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Discussion Starter #1
My truck, 1976 Dodge D-200 (3/4 ton) with a 318, is being transformed into a mud truck.

I have a few questions about what can and can't be done with my motor to give it a little ''boost'' of power.

Current setup;
Mopar 318 stock
2 Barrel carburetor (500cfm holley)
10.5:1 compression
(currently dynos at 324 horses at tires and 631 torque)

I want the truck to have alot of power without going to bigblock.
I have been thinking of a Blower for this motor for some time now. My question to you is this what is the difference of a 4-71 6-71 and 8-71.

I would like to produce and extremly high amount of power and torque. The motor does not have to last (I have about 12 318s lying around the house. But the truck needs enough power to get to some of the thickest mud (also 4 feet deep).

A nitrous shot of 250 will also be on the motor.

What would be the best blower?
Eric
 

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If you put a blower on it wouldnt it suck in all the mud or will you have somekind of system for that? because even an air filter will get clogged really fast.
 

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Sounds like a wild project! The 71 series of GMC blowers are sized to fit diesel engines with identical bores and strokes > 71cuin displacement per cylinder, just different number of cylinders. Thus the make 3-17, 4-71, 6-71, up to 12-71 blowers. A 6-71 goes on a 6 cylinder engine with 71 cubic inch displacement per cylinder for a total displacement of 426cuin. Thus the 6-71 is the proper choice for most medium sized V8s.
 

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Discussion Starter #6
Dont ask me how that happened.... had it dynoed at the local machine shop and that was the numbers the computer spat out. So a 6-71 would be a perfect sized blower. What would going overkill on a blower do?

Eric
 

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These are positive displacement pumps so you would start blowing seals, over-pressure the cylinders and blow the heads off the pistons when the charge ignites and stuff like that.
 

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Good eyes Bracket! Didn't notice that detail. Yes, 10.5:1 compression + roots supercharger AND nitrous; how far do you think he can launch engine parts? I'm guessing at least 1/4mi.
 

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Discussion Starter #11
I've 12 of the motors, not sure if I'm going to run nitrous yet. I'll be videoing the mud pit so if it explodes you can see it for free. lol.

I'm getting a 4-71. Should be better then the naturally aspiration. Even with the ''chance'' of it exploding, if it does i'll measure the radius for all of you...

Eric
 

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Please if you are serious about a supercharger, change your pistons for 8.5:1. I guarantee if you keep the 10:1, you will grenade the engine with even a small boost in pressure.
 

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Id be talking to a different machine shop. Its not exactly easy (not especially hard though) to make a NA 318 produce 324 but their torque number is way off.

I don see any way that your 318 is producing 600+ lb. ft of torque.
 

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Discussion Starter #14
I'm not that woried about the engine in it now, I ordered pistons for another one of the 318s so I will have an engine with a 7.8:1 compression ready for when this motor explodes its enevidible it has well over 300K on it, It needs to be sent to heaven, I strengthen the firewall if that makes you feel any better.

Not sure about the torque, thats what they said. I know I have 7.17 gears in the rear end (Dana 60) yes they do go that high. Would that cause that reading?

Eric
 
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