Hemi vs. Wedge Shootout:

Jon Kaase settles one of the most fiercely debated topics of all time with the ultimate dyno test.

http://www.hotrod.com/how-to/engine/1602-hemi-vs-wedge-shootout-jon-kaase-settles-one-of-the-most-fiercely-debated-topics-all-time-with-ultimate-dyno-test/

There was a glitch in the dyno or something was jacked up in the fuel curve of the carb on the P51 package.

It made 805 @ 6,400 RPM
Dropped to 781 @ 6,600 RPM
Jumped back to 801 @ 6,700 RPM

Peaking at 6,400 on a 521" with a 273* @ .050" intake lobe is quitting early in my opinion......6,700 would be more like it.

Wonder if this will finally shut the guys with happy flow benches up

yellowhorse7 wrote:Wonder if this will finally shut the guys with happy flow benches up

Nothing ever shuts people up

yellowhorse7 wrote:Wonder if this will finally shut the guys with happy flow benches up

Tell me who are these guys? I can't offer an opinion w/o knowing who you are speaking of.

Lem Evans wrote:

yellowhorse7 wrote:Wonder if this will finally shut the guys with happy flow benches up

Tell me who are these guys? I can't offer an opinion w/o knowing who you are speaking of.

Just people in general. We see the argument over and over and over and over.....

"My (insert heads here) flow better than (the other head goes here) and make more power on the dyno." How many "discussions" have we had here or on the internet in general about this subject? That's why I laugh when I see things like the cylinder head pecking order at the top of the page.

yellowhorse7 wrote:Wonder if this will finally shut the guys with happy flow benches up

Even those who have no flowbenches at all but, totally believe the propaganda that air flow AMOUNT is everything. .

yellowhorse7 wrote:

Lem Evans wrote:

yellowhorse7 wrote:Wonder if this will finally shut the guys with happy flow benches up

Tell me who are these guys? I can't offer an opinion w/o knowing who you are speaking of.

Just people in general. We see the argument over and over and over and over.....

"My (insert heads here) flow better than (the other head goes here) and make more power on the dyno." How many "discussions" have we had here  or on the internet in general about this subject? That's why I laugh when I see things like the cylinder head pecking order at the top of the page.

The "pecking order thing" ...I'm not finding it but I do known it was there.

That's an issue with 'sticky' deals .....a decade latter the info is just wrong.

Now that I have had time to read the whole of the mag. article ......the thing that hits me between the eyes is ..."out of the box Victor" which is a restrictor plate deal

Mafia would have brought them closer

The hemi chamber MAY be better for HORSEPOWER than a wedge but, THIS is not a good measure of all combustion chamber differences.
Valve sizes are completely different and each head was not optimized for what it needs. This was probably a decent comparison of the two particular heads presented however, that is as far as it goes.

Good magazine fodder, though.

A head with the same size valves, (like an A460 with an older Motorsport intake for about the same carb pad height), with closer valve angle to port angle and with camshafts optimized for each, given a certain RPM range, would have been a much better test; though still not really comparable simply because there is so much more involved in an engine for different venues than horsepower.

The outcome for horsepower may have very well been the same, (although a lot closer), if using a more comparable wedge head.

However, Kaase does not manufacture an A460 head so, I understand the test and take it for what it is worth.

rmcomprandy wrote:The hemi chamber MAY be better for HORSEPOWER than a wedge but, THIS is not a good measure of all combustion chamber differences.
Valve sizes are completely different and each head was not optimized for what it needs. This was probably a decent comparison of the two particular heads presented however, that is as far as it goes.

Good magazine fodder, though.

A head with the same size valves, (like an A460 with an older Motorsport intake for about the same carb pad height), with closer valve angle to port angle and with camshafts optimized for each, given a certain RPM range, would have been a much better test; though still not really comparable simply because there is so much more involved in an engine for different venues than horsepower.

The outcome for horsepower may have very well been the same, (although a lot closer), if using a more comparable wedge head.

However, Kaase does not manufacture an A460 head so, I understand the test and take it for what it is worth.

(The outcome for horsepower may have very well been the same, (although a lot closer), if using a more comparable wedge head.); quote


And then a better BOSS HEMI head could of been used as well

I think he has a back order on P51's and a supply of Hemi's. We're all smart enough to know that an equally matched test would produce equally matched results. However, I would love a late model mustang with a big Hemi in it.

BOSS 429 wrote:

rmcomprandy wrote:The hemi chamber MAY be better for HORSEPOWER than a wedge but, THIS is not a good measure of all combustion chamber differences.
Valve sizes are completely different and each head was not optimized for what it needs. This was probably a decent comparison of the two particular heads presented however, that is as far as it goes.

Good magazine fodder, though.

A head with the same size valves, (like an A460 with an older Motorsport intake for about the same carb pad height), with closer valve angle to port angle and with camshafts optimized for each, given a certain RPM range, would have been a much better test; though still not really comparable simply because there is so much more involved in an engine for different venues than horsepower.

The outcome for horsepower may have very well been the same, (although a lot closer), if using a more comparable wedge head.

However, Kaase does not manufacture an A460 head so, I understand the test and take it for what it is worth.

(The outcome for horsepower may have very well been the same, (although a lot closer), if using a more comparable wedge head.); quote


And then a better BOSS HEMI head could of been used as well

A better hemi head would not have made a good test for comparing combustion chamber / valve arrangement; the heads being most comparable would.

That was the point I was trying to make.

yellowhorse7 wrote:

Lem Evans wrote:

yellowhorse7 wrote:Wonder if this will finally shut the guys with happy flow benches up

Tell me who are these guys? I can't offer an opinion w/o knowing who you are speaking of.

Just people in general. We see the argument over and over and over and over.....

"My (insert heads here) flow better than (the other head goes here) and make more power on the dyno." How many "discussions" have we had here  or on the internet in general about this subject? That's why I laugh when I see things like the cylinder head pecking order at the top of the page.

Hemi vs Wedge isn't a fair comparison of flow......

And as far as flow bench numbers a 420 cfm wedge head will make more power than a 350 cfm head of the same type and valve location.

lol to this whole thread,


all Jon did was show the hemi as being better, and no one likes to hear that.

some cant handle the truth

rmcomprandy wrote:

BOSS 429 wrote:

rmcomprandy wrote:The hemi chamber MAY be better for HORSEPOWER than a wedge but, THIS is not a good measure of all combustion chamber differences.
Valve sizes are completely different and each head was not optimized for what it needs. This was probably a decent comparison of the two particular heads presented however, that is as far as it goes.

Good magazine fodder, though.

A head with the same size valves, (like an A460 with an older Motorsport intake for about the same carb pad height), with closer valve angle to port angle and with camshafts optimized for each, given a certain RPM range, would have been a much better test; though still not really comparable simply because there is so much more involved in an engine for different venues than horsepower.

The outcome for horsepower may have very well been the same, (although a lot closer), if using a more comparable wedge head.

However, Kaase does not manufacture an A460 head so, I understand the test and take it for what it is worth.

(The outcome for horsepower may have very well been the same, (although a lot closer), if using a more comparable wedge head.); quote


And then a better BOSS HEMI head could of been used as well

A better hemi head would not have made a good test for comparing combustion chamber / valve arrangement; the heads being most comparable would.

That was the point I was trying to make.

You said >more comparable wedge head, whats your idea of a more comparable wedge head then?

"lol to this whole thread"

Rich, It matters not to me that you are laughing at me but, I am amused that you can not see that the natural HP spread between was skewed by manifolding.  

While the BOSS cylinder head is the better architecture compared to a CJ style head with the  production low inlets and exits, it is my opinion that other things are not equal and the actual spread is not 109 HP.

I have already spoken to the un-ported Victor on the inlet side.

Please bother to look at the headers: The P51 engine had a very nice set of 4 into one black painted headers - the Boss engine headers were 4-2-1 merge coated [left over from engine masters testing I suspect] which puts a butt load of tq in an engine & don't seem to hurt the power either.

I'm sure Jon used the best stuff he had available......I'm just saying the 'stuff' for the P51 unit was not as highly developed.

The die hard followers of Super Chevy magazine can rest assured that only the BOSS 9 Fords are to be reckoned with.

no question the boss heads make more power, but from 4600 to almost 6000 rpm there is only about a 30hp difference .

BOSS 429 wrote:

rmcomprandy wrote:

A head with the same size valves, (like an A460 with an older Motorsport intake for about the same carb pad height), with having closer to the same valve angle to port angle and with camshafts optimized for each, given a certain RPM range, would have been a much better test

You said >more comparable wedge head,   whats your idea of a more comparable wedge head then?

Did you actually read the entire post you had previously quoted...?
It was all pretty much spelled out there.

The magazine article is telling readers that this is a "level playing field" test of the two TYPES of combustion chamber / valve placement criteria and it certainly is not. This test is NOT truth to that affect. It simply is a test between THOSE TWO heads. [/quote]

so, just to recap.....exhaust flow doesn't matter.....intake flow was similar....the head with significantly more exhaust flow made significantly more power.

Carl wrote:so, just to recap.....exhaust flow doesn't matter.....intake flow was similar....the head with significantly more exhaust flow made significantly more power.

The extra 17 or whatever flow on the intake is a big deal  at that performance level...in my opinion.

The talk about 'flow' is sometimes a diversion.... which head had the biggest valves?  Biggest issue would be on the intake side.....but......the 1.76" P51 aint gonna get any help from the 7* intake/exh split cam that was in that deal.

A lesser exh. with a decent  shape can be camed to....and it aint 7*.

Lem Evans wrote:"lol to this whole thread"

Rich, It matters not to me that you are laughing at me but, I am amused that you can not see that the natural HP spread between was skewed by manifolding.  

While the BOSS cylinder head is the better architecture compared to a CJ style head with the  production low inlets and exits, it is my opinion that other things are not equal and the actual spread is not 109 HP.

I have already spoken to the un-ported Victor on the inlet side.

Please bother to look at the headers: The P51 engine had a very nice set of 4 into one black painted headers - the Boss engine headers were 4-2-1 merge coated [left over from engine masters testing I suspect] which puts a butt load of tq in an engine & don't seem to hurt the power either.

I'm sure Jon used the best stuff he had available......I'm just saying the 'stuff' for the P51 unit was not as highly developed.

LOLing at you ? No LOL at all the boards where people are making excuses about this test .

rmcomprandy wrote:

BOSS 429 wrote:

rmcomprandy wrote:

A head with the same size valves, (like an A460 with an older Motorsport intake for about the same carb pad height), with having closer to the same valve angle to port angle and with camshafts optimized for each, given a certain RPM range, would have been a much better test

You said >more comparable wedge head,   whats your idea of a more comparable wedge head then?

Did you actually read the entire post you had previously quoted...?
It was all pretty much spelled out there.

The magazine article is telling readers that this is a "level playing field" test of the two TYPES of combustion chamber / valve placement criteria and it certainly is not. This test is NOT truth to that affect. It simply is a test between THOSE TWO heads.

[/quote]









You said >more comparable wedge head, whats your idea of a more comparable wedge head then?[/quote]

/\ this is what I asked, incase you missed it?