Supercharge or not?
 

In anybodies opinion, which would have more longevity: A carbureated 500 HP built to 525 HP or the same engine mildly supercharged with say a B & M 250 or something similar to the same H.P.

Thanks..........

I have been thinking the same thing!

Personally,
I prefer making power without a supercharger. Although I don't have any supercharger experience.
I have heard they are extremely hard on crankshafts (snouts), take allot of HP to make HP and require premium gas.
If you want to make up to 700HP that can be reliably made without supercharging, anything over that I do agree that a supercharger is the way to go.
To make 525HP , I think naturally aspirated is the only way to go.
I currently run a 540ci that is making between 650-675hp and I run it on 89 octane. It starts fine , and idles a 600-700rpms with no problems.
:D

I did the blower thing with my 500hp, 420 mega blower and two holley 850s,msd dis, and ignition, 700hp and always turn key and reliable

2-air,
My blower motor had 200 hrs on it last winter when freshened it up. The cyls, pistons,crank, and bearings all checked in at new specs. This is a 502 with a B&M 250 running 5 lbs. Reason for refresh was to install a roller cam with a different grind so that I can run silent choice.

blowers would allow you to make more an xtra 25 HP. If you spend $2500 you are going to amke at least 150 extra HP with a blower. Where asto make 150 xtra HP with an NA motor its goign to cost more than that.

Puder,
I disagree. Let's say we have a stock 502 (415hp) .
Well if you Procharge it, doing everything the right way you could easily make 650hp right ? Well how much is that $7500 ?

You could spend half that cylinder heads , and camshaft and make 600-625hp , that runs on pump gas and is WAY more fuel efficient.
And think of all the hassles with a intercooled blower set up. Hatch clearances , intercooler plumbing , etc
If you aren't trying to make BIG power 700+ then stick with a N/A set up, it will be cheaper to build and to run.

???? about a 454 non-mag
 

Hey guys,, I have a 454 300hp carbed, non-mag and wanna make more hp and do it NA of course... what parts would get me what hp, how much would it cost, and how reliable would it be...

26scarab,

The real cost of supercharging is closer to $10K with the necessary drive upgrades, extra guages and chit.

But I still like it!!!!!!!

Weeeeeeeeelllllllll as one who may be stopping up to Huffer motors I can only say one thing.............BLOW ME!!!!!!!!:D

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

I agree with 26Scarab---naturally aspirated is a much better way to go in my opinion. Less parts, less pulleys, much easier on parts, less maintenance, less of a chance of something to go wrong, more fuel efficient. I would opt to just build larger cubic inches over a blower. It also depends on how much $$$ you're willing to spend too. If I had an Apache then I would perhaps consider supercharging an engine because it takes bit power to move one of those dudes...but I would always consider a LARGER NA engine first. $$$ and the priorities you have with it usually is a major factor and at the top of the list when considering all this stuff.---basically, it's how much you can afford and how much you're willling to lose if something goes wrong I guess.

How much HP to drive a blower?
 

How much parasitic HP is used to turn the blower and make the boost? I know it will vary. If there are 2 motors making 700 HP at the crank, 1 N/A and 1 W/ a 250 blower at say 6 LBS of boost. Does it take 50 HP to run the blower? Will the blower motor essentially be working harder to get equal crank HP as a naturally aspirated motor? I know this is way extreme, but I once heard on top fuel drag motors it takes about 800 HP to turn the blower at max rpm. Just curious to see if anyone has any data on some of the blowers used on boat motors.
Thanks

I also feel that the torque (down low) of blower motors KILLS bravo's. I run a Natural 632 that makes 900hp and 806TQ....(but not killer TQ in the mid range) so far have only broken 1 drive...when it was "new", set up too loose. Anyway, I'm sure I'll break one now since I posted that. But if you can make as much power for less cost and complexity, while helping your already "strung out" bravo, I don't see the need for a blower. You really need to do your homework for the right hardware combination and find an experienced engine builder to make the NA set-up sing.;)

Yes, I forgot to mention (directly) the effects of a supercharger on an outdrive...especially a Bravo!!! I think you would greatly shorten the life of a Bravo One drive...maybe not right away but eventually with a supercharged engine where the torque comes on like GANG BUSTERS!!!...and-----UT-OH!

Kaama ,
I was waiting for you to help me out !:D

I totally agree with what Kaama , WetteVette, and Jdnca say about Blower motors.
I actually thought I had a pretty good combination until I heard about Kaama's 680hp with a hyd. roller cam, yeah baby ..no more lashing valves !!

Blowers, we don't need no stinking blowers !!!!!

Now if I had a 47 Apache with triples it would have the biggest displacement motors and the biggest blowers I could find sticking out of the hatch !!!

Although a trio of 632's with Big Chiefs and sheet metal tunnel rams would look killer too:D

Actually, my dyno sheets said my 540's made 699HP @5750rpm....but I don't think I want to turn them that high. The highest I want to turn them is 5500rpm ---they make 682hp at that rpm which is good enough for me. :)

KAAMA, Scarab,
You guys are both putting out some real nice HP numbers. It makes me wonder what my 496 is putting out. I guess it doesn't really matter since my boat is running better than I had ever hoped, but it would be nice to know. I always assume 700 plus as a conservative estimate. Maybe someday I will take a ride to Grand Rapids and throw it on the dyno.:D