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View Full Version : What cam is right for my mild built SBC?



20' VIP
01-14-2009, 03:10 PM
I have a 20 foot VIP valliant with a small block 350. Last summer i gave it a set of edelbrock performer RPM aluminum heads and a wiend single plane alum intake and a set of EMI thunder performance manifolds. but I never got around to caming it and geting a new carb. I was thinking on a demon 750 and a cam in the upper 400s or so. the stock cam in it is a 401/410 lift, but I need some expert advice on what to buy. Rt now it turns a 23 pitch 14 3/4 inch prop at 5300 RPMS at 64.9 on gps. Im wanting to turn a 25 pitch at 4800 or 4900 rpms it will only turn the 25 at 4300 rt now.

Bondo
01-15-2009, 07:52 AM
Ayuh,...
I would think that the single plane Manifold is Killing your down low Torque....
And,.. A 750cfm Carb is Way too Big for a SBC...
It appears your adding parts for a Hot Rod, instead of a Hot Boat....
As for Which Cam,....
Without knowing more about Exactly what components the motor was built with,...
I just Can't say...

20' VIP
01-15-2009, 10:31 AM
What all info do you need? The bottom end is a stock 350 mag. the heads are 68 cc chambers with 202/160 valves, Crane gold 1.6 roller rockers, and the low end torque is not where the problem is. I can spank any big block "non jet boat" on my home town lake out of the hole. its the top end were thay get me. theres 2 guys I run with that run upper 60s and Im at mid 60s. My boats extreamly lite. it weighs only 2700 lbs. It plains out instantly and gets to 50 in seconds. I m sure the right cam and carb would get my boat in the upper 60s and Id be happy.

rrocky
01-15-2009, 03:54 PM
Call Bullet Cam and ask them they did me right . They sent my cam CHS 288/296-10HR Dur @.050 Int 223 Exh 231 lift .531/.548 I picked up 3 mph by switching from crane #100132 dur @.050 222/222 lift 467/467 .I still have the crane cam if you want it $65.00 plus shipping.
Bullet Racing Cams 662-893-5670
Joby

rrocky
01-15-2009, 04:01 PM
Take a look at SBC Recipe thread !!! :D

20' VIP
01-15-2009, 07:26 PM
Thanks. Ill give them a call. Sounds like you got a pretty good deal, 3 MPH for just a cam change.... dosnt speed usually go for a grand per MPH in the boat world. LOL!

rrocky
01-16-2009, 06:56 PM
Thanks. Ill give them a call. Sounds like you got a pretty good deal, 3 MPH for just a cam change.... dosnt speed usually go for a grand per MPH in the boat world. LOL!
I still have The Crane cam and lifters they have 39 hours on them $65.00 plush shipping 222/222 467/467 110 centerline. :D

20' VIP
01-17-2009, 10:56 AM
For a small block? I figured your boat would have a BB in it? and is that a Hyd Roller cam? I think thats what mine has? Sounds like a great deal thoe. Ill call bullet and see if that would be a good up grade for me and Ill let ya know.

rrocky
01-17-2009, 07:31 PM
For a small block? I figured your boat would have a BB in it? and is that a Hyd Roller cam? I think thats what mine has? Sounds like a great deal thoe. Ill call bullet and see if that would be a good up grade for me and Ill let ya know.
Yes the boat I have now is twin bb 515's , the small blocks were in the 27 . :D

20' VIP
01-18-2009, 09:31 AM
Damn. Thats nice! Whats that top out at? Hopefully I can afford somethin like that some day. Im only 27 and this is my first boat. I always had jet skis before. But about that cam. do you know if it is a hyd roller?

rrocky
01-18-2009, 06:19 PM
Damn. Thats nice! Whats that top out at? Hopefully I can afford somethin like that some day. Im only 27 and this is my first boat. I always had jet skis before. But about that cam. do you know if it is a hyd roller?
The Hp 500's pushed it to 68 on GPS, We are building the 515's now so I dont know . The cam I have is not a HYD Roller ,it's a flat Tappet but it made good power. These are the 383's in the 27 . I know you only have a 350 Mag but the right cam will help you. Some days I wish I still had the 27. :idea: