Adding HP, need advise

[jbone]

Okay, I've got the carberatued Indmar 502. It was an upgrade engine from Shockwave. They say it puts out about 415 hp.
I'm looking to add about 100 hp and am looking for input. At this time a Pro Charger or Whipple is not an option.
I have a mechanic that knows BBC very well, but I wanted input from you guys before I buy parts.
I was thinking about a cam, alum. heads, intake, ignition and a Carb if needed.
My question is with the Indmar, does anyone know what will work, and where is a good place to buy. It came with an RPM performer intake and 750 Holley w/mech secondaries. I believe the current comp ration is 8.5-1.
J

[Squirtin Thunder]

A bump stick a intake and a carb will get you there. I would think about your exhaust too.

[jbone]

Jim,
What are you still doing awake.
We talked about 2 weeks ago about my setup. Still waiting to get to the lake to get some numbers for you.
Trying to get back to original setup after making too many changes at once, remember?
Once I get some numbers, I'll be calling you to get your thoughts.
J

[Squirtin Thunder]

Edelbrock makes a good marine head with 3 choices on the combustion chamber size, if you want to increase comp ratio. 9.3 is max for reg 87 oct. but 89 would work better.

[ECeptor]

What heads are on it right now?
Cam, intake, exhaust and some head work might be all you need. 515hp from a 502 should be fairly easy.
I assume you have forged pistons....

[Infomaniac]

Make it a 540. Change the cam and intake and there you go.

[jbone]

I just took the valve covers off. THe casting numbers on the heads are 12562934. The intake man says Edlebrock Performer RPM.
I everyone agrees that a cam is a must, which one should I use?

[BRETTSKI]

No Pro Chargers EverY Motor BlowS Up WITH PRO CHARGERS

[MikeF]

No Pro Chargers EverY Motor BlowS Up WITH PRO CHARGERS
What makes them blow up? Fueling problem or superchargers coming apart? Inquiring minds want to know.

[born2burn]

What makes them blow up? Fueling problem or superchargers coming apart? Inquiring minds want to know.
Some have troubles with tunning and run them too lean.......not a supercharger problem itself but rather tune up.

[steelcomp]

With the right set up, heads, cam, and carb could very well give you the 100 hp you're looking for. Do the research, though. Decide what rpm range you're going to run in most, buy the heads, intake and carb accordingly, have the heads flowed, and then get the right cam. If you don't takae the time to go through thede simple steps, you'll only be guessing. Maybe you will....maybe you won't get your power.

[jbone]

Thanks, for the advise.
This maybe be a stupid question, but does someone have a "kit" or something that is designed to work best. Isn't there a head, cam, intake, carb setup that has already been proven to work well together?
J

[Squirtin Thunder]

I have some basic #s for you !!!

[steelcomp]

Thanks, for the advise.
This maybe be a stupid question, but does someone have a "kit" or something that is designed to work best. Isn't there a head, cam, intake, carb setup that has already been proven to work well together?
JThere were some mfgr's going down that line, like Holley, Edelbrock, and I think even Dart. It's a good idea, but still, there's too many different combinations and applications that one package just won't cover it. For the power increase you're looking for, you're better off asking as many questions as you can, and putting together your own package, for your specific application. It's really not that hard, and you'll learn a lot in the process.
How about the 502/502 package?

[franky]

I took a 502/502 GM short block and tore it down. Blueprinted (decked, line bore and hone) and balanced (GM machins work sucks!). Added Merlin oval ports which were "mini square ported" and gasket matched, Dart intake, Holley 850 cfm, custom Comp hydraulic roller cam, lifters and rockers. Makes 598 HP (corrected) and runs great. If you want the cam specs I will send you the card.

[cstraub]

Thanks, for the advise.
This maybe be a stupid question, but does someone have a "kit" or something that is designed to work best. Isn't there a head, cam, intake, carb setup that has already been proven to work well together?
J
Had a customer at www.cfm-tech.com come up with a kit to do exactly what you want. He took a base 502 Carb engine with 415Hp and developed a kit with heads/intake/carb/lifters/cam/head gaskets as a package and made 540HP and 570#/ft of torque with wet exhaust and all the accessories. You can contact him at that website.
Chris

[jbone]

Thanks Chris,
I just e-mailed them.
I'll try calling tomorrow if I don't get a response.
J

[cstraub]

Here I found where I posted the package on this site:
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
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
I was off on the power numbers, damn my conservative nature!!
Chris