Re: P51 guys

supervel45 January 19th 2014, 10:04 pm

I have heard that some of the Pro's say 2 heads can flow the same numbers on the flow bench, but on the Dyno, on the same shortblock, one will out perform the other, as far as peak HP numbers, due to port velocity. Aplication and actual HP numbers, would seem to be a consideration also, when chosing. The definition of better is relative.

richter69 January 19th 2014, 10:09 pm

Flow bench nationals...

hey Tony are these heads like your old Doves? The ones that had the intake ports totally removed and secrions of pipe jamed in there?

rmcomprandy January 19th 2014, 10:12 pm

supervel45 wrote:I have heard that some of the Pro's say 2 heads can flow the same numbers on the flow bench, but on the Dyno, on the same shortblock, one will out perform the other, as far as peak HP numbers, due to port velocity. Aplication and actual HP numbers, would seem to be a consideration also, when chosing. The definition of better is relative.

THAT is definitely true ... it is a very dangerous thing to try and race air flow numbers as it only tells about PART of the total package.

supervel45 January 19th 2014, 10:18 pm

I think it may have been Sonny Lennard, and maybe few other bigdog's that mentioned the point, about the flow numbers. Peak HP dyno numbers are not always foolproof either, but in a full out race motor are a nice guage.

LivermoreDave January 19th 2014, 10:23 pm

I listened to Richard Maskin's answer to an air flow question, he replied " air flow should be your least concern, it's simply the result of a well designed port". David Reher sitting next to Maskin nodding his head with approval!

Just sayin,
Dave.

yellowhorse7 January 19th 2014, 10:23 pm

richter69 wrote:Flow bench nationals...

hey Tony are these heads like your old Doves? The ones that had the intake ports totally removed and secrions of pipe jamed in there?

Wouldn't have it any other way. Big Tig and lotsa filler

Funny story. There was a set of BES A heads that were on a very successful x275 car. Set numerous records and still holds a few. He swore up and down that they were just really well ported A heads. Long story short, the valve covers came off and low and behold the only thing left that was A Head was the exterior casting. Amazing what a CNC can do to a block of aluminum. BES claims to know nothing of it. But the radial tire world sure does.

Nothing really to do with 51 heads though

yellowhorse7 January 19th 2014, 10:24 pm

supervel45 wrote:I think it may have been Sonny Lennard, and maybe few other bigdog's that mentioned the point, about the flow numbers. Peak HP dyno numbers are not always foolproof either, but in a full out race motor are a nice guage.

X2.

ET WINS RACES!

whitefield January 19th 2014, 10:29 pm

Just a stupid thought or question !

Doesn't bore size and stroke along with cam have an effect on head flow as well as air speed ?

supervel45 January 19th 2014, 10:34 pm

Yes Sir. And it's all about the Combination, of the total package, sitting behind the green light when it drops.

whitefield January 19th 2014, 10:41 pm

supervel45 wrote:Yes Sir. And it's all about the Combination, of the total package, sitting behind the green light when it drops.

So then flow bench numbers and dyno numbers are just tuning tools !

Compression , headers and intake would change the flow numbers too ?

yellowhorse7 January 19th 2014, 10:45 pm

whitefield wrote:
supervel45 wrote:Yes Sir. And it's all about the Combination, of the total package, sitting behind the green light when it drops.

So then flow bench numbers and dyno numbers are just tuning tools !

Compression , headers and intake would change the flow numbers too ?

Weeny swinging tools I love you

supervel45 January 19th 2014, 10:55 pm

That is not what I am saying. Other varable's play a part in a cylinder head choice, like you mentioned on bore and stroke. I meant that dyno number's are "actual verifiable numbers" on one sample engine, with the "actual heads" that you are useing. The E/T is the final goal, with the whole combination (Vechicle engine, trans chasis, ect. . It's seem's like the torque/horsepower debate, which one wins races, is what this is coming to. That was not my intention.

whitefield January 19th 2014, 10:57 pm

yellowhorse7 wrote:
whitefield wrote:
supervel45 wrote:Yes Sir. And it's all about the Combination, of the total package, sitting behind the green light when it drops.

So then flow bench numbers and dyno numbers are just tuning tools !

Compression , headers and intake would change the flow numbers too ?

Weeny swinging tools

That's funny ! lol!

supervel45 January 19th 2014, 10:59 pm

What was this thread about again? Suspect

whitefield January 19th 2014, 11:03 pm

supervel45 wrote:That is not what I am saying. Other varable's play a part in a cylinder head choice, like you mentioned on bore and stroke. I meant that dyno number's are "actual verifiable numbers" on one sample engine, with the "actual heads" that you are useing. The E/T is the final goal, with the whole combination (Vechicle engine, trans chasis, ect. . It's seem's like the torque/horsepower debate, which one wins races, is what this is coming to. That was not my intention.

I understand and agree with what your saying!

I am just posting my thoughts and asking some questions that some want explained and are afraid to ask!

Lem Evans January 19th 2014, 11:39 pm

LivermoreDave wrote:I listened to Richard Maskin's answer to an air flow question, he replied " air flow should be your least concern, it's simply the result of a well designed port". David Reher sitting next to Maskin nodding his head with approval!

Just sayin,
Dave.

I've heard this deal several times but, what is much over looked is that these guys have designed ports that the SCJ/P51/C460/etc castings don't have room for.

supervel45 January 19th 2014, 11:56 pm

IDT-572 wrote:
yellowhorse7 wrote:Sad to see that all everyone got out of this is a perception that P51's are weak. No one ever said that. In fact, the whole point of the discussion was ignored and really never answered. EXACTLY HOW MUCH BETTER, AND WHERE, ARE THEY BETTER THAN SCJ's. Blake and John are examples of people making them work. Yes they will pick up but not enough to substantiate an "upgrade".

My opinion is from my hands on experience is, out of the box there is a huge difference in performance between the two heads. For someone wanting to just change heads on a 750 hp SCJ with no other mods to his engine, this would be a very worth while up grade.

Now, looking at fully ported casting to fully ported castings stepping up a valve size in both castings, there is going to be around a 50 to a 70 hp increase going to the P-51.s.

Keep in mind you may have a rule deal holding you to the SCJ casting. You can sell the SCJ's and recover most of the cost of the P-51's. It is a personal choice how much you want to spend to pick up 50-70 hp.

I have seen several 900-950 hp P-51 builds that are easy to duplicate. and also several easy to build 1000-1050 hp A head builds. People step up to the A head engines for 100 hp increase all the time and have to buy intake, pistons, headers, ect. for not much more power but a good bit more coin.

Its all a personal choice. Also one could look at it in another aspect. They could be stepping up from a stock type head and are buying pistons and bypass the TFS Streets SCJ's and all the others and go straight to the Kasse's.

I don't understand why this is such a big deal............. it's all a progression to better heads for us. It hasn't been that long ago we didn't even have an aluminum head.

And running mid fives 50-70 hp is a little over a tenth of a second. 150 hp is worth less than 3 tenths. it takes a good bit of hp to go a little bit faster at that E.T.

This Covers alot of Ground and Brings up good Points. After re-reading the Whole Thread this post stood out to me as to what I was trying to Convey.

LivermoreDave January 20th 2014, 12:51 am

Lem Evans wrote:I've heard this deal several times but, what is much over looked is that these guys have designed ports that the SCJ/P51/C460/etc castings don't have room for.

As Maskin stated of air flow and good, better or best designs for a given cylinder head and it's related port, the port design and construction have improved from the D0OE-R to the A429 to the SCJ and onto the P-51. A better path was found through similar architecture, therefore a better functioning cylinder head. The flow improvement was simply a by-product.

Dave.

IDT-572 January 20th 2014, 9:15 am

It just gets to a point to where you can only get so much air through a low port entrance head. Hard to keep the air on the short turn when it enters below it and exits below it. Air is making a big turn for a long distance.

LivermoreDave January 20th 2014, 2:22 pm

IDT-572 wrote:It just gets to a point to where you can only get so much air through a low port entrance head. Hard to keep the air on the short turn when it enters below it and exits below it. Air is making a big turn for a long distance.

I agree Blake, as with the OEM architecture of the heads this thread discusses and their limitation. When the design of a specific cylinder head in regard to it's intended application no longer provides positive results, one should move to the next level of design in which their application will allow. We all know we can't install a C headed engine into a unmodified 1967 through 1970 Mustang engine compartment and have hopes of installing headers .... don't we?

Dave.

5pointslow January 20th 2014, 3:08 pm

if anyone has any P51 heads that they dont like for whatever reason i can Pm you my adress and will gladley under achieve with them ..lol

Razz

dfree383 January 20th 2014, 5:59 pm

richter69 wrote:Flow bench nationals...

hey Tony are these heads like your old Doves? The ones that had the intake ports totally removed and secrions of pipe jamed in there?

Those crazy grudge racers will do anything to say they have stock heads. Laughing

fordmanmatt January 20th 2014, 8:39 pm

Me too

5pointslow wrote:if anyone has any P51 heads that they dont like for whatever reason i can Pm you my adress and will gladley under achieve with them ..lol

Gary Blair January 21st 2014, 11:02 am

rmcomprandy wrote:
supervel45 wrote:I have heard that some of the Pro's say 2 heads can flow the same numbers on the flow bench, but on the Dyno, on the same shortblock, one will out perform the other, as far as peak HP numbers, due to port velocity. Aplication and actual HP numbers, would seem to be a consideration also, when chosing. The definition of better is relative.

THAT is definitely true ... it is a very dangerous thing to try and race air flow numbers as it only tells about PART of the total package.

Amen

KY JELLY January 21st 2014, 11:13 am

fordmanmatt wrote:Me too

5pointslow wrote:if anyone has any P51 heads that they dont like for whatever reason i can Pm you my adress and will gladley under achieve with them ..lol

Are you jokers saying p51 s run better than they should ? Naw couldnt be we dont have any examples of them doing it without nos or 10" tires lol.

Sponsored content