High Rpm Pump gas 456ci P51 combo..advice please

Hi All..

A good friend of mine is planning a new build for his True street/strip car..
He prefers rev's over "brutal torque" so he doesn't want a real big inch engine, will be using a 429 steel truck crank, Thanks to Paul Kane..

With the current 434ci 10 to 1 pump gas, crane F246 solid, cleaned up A429 heads + 200 NOS.. it has gone 10.72 at 131
Ultimately he would like to be at real low 10's and hopefully one day run a high 9..with the new P51 456ci + 300hp of NOS combo..

3950lbs with him in it.
3.590 x 4.500 bore.. 456ci
4.11 rear gears.
28x 10.5 tyres.
C6.. 3800 stall now, 4500+ converter what ever it needs for new combo..
2.5" exhaust with the old ford racing XR-1 turbo racing mufflers.
4 into 1 tuned length pipes 2" primary 34" long 3.5" collector.
A460 block
Stock complete P51"s heads to suit solid roller..  
Custom solid roller cam purchased from one of the cam experts on this forum.
fully ported Wilson victor 4150..
w&w shaft rockers.
C&S Aerosol billet carb 900cfm wet flow, supposedly flows over 1000cfm.
4.500 bore around 11 to 1 comp pistons .. to run on 93-94 octane.  

He would like to make (if possible) 650-700 HP between 7200 to 7400rpm and shift around 7500 to 7700rpm.
250 shot of Nos..

Things that worry me the Exhaust, and possibly The Victor Manifold.. would it need some "Radical reworking" and or a Domi Base to make power up that high ?

any (Advice or opinions) on the "Good Bad and the Ugly" of this combo it would be greatly appreciated..

is he trying to go slow deliberately?

He can easily make a whole bunch more power and make it last longer adding the inches

Haha.. Dave I understand your point of view totally..

But one of my friends biggest concerns is having the brutal torque of a 550ci plus cubic inch engine.. wreak havoc on a mint survivor body. it has been stitch welded and has sub frame connectors though.

https://www.429-460.com/t24380-429-steel-truck-crankshaft

Don't know if he got his crank yet but, here is an idea if he did not. I am Old School like you buddy also and like to keep engines under 500' inch's myself. Also considering one of these cranks also, so my short block stays all Ford.

nascar429 wrote:Haha.. Dave I understand your point of view totally..

But one of my friends biggest concerns is having the brutal torque of a 550ci plus cubic inch engine.. wreak havoc on a mint survivor body. it has been stitch welded and has sub frame connectors though.

It's all in the convertor and gearing

nascar429 wrote:Haha.. Dave I understand your point of view totally..

But one of my friends biggest concerns is having the brutal torque of a 550ci plus cubic inch engine.. wreak havoc on a mint survivor body. it has been stitch welded and has sub frame connectors though.

Na, HP and RPM never wreak Havoc on anything.LoL

Nothing wrong with big bore short stroke ! RPM , good parts and a good maintenance program . Get a 429 truck crank and have it machined back to the 3.85 stroke

dfree383 wrote:

nascar429 wrote:Haha.. Dave I understand your point of view totally..

But one of my friends biggest concerns is having the brutal torque of a 550ci plus cubic inch engine.. wreak havoc on a mint survivor body. it has been stitch welded and has sub frame connectors though.

It's all in the convertor and gearing

Dave.. do you mean in the context of more aggressive gearing and converter..ie: 4.33, 5000rpm converter possibly not loading the chaassis as much ? Am i correct in that thinking maybe i'm wrong..

dfree383 wrote:

nascar429 wrote:Haha.. Dave I understand your point of view totally..

But one of my friends biggest concerns is having the brutal torque of a 550ci plus cubic inch engine.. wreak havoc on a mint survivor body. it has been stitch welded and has sub frame connectors though.

It's all in the convertor and gearing

YEP ... personally, I certainly would not call an engine with 3,400  stall speed in a 3,900 pound vehicle ... a "High Revving" situation..

Randy.

yes good point.. it's far from ideal at the moment.. I know he would change his converter to optimize the combo.. it's a must do in my opinion
.

Tighter convertor, less gear and big ass engine.

More street able and lasts a lot longer.

Let it eat

I agree with some of your points Dave.. I had a pump gas 562ci in a similar car, with 3.7 gears..3500 converter great combo..

I'm going to talk with him some more even if he went 4.150 stroke and bored it out... to get rid of 15lbs of bore weight that would be a bonus..lol

nascar429 wrote:I agree Dave.. I had a pump gas 562ci in a similar car, with 3.7 gears..3500 converter great combo..

I'm going to work on him some more even if he went 4.150 stroke bored it out to 4.560 for around 543ci and get rid of 15lbs of bore weight a bonus..lol

If he's spending the money on a good crank no sense wasting it on a 4.15...... Go 4.5 or 4.75 or stay on the porch.

whitefield wrote:Nothing wrong with big bore short stroke ! RPM , good parts and a good maintenance program . Get a 429 truck crank and have it machined back to the 3.85 stroke

This is the way to go if you want to stay closer to 460. This crank will handle anything you are talking about. I had Adney do one of these for my pulling truck and it is now about 9 years old and still going strong. Buzzed 8400-9000 every time we pulled.

You say HIGH rpm, what exactly are you considering high rpm...? The Victor may very possible may not be the best manifold. Not enough runner entry Cross section for the 500 incher at higher rpm. A Trick Flow mafia would be better suited. Depending on RPM desired valvetrain may have limitations. The P51 intake valves are pretty heavy.

Sooo....

Sorry, just went and re read.... 7200-7400 peak on a 501 will merit a Mafia manifold, and would be borderline high for theose heavy intake valves. That all depends on cam and valvetrain....

I do have a pump gas 572" P-51 engine for sale

Dave is that your engine masters entry?..

I'll let my BBF friend's know.. do you have it advertised so I can show them the link?

We shift our X275 big blocks at 8300-8400 and don't really consider them that high reving. Everything looks great year after year and we do not have bearing, ring or spring issues. I guess that's what you have to do with 584 ci with heads that flow 525 cfm at 1.00".



As far as this build, let him build anything he wants. If everyone had the same engine it would be boring out there.

3900+ lbs??...what type of car?? Big Torino??..Galaxie??..Thunderbird??

similar to a 70 Torino.. Yes 3950lbs with him in it..

https://www.429-460.com/t24380-429-steel-truck-crankshaft

I would offset grind one these, maybe have it lightened also
, get a good four bolt block, factory or FRPP, good rods with light forged pistons, a big cam mechanical flat tapped or mechanical roller, a ported Victor intake, or maybe a Mafia, a Holley Dominator, Crower SS rockers and a stud girdle and be pretty content.

Currently 429ci+200Nos 10.72@131 full street trim.

Any leads on a 68 Faclon XT GT grill (dual Light) PM if you know of one.

bbcoupe wrote:Currently 429ci+250Nos 10.72@131 full street trim.

With a forged crank a good four bolt block, he can double the nitrous and up the Rpms a little and the ET

's will drop quite a bit. Nice ride by the way.

supervel45 wrote:https://www.429-460.com/t24380-429-steel-truck-crankshaft

I would offset grind one these, maybe have it lightened also
, get a good four bolt block, factory or FRPP, good rods with light forged pistons, a big cam mechanical flat tapped or mechanical roller, a ported Victor intake, or maybe a Mafia, a Holley Dominator, Crower SS rockers and a stud girdle and be pretty content.

Some good points.. he has found a factory steel 429 crank..(Thanks to Paul Kane).. and plans to leave it stock stroke, A460 block 4.500 bore, 6.605 Carrillo rods and lightened pistons when ordered.
WW shaft rockers, crower bushed lifters, custom solid roller, roughly around 260 270-ish Intake @ .050" 700-750 lift max.. (it is at dual purpose street/strip car) so can't go to nuts..

Has a Wilson ported Victor 4150..also looking into converting to Dominator, has a Domi Mafia to possibly try as well on the dyno.. new stall converter will be around 4500-5000..

Yes it is small cubes but will see High rpm 7500+ ..what did the Old Hotrodders do 40 years ago before stroker Cranks were easily available..