Question
09-14-2006, 10:55 PM
#1
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Question
anyone running a roots style blower say what u can to help.Im runnin a 327 bored .040 and im lookin to get a blower.It will be a street car but i also want to be runnin it at the track.Im lookin at the weiand 177 setup.I was just wondering what kinda supporting mods i should have for the motor to support the blower.so anyone has input let me hear it. This will have a built 350 trans and a set of 3:73's or gears around there.
09-15-2006, 05:36 PM
#5
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09-19-2006, 03:07 PM
#13
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Re: Question
Originally Posted by Rice Killer87
Running 10's in a 327 = ALOTTA $$$$
i gave up on making my 327 faster, goning to change to LS1.
BTW i have seen 450+hp 327.
wouldn't heads, cam, blower, ignition, intake man, exhaust, ignition do the trick? thats way cheaper than a LS1 swap.
09-20-2006, 12:34 PM
#15
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Re: Question
I have a much milder combo than you plan- 383 with good heads and a little Weiand 142 on top. Good enough for mid 12s on street rubber with no traction. With traction I'm sure it could crack an 11.
You'll need the larger 177 unless you have a light car- the 142 is about pooped out at 500HP (I make 475 at the crank, 390 at the rear wheels and I'm one set of pulleys from maxed-out). I think you're going to need more than 500HP to hit 10s.
LOW COMPRESSION. I can't drill this through your head any more strongly than this. I'm talking 8:1 MAX if you're even thinking about running pump gas. Prefferably in the mid 7s. BOOST makes power, not high compression. And detonation with a roots blower is always lurking around the corner. DO NOT push the envelope and say "I think I can get away with 9:1." You can't on pump gas so don't even think it. Don't compare these motors to a nitrous motor or a centrifugal/turbo motor. They're a different bag of snakes.
Forged pistons with top rings set for a blower application (about .004-.005" wider gaps than usual). You don't need anything super-exotic but they must be forged and prepped right (remove sharp edges and such to help avoid detonation). Obviously, a good crank and rods to go with it. Nothing super-exotic, but good forged pieces.
Cam..... ask a guy who really knows blowers for a recommendation, but in general the LSA will be wider than a N/A combo. Something around 230-240* @ .050 on a 114-115* LSA is probably roughly in the ballpark. But I've never run 10s with a roots blower so don't take my word for it.
Good heads. Just as important with a blower as it is N/A. Don't worry if the intake ports are a little big- you'll have more low end power than you can handle with a roots blower.
Big carb. Biggest you can put on top of the blower. That would be an 850DP, or one of the more exotic HP series, Demon, etc. On a mild combo you don't need a boost-reference power valve, but on something like this I would actually use a blower-specific carb with a boost-referenced power valve. Or, on the cheap, remove the power valves completely from a standard carb and jet up (miserable for driving on the street, though).
Good exhaust. Blower helps it in, but it still comes out just like a N/A motor- except a lot more of it. Think bigger than you normally would.
Good fuel system. Can you support the kind of HP this motor will make? Running lean in a boosted motor is death. Never do it. Parts go "bang." Trust me.
You might also want to check out a very good technical article on Holley's website about setting up a motor for use with a roots blower. I've found that article to be very accurate in the real world.
You'll need the larger 177 unless you have a light car- the 142 is about pooped out at 500HP (I make 475 at the crank, 390 at the rear wheels and I'm one set of pulleys from maxed-out). I think you're going to need more than 500HP to hit 10s.
LOW COMPRESSION. I can't drill this through your head any more strongly than this. I'm talking 8:1 MAX if you're even thinking about running pump gas. Prefferably in the mid 7s. BOOST makes power, not high compression. And detonation with a roots blower is always lurking around the corner. DO NOT push the envelope and say "I think I can get away with 9:1." You can't on pump gas so don't even think it. Don't compare these motors to a nitrous motor or a centrifugal/turbo motor. They're a different bag of snakes.
Forged pistons with top rings set for a blower application (about .004-.005" wider gaps than usual). You don't need anything super-exotic but they must be forged and prepped right (remove sharp edges and such to help avoid detonation). Obviously, a good crank and rods to go with it. Nothing super-exotic, but good forged pieces.
Cam..... ask a guy who really knows blowers for a recommendation, but in general the LSA will be wider than a N/A combo. Something around 230-240* @ .050 on a 114-115* LSA is probably roughly in the ballpark. But I've never run 10s with a roots blower so don't take my word for it.
Good heads. Just as important with a blower as it is N/A. Don't worry if the intake ports are a little big- you'll have more low end power than you can handle with a roots blower.
Big carb. Biggest you can put on top of the blower. That would be an 850DP, or one of the more exotic HP series, Demon, etc. On a mild combo you don't need a boost-reference power valve, but on something like this I would actually use a blower-specific carb with a boost-referenced power valve. Or, on the cheap, remove the power valves completely from a standard carb and jet up (miserable for driving on the street, though).
Good exhaust. Blower helps it in, but it still comes out just like a N/A motor- except a lot more of it. Think bigger than you normally would.
Good fuel system. Can you support the kind of HP this motor will make? Running lean in a boosted motor is death. Never do it. Parts go "bang." Trust me.
You might also want to check out a very good technical article on Holley's website about setting up a motor for use with a roots blower. I've found that article to be very accurate in the real world.
Last edited by Damon; 09-20-2006 at 12:41 PM.