big block comparison
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big block comparison
i am wanting to build a big block but i am new to chevy. when you compare piston to rod ratio, everything else being the same,compration,heads,cam,intake,exhaust . what engine is the best starting point,427,454,496. thanks
Team Owner
Joined: Jan 2006
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From: Crossville TN
An engine with larger piston-travel than piston-diameter (over-square) will produce more torque than one with shorter throw than diameter. But, the latter design will be able to rev higher. Choose your engine design according to what you expect from the engine.
Melting Slicks
Joined: May 2000
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From: Crescent City, CA
What are you going to use this engine for?
From an engineering standpoint, long rods are the only way to go in a short stroke, high RPM drag race engine. This is due to the fact that the piston dwells longer at and near TDC. With proper cam timing and header design, the additional dwell time will help with cylinder filling by effectively scavenging the intake tract. A secondary benefit of long rods is the fact that they will slightly reduce piston side loading.
None of this, however is much of an issue in a street or street/strip engine. An engine that is properly designed to benefit from long rods will be severly lacking in low and mid range torque.
For the street, go with a 454 stroker. You will love the torque.
Just my opinion.
From an engineering standpoint, long rods are the only way to go in a short stroke, high RPM drag race engine. This is due to the fact that the piston dwells longer at and near TDC. With proper cam timing and header design, the additional dwell time will help with cylinder filling by effectively scavenging the intake tract. A secondary benefit of long rods is the fact that they will slightly reduce piston side loading.
None of this, however is much of an issue in a street or street/strip engine. An engine that is properly designed to benefit from long rods will be severly lacking in low and mid range torque.
For the street, go with a 454 stroker. You will love the torque.
Just my opinion.
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i want it very driveable, using an automatic. tame enough for the wife to drive. want to get there ,not concerned how fast. would brefer torque ,off idle to 5500.has to have a great sounding sidemount exhaust tone and mild cam noise. and get decent mileage. pulling 3.08 gears ,like to get around 15 mpg. impossible? thanks
Drifting
Joined: Jul 2011
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From: Syracuse NY
i want it very driveable, using an automatic. tame enough for the wife to drive. want to get there ,not concerned how fast. would brefer torque ,off idle to 5500.has to have a great sounding sidemount exhaust tone and mild cam noise. and get decent mileage. pulling 3.08 gears ,like to get around 15 mpg. impossible? thanks
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i know that the way to go would be to install an ls motor, it wont be any cheaper and get way better mileage, but i has to have the kooks and feel of a big block. thanks for your help. it looks like i will build a 496,turbo 400 and 3.08 gears.
Burning Brakes
Joined: May 2008
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From: Middleburg Florida
My BB gets 16mpg on the highway with the A/C on, back in the day (late 70's early 80's) I got 9 with the 396 in my 69 Chevelle SS. So even though the vettes mileage isn't great, it's not too bad for warmed up BB. Guess I might have learned a few things in 30 odd years of this.... LOL!
Team Owner
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From: Crossville TN
Go with a 396 or 427 BB, if you want (instead of 454 or larger that will use more fuel). But install a 'mild' performance roller camshaft and a decent set of 9.0-9.5 CR heads on it. The car will be very driveable...even in city traffic; but it will have plenty of torque when you push the throttle down. Best of both worlds.
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Le Mans Master
Joined: Jan 2006
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From: Butler Pa
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
If you look in the engine compartment, any BB is still a BB. And any BB looks better in the engine bay than a SB (even though I have one).
The man didn't say he wanted a lot of power. Any BB will have plenty of torque for that vehicle.
P.S. I offered my opinion. Why don't you just offer your opinion....instead of passing judgement on mine.
The man didn't say he wanted a lot of power. Any BB will have plenty of torque for that vehicle.
P.S. I offered my opinion. Why don't you just offer your opinion....instead of passing judgement on mine.
Le Mans Master
Joined: Oct 2006
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From: El Cajon California
A 1970 Pontiac 455 will give you about 500 lbs of torque at 2900 RPM, it has a 4.21 stroke. I had a Firebird as a young man with an automatic and 3:55 gears. Instataneous torque is amazing to behold, not great for racing but was very fun on the street.
Melting Slicks
Joined: Apr 2007
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From: Tolland CT
Le Mans Master
Joined: Jan 2006
Posts: 6,497
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From: Butler Pa
