More on Fans & Fan Clutches..

[Craig Jewett]

Thank you Jack for sharing your knowledge on fan clutch testing.

I have a couple of more questions re fans.. What is the correct fan assembly part number for a '67 327/350 with A/C ? Mine has a 7 blade fan with part numbers on each blade. At this moment I do not have the number handy. However, the NCRS Judging manual states that a 5 blade fan should be fitted, yet the AIM lists two part numbers for the fan under the C60 options section. There is an "optional" fan part number..could this be the 7 blade unit ? This would indicate that perhaps the Judging Manual should be revised. I had the car judged last week and was told that a 7 blade fan was incorrect...and received the "appropriate" deduction..

Thanks again everybody..

Craig Jewett # 28049 '67 L-79 A/C coupe

[Joe L.]

Re: More on Fans & Fan Clutches..

Craig----

According to the information that I have, 66(second design)and 67-68 327s with air conditioning used fan GM #3789562. This fan is an 18" diameter with 5 blades. However, 64-65 and first design 1966 used fan GM #3853943. This is an 18" diameter fan with 7 blades.

If I were you, I'd check the part number on the fan blades. If it matches the number presented in the AIM for either of the 2 "optional" fan blade assemblies, then I'd say you have a VERY good case for it being original.

[Joe L.]

Re: More on Fans & Fan Clutches..

Craig----

According to the information that I have, 66(second design)and 67-68 327s with air conditioning used fan GM #3789562. This fan is an 18" diameter with 5 blades. However, 64-65 and first design 1966 used fan GM #3853943. This is an 18" diameter fan with 7 blades.

If I were you, I'd check the part number on the fan blades. If it matches the number presented in the AIM for either of the 2 "optional" fan blade assemblies, then I'd say you have a VERY good case for it being original.

[Jack H.]

Re: More on Fans & Fan Clutches..

Joe gives you solid advice. In the late mid-year era there are known and documented cases of 5-blade/7-blade substitutions. I'd have to double check my JG set (not here) to see what MY cars the JG's actually do define the substitution sets for lie in ('65, 66 and/or '67).

But, Joe's point is read the PN that's wacked on your blades (actually I remembered the 7-blade fan coding/dating process starting after the mid-year era) and compare it what the AIM calls out as well as what's in the JG. Even if it turns out the fan is factory incorrect for your car, you just might have a windfall!

Shark A/C cars have 7-blade fans with P/N and mfg date codes embossed. Your 'trash' just might be somebody else's 'treasure' with you coming out ahead and helping a desparate Shark owner restore/maintain his car!

Last, don't believe EVERYTHING you hear at a given meet. There are so many judges to go around each with individual strengths/weakness. Take each deduct as what it is -- one/two man opinion that day given existing time constraints. Like the policeman that pulls you over and writes a citation, he's not the last word. There are higher authorities and you HAVE the right to question/appeal. Sometimes, in the process, NCRS and it's rule books gain from the effort....

[Jack H.]

Re: More on Fans & Fan Clutches..

Joe gives you solid advice. In the late mid-year era there are known and documented cases of 5-blade/7-blade substitutions. I'd have to double check my JG set (not here) to see what MY cars the JG's actually do define the substitution sets for lie in ('65, 66 and/or '67).

But, Joe's point is read the PN that's wacked on your blades (actually I remembered the 7-blade fan coding/dating process starting after the mid-year era) and compare it what the AIM calls out as well as what's in the JG. Even if it turns out the fan is factory incorrect for your car, you just might have a windfall!

Shark A/C cars have 7-blade fans with P/N and mfg date codes embossed. Your 'trash' just might be somebody else's 'treasure' with you coming out ahead and helping a desparate Shark owner restore/maintain his car!

Last, don't believe EVERYTHING you hear at a given meet. There are so many judges to go around each with individual strengths/weakness. Take each deduct as what it is -- one/two man opinion that day given existing time constraints. Like the policeman that pulls you over and writes a citation, he's not the last word. There are higher authorities and you HAVE the right to question/appeal. Sometimes, in the process, NCRS and it's rule books gain from the effort....