Chris232
 

I can't make any guarantees, but my first motor was a carbed 300hp ('97). I used a 226/236-587/610-112 roller cam with edelbrock oval port heads and headers with an rpm intake. The boat gained 10 mph. Changed ignition module to hp unit with no limiter. Motor made power at 5500rpm. didn't have to change prop. That was the most fun with a motor I've had since. Then put a 250 blower on it next season at 6lbs boost. This motor still had cast pistons, crank and 3/8" rods. When I sold the short block to a friend, things still looked new inside. I think those motors are a little tougher than people think, if they are treated reasonably.

Good luck!

Making the same amount of HP a blower motor (roots) should make less torque. Since to get the same type of power N/A you'll need more stroke. This should in theory be easier on your drive, and your pocket.

Rumrunner,
I thought it was just the opposite. I always thought a blower motor made more torque. I will have to dig up the dyno sheet on my old 625hp 502 . That motor had 8:5.1 CR . And see what kind of torque it made.


Hey Birddog,
Okay that is one of the benifits of having a blower motor. There is all kinds of cool funny things to say !:D

I am in the middle of mods to my HP500 carbs I will not have dyno results but can give you the mph difference in a couple of weeks. I had the heads re-done and changed cams.

Doubt I have even 1/2 that in mine. But then my outdrive is still in one peice so far.

W/O blower, 68mph or so. With blower, 80mph. Same prop, just can spin a little faster. :)

The acceleration is unbelievable, Night and Day.

US1,

Sounds like me , stock 502 I ran 65mph and now with the 540 I just broke 80. I can still run low octane gas how about you ?:D

26scarab i was thinking abotu usign used parts. You can find used blower s in good shape for not to expensive. Whereas I woudl be apprehensive to biuld up a motor based on used heads or pistons or crank. Prochargers are EXPENSIVE. but yeas plumbing them can be ahassle. But then again to rebiuld an N/A motor you are going to need to pull it from the boat and do a rebiult.

Brad, thanks for the info...
 

The reason why I am not interested in a blower is I have heard that they wont fit in my baja without cutting out some of the back seat.. I only have about 2 inches between the pulley's and the seat the way things are situated in its current configuration.. I believe I would need a few more inches,, but then again,, couldn't we all... :D ;)

26 Scarab:

What I was refering to was the difference in cubic inches to make the same horsepower N/A vs. Blown. To make the same amount of power N/A you'll need a bigger engine which generally means more stroke, more torque.

Doug.

Torque is torque is torque. For a given HP at a specific RPM, the torque is constant. Doesn't mater if it's a blower or stroker or an overbore that you use to get the HP.

A blower "effectively" increases the CU by packing in more air, so it will fatten up the torque curve pretty much the same as a large displacement NA motor.

If you want more HP without high torque you have to spin it faster. There is a limit to this too, as it seems that most drives don't like much over 6000 RPM.

-Greg