2 jet boat stroker builds and suggestions

I've got 2 460 powered jet boats ,
One is a 77 18" Challenger  the other is a 78 18.5 foot omega open bow .
The omega was a jacuzzi,  but has an AT energizer now with A impeller
The Challenger has a berk jc with a bronze A impeller and loader .

I was thinking I wanted to do motors in both and started my parts collection.
I'm thinking since the Omega is a bit more family or recreation oriented with its open bow I want a strong motor that will do 5500-5600 rpm on its pump i.e. approx 575-600 hp at 5600- 5700 rpm .
The Challenger I'm wanting a bit more. Something that will run it 6000-6100 rpm  i.e. 675-700hp at that 6000-6100rpm mark.

Prefer both motors to be pump gas friendly and the omega wet headers, the Challenger may be wet or dry .

I have 3 blocks 1 d1 and 2 d9 blocks , the d1 is .040 over now  
Parts gathered so far are:
1 set of AFR 280 bullitt heads sprung solid roller. 75cc
1 set of Eddy rpm heads 6067 75cc, some extra porting .unsprung.
1 scat 4.3 cast crank
1 set 6.8 scat hbeams
1 set of wiseco 4.440 flat tops -6cc 1.350 ch  , probably won't use.  To much compression but came with the rods.
3 cams.
A) lunati voodoo solid roller 267/273  237/243@.050 .650/.666  106lc 110ls .018 lash
B) lunati  solid street roller  278/286 242/249@.050 .642/.642 106lc 112ls  .02/.022 lash
C) comp hydr roller 307/324 251/260 596/612  110ls  custom grind. 3538 thumper intake lobe and there slw 20535 ex lobe.
1set of howards max effort hyd rollers.
One set of insky 9965 tool rm springs with 10° ti retainers
1 stealth intake
1 offy single carb tunnel ram
1 Eddy torker 2 intake
1 750 holley marine
1 850 demon
2 msd pro billet dizzy's

I have about 4k more to spend , and still need one rotating assembly  4.3 or 4.5 stroke ??  Solid roller lifters , rockers pushrods and timing sets.

Still trying to find 1 lunati  20340712 voodoo hyd roller, 231/239@.050.  .611  110lc  or howards 243385-10 very similar.

Between what I have how would you combo the parts to make the above 2 motors and what changes would you make and why ,  

Let em fly , good or bad let's hear it.
Thanks.

"Maintenance" should be your biggest concern.
So, choose parts accordingly.

rmcomprandy wrote:"Maintenance" should be your biggest concern.
So, choose parts accordingly.

Since I'm a Millwright/maintenance Tech and mechanic/fabricator by trade I have no problem with running some occasional valve lashes or pulling an intake to inspect rollers, I gues my maintenance considerations would be more on the Omega lower hp build as that's the boat most likely to be sold in the future and that's kinda the plan for a hyd roller application,  really think the lunati 20340712 cam that I'm not finding anywhere would be a good match for that projected rpm but it also depends on what displacement that motor is built at I would think ?

Strokedbronco wrote:

rmcomprandy wrote:"Maintenance" should be your biggest concern.
So, choose parts accordingly.

Since I'm a Millwright/maintenance Tech and mechanic/fabricator by trade I have no problem with running some occasional valve lashes or pulling an intake to inspect rollers, I gues my maintenance considerations would be more on the Omega lower hp build as that's the boat most likely to be sold in the future and that's kinda the plan for a hyd roller application,  really think the lunati 20340712 cam that I'm not finding anywhere would be a good match for that projected rpm but it also depends on what displacement that motor is built at I would think ?

Here's that Horward's Camshaft you are after. Competitions Products is a Howards Dealer and the other Howards camshafts I have checked on, on the phone were in stock as their webpage showed.

https://www.competitionproducts.com/Howards-Cams-Retro-Fit-Hydraulic-Roller-Camshaft-Ford-BB-429-460/productinfo/HRC243385-10/

You might also check with Paul Kane at High Flow Dynamics who is a member here that is big on Jet Boats and see what he thinks and what he may have in stock

Strokedbronco wrote:I've got 2 460 powered jet boats ,
One is a 77 18" Challenger  the other is a 78 18.5 foot omega open bow .
The omega was a jacuzzi,  but has an AT energizer now with A impeller
The Challenger has a berk jc with a bronze A impeller and loader .

I was thinking I wanted to do motors in both and started my parts collection.
I'm thinking since the Omega is a bit more family or recreation oriented with its open bow I want a strong motor that will do 5500-5600 rpm on its pump i.e. approx 575-600 hp at 5600- 5700 rpm .
The Challenger I'm wanting a bit more. Something that will run it 6000-6100 rpm  i.e. 675-700hp at that 6000-6100rpm mark.

Prefer both motors to be pump gas friendly and the omega wet headers, the Challenger may be wet or dry .

I have 3 blocks 1 d1 and 2 d9 blocks , the d1 is .040 over now  
Parts gathered so far are:
1 set of AFR 280 bullitt heads sprung solid roller. 75cc
1 set of Eddy rpm heads 6067 75cc, some extra porting .unsprung.
1 scat 4.3 cast crank
1 set 6.8 scat hbeams
1 set of wiseco 4.440 flat tops -6cc 1.350 ch  , probably won't use.  To much compression but came with the rods.
3 cams.
A) lunati voodoo solid roller 267/273  237/243@.050 .650/.666  106lc 110ls .018 lash
B) lunati  solid street roller  278/286 242/249@.050 .642/.642 106lc 112ls  .02/.022 lash
C) comp hydr roller 307/324 251/260 596/612  110ls  custom grind. 3538 thumper intake lobe and there slw 20535 ex lobe.
1set of howards max effort hyd rollers.
One set of insky 9965 tool rm springs with 10° ti retainers
1 stealth intake
1 offy single carb tunnel ram
1 Eddy torker 2 intake
1 750 holley marine
1 850 demon
2 msd pro billet dizzy's

I have about 4k more to spend , and still need one rotating assembly  4.3 or 4.5 stroke ??  Solid roller lifters , rockers pushrods and timing sets.

Still trying to find 1 lunati  20340712 voodoo hyd roller, 231/239@.050.  .611  110lc  or howards 243385-10 very similar.

Between what I have how would you combo the parts to make the above 2 motors and what changes would you make and why ,  

Let em fly , good or bad let's hear it.
Thanks.

On a 720HP @ 6,100 RPM  521CID 10/1 Compression (May have been 9.7/1 if he had 39cc pistons) this is likely how much camshaft you will need with good P-51 heads and a TFS Mafia intake.

AFR heads showed great Dyno numbers and Flow numbers when they came out, I alway's take some of that advertising stuff with a grain of salt though.

https://www.429-460.com/t28022-521-with-holley-sniper-4500

Just threw it in there if you had not seen it. CompCams 34-715-9 Solid Roller is the cam it had. It's also on a 108LSA. It's quite a bit bigger then the ones you listed. 268/276 at .050" .727"/.727"

There have been test's that showed 700 HP with SVO SCJ heads and a CompCams XR292 Solid Roller in a 514 Crate Engine, (I think they had 9.8/1 compression). That Cam is also bigger then the big solid roller you listed, XR 292 spec.'s are 254/260 110 with around .675-.678" lift.

I would stick with the 4.3" crankshaft to keep the wear down myself.

@supervel45
And in the same token motortrend did a 502inch afr 280cc headed dyno with a 239/251 .625/.668 roller that peaked at 650@6100 and carried over 640 to 6400 , I realize we're talking adding another 25 inches to the motor , but a boat impeller is literally like a dyno in the sense if the motor won't make more power at a given rpm it's not going to continue to rpm the impeller any higher, an American Turbine A cut impeller takes roughly 670hp@6000 rpm if the motor pks at 6000 at say 650 but at 6200 it's 670 your not getting that impeller to 6k,  2ways to do it , overbuild the hp at the rpm you want to have actual pk hp at , or build it then trim the impeller to get the motor to it's pk hp rpm . And thus why I'm here , trying to decide or learn if I've got enough cam with the afr heads to get me to my goal of near 700 at 6k on 521-532 inches  and also if the rpm heads can get me near 600 at 5600 or so with say the smaller roller I have at that same 521-532 inch of motor.??

And that's where I was thinking that lunati or howards hydr roller may fit well , 5600rpm at 525ish inches with the Eddy heads and the stealth intake , and be a bit more maintenance  friendly as Randy politely referred to lol.

I do feel or have seen the use of a tunnel ram raise the pk hp rpm by 2-300, over a single plane high rise like the afr or Victor intakes utilizing the same cam  and fortunately in a jet boat we have no hood clearance issues to worry about lol.
I spoke to my machinist who has recently done another bbf afr headed build where they used the victor rather then the afr intake and he said the port mismatch really wasn't that bad, and didn't take much to blend there transitions i.e. square up the viictor port some and oval out the afr intake port a bit. They did not dyno that motor so who really knows how bad if at all it hurt potential output.

And in total reality, I'm not going to be butt hurt or disappointed if say whatever build in either boat misses the rpm goals by a hundred or so, there's other ways to gain the speed difference then just hp lol.