65-396 fan configuration

[Jaime G.]

Can someone illustrate for me the differences between a 65-396 fan
and one for a 66-67 427 motor?
Thanks

[Wayne M.]

Re: 65-396 fan configuration

Can someone illustrate for me the differences between a 65-396 fan
and one for a 66-67 427 motor?
Thanks

Jamie -- here's two reproductions of the GM drawings (from Noland's Vol 2) for comparison.

You'll notice the reference to the 396 fan part # at the bottom of the drawing of that for the 427 #388366, as "similar to" the '962'.

[Mike M.]

Re: 65-396 fan configuration

Hi Guys,
Looks like the radius length is different.
792-17.0"
366-17.5X
The blade pitch shown on the 366 is 34.3 degrees.
I can't find verification of the 793. Maybe some else can confirm if there is a difference.
HaND

[Jaime G.]

Re: 65-396 fan configuration

thank you both

[Wayne M.]

Re: 65-396 fan configuration

Jamie, Mike -- Here's another theory of mine that relates to service 396 fan blade assemblies (and I'm sticking to it ).

The '65 L78 assy. #3872792 was still available as of Jan '70, as indcated in the P&A30B (Corvette-only parts catalog). [Joe L. may know when it no longer was].

The [then] owner of my 396 "probably" replaced the fan following a front-end incident with a school bus, in 1970 (He gave me some photos he took). He didn't replace the rad support, which he straightend (well, sort of ).

The fan's still on the car and is exactly the same as the '66-up big block fan (FRONT and H and '66' stamped on front hub; 'W' on the back of one of the spiders) EXCEPT the blades are each 1/4" shorter than those of the #3888366 (shown on dwg as 5.68" and 5.93", respectively, which results in the half inch diameter difference of these two assemblies. Otherwise the blades are the same (width and corner radii). No evidence of shaving the 1/4 inch off each blade, so I assume that the source supplier just continued to attach short blades to the '66-up BB hub/spider assembly, and they were still sold OTC under the L78 '792' part #.

[Jaime G.]

Re: 65-396 fan configuration

makes sense to me. I cant dispute the idea. Interesting
thanks for the research.

[David L.]

Re: 65-396 fan configuration

Both fan have the same pitch, about 2 1/4" (or about 34.5 degrees). The only difference must be the diameter, 17" and 17 1/2".

[James W.]

Re: 65-396 fan configuration

Pictures of my '65 396 fan.




Regards,

James West