Unusual Intake Manifold for SBC-Thermodyne

By reading the dyno results this manifold did EXACTLY what was intended. 5 hp more over stock at 2500-3000 rpm right where engines run 99% of the time. I’ll bet it was better from 1500 up to 2500 but wasn’t tested or reported there. It’s just like taking off a 750 Holley and installing a 465 Holley. Better low end response and drivability due to atomization and a higher vacuum signal by the venturiis. Just not the hp at 5000-6000rpm where engines never drive.

 

I'm thinking Mack's version was light years better lol...

 

Thermodyne was an emblem on 50's Mack B trucks...It was the name of their Diesel engine.....

 

Up in the 70’s also. Drivers didn’t like them because you didn’t shift them much. Wife’s cousin had one hauling a moving van trailer. Got 5mpg and only had a 5 speed trans. I drove it once from Lemore to Kingsburg Ca. Great torque.

 

Actually, that was the Maxidyne- and every driver I know loved them, including me, be cause you don't have to shift much- you just had to get used to it. Peak torque at 1200 RPM and sounded great doing it

 

The Thermodyne was the exact opposite. Very narrow power band, and if you got out of the power band, you better be shifting or getting off the throttle, because the EGT's would go through the roof and you would melt a piston quickly. Not unusual to find old Thermodynes with 5x4 transmissions (20 forward gears).

 

Here ya go…..

 

Thanks.