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IGDOG
11-08-2000, 08:20 AM
Anyone have any tips on cam selection for a 468 chevy with big oval ports,strip dominator intake,holly 750, and a stinger ignition?Thanks.

GlastronGuy
11-09-2000, 07:56 PM
What compression and exhaust are you running?

MoJetBoPar
11-10-2000, 05:06 AM
I'm new to the Jet Boat hobby but there is a lot to be considered when choosing your cam specs. Like powerband (rpm limit) for top speed, which is dependent on the impeller you have. And unlike cars, horsepower is not necessarily what your striving for, it's max torque to move the hull thru the water. So my gut instinct is to err on the coservative side with some thing in the 235 to 240 duration @ .050 with all the lift available for a cam in that range.

GlastronGuy
11-10-2000, 08:45 AM
Mo, you better read this: http://www.concentric.net/~Jjlee/TheBiz/final.shtml

IGDOG
11-11-2000, 08:46 AM
Exhaust is Bassett thru transom headers,the comp. ratio is in the 8.5/1 neighborhood.

GlastronGuy
11-11-2000, 09:49 AM
As Mo said, you want to run in the powerband that your impeller allows you to spin too. You generally can go a little bigger (cam) in a jet boat than you can in a car. That's because there is less concern with a decent idle. Another thing with a jet boat is the powerband itself. When you "floor" a car. the RPM's gradually increase. With a jet boat you are at max RPM almost instantly. Depending on what you are trying to build, a hot rod or a family boat, that is what will help you choose a cam. The range Mo spoke of is good for a family boat and you will get a decent idle. A hot rod will need a bigger cam. If you want some good info from some hobbists like myself and some pro, such as racers and builders go here. http://members.nbci.com/***boats/realjetboats.html The "Jet head message board" is full of good advise.

IGDOG
11-11-2000, 07:43 PM
Thanks Glastron Guy, I'll let you know what I come up with.I'll check the site too.

IGDOG
11-12-2000, 09:35 AM
What about reversion with the wet headers?Also checked out realjetboats.com and locked up my computer twice!I don't have that kind of patience.

GlastronGuy
11-12-2000, 02:55 PM
Reversion is a problem with the big cams. try this link. http://321website.com/members/forum/plus.mirage?username=realjetboats

Squirtcha?
11-29-2000, 05:54 PM
Hey igdog
When you're using the RealJetBoats message board let the top header load then hit the stop button (no more than a minute or two after header loads). Too much text will lock your machine up every time. It'll load more messages than you think in just a minute or two. If you're using AOL I don't think it has a stop button so I'm not sure how to to that one. Trust me this'll work for ya and it'll be worth it.

sleek
12-10-2000, 04:55 PM
I HAVE A 73 SLEEKCRAFT W/455 OLDS. I AM IN THE MIDDLE OF A REBUILD AND WANT TO CHANGE THE CAM TO A MORE ROUGH LOPEY IDLE. I CURRENTLY HAVE A LUNATI 00083 CAM, WHICH IS 234 DURATION AT @.O50. AND 496/520 LIFT. THE BOAT REALLY RAN WELL BUT I HAVE TO BORE THE BLOCK AND WANT TO BUMP UP THE COMPRESSION BUT I CAN NOT DECIDE OR FIND A CAM I WOULD LIKE TO BUY. ANYONE HAVE ANY IDEAS. I AM NOT SURE WHAT IMPELLER I HAVE. IF IT HELPS, I RUN ABOUT 4500RPM AT ABOUT 55 TO 60?

sleek
12-10-2000, 04:57 PM
Originally posted by MoJetBoPar:
I'm new to the Jet Boat hobby but there is a lot to be considered when choosing your cam specs. Like powerband (rpm limit) for top speed, which is dependent on the impeller you have. And unlike cars, horsepower is not necessarily what your striving for, it's max torque to move the hull thru the water. So my gut instinct is to err on the coservative side with some thing in the 235 to 240 duration @ .050 with all the lift available for a cam in that range.
WHO MAKES A CAM FOR US MORE RACE ORIENTED BOATERS FOR A 455 OLDS. I CAN NOT FIND ONE THAT IS VERY LARGE(NOT OVER 520 LIFT, LUNATI)

sleekcrafter
01-02-2001, 08:10 PM
Try CompCams they have a large variety of off the shelf cams for jetboats.

superdave013
01-03-2001, 11:51 AM
Talk to George at Clay Smith Cams. He has done it all with jet boats. He cams are ground in house and can grind anything you want. The steel billet roller cam I got from them was shot peened and looked like it was made by a jeweler.

GlastronGuy
01-03-2001, 05:43 PM
Olds performance parts. Here is the King. http://www.mondellotwister.com/

mario
02-02-2001, 07:12 PM
Originally posted by sleekcrafter:
Try CompCams they have a large variety of off the shelf cams for jetboats.I just ordered a cam kit from Isky. Talk to nolan there marine tech. ask about there mega series. good luck.