Pros/Cons 383 vs. 454
04-18-2007, 04:31 PM
#1
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Pros/Cons 383 vs. 454
Ok guys I'm in the process of deciding what I will use to power my next and hopefully final project.
It's a 1985 Scorpion 24' that weighs approx. 4500 - 4700 with engine, drive, fuel etc. It currently is set up with a 454 400 cyclone and TRS.
Core Requirements: 75 mph and as reliable as possible.
I want to know what would you do? I'm thinking a mean 383 or do I go 454 or 502? Give me all your input.
Please pass the popcorn.
It's a 1985 Scorpion 24' that weighs approx. 4500 - 4700 with engine, drive, fuel etc. It currently is set up with a 454 400 cyclone and TRS.
Core Requirements: 75 mph and as reliable as possible.
I want to know what would you do? I'm thinking a mean 383 or do I go 454 or 502? Give me all your input.
Please pass the popcorn.
04-18-2007, 04:51 PM
#3
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You will get more bang for your buck with the big block. But I am in the process of installing two 383 MPI's in my 23' Formula. I am a small block guy at heart..... comes from many years of oval racing.
There's no replacement for displacement..... except for RPM and airflow.
A 8000 RPM small block aint gonna work in a boat, so you have to supercharge it to get that kind of power.
There's no replacement for displacement..... except for RPM and airflow.
A 8000 RPM small block aint gonna work in a boat, so you have to supercharge it to get that kind of power.
04-18-2007, 05:45 PM
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basicaly it comes down to power to weight. to move weight you need torque and that will only come from cubes. reliably anyway's. small blocks are great for say a 22 velocity or donzi. but i would think a 500 or 525 would do it with great resale and reliability.
04-18-2007, 05:58 PM
#7
My 502 MPI Mag ... 500 EFI cam ...Crane Roller Rockers ...good exhaust ...= ~ 500hp .....
The Square Root of (Total Shaft Horsepower / Weight ) x Constant = Speed
Square Root of (500/ 4700 ) x 250 = 82 mph
Drop it in .. turn key ... go ..... 7000.00 delivered ....
The Square Root of (Total Shaft Horsepower / Weight ) x Constant = Speed
Square Root of (500/ 4700 ) x 250 = 82 mph
Drop it in .. turn key ... go ..... 7000.00 delivered ....
04-18-2007, 06:27 PM
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Last year I built a 383 that should put out 400Hp (no dyno #'s but a extremely similar build put out more with worse heads)
However, I have more $ into than a crate 502
Just like offthefront says.
However, I have more $ into than a crate 502
Just like offthefront says.
04-18-2007, 06:35 PM
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Is there something missing in your formula?
EDIT: OK, square root of the function (500/4700). I guess that's why the parenthses! Duh!
Last edited by jayhawk261; 04-18-2007 at 06:37 PM.
04-18-2007, 08:16 PM
#10
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Boy, is this ironic! I just finished on the dyno today with a 383 Chevrolet small block combo. Engine has 10.2:1 compression, hyd. roller camshaft, 1X4 750 Holley carb, Brodix Mild ported heads. Single plane intake. - 485 ft.lbs of torque and 508 HP. Marine application. Engine was dyno'd on 91 octane unleaded.
