Reply With QuoteWhat boat, what size impeller, and what is your hp target?
Sounds like you're going to have a stock engine (nothing wrong with that), so no need to do anything fancy with the cam, intake, or exhaust.
I dunno if you can run that on 87 oct.
I posted earlier about my build and had a plan in mind and got some great advice. Well now that things are in motion plans have been skewed a bit.
Here is what I got so far....
C93VE heads (Mild Porting) fresh w/stock valves
1.80 Roller Rockers
CAM is still up in the air...Will match the vlv. springs up w/cam though.
Intake & Carb: CARB is for sure going to be a 750-800 Edelbrock, Intake Torquer or Performer?? Have a line on a Torquer but have read negative information on them??? Some say they have ran both and not noticed a differance and others report otherwise...heh??
Stock Rods with ARP bolt set.
Cast Dish Pistons to net approx. 9.2.1 compression or there abouts. I believe the heads are 72 or 74CC?? Want to be able to run 87 Octane.
Have a line on some water injected TT Basset Headers that I plan on getting.
Have Billet MSD Dizzy.
Comments...Advice, suggestions??
Brad
What boat, what size impeller, and what is your hp target?
Sounds like you're going to have a stock engine (nothing wrong with that), so no need to do anything fancy with the cam, intake, or exhaust.
I dunno if you can run that on 87 oct.
Dump the cast pistons. Forged are priced reasonable enough not to use them. Summit price on Speed Pro #2404L $335.00 a set. Cheapest insurance money can buy.
Do NOT use cast pistons if you want to run cheap gas. Nothing kills more jetboat motors than detonation, its not a car motor! Skip right past the Hypereutectics too you will thank yourself later. If this is the only item you spend good money on do it!
Other than that I'd recommend you call some cam companies and let them know basically what you just told us, they have some very knowledgeable people who can recommend something that will work nice with your setup. I did that with Comp and they were great, knew a fair bit about jetboats too(see below)
I'd suggest running CJ rods if you find a set easily. The rod bolts are a good call as well.
I'd personally throw in my vote for the Weiand Stealth intake. I ran that with a 750 edlebrock and it was great.
Don't aim too "low" with that 460, it doesn't take much to really get some good power out of them.
Cheers
http://www.***boat.com/image_center/.../Comp_CAMS.jpg
I went with the Weiand Stealth manifold on mine. I decked the block, went with an Isky cam cut specificaly for A pump jet boats and double valve springs and the most important part, Dooley 10 qt pan w/ rear pickup. I would use a standard oil pump as well, dont waste your money on a high flow pump. I used an MSD billet dist and 6AL box with a 6000 rpm rev limiter pill. I have a heavy 20ft Hallett and turn about 5200 rpms through logs and am licking 60mph. I have a 780 vac secondary carb. I use my boat just to party and ski/wakeboard.
Are you going for the gusto or just to get around?
I
C9VE heads (Mild Porting) fresh w/stock valves
1.80 Roller Rockers
CAM is still up in the air...Will match the vlv. springs up w/cam though.
Intake & Carb: CARB is for sure going to be a 750-800 Edelbrock, Intake Torquer or Performer?? Have a line on a Torquer but have read negative information on them??? Some say they have ran both and not noticed a differance and others report otherwise...heh??
Stock Rods with ARP bolt set.
Cast Dish Pistons to net approx. 9.2.1 compression or there abouts. I believe the heads are 72 or 74CC?? Want to be able to run 87 Octane.
Have a line on some water injected TT Basset Headers that I plan on getting.
Have Billet MSD Dizzy.
Comments...Advice, suggestions??
BradYou will not be able to run 87 octane pump gas with your combo and any suitable camshaft and
still make power with an ideal tune, especially with the EdelBROCK carburetor.
#1, first and foremost: dump the EdelBROCK carb fast and get a Holley 850 double pumper, list # 4781. It is not
too big for your jet boat application...460's love a lot of air & fuel.
If you buy the Torker intake, do us all a big favor and take it immediately to the foundry and have them
melt it down. A Weiand Stealth # 8012 will work for your engine and so will a Victor 460; I much prefer
the latter, given the application.
Marine appplication engines are essentially categorized under "severe duty" engine application and while the engine will
run with the OEM valves and cast pistons, just remember that you are better off with 1-piece stainelss valves and
forged pistons. (If you are trying to make the most of an existing passenger car engine and simply porting the heads and
freshening before installing into a jet boat, okay, but start collecting parts for your next time the motor is out
of the boat for a rebuild.)
LO
I would use a standard oil pump as well, dont waste your money on a high flow pump.
Money invested in a HV pump is a wise move, it is not "wasted."
The standard passenger car oil pump works very well in a standard passenger car engine, but I wouldn't
be too quick to dismiss HV oil pumps. Oil pressure is oil pressure, regardless of the gerotor's dimensions used to draw
oil from the pan. And in the case of the 385-Series factory-style oil pump, the excess engine oil that's not needed is
bypassed right back into the rotor's intake side of the pump...so having that increased volume available, if and when needed,
can be a blessing. Especially when you're running your engine at 5000 rpm sustained.
I think that running a high volume oil pump in most jet boat applications is an excellent idea. These engines were originally
intended to be cruising down a smooth asphalt highway at 2200 rpm. Due to the severe abuse of the marine application and
the extended high rpm's, one must rely on the virtues of engine oil a LOT more than during the other real world
applications of these engines.
Engine oil:
lubricates
acts as a cooling agent
acts as a cleaning agent
acts as a seal
is an anti-corrosion inhibitor
often serves as a hydraulic fluid (pressure-backed chain tensioners, hyd lifters, etc.)
aids in cold starting (multi-viscosity knows when to be thin).
Still don't think a good oiling system is important? Try this with two identical engines:
Engine #1) Drain all the coolant from this engine's cooling system but leave the oil in the pan. Start it up and see how long it will run...and run...and run.
Engine #2) Drain all the oil from this engine's oiling system but leave the water in the cooling system. Start it up and see how quickly it grenades. :jawdrop:
Don't cheap on your jet boat motor's oiling system. Not in the pan, not in the pump, not anywhere.
LO
Dump the cast pistons. Forged are priced reasonable enough not to use them. Summit price on Speed Pro #2404L $335.00 a set. Cheapest insurance money can buy.
Definitely!
there is nothing wrong with kb hyp.pistons.ring end gap is very important run 2 less timing with these pistons and ive ran them hard for years with and with out nos. but with that said go ahead and buy the forged.
go ahead and buy the forged.
I agree with hotbo and all the others that said to buy the forged.
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