Hello all ..I have been on here for a wile asking diffrent questions.. there is 3 questions that i need straight up answers to from exp supercharger people.. this is what i have and what i wont to do .

383 short block
scat 9000 crank
full out race prep 96 fast burn votec heads
eagle rods arp blots
speed pro forged 10.7 flat tops
super victor intake for vortec
comp cam 265 275 @.050 Dur .614 .615 lift with 1.5 I'm using 1.6 it will increase lift to around 660 its ground on a .950 base circle

I now that the cam and compression is wrong for turbos and blowers I'm not worried about getting massive hp right now wonting to fab all the pluming for blow Through system using a roots style Eaton supercharger off a thunderbird supercoupe just something to play with ..i have been building all out racing engines for years.. i now the basic of how they work.. turbos and blowers that is but they are new to me as far as app ..

Questions

1) If i build this all this with 3-4 lb boost do ya think it will work and not explode after 5 min after start up ..

2) If i run 3-4 lb of boost with 10.7 flat top pistons what do you think the final compression will be ..

3) and what size pulleys will make 3-4 lb of boost pulley size in inches diameter across the pulleys need Eaton and crank pulley size

P.S thanks to all the people that has answered all my other questions and these as well..I have printed every answer for future reference.thanks a bunch...

Tim

 

Doesn't look like anybody's going to jump on this so Here I go...

Questions

1) If i build this all this with 3-4 lb boost do ya think it will work and not explode after 5 min after start up ..

If you've been building engines for years it shouldn't.

2) If i run 3-4 lb of boost with 10.7 flat top pistons what do you think the final compression will be ..

Compression ratio under boost = 12.11@ 90% VE.

3) and what size pulleys will make 3-4 lb of boost pulley size in inches diameter across the pulleys need Eaton and crank pulley size

I can't understand why you'd use that blower, it'll ruin your top end. Now if'n ya wanna talk a little more applicapable blower, I'll figuire out the ratios for ya.(Eaton 112's are nearly as cheap, everywhere, and much better suited than the eaton 90.

P.S thanks to all the people that has answered all my other questions and these as well..I have printed every answer for future reference.thanks a bunch...

Tim
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That combo will be fine w/ 3-4 lbs as long as you keep it fat (11.0-12.0 A/F ratio) and conservative on timing. I am not a fan of "final" or boosted compression estimations, that isn't really a good way to judge octane requirements etc as there are more complex dynamics at work.

I would suggest putting in a thick head gasket to bring the comp down if you are worried about the comp ratio (lower would be better).

I can't help you with th epulley combo, I haven't ever seen anyone running a setup quite like that.

Good luck,

Chris S.
Midwest Turbo & Performance

 

mike yes i am interested in the eaton 112 pully configuration ..

and thanks guys if you find or run accross anything on these that you think maybe usefull pleasesend me a pm ..or anyone else ..


thank again
tim

 

i think you will be ok with 3-4 lb. boost with that combo but not so sure if the supercharger is big enough for 383 ci. got to remember it was designed for a 3.8L make sure it will pass enough air with out over heating the air going in the motor or you will most likely blow the thing up better to find out before you fab it up another option might be a 4.6 cobra blower might find one on ebay cheap enough just my two cents

 

thats cool thanks if one isant enought flow ill do the math and may run 2 of them what do you think...

 

Using 85% ve, you'd want to turn the compressor on a 112 3 x crank speed.

You can bounce the numbers around to whatever's available. A 6" dia. crank pulley with a 3" blower pulley works out about right, and I believe there are a lot of pulleys available in that range. I'd allow some wiggle room on the blower pulley to go smaller, I can't believe anybody would leave it at 4#

 

thanks no im not going to leave it at 4 lb just starting small ( make a run read the plugs then go from there....

 

Just out of curiousity, is their any reason in particular that you wouldnt consider fabbing a turbo system instead? It seems like just about the same work involved as fabricating the custom bracketry to mount the roots blower.

 

well i havent really decided on what im going to use the roots blower i already have 2 of them i got for free ..