Thread: advice on 489

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im in greenfield nh, according to google im about 840' above sea level. at work right now, but i will take a look at that link when i get out. one of the things im considering is building the motor for use with the blower, but running it without one until i can afford one.... will 8:1 scr be a complete dog without that blower?

Originally Posted by cvfb97

im in greenfield nh, according to google im about 840' above sea level. at work right now, but i will take a look at that link when i get out. one of the things im considering is building the motor for use with the blower, but running it without one until i can afford one.... will 8:1 scr be a complete dog without that blower?

Let's see what pistons are available to match up with the available chambers, then decide what to do. Naturally aspirated at ~8.00:1 wouldn't necessarily be a dog, but it wouldn't be a world beater either. Ideally, you would want to run less cam to match up with the 8.00:1 static compression ratio running naturally aspirated, then change back to more cam with the blower. The bigger cam might be OK though, with the 3000 stall converter that i suggested.
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Pump gas----------for whatever you may end up with-start looking around at the different stations to see what they have for octane ratings AND what ones have E85-------

Crankshaft---------is the one you have cast or forged????????
a properly balanced BBC forged crank will take whatever you can throw at it if your clearances and oil supply is adqute------

If you lower your CR enough to be able to run higher boost at times-----------you will have a terrific time keeping your fuel mixture in your tank up to the Octane you'll need when you do decide to stand on it-----------Supercharged BIG INCH engines are unnecessary on the street and those engines are real pooches at lower speeds-( do you use VALET parking?)

the stock stroke one that came with my block is cast, was planning on getting a pre-balanced stroker kit (forged pistons/ rods, cast crank). when i get the supercharger i plan on removing the rotating assembly, adding a forged crank and having everything balanced together. If anything did somehow happen to the forged crank i would at least have a spare

would ~9:1 with an intercooler on 4psi running 91 be a happy medium?

Originally Posted by cvfb97

would ~9:1 with an intercooler on 4psi running 91 be a happy medium?

Yes, but I would just as soon run naturally aspirated with juice as I would to throttle down a good blower build. It would be far less expensive and the output would be close to the same in my opinion.
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You seem a little new to the engine build---How do you know the crank is cast? The cost added to "balanced assy " be negated if you take it apart to change ANYTHING with a crank change--put in the best one first time with rods and pistons that will work with the blower------4psi won't do much for you except at wide open and you will just get blown away by someone else running 6 psi------