seat contact point looked great.

[Steve C.]

Heart Shape Combustion Chamber Dyno Test

http://www.sdperformance.com/newsStory.php?newsID=41

[Skip Fix]

You would almost have to do a head swap on the dyno same induction, same shortblock, same CNC porting to tell.

[slowbird]

Originally Posted by Steve C.

Heart Shape Combustion Chamber Dyno Test

http://www.sdperformance.com/newsStory.php?newsID=41

I can believe the less timing and maybe 10hp more. But i doubt there is much more than that imo

[slowbird]

Originally Posted by steve25

The smaller seats are less apt to run too hot and distort in the middle of the chamber, no less burn out that beak of chamber floor between the valves.

I have seen many Aluminum heads pulled down after just one full season of racing where you could not get the seat of each valve to lap in at the junction of the Intake and Exh seats even though the rest of the seat contact point looked great.

A 2.19 valve is ok for some but bigger engines with bigger bores need more valve. So what would you rather have a 535 with a 2.19 valve and new chamber or old chamber and 2.25-2.28 valve?

[mgarblik]

Originally Posted by Skip Fix

You would almost have to do a head swap on the dyno same induction, same shortblock, same CNC porting to tell.

That would be the way to get the absolute reliable results the OP was asking for. The best I can do is relate that the heart shape chambers I have run on our dyno have showed the best tolerance for low grade fuel vs other chamber shapes in in Chevy, Mopar Wedge and Pontiac applications. Especially good at light/medium load with vacuum advance, and some centrifugal advance in play. I have some doubts as to any benefit at high RPM, maximum load... Seems the hemi chamber is damn good under those conditions. FYI, hemi chamber is just terrible at low loads, low RPM. Two plugs are absolutely necessary as well as small squish and quench pads or they would never meet current emission standards. Heart chamber has allot of nice mixture motion without the turbulence of say a vortech head. The wet flow bench showed us that pretty clearly.

[Dragncar]

From what I hear the new Eddy heads with LS chambers require less timing than the High Ports with their heart shaped chambers. Even more efficient.
These new E heads forte could be pump gas builds.

[slowbird]

Originally Posted by Dragncar

From what I hear the new Eddy heads with LS chambers require less timing than the High Ports with their heart shaped chambers. Even more efficient.
These new E heads forte could be pump gas builds.

Where did you hear the chambers take less timing than hp heads? Pump gas kre heads are 28-30. Im having a hard time seeing it being less.

[charlie66]

Its better because the plug location changed. Its now 5/8" closer to the exhaust valve..

[slowbird]

Originally Posted by charlie66

Its better because the plug location changed. Its now 5/8" closer to the exhaust valve..

How much better?
Not arguing that's it's better'ish but how much? 10 20 30hp?

[PAUL K]

We've had several builds and a few swaps from old style to new style chambers and noticed very little.... Just like with any other heart shaped chamber. I'm sure it helps with emissions and they do require less timing. Back around 2002 we made a CNC program that we originally designed for the Butler's Engine Masters build to heart shape the chamber and bring the CC's down. We did quite a few sets of heads and would get the chamber size down to 58cc. It was great for power because you could get decent compression with a flat top piston and not have to mill the heads a lot. But comparing the original chamber to the new one I think you might see as much as ten horse power but that'd be on the high side, IMO.

[charlie66]

Originally Posted by slowbird

How much better?
Not arguing that's it's better'ish but how much? 10 20 30hp?

I couldnt say hp wise. I will know when it goes back on the dyno .

I say better because my plugs burn/look better. Motor definitely runs better.

Also needs less boost racing the same guys . I know im going to get crap about my reasons but im saying it anyway... I actually did go from the old E head to this new one .. And this one was out of the box stock where my other one was ported to 325cfm..

[slowbird]

Originally Posted by charlie66

I couldnt say hp wise. I will know when it goes back on the dyno .

I say better because my plugs burn/look better. Motor definitely runs better.

Also needs less boost racing the same guys . I know im going to get crap about my reasons but im saying it anyway... I actually did go from the old E head to this new one .. And this one was out of the box stock where my other one was ported to 325cfm..

Any other changes? Cam, compression, windage control, pistons and/or ring pack

[charlie66]

Originally Posted by slowbird

Any other changes? Cam, compression, windage control, pistons and/or ring pack

Its kind of a long story but in short, The new head has a smaller chamber and at first being its boosted it was making alot more power per pound of boost . So i put a 24 cc dish piston in and its back to the same cranking pressure . It does still feel faster but at this point i have no proof other then racing my friends . Cams the same . No windage. Rings are the same..

[Dragncar]

Originally Posted by slowbird

Where did you hear the chambers take less timing than hp heads? Pump gas kre heads are 28-30. Im having a hard time seeing it being less.

I am going to find out where High Ports on pump gas like the timing set at. But kicking it up from 10.80 to 11.24 CR. Its looking like I will dyno the thing after all.

[lust4speed]

The new Edelbrock heads do require less timing than their old heads and that has nothing to do with what Kaufman heads like. My old 349 CFM Edelbrocks preferred 41° on the dyno and the few newer heads I've seen tested preferred 34°.

[slowbird]

Originally Posted by lust4speed

The new Edelbrock heads do require less timing than their old heads and that has nothing to do with what Kaufman heads like. My old 349 CFM Edelbrocks preferred 41° on the dyno and the few newer heads I've seen tested preferred 34°.

That's a pretty big difference. What compression was run with the 349cfm heads?

[PAUL K]

Originally Posted by Bill Eveland

My highports took 28 total.

Thanks Bill good info...

That reminds me of a story my next door neighbors boyfriend told me, that his uncle told him, who by the way was neighbors with Tom Molnar and gave his three legged dog biscuits occasionally. He owns a dyno and was somewhat in the know because he was neighbors with Tom who was in the know because he was a heavy hitter in the rod industry. This was back when Tom was with Oliver and my next door neighbors boyfriend's uncle who owns a dyno still lived in Michigan. Anyways he said that air/fuel ratio will effect timing. So you should get the A/F close, then hunt for timing. After you find the best timing go after the A/F again and double check the timing is correct. After the dyno session both should be checked again in the car because it may change.