Any idea on rpm/hp #s?

Im building a new motor. Its a 515 CI, 4.615 bore X 3.85 Stroke. Compression is 14.5-1, A460 block, billet crank, aluminum 6.800 rods, diamond pistons, 0.043 ring pkg. Target bob weight around 1940g range....
Heads are the TFS A-460's (older ones) 2.400 & 1.900 titanium valves, and older TFS intake......both are getting fully ported (470+ range).
Cam that I will be "trying" is a 286-301 @ 0.050, 825/780 lift, 112CL.
I will have room to run up to a 2" spacer. Carb will be what ever is neccessary.


Any ideas on rpm/power?

feetfirst wrote:Any ideas on rpm/power?

7200/945

feetfirst wrote:Im building a new motor. Its a 515 CI, 4.615 bore X 3.85 Stroke. Compression is 14.5-1, A460 block, billet crank, aluminum 6.800 rods, diamond pistons, 0.043 ring pkg. Target bob weight around 1940g range....
Heads are the TFS A-460's (older ones) 2.400 & 1.900 titanium valves, and older TFS intake......both are getting fully ported (470+ range).
Cam that I will be "trying" is a 286-301 @ 0.050, 825/780 lift, 112CL.
I will have room to run up to a 2" spacer. Carb will be what ever is neccessary.


Any ideas on rpm/power?

Tunnel ram ? one carb or two ?

feetfirst wrote:and older TFS intake......

I'm guessing one carb!

IDT-572 wrote:

Tunnel ram ? one carb or two ?

No, single "low" TFS intake.

Curt wrote:

feetfirst wrote:and older TFS intake......

I'm guessing one carb!

Your probably right , But I thought maybe he was running the old Holmes tunnel ram.

feetfirst wrote:

IDT-572 wrote:

Tunnel ram ? one carb or two ?

No, single "low" TFS intake.

1071hp @ 7500 rpm. Hows at grab ya.....................

And by all means, if someone feels there are serious gains to be had by changing something, feel free to add to the cause. I know the cam is a little weak, just not sure on the gains that are possible with a swap.....or the maintenance that goes with it...

IDT-572 wrote:1071hp @ 7100 rpm. Hows at grab ya.....................

Are you serious???

feetfirst wrote:And by all means, if someone feels there are serious gains to be had by changing something, feel free to add to the cause. I know the cam is a little weak, just not sure on the gains that are possible with a swap.....or the maintenance that goes with it...

I think a litle more split would help between the intake and exhaust. But at 14:1 you may be close enough.

you get you a glide yet feet??????

feetfirst wrote:

IDT-572 wrote:1071hp @ 7100 rpm. Hows at grab ya.....................

Are you serious???

With that short of a stroke, I probably missed the rpm peak. It's going to be a good bit higher probably around 7500 if the intake will let it.

With 470 cfm It's gonna make big hp, if your intake don't kill it. It needs ported to complement your heads.

Big bore short stroke........... good combo for hp.

Jon, I have a trick ATI cased deal....also going to a 29.5 x 10.5 tire....

IDT-572 wrote:

feetfirst wrote:

IDT-572 wrote:1071hp @ 7100 rpm. Hows at grab ya.....................

Are you serious???

With that short of a stroke, I probably missed the rpm peak. It's going to be a good bit higher probably around 7500 if the intake will let it.

With 470 cfm It's gonna make big hp, if your intake don't kill it. It needs ported to complement your heads.

Big bore short stroke........... good combo for hp.

Holy hell.........
I was gearing the build to go 8500 or so thru the traps.....this is going to be very interesting..
Everything listed, I have already.

The intake is getting fully ported as well...

With that short of a stroke I would guess the HP peak 7500-7700 and 975 hp.

guessing...935hp@7500....735tq@6000 Should be bad

feetfirst wrote:Jon, I have a trick ATI cased deal....also going to a 29.5 x 10.5 tire....

IDT-572 wrote:

feetfirst wrote:

IDT-572 wrote:1071hp @ 7100 rpm. Hows at grab ya.....................

Are you serious???

With that short of a stroke, I probably missed the rpm peak. It's going to be a good bit higher probably around 7500 if the intake will let it.

With 470 cfm It's gonna make big hp, if your intake don't kill it. It needs ported to complement your heads.

Big bore short stroke........... good combo for hp.

Holy hell.........
I was gearing the build to go 8500 or so thru the traps.....this is going to be very interesting..
Everything listed, I have already.

The intake is getting fully ported as well...

I think you will need a tunnel ram to get the rpm that high. I have one you can borrow to dyno with if you want it.............

IDT-572 wrote:

feetfirst wrote:

Holy hell.........
I was gearing the build to go 8500 or so thru the traps.....this is going to be very interesting..
Everything listed, I have already.

The intake is getting fully ported as well...

I think you will need a tunnel ram to get the rpm that high. I have one you can borrow to dyno with if you want it.............

No,no.......the lower the rpm the better!! Easier on parts.. Plus its a 100 lb hit for dual carbs....... I personally guessed 8000 peak power or so, but it sounds like its too high, which is great!!!

An engine is a air pump. It will take a certain amount of rpm to work the heads to their full potential . What about a tunnel and one carb?

IDT-572 wrote:An engine is a air pump. It will take a certain amount of rpm to work the heads to their full potential . What about a tunnel and one carb?

Yes, a cast deal is fine..........just not sure on the extra hood height needed? I'm getting away with a 3.5" cowl hood having room for at least 2" for spacers if neccessary with the low TFS intake.

What would be an approximate power difference?

I would think a good bit over that old A intake. The runners are angled shallow and so is the plenum. Also, talking to Lem last night he said the cross section was small also. but if they ported it correctly the cross section may be bigger now.