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Discussion Starter · #1 ·
:spank: OK GURUS, HERE WE GO...
I WANT TO BUILD A "QUICK WINDING" MOTOR, MAXING OUT @ 62-6500 RPM I DONT WANT TO SPEND HUGE MONEY... AND I DONT WANT TO GO 140 MPH!

IM THINKING 377 (BIG BORE/SHORT STROKE)

AM BUILDING A 31 MODEL A ROD FOR STREET USE... TREMEC 5 SP, JAGUAR REAR W 3:70-ISH RATIO, 32INCH TALL CHEATER SLICKS.

THE WHOLE RIG SHOULD WEIGH LESS THAN 2000 #

NOW HERES THE KICKER, THE CAR CAME W A 671 ROOTS BLOWER AND 2 FOURS. SO IM PRESUMING THAT WILL MAKE UP FOR ANY LOW END TORQUE PROBLEMS.

I HAVENT BOUGHT HEADS YET BUT HAVE A NICE COMP ROLLER CAM THAT LIVES @ 2000-6500 RPM...

AM THINKING SOME SEMI MILD ALUM HEADS THAT WILL FLOW @ THESE RPM RANGES.

DO YA SEE ANY HOLES IN MY PLAN SO FAR??
 

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great idea. maybe elaborate on the camshaft? are you using the blower? heads dont flow RPM per se,they flow cfm and the cam duration gives the heads "time" to flow and valve lift working with heads will determine a total possible flow of air.how much power do you really need in that car? are you looking for the power to be linear? what size carb(s) are you using?
are you using a stock GM block? if so,2 bolt or 4? what CR will you use?
 

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2 Holes:

1) i would build the car first then worry about the engine.

2) a stock 305/350 that has been balanced and blueprinted should be able to spin 6500 rpm with no problems, reach that rpm fairly quickly, and enjoy doing it.

This is the cheapest way.

3) If the car is going to be under 2000lbs., you don't need to worry about any "supposed' low-end torque problems.
 

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Discussion Starter · #4 ·
Cam specs, i'm not positive... Card is at home, i know its a lumpy comp cam set up w roller lifters... Looking at some 195-ish heads... 8-8.5 compression ratio i think... Only looking to push to mid to hi 400 h/p range... I want a toy, not a death machine... D/b
I JUST WANT IT TO WIND UP LIKE A BANSHEE... GO LIKE HELL TO ABOUT 85-90 MPH AND THEN IM GONNA "CHICKEN OUT"... DONT NEED ANY NEW FRIENDS IN BLUE UNIFORMS... :)
 

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Cam specs, i'm not positive... Card is at home, i know its a lumpy comp cam set up w roller lifters... Looking at some 195-ish heads... 8-8.5 compression ratio i think... Only looking to push to mid to hi 400 h/p range... I want a toy, not a death machine... D/b
I JUST WANT IT TO WIND UP LIKE A BANSHEE... GO LIKE HELL TO ABOUT 85-90 MPH AND THEN IM GONNA "CHICKEN OUT"... DONT NEED ANY NEW FRIENDS IN BLUE UNIFORMS... :)
You're going to want more compression, at least 10:1 if you have a "big lumpy cam". 6500 RPM is EASY for just about any sbc as long as its well balanced and assembled. Your VALVETRAIN is critical though, if you're not worried about power go with a very mild solid cam, with beehive springs and you should be able to run stock rockers and valves.
 

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327, .030. Scat 6.125 Rods, Forged 350 pistons. Forged crank if you can afford it. Solid cam. Killer street hi reving street motor.
At only 6500rpm a 3.75" stroke will live just fine. and if you're going short stroke you may as well go for the 3" stroke with a 6.250" rod- but the rest of your engine will be QUITE expensive.
 

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7.5-8:11 CR would be a good compression to shoot for if your using a blower.
Forged pistons are a very good idea. You'll also want to get a cam designed for use with a blower, as they generaly have a wider LSA.
You ought to do some research on the torque capacity of the Jag rear end you have. I can't say from experiance, but from what I've read and heard, putting one behind a blown motor may not be a good idea. Jag engines are not really known for producing high torque.
FWIW
ssmonty
 

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Im back,,, If you build a blown,stroker small block of 377/391 range you could get 750 plus horse power using a 671 blower /roller cam and 195 heads. your throttle response will be instant. The car will scare the pants off ya.
lets go over the parts list you need/want. you can make 450 hp with out the blower,,,, post or PM the cam specs and what you have and lets shred some tires,,,seriously a blown big bore small block in a car weighing 2000 pounds will break the tires loose at 60 mph just by dipping deep into the throttle.
 

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7.5-8:11 CR would be a good compression to shoot for if your using a blower.
Forged pistons are a very good idea. You'll also want to get a cam designed for use with a blower, as they generaly have a wider LSA.
You ought to do some research on the torque capacity of the Jag rear end you have. I can't say from experiance, but from what I've read and heard, putting one behind a blown motor may not be a good idea. Jag engines are not really known for producing high torque.
FWIW
ssmonty
I agree with the 7.5:1 to 8.0:1 static compression ratio with a blower. That will allow you to push 8 lbs of boost into the motor on pump gas. I see the cam LSA differently though. Blower Drive Service says you can use a wider LSA on ALCOHOL, but 110 works best on gasoline.
 

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You're going to want more compression, at least 10:1 if you have a "big lumpy cam". 6500 RPM is EASY for just about any sbc as long as its well balanced and assembled. Your VALVETRAIN is critical though, if you're not worried about power go with a very mild solid cam, with beehive springs and you should be able to run stock rockers and valves.
Naturally aspirated, I agree you need more static compression ratio with a big lumpy cam. With a blower though, you need to reduce the SCR to prevent detonation and still run the big lumpy cam. Here's a recommendation from Blower Drive Service.....
Blower Drive Service: We Deliver Horse Power! - Blower Drive Systems, Blower Kits, Blower Cams, Custom Carb Service
 

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Naturally aspirated, I agree you need more static compression ratio with a big lumpy cam. With a blower though, you need to reduce the SCR to prevent detonation and still run the big lumpy cam. Here's a recommendation from Blower Drive Service.....
Blower Drive Service: We Deliver Horse Power! - Blower Drive Systems, Blower Kits, Blower Cams, Custom Carb Service
yea, I forgot the blower part- my mistake.

For good power with a blower you'll want a smaller cam than NA, with a slightly wider LSA. A "big lumpy cam" may just result in a lot of fuel consumption and heat rather than power.
 

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Discussion Starter · #13 ·
cam specs

i jus looked at the box... comp cams roller hydraulic lifters...
adv duration @ 286 both int/exh
@50 degrees- 230 both intake and exhaust
110 lobe seperation
w 586 lift int/exh
have roller rockers @ 1.6 ratio so should have plenty of air

never ran blower before...
thinking 1:1 ratio, looking for 6-8# boost

should push 500 hp?
 

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2000 lb car with a sbc and a 671. You wont need to worry about how fast it winds up. lol
Whatever you build just be sure the compression ratio and piston type are blower friendly.
My 1700LB t-bucket with a 142 blower winds up real fast and is a hand full.
 
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