Bore x Stroke x Boost = ??
03-10-2006, 03:00 PM
#1
Bore x Stroke x Boost = ?? Just a question ive been thinking about. I see alot of people building strokers for boost. Naturally aspiratated its good for torque, but boosted is it as beneficial? Or would a short stroke big bore engine be a better boost engine?
Since it is forced induction I would think that less rotating mass would be a better route.
I plan on building a shortblock in the near future, just trying to figure the optimal combo for a turbo.
Anyone have any info on this or am I going to have to experiment?
thanks.
Since it is forced induction I would think that less rotating mass would be a better route.
I plan on building a shortblock in the near future, just trying to figure the optimal combo for a turbo.
Anyone have any info on this or am I going to have to experiment?
thanks.
03-13-2006, 12:52 PM
#2
Originally Posted by pwrtrip75
Just a question ive been thinking about. I see alot of people building strokers for boost. Naturally aspiratated its good for torque,
Actually, it just the increase in cubes that boosts the power. More torque via a longer arm/lever is an urban legend!
03-13-2006, 11:14 PM
#4
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Big bore/short stroke vs. long stroke/small bore has been a discussion that reaches back 40 years! I'm serious!
Long stroke seems to bring in lower rpm torque. Short stroke wants higher rpm. The original Chevy Z28 (IIRC 305 ci) was a short-stroke, high-winding small block that made amazing hp up high, but gave way to the 350 SBC for everyday driving and streetability. The power curve is what you want to tailor for your specific application, If you want 8500+ rpm, the short stroke is nearly the only answer. For anything less, say 7000-, the trade-off is a lot less clear. Have fun and good luck.
Long stroke seems to bring in lower rpm torque. Short stroke wants higher rpm. The original Chevy Z28 (IIRC 305 ci) was a short-stroke, high-winding small block that made amazing hp up high, but gave way to the 350 SBC for everyday driving and streetability. The power curve is what you want to tailor for your specific application, If you want 8500+ rpm, the short stroke is nearly the only answer. For anything less, say 7000-, the trade-off is a lot less clear. Have fun and good luck.
03-14-2006, 04:28 PM
#5
My combo: 8.5/1 compression, AFR 210's, 224/236 cam, LT4 intake, 58 mm TB, T-76GTS turbo at 13 psi, Custom 450 ci water/air intercooler, TH350, Vigilante '0' pump.
383 cid (4.030 x 3.75): 604 rwhp
363 cid (4.060 x 3.50): 572 rwhp
383 cid (4.030 x 3.75): 604 rwhp
363 cid (4.060 x 3.50): 572 rwhp
03-14-2006, 06:20 PM
#6
If you are going turbo, I would choose the shorter stroke. You will be able to spin the motor higher with a shorter stroke and increase your usable RPM band. An extra 1k rpm can make a big difference if your setup lags (ie big turbo). The extra 1k rpm under full boost up top is going to greatly offset any low-boost rpm toque increase that you would see from a stroker motor.
