Hemi head?

quote:

Originally posted by NC3x58:
Hemi head?

I was thinking early Hemi, but they don't have short runners.
Maybe FE ford?

Gen 3 Hemi heads on your steamer ! Impressive numbers, IMO.

quote:

Originally posted by KWig:
Gen 3 Hemi heads on your steamer ! Impressive numbers, IMO.

Go get your chicken dinner!

quote:

Originally posted by "The Bender":
As we all know, flow numbers aren't everything, but they are meaningful. That being said look at these and let's discuss them. I'm not saying what head it is or who built it and tested them. I will say these are intended for a 390-430 ci in engine.

I .200 160 E 122
I .300 255 E 170
I .400 330 E 213
I .500 371 E 240
I .600 390 E 254
I .700 394 E 261

Gotta be the new brodix 21° heads

quote:

Originally posted by SP 124X:

quote:

Originally posted by "The Bender":
As we all know, flow numbers aren't everything, but they are meaningful. That being said look at these and let's discuss them. I'm not saying what head it is or who built it and tested them. I will say these are intended for a 390-430 ci in engine.

I .200 160 E 122
I .300 255 E 170
I .400 330 E 213
I .500 371 E 240
I .600 390 E 254
I .700 394 E 261

Gotta be the new brodix 21° heads

Nope, see above........

quote:

Originally posted by "The Bender":
Stock head CC for this engine are 190, the heads I gave the flow #'s for are 205 CC. So, not a bunch bigger, volume wise.......

Stock intake valve size 2.06, these heads have a 2.165 valve

Heads with better flow numbers will almost always perform better on the track, unless the original heads are too large already. In this case the original heads are stock heads and designed for a daily driver production car/engine with 50 less cu in than the engine these heads are going on, not to mention this engine will be a race engine with a higher RPM operating range than the stock engine.

Bender – following up, did you get the dialogue you were looking for? Seems to have been more of a “guess that head” than open thoughts on the test results.
I read that most of the general/technical points have already been discussed …without one very important fact; those things die hard well before .500, this area is the worst place for that to happen as most any performance cam will have good lift dwell numbers in that area.

If you are going even larger cubes, it will probably ET the best when shifted at 5K – lol. I don’t know that – just funning with the fact these things are obviously not geared around acceleration, they look to be more of a range operated design….just like an OEM head is intended for, imagine that.

The experience I have with the third gen you can stick on a pin head, although I have a family member who bracket races a stock third gen 5.7 R/T @ 4200 lbs (does have cold air, long tubes with full borla system and basic lap top tune) and we quickly came to realize, it doesn’t like or respond to RPM, it runs its best ETs when shifted around 5400. Keep us posted on the results if used as is.

Jerry, I think what you are seeing with the flow #'s I posted is that the low lift flow #'s are very good, therefore the higher lift #'s look like they are not good.

That being said, I compared my #'s with Brodix 18° SBC fully ported heads #'s, these are #'s right from Brodix. These gen3 Hemi heads are head and shoulders above the Brodix heads. At .300 lift they are 40cfm Intake and 20cfm better exhaust. At .400 they are 70cfm and 15cfm better, at .500 it's 70cfm and 15cfm, .600 60cfm and 23cfm. As you can see the exhaust side is a little weak compared to the intake, I took that into consideration when specing a cam. I also have a dyno test with these heads on a 426" engine with a very similar cam to what I'll be running, it made peak HP (755) at 7400.

The engine in the car now is the same cu in as the engine the new heads are going on, but has ported stock heads with smaller valves and it has a very mild cam that was designed for a daily driver EFI street car, it has no "cammy" idle whatsoever, at the track it likes to be shifted at 6200rpm for best ET. This engine is not EFI, but rather carbureted. It has run a best of 6.55@103 at 3200+ lbs, through the mufflers. The example you gave of the 5.7 that likes to be shifted at 5400 is not surprising given it has a stock cam, heads and low RPM designed intake manifold.

Even though some of the numbers are larger for the gen 3, they are better bunched with the brodix (check point deltas) which will almost always provide a better velocity. The hemi accelerated great at the lower lifts but dies faster as it progresses into the flow curve (I had to look up the 18º on the brodix site to see your reference). With them being flowed at similar bore sizes, I would fully expect to make more power with the brodix than the gen 3 where it matters most. Essentially you will always want good, progressive mid lift acceleration as that is where the valve spends most of its time when open, this is where the brodix will prevail.
If your pulling a trailer or looking for gas mileage, then the gen 3 would be the winner.

quote:

our goals should be stated but here's some info for you:

- They should support up to 725 to 775 HP (assumes all other parts are sized accordingly)
- the E/I ratio is about 65% so it will want more duration on the EX side for your cam.
- Port air speed is another key factor missing
- Your carb size is a good size for the 700HP range
-Can't comment on your target RPM until you

TOP38
All this knowledge and expertise and you can still only muster medium dragster ets

quote:

Originally posted by Jerry Kathe:

quote:

Originally posted by "The Bender":
Stock head CC for this engine are 190, the heads I gave the flow #'s for are 205 CC. So, not a bunch bigger, volume wise.......

Stock intake valve size 2.06, these heads have a 2.165 valve

Heads with better flow numbers will almost always perform better on the track, unless the original heads are too large already. In this case the original heads are stock heads and designed for a daily driver production car/engine with 50 less cu in than the engine these heads are going on, not to mention this engine will be a race engine with a higher RPM operating range than the stock engine.

Bender – following up, did you get the dialogue you were looking for? Seems to have been more of a “guess that head” than open thoughts on the test results.
I read that most of the general/technical points have already been discussed …without one very important fact; those things die hard well before .500, this area is the worst place for that to happen as most any performance cam will have good lift dwell numbers in that area.

If you are going even larger cubes, it will probably ET the best when shifted at 5K – lol. I don’t know that – just funning with the fact these things are obviously not geared around acceleration, they look to be more of a range operated design….just like an OEM head is intended for, imagine that.

The experience I have with the third gen you can stick on a pin head, although I have a family member who bracket races a stock third gen 5.7 R/T @ 4200 lbs (does have cold air, long tubes with full borla system and basic lap top tune) and we quickly came to realize, it doesn’t like or respond to RPM, it runs its best ETs when shifted around 5400. Keep us posted on the results if used as is.

Jerry

I wouldn't say that the flow number take a dive after .500 lift,,,, it's just running out of valve size, or a valve limited head vs a port limited head. The air flow per SQ inch of valve is good.

quote:

Originally posted by jenavet:

quote:

our goals should be stated but here's some info for you:

- They should support up to 725 to 775 HP (assumes all other parts are sized accordingly)
- the E/I ratio is about 65% so it will want more duration on the EX side for your cam.
- Port air speed is another key factor missing
- Your carb size is a good size for the 700HP range
-Can't comment on your target RPM until you

TOP38
All this knowledge and expertise and you can still only muster medium dragster ets

Mikey

You are always good for a laugh!

Hope you have a Merry Christmas!

I'll update this thread when I get to the track with this new combo, in a few months.

The proof is in the pudding......

Bender – [QUOTE] Proof is in the pudding [QUOTE] I think (and hope) you find some gain as obviously that’s your objective and if you found some CFM on the heads, and are more focused on combination compatibility, as maybe opposed to the bullet prior(?) then sure, some power gain and ET reductions of some amount should be achieved.

Top – [QUOTE] “I wouldn't say that the flow number take a dive after .500 lift” [QUOTE]….thats good because neither did I – lol, my concern was the stall beginning long prior to .500.

I would bet that if you lose the high speed miss that you will find some more ET.