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How much boost can I run??

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Old 12-04-2002, 10:28 PM
  #11  
Allan4
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I was pretty sure these were the type of responses I would get. I'm not so much worried about the small blower, but more the risky cr. I obvoiulsy built this as a n/a motor last year. I kinda hate to crack it open and swap pistons, motor only has about 70 hours on it, trouble free. I might be able to grab a B&M 250, but that would increase my cost, plus I would need to pick up another carb. Or would a single 850 run okay on a 250.

I have never played with blowers, so I appreciate all the help here. So, the 250 would be safer than the 177?? Single 850 is okay??

If I have to break the motor down and lower the cr to be safe on 93octane, then this project is going to wait until next year/more running hours when the motor should be gone thru anyways.

Basically I am looking for about 650hp, or a 130hp gain. Can I safely hit this without risking a meltdown?? Will a 250, single 850 with 3psi be safe and get me close to that 650hp mark??

Cory, not sure on those numbers.

Thanks guys, really appreciate it. I have too much $$ into this motor to break it by going to radical. By the way, cam is a Crane 139731, 226/234 and .598/.610. 112 and .050 gross lift

Allan
 
Old 12-05-2002, 01:14 AM
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I would really be careful, for that power level, that SC is way too small, even if you want too create 1lb. of boost is going to create a large temp. increase and will probably make less power than now until you get to 2-3lbs. of boost. And with that compression, it will probably detonate its head off without race gas or severly retarded spark advance. I would not even mess with it wihout an intercooler and then the SC is too small to overcome the pressure drop. Your asking for trouble with that setup. I really think you need a bigger supercharger and you really need an intercooler to be safe with that much compression.

Thanks,
Dustin
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Old 12-05-2002, 01:37 AM
  #13  
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i think you got a definative answer there from a fairly reliable source huh???
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Old 12-05-2002, 08:14 AM
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ALLAN;

I think you would need at least a 1050 Dominator if you went the single carb route on a 250 Blower.
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Old 12-05-2002, 02:03 PM
  #15  
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Dustin, thanks for the great advice, same with everyone else. Dustin, is it okay to e-mail you with some more questions??

Cory, the problem is that means more $$ I do not have, need to rethink this thing in light of all the info I am gettng here. Seems to be a pretty consistent "your gonna creat Cheranobal II if you put this thing together". Better regroup (okay, I really don't have a group to "re"). Damn.............now what, I want more power, and don't have the coin to go with a blower, intercooler and and new carb. Any other ideas anyone?? Thanks for th info guys, A4
 
Old 12-05-2002, 02:47 PM
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Could he just CNC the chambers on the heads to lower the CR?
Then maybe an 8-71 or a Holley420?
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Old 12-05-2002, 03:02 PM
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cam change perhaps???? it might idle like crap but you might make more power.
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Old 12-05-2002, 03:08 PM
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Allan;

Thats easy...150hp shot of N.O.S. You'll pick up more power for a lot less $$$. I don't know what ignition or fuel system you have but it is by far the best bang for the buck. All you'll need is a kit, an auxiliary fuel pump (most likely), and a retard box. You'll pick up an instant 500 RPM and when you get off it you'll maintain probably 200 of that. I'm being serious here, its cheap easy power for any combo, even a stock 502mag bottom end.
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Old 12-05-2002, 04:05 PM
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Why are you worried about the money for a blower, intercooler, and carb (you forgot ignition too). After you add another 100+hp, you end up blowing your bravo up.
A couple options,
1) run the 509 till it gets tired, then rebuild it with lower CR pistons and a bigger blower. I'm not sure if an intercooler is really needed with only around 5psi.
2) Try an extension box or higher X dimension. Those could be good for a few mph with no more HP. BTW, what kind of hull are you running?
My $0.02
Gary
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Old 12-05-2002, 06:59 PM
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Allan4, go ahead and email, [email protected]

If you don't want to run minimum 100 octane, then I would do what Gary said is run the 509 until it's tired, then put new low compression pistons in, then get a bigger supercharger, where the intercooler can be optional depending on your boost level.

Thanks,
Dustin
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