.060 over 460, Power to 5,800 rpm: What intake manifold ?

So if you were building a 10:1 472" and wanted to make power to 5,800 for a jet boat what intake would you use.

Lets assume it's an 850 Holley carb and the engine will spend most of it's time pulling a tube, wake board and water skiers at 2,800 to 3,200 rpm but the owner wants to go run with the boys at the end of the day.

What intake....... RPM Air Gap, Victor Jr, Blue Thunder dual plane, Performer or other?

At the 3,000 rpm heavy load part throttle running I wonder how much better a dual plane would be?


Edit: I guess I should have stated Edlebrock heads, or very well ported Dove heads.

G-

Jon

Edelbrock RPM IMO, The BT would probably work well too.

For more power than the dual planes at and above 5,000 rpm and more guts than a Victor in the middle......Torker II.

Lem Evans wrote:For more power than the dual planes at and above 5,000 rpm and more guts than a Victor in the middle......Torker II.

I think I've seen RM state that before....maybe the best over-all compromise. Some dyno testing and water testing would be interesting.

g-

Why the RPM for me is the "most of the time at 2900-3200" lugging skiers up out of the water.

Dave...it does not take much power to turn a jet pump 3,000 rpm. The dual plane stuff will help where help is not really needed.

OK I' guess I'm thinking like the boat has a prop.

Lem Evans wrote:Dave...it does not take much power to turn a jet pump 3,000 rpm. The dual plane stuff will help where help is not really needed.

I was thinking better idle quality and if the part throttle running would be smoother with the dual plane. It sure doesn't take much power to turn an impeller at the lower rpm range, but beyond 5,200 the curve gets steep.





G-

Idle will be more about the cam than the intake manifold. The guy wants 5,800 at the top......he better be packing some cam and a single plane intake manifold. A smallish impeller will let the engine run higher but not the deal [i.m.o.] for tubes and boards.

A few years ago we tested this on a customer's 454 Chevy jet boat engine. It was a simple build with mildly ported oval port heads, Comp street roller cam, moderate compression etc. Anyway in our testing it made 509 horsepower at about 5300rpm. We tested the engine using a Weiand Stealth intake as well as a Strip Dominator from the swap meet. We were testing from 3000-5500rpm and there was NO place that the dual plane was better than the single plane for torque and horsepower. Idle quality differences were non existent so we went with the single plane. He ran that engine in the boat for about 4 years before selling it to build a larger engine and it always ran great.

Sounds like the dyno testing has been done

Lem Evans wrote:Sounds like the dyno testing has been done

Hey now he said " 454 Chevy"

I'm not going to the bank on that and he used a Stealth not an RPM Air Gap. I wonder if anyone has ever modified the base or an air gap for a dommy? Was it Ford Power Parts or Blue Thunder that had a big breathing dual plane with a dommy base ?

I'd sure like the opportunity to play with one.

G

both of them have them.

I've got a BT CJ one.

G-Code wrote:

Lem Evans wrote:Sounds like the dyno testing has been done

Hey now he said " 454 Chevy"

I'm not going to the bank on that and he used a Stealth not an RPM Air Gap. I wonder if anyone has ever modified the base or an air gap for a dommy? Was it Ford Power Parts or Blue Thunder that had a big breathing dual plane with a dommy base ?

I'd sure like the opportunity to play with one.

G

I have used a Stealth with a 2 inch open adaptor to a dommi with good results on engines like you described. If hood clearance permits. (very tall) .

But I feel Lem has answered you question correctly.................

So, what impeller is this guy gonna turn 5,800 rpm?

Lem Evans wrote:So, what impeller is this guy gonna turn 5,800 rpm?

"A" impeller is a tad over 600 at 5,800. Problem is that's 600 observed, for the insurance of being able to achieve his goal I'm suggesting a 512" stroker so he has power in reserve. He can do it with a 472" but he wants very mild, but he's going to need some heads either way. He can always trim the impeller to an A/B if need be.

Way way back in '89-90 my first roller cam engine was a 472" with Dove-C heads and a Ford Power parts dual plane with a 150 shot of Nos 10:1 compression pump gas deal and it turned an "A" just short of 6,000.
The cam it that engine was by Danny Crower 250/254 @ .050 .640 lift on a 108 lobe sep. Wow what a difference from the Comp 280H cam. Seemed like a different engine.

G-

Dear G- ,
I ask what time it was...not how to build a watch

600 hp to turn "A" impeller 5,800.

G-

It's time to get real.....dual plane manifold...A...impeller....3.85" stroke..wants 5800 rpm...

It's interesting what you can do with the right collection of parts. And it certainley takes the right cam.

I guess you should have read the long post I mentioned a 512" and I mentioned that he might have to turn the impeller to an A/B if he doesn't do the stroker. I mentioned my 472" turned a bit under 6,000, but I think it was 5,800 and 6,200 - 6,300 on the nos. Yes a dual plane..Ford Power Parts. How real do you need me to get ?

G-

dfree383 wrote:both of them have them.

I've got a BT CJ one.

I wonder how those large volume dual planes do against the RPM air gap. The Torker II sounds like a good compromise though



G-

Lem Evans wrote:It's time to get real.....dual plane manifold...A...impeller....3.85" stroke..wants 5800 rpm...

Lem, you know better than to get involved in matters of inefficiency! ..... .....

Dave.

LivermoreDave wrote:

Lem Evans wrote:It's time to get real.....dual plane manifold...A...impeller....3.85" stroke..wants 5800 rpm...

Lem, you know better than to get involved in matters of inefficiency! ..... .....

Dave.

Since the owner is hell bent on not exceeding 10:1 compression, yet wants as "much as he can get out of it" but wants to keep a tight budget (I'm sure you all know the type) I think I have him convinced to do a 508" (4.42 x 4.14 ) with a mild roller cam. He has to review his budget for a set of heads, so we'll see.

I just might have to do a 472" with a dual plane some time just to see what it's worth at 5,800.

G-