My 1883cc Porsche 356 912 Blog

Chronology of a hot-rod street Porsche 356/912 1600 to 1883cc conversion based on LN Engineering's Nickies big bore kit.

Monday, July 31, 2006

Fan Belt

I had been working on my 356 and noticed that the contitech fan belt was tighter than the fan belt on my 912, which had a Gates belt procured from Napa. It also would appear that the Napa belt was also a bit longer by how it sat on the pulley. The top of the belt was roughly at the o.d. of the pulley, and even with one shim only between pulley halves, the belt had at least an inch of deflection.

I decided to try installing a Contitech belt, 10x825, that I bought from Zims. With very little deflection, probably a hair higher than the factory spec, it took four shims between pulley halves rather than the single shim before wth the Napa belt.

Now to the oil testing results. From my last run with the Napa belt, here were the results:

Stop 1: 204F
Stop 2: 214F
Humidity: 60%
Barometer: 29.86 In Hg Falling
Outside Temp: 95F (109F heat index)

Now, with the Contitech:

Stop 1: 202F (200F)
Stop 2: 202F (200F)
Humidity: 64%
Barometer: 29.82 In Hg Rising
Ouside Temp: 97F (115F heat index)

It would appear that the new, correct diameter belt helped reduce the oil temperature. I also noticed that the head temperature dropped significantly, about 25-35F and once the load was reduced, the head temps dropped faster.

Moral of the story, make sure you have the right fan belt :-)


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