what is correct fan clutch code?

[Garry B.]

I know what the jg says, but what is the correct fan clutch code for my '67 327/300 with factory AC? Thanks.
Garry

[Tony S.]

Re: what is correct fan clutch code?

Garry, what do you mean by the fan clutch code? A small block may have the initials CJ and a date code on the face of a Eaton FC.
The Schwitzer FC may have a CJ on the face and a date on the outer attachment flange.

Tony

[Garry B.]

Re: what is correct fan clutch code?

Tom, yes you interpreted my question accurately. My question back to you is you state "may have" a CJ in both of your examples? I am sure many have lost their ink stamp over the years and there are other ways to determine the correct one such as shaft length. Is there a specific code for SB with AC, or were they all CJ. I am working towards having the car judged and will need to show the correct code and possibly date. Thanks for your response. Garry

[Edward J.]

954581BC-AC9F-4E8F-8E5E-7DADD00127E0.jpg

[Tony S.]

Re: what is correct fan clutch code?

Garry, the existence of A/C has no impact on the coding on a FC. It is either a small block (CJ) or a big block (CK).
The example that Edward posted is a small block dated April 12, 1968 (D12I).

In 1965 and 1966, I would expect a FC to have either a CJ or a CK on the face of the FC. I'll let Jay or Reg answer the FC question for 1967.

1963 and 1964 cars may, but research continues. Some have suggested that the CJ/CK distinction didn't come into play until the introduction of the first big block in 1965. The difference between the SB and BB FC is the length of the shaft. The BB shafts are shorter due to radiator clearance.

So to answer your original question, if you have an Eaton fan clutch, I would like seeing the stamped date code and the CJ on it. If you present your car with a Schwitzer FC, then I would like to see a CJ stamped on the face. As for dating of the Schwitzer, dating didn't start until the 1965 model year although they were used earlier than that during C2 production.

Hope this helps.
Tony

[Garry B.]

Re: what is correct fan clutch code?

Tony, I know what I have on my car now is not correct. It is a SB factory AC car, but the prior owner installed a seven blade fan and a CK fan clutch that looks to be a reproduction. Pretty clear he wanted more air flow with AC on. So, I have found a correct 18" five blade fan and want to be sure I have the correct fan clutch. I believe CJ is the right code but wanted to confirm. I am still interested in knowing what a judge would expect to see on a '67. but suspect it will be the same. Thanks.

[Tony S.]

Re: what is correct fan clutch code?

Gene Leonard and I are the National chassis judges for the 1965 and 1966 teams. We don't judge on the 1967 team. What does the 1967 TIM JG say?

[Garry B.]

Re: what is correct fan clutch code?

6th edition says CJ for SB and CK for BB. I suspect it is the same as '66 and possibly '65. I kept running into people making comments on various sites as having a CK coded clutch fan on their SB Corvettes, so it was time to come to the people who know. There is even one CK for sale in the NCRS classifieds that says it came off of a SB. May have, but not correct application apparently.