I am rebuilding the 454 for my Rogers Super Cyclone. The motor was origional and never apart before. Its a rectangular port 454 high performance casting block and heads. I don't want to go crazy on this one as I have a tendency too on motors and I don't want to be tuning and adjusting all the time out in the water. I have done some mild porting to the heads which are open chamber type. I am running headers, a Team G manifold, 850 Holler DP, and a recurved HEI. The jet is a Berkley that was rebuilt by Harmon Marine a couple of years ago with a B impellar. What would be a good camshaft for this combination? I am going to shoot for around 10.1 compression. When I first got the boat it had a cast iron two plane manifold and transom type exhaust. Motor was pretty tired as was the jet I later found out, but still mustered 62 mph on the river with GPS at 4200rpm. After adding headers, Team G manifold with 1 inch spacer and rebuilding the jet it got up to 4500 rpm. Never GPS checked it but I would guess that is a little better than 65. Don't know what these boats did fresh out of the factory but thought I would make some minor changes for improvements without going to crazy on $$$$ and reliability.

Thanks

Unless you're willing to step up to a hydraulic roller I would recommend this cam.  I'm using the same cam currently and was suprised how much it helped wake up the performance over the 280H that was in it.

http://www.google.com/url?sa=t&rct=j&q=cl11-240-4&source=web&cd=13&sqi=2&ved=0CGYQFjAM&url=http%3A%2F%2Fwww.compcams.com%2FTechnical%2FSearch%2FCamDetails.asp%3FPartNumber%3D11-240-4&ei=pp1TT-SrHoKqiALF8-S0Bg&usg=AFQjCNEI--YgA9VZFKSHFLoeOmFNlSJnxA&sig2=1FOWmLV8v8oJoN8b4g0flw

Have the same cam for White Trash....Has a killer idle "rumpidy rump" and runs hard all the way to 5,200 RPM.

I would strongly urge you to go hydraulic roller though....

GT

you can get 6000+ sure. Just depend on how you want or need everything to run. The jet and impellar will make a big impact on rpm too. Check out this http://www.jetboatperformance.biz/pages/Jetdrive_Impeller_calculator.html it might help you out. Oh and comp cams has full kits too since you are doing a rebuild. Here is a kit with the same cam http://www.ebay.com/itm/COMP-Cams-Xtreme-Marine-Cam-and-Lifter-Kit-K11-240-4-/330686188755?pt=Motors_Car_Truck_Parts_Accessories&hash=item4cfe6eccd3&vxp=mtr
Hope that helps 

Don't need to turn more than about 52-5500 RPM unless you are planning on spending a whole bunch of money on building a pump and have a stupid light hull....

GT

Well as I mentioned before its a Rogers Super Cyclone. Is that considered a light hull or for that matter a good hull?

Had this cam in my .030 over 454, 10.5:1, Headers, victor jr. airgap, 781's detailed "B" imp, 55-5600 r's ran 71.8 gps
(XM 298H) http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=407&sb=2
Id run that cam again, especially if it was a roller..

Daniel
Mash on it

Curious what CR you have in it now....

You're looking to pick up over 250 HP by doing a rebuild and a cam change? Hate to say it, but very tall order..Maybe. 

The reason I threw 5,200 RPM at you is because that seems to be the sweet spot for most big block powered jets sporting a Berkeley.

I have seen guys thinking they want to see 6000+ RPM and watched boats running 5K walk right passed them. It's all in  the set up and matching of parts..

Most important, forged pistons and crank with a good set of rods. A two bolt block is adequate, but I would recommend studding the mains and balancing it to within 1-1.5 mils...Studding the mains will require a line hone.

The cam is really part of a bigger picture....carburetor, intake, exhaust and valve size all need to be working in perfect harmony...

If you get the HP to where you think it will be, you may find yourself putting an "A" impeller back in it...


Off to work.   

GT

If I am understanding you right you are saying that a 454 Rectangular port HI Perf Block only has 250 HP. I was just basing my estimate on tech articles, Horsepower TV etc. 500HP shouldn't take much with a 454 rectangular port. Is there something I am missing here?

If I am understanding you right you are saying that a 454 Rectangular port HI Perf Block only has 250 HP. I was just basing my estimate on tech articles, Horsepower TV etc. 500HP shouldn't take much with a 454 rectangular port. Is there something I am missing here?

If you are only turning a B impeller to 4500 RPM, I don't think you are breaking the 300 HP mark, not by quite a bit....

I have a small block Chevy that will turn a "B" to just over 4500 RPM....

The cool thing about a jet pump is it's like having a built in dyno...

Take a look at the pump curve charts and I think you will be somewhat disappointed...I'm sort of hoping your tachometer is off...

GT

If you are only turning a B impeller to 4500 RPM, I don't think you are breaking the 300 HP mark, not by quite a bit....

I have a small block Chevy that will turn a "B" to just over 4500 RPM....

The cool thing about a jet pump is it's like having a built in dyno...

Take a look at the pump curve charts and I think you will be somewhat disappointed...I'm sort of hoping your tachometer is off...

GT

LOL now I know what the misunderstanding is. At the time before it spun a rod bearing I had as much as 60% leakage in some of my cylinders mostly valves but rings werent that good sounding either on the leakdown. Highest cranking pressure was 150 and low was 115 between cylinders. I called it emphysema but it ran pretty hard believe it or not. Says alot I think for the hull for that tired of a motor to still break into the 60's. 4200 was before jet rebuild, intake,headers and reworked distributor. Then it was about 4500. Tach was replaced by the previous owner right before I bought it in 2007. Could be off but I doubt it. I think that is all the motor had left in it. 35 years and never been apart

I would definitely give it some thought to what GT is saying, he knows his stuff. I ran a healthy 11.5-1 aluminum head 427 with the comps XM288H and it would run like hell from 3500rpm but was a bit of a dog until then.