Automotive Air Conditioning Information Forum (Archives)

artieb on Fri March 21, 2014 7:53 AM

Year: 1995
Make: dodge
Model: Ram 2500
Engine Size: 5.9 dies
Refrigerant Type: 134a
Country of Origin: United States

Hi, I have a Sanden sd7h15 on a 1994 Dodge pick up truck with a 5.9 L Cummins. I would like to know if the Sanden SD7 enhanced is available, direct fit? If so what would the part number be?
Would newer replacements, ie four seasons, etc, be the enhanced version?
Are the SD7 really improved or just "enhanced"?
Last, do the enhanced use less horsepower to operate ? I sure appreciate help with my decision, Artie

ice-n-tropics on Sun March 23, 2014 6:20 PM

Following may be more than you want to know:
SD7 Enhanced is similar to porting and polishing & shaving cylinder heads. Downside is more pumping noise, but not discernible on a diesel.
Volumetric efficiency is increased through better breathing and more complete scalvaging of the compression chambers. Increased suction pressure inside the compression chamber results in more mass flow of refrigerant and horsepower increase. Deeper suction valve stops in the cylinder wall allow the suction valve to open wider analogous to a higher lift cam. Larger discharge holes in the valve plate and higher lift discharge valve stops allow the high pressure gas and oil mist to flow out easier. Wings on the discharge valve plate fill the gaps alongside the valve and reduce re-expansion. Shot blasting the discharge valve reduces the discharge flutter due to the Bournelli Effect (pressure/velocity pressure relationship) and oil stiction and wire drawing (inhaling discharged gas) is reduced.
Isentropic efficiency is improved which restores some of the horsepower penalty.
You could fit your diesel with enhanced by using your present cylinder head and clutch on a enhanced compressor body and valve plate assembly. Your limited rpm diesel could use a more efficient compressor to balance the low rpms.
Hope this helps,
hotrodac


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Isentropic Efficiency=Ratio of Theoretical Compression Energy/Actual Energy.
AMAZON.com: How To Air Condition Your Hot Rod

Edited: Mon March 24, 2014 at 10:13 AM by ice-n-tropics

artieb on Mon March 24, 2014 7:41 AM

Thanks ice-n-tropics, believe it or not, that's exactly what I wanted to know. Sanden ' s website has many specifications, pertaining to their pump, not vehicle application. I'll see if I need a compressor, then what would be involved in fitting an enhanced 7H.