6-71/8-71 history

[Oilburner]

I know the 6-71 and 8-71 were originally on the old GMC 'Screamin Jimmies', but how are the different from the one used on gas engines?

 

[Riley P]

67Heaven, where are you? But first, let me giver a shot as I really want one of these on my Chevelle some day.

Technically, the 6-71 and 8-71, etc were Detroit Diesel engines (Detroit Diesel being a division of GM). Each cylinder displaced 71 cubic inches and the 6 and 8 correspond to how many cylinders the engine had. They came in 1, 2, 3, 4, 6 cylinder versions as well as V-6, 8, 12 and 16 cylinder variations. They had suffixes on the end of the engine name stating whether they had turbos, an intercooler, or roots blower (what we call the 6-71). However, an engine could have all three which would be called a 6-71TIB. As so many of these engines used the roots blower, people adapted them to their car engines and I'm assuming because these blowers were known to the Detroit Diesel engines, people just named it after what engine it came off of.

 

[buckhorn76]

add enderle injection and some 90/10 and hang on. " nitromethane - breakfast of champions "

 

[Oilburner]

I'm famiar with the Detroit side of them, but how different is a roots blower on a diesel compared to a store bought performance (hotrod) blower.

 

[buckhorn76]

the manifold, plenum, and drive are different. blower is basically the same , the rotors i believe are machined a little differently and the tolerances are better.

 

[Riley P]

I'm famiar with the Detroit side of them, but how different is a roots blower on a diesel compared to a store bought performance (hotrod) blower.

Feel free to ignore my post then! The question you asked is actually quite good and now that I know what you were asking, it's good to hear and find out what the differences are.

 

[67HEAVEN]

67Heaven, where are you?

I've had little interest in drag racing over the years. My main interest is directed towards road course racing, the type of racing best suited to sports cars like the Corvette. And, Corvette's IRS isn't really suited to hard-off-the-line drag racing anyway. Corvettes excel where it counts - turning corners.

Thus I have no interest in and know little about blowers.

One of those pieces of furniture sticking through the hood makes it difficult to see around the corners at tracks like Mosport.

They belong on drag racers or in car shows.

 

[buckhorn76]

and they enjoy nitro more than angina patients !!!

 

[Oilburner]

Good point 67heaven! Although it will be some time before my project gets to that point, its something to think about.

 

[buckhorn76]

67 is right on the money. the last successful competetive corvette drag cars were the c2's due to the solid rear end. a c3 rear just won't withstand the shock of hard launching and he who launches hardest and straightest wins. even with with high dollar beefing up most likely there will be 1/2 shaft and yoke shrapnel, not to mention fluid, everywhere.

 

[67HEAVEN]

67 is right on the money. the last successful competetive corvette drag cars were the c2's due to the solid rear end.

You probably meant to type C1

 

[67HEAVEN]

most likely there will be 1/2 shaft and yoke shrapnel, not to mention fluid, everywhere.

 

[buckhorn76]

yup, c1 bob. some-teimers is kickin' in again !!!

 

[CCO]

yup, c1 bob. some-teimers is kickin' in again !!!

A common aflicshon.

C.

 

[Oilburner]

Thats awesome - looks like a drill bit!

 

[Oilburner]

I understand there is a lot of other mods for a 1/4 mile car, steering, suspension etc. I'm not there yet, but I am interested in big power! I know I can't afford to go as big as I want but its nice to know how its done. It looks like there is a lot of knowledgeable people here - thanks for all the input, keep it coming!

 

[67HEAVEN]

Big torque...sticky rubber...and an IRS can easily result in this.

As you visualize the loose ends of a half shaft flailing around just behind your seat, try to imagine what the fibreglass floors and stowage compartments end up looking like in the aftermath.

 

[Canuk]

Big torque...sticky rubber...and an IRS can easily result in this.

As you visualize the loose ends of a half shaft flailing around just behind your seat, try to imagine what the fibreglass floors and stowage compartments end up looking like in the aftermath.

That is why anyone with big power in a C5 or C6 vette is a fool not to get these.....

ECS Axle Safety Loops


They went on my car at the same time as the blower.

 

[buckhorn76]

mandatory at tech too, no ?

 

[Oilburner]

Big torque...sticky rubber...and an IRS can easily result in this.

As you visualize the loose ends of a half shaft flailing around just behind your seat, try to imagine what the fibreglass floors and stowage compartments end up looking like in the aftermath.

I've something similar on an oilfield vac truck. When the drive shaft got loose it took out everything in its reach! Couldn't imagian the carnage it would do to a fiberglass vette!