Mods for 502???

[jbone]

I'm considering some off season modification to my Indmar carberated 502.
I'm considering a cam, intake, and gear drive. It has a 750 Holley and according to the builder it is putting out about 415 hp.
Are there any recommendations on the cam and intake I should use, and if there is something else I should do while I'm in there.
The engine will only have about 45 hours on it at the end of the season, and is a simple crate engine at this point.
Thanks,
J

[ECeptor]

Here's a post I copied and archived from a while ago. I'm not sure who wrote it, but maybe someone here will recognize it.
"This combo was designed for the boater with a 502 engine that didn't want to spend the big $$$ for a an HP500 upgrade. The engine builder wanted:
Smooth Power
Good Idle Characteristics
Could be used with stock type exhaust / silent choice
Max power for a stock bravo unit
Cost effective
I did some "consulting" and designed the cam around an engine to turn a max of 5500 rpm. Here is the results:
502cid - 100% stock short block other than min. deck cut to make flat
8.8 compression. Did not zero deck - pistons .012" down + .040" headgasket
850 Sea Demon 82P 90S
HVH 1" Super Sucker
HV/Brodix 2000 Intake
Canfield 310 heads / CNC Chamber / No Port Work
Cam - custom Hyd Roller Just under 225 at .050 I w/112LSA around .600" lift
2" Primary Schoenfield Headers - dyno mufflers
Will test Gill Exhaust again when done testing in this state
Belt driven Sea Water pump working - cross over - alternator working - no PS pump.
89 octane fuel - yep, Winter Blend right from the gas pump.
35 Degrees total timing - HEI external coil distributor ( yes, the computer one) with Jacobs amplifier/coil
RPM HP Torque
2100 194.3 483.8
2200 206.6 495.67
2300 217.5 498.52
2400 231.0 505.70
2500 243.9 512.60
2600 256.8 519.00
2700 269.2 523.36
2800 279.9 524.64
2900 288.2 521.78
3000 295.2 516.70
3100 302.8 513.17
3200 312.2 512.08
3300 323.2 514.40
3400 336.7 519.97
3500 351.9 527.69
3600 374.4 542.69
3700 387.9 550.14
3800 406.6 562.41
3900 424.7 572.21
4000 440.7 578.35
4100 457.4 584.13
4200 468.2 586.44
4300 480.3 586.50
4400 490.9 585.93
4500 500.4 583.75
4600 508.8 580.29
4700 515.1 576.90
4800 526.3 575.77
4900 531.4 569.77
5000 536.0 563.20
5100 540.2 556.26
5200 540.9 546.34
That bullet will move any 4Klbs boat very nicely."

[cstraub]

That person would be me.
Chris

[ECeptor]

That person would be me.
Chris
I hope you don't mind me quoting you. If so, let me know and I'll delete it.
With that said, I don't save the details of a lot of people's builds so consider it a complement!

[cstraub]

No, I don't mind. That build was designed for a guy wanting HP500 power, that had an existing 502 sitting in his, did not want to spend a ton of money, and wanted to do it his self.
Chris

[jbone]

Thanks for the input.
My current factory setup limits me to 4800 rpm. I am currently only getting about 57 MPH wot at 4700 (gps). It has the AT "A" impellor.
I was hoping with some minor mods, I could safely get to around 5000 rpm without harming the engine.
The boat is a 21' open bow. It is pretty heavy. I would like to get 60+.
Is a cam and intake upgrade something that could get me there? If not, I'm open to suggestions.
I'd like to keep cost around 1K for parts.
J

[ECeptor]

What is your head's casting number?
I would think a 502 should push a 21'er well over 60mph.

[jbone]

What is your head's casting number?
I would think a 502 should push a 21'er well over 60mph.
Without taking the covers off, the only number i see is M 14097043.
As far as the speed, this is not bad for 3000+ lb boat.
Most in this class are at about 53-55 top speed.
J

[nodigg]

I think you should buy my Whipple set up I am taking off my 502...it should be newly replaced under warranty by Oct-Nov 2005. Taking offers now.

[Krumbsnatcher]

I think you should buy my Whipple set up I am taking off my 502...it should be newly replaced under warranty by Oct-Nov 2005. Taking offers now.
pics please