Finger Guard or Shroud?

From the questions asked of me by various Chevelle owners, it seems there is some confusion regarding the correct original equipment installation of plastic fan shrouds vs. metal finger guards on '66 SS Chevelle radiators. I would like to share some research I have done regarding this issue.

Since finger guards, to my knowledge, are not reproduced, and were not ordered as a separate replacement part, many people may not be familiar with a fingerguard. The finger guard is a small thin metal plate that extends from the top of the radiator, back over the radiator cooling fan area. The purpose of the finger guard was to provide a barrier for protection from a circulating radiator cooling fan. Plastic fan shrouds are readily available from many reproduction Chevelle parts vendors. Many Chevelles I see at various events have fan shrouds installed, some even have both the finger guard and plastic fan shroud. It is obvious the use of a plastic fan shroud provides improved air circulation and has assisted Chevelle owners in keeping their Chevelles cool. The need for, or the efficiency of fan shrouds is not the issue I want to address. The issue is, what was the original equipment installation on '66 SS Chevelle radiators, plastic fan shrouds or metal finger guards?

Over the years, it has been my experience that only '66 SS Chevelles with air conditioning or air injection systems, were equipped with plastic fan shrouds as an original equipment installation. To support my point, I offer information from three Chevrolet manuals. The first illustration comes from, Super Chevrolet Service Training Program Booklet, dated August '65. It was distributed by the Technical Service Department, Chevrolet Motor Division, General Motors Corporation. My reference is on page 106, section 13. This section is regarding Chevy II, Chevelle, and Chevrolet radiators. "Some radiators have changed and are new due to inlet fitting location which changes from the right to left side with V8 engines and also channel mounts for radiators used with RPO K19 (air injection reactor system) and A/C that must use new plastic fan shrouds."

The second and third illustrations are from the Chevrolet parts atalogs, dated October 1, 1965, and January 1, 1966. These catalogs were distributed to Chevrolet dealers by General Motors Parts Division, General Motors Corporation. I will be looking at page 76, section 1.277, titled, "Shroud Assembly Radiator Fan." The one listing in the October 1, 1965, printing for a '66 SS Chevelle with a plastic fan shroud, part number 3880679, has, "C.A.C., H.D.Radiator", in parentheses after the application listing. There is no listing for a one piece plastic fan shroud for any '66 396 SS Chevelle unless it had, "C.A.C., H.D. Rad." All C.A.C. equipped cars were required to have H.D. radiators. The Chevrolet parts catalog revised January 1, 1966, list part number 3891464 for a '66 Chevelle SS, El Camino "w/C.A.C., H.D. Rad., w/A.I.R., (396)."
Again, there is no evidence of a plastic fan shroud being installed as original equipment on any '66 SS Chevelle unless it met the C.A.C. or A.I.R. requirements. As the parts catalogs are updated, GM had a tendency to change some of the original equipment installations made during the model production year. I have other parts catalogs with later revision dates, but none indicate a update or change from the previous two parts catalogs given as references.
Some Chevelle owners have made reference to the '66 Chevelle Assembly Instruction Manual page 475 as proof that plastic fan shrouds were installed on all '66 SS Chevelles. This page illustrates a fan shroud with part number 3891464 being installed on all RPO L34, L35, and L78 Chevelles. Assembly Instruction Manuals were written many months before the cars actually went into production. These manuals were redrawn, redesigned and updated before and after production began. Some of the revision dates listed in the '66 assembly manual were dated March '65. That date was long before the production of the '66 Chevelle ever started. Also, at the bottom of page 475 in the "revision record" section at the bottom of the page, is a redesign and redrawn revision note. So, there was a revision of this page at a later date. I think the obvious question is, if fan shroud part number 3891464 was installed as original equipment on all RPO L34, L35, and L78 Chevelles, as the assembly manuals list, then why do they appear as replacement parts for, "C.A.C., H.D., or A.I.R." equipped cars only, in the Chevrolet replacement parts catalogs I have listed?

It is conclusive, after examining this information that plastic fan shrouds were introduced and intended for use on '66 SS Chevelles with air conditioning or air injection reactor systems only. To take this conclusion a step further since air conditioning was not available on any standard production '66 L78 SS Chevelle, one can conclude that no '66 L78 SS Chevelle had a fan shroud unless it had an air injection reactor system, which was usually reserved for West coast distribution. I also think, this same reasoning can be applied to the '67 model production year for SS Chevelles. The publications I have given as references are dated '66, but I have seen no revised information that would indicate a change for '67 SS Chevelles in the Chevrolet parts catalogs dated'67.

I have written this article to share information and knowledge with other Chevelle owners that are interested. There are exceptions to many policies and one "never says never." I think this information should be helpful if you have questions regarding the original equipment installation of a finger guard vs. a plastic fan shroud on your '66 SS Chevelle.

That is the way it looks from here.......Mr. Bill

 

1966     Some people say the Beaumont is similar to  aChevelle

Hi Andrew, I don"t care about  it looking stock or not, just trying to get it to run cooler especially down south in the summer. I have looked into the aftermarket shrouds, but they say that they are not attachable to my rad? See pictures in the thermostat thread. The thermostat I took out had the  4 holes in it, and I replaced it with a normal one (no holes) 180 degree . may try to look at the aftermarket shrouds again and see if they can be adapted. Also thinking of going to 160  thermostat, and 7 blade fan.   Ted

Hi, definitely take a look at the high flow thermostats (like a milodon or robertshaw). i see what you mean about the repro shroud, a factory rad must have had flange on the side for the shroud to bolt to... i would still try it, either attach it by using the same plastic ties that are used to hold on an aftermarket trans cooler (they clip through the rad, and work like a plastic zip tie if you havent seen them), if you didnt want a plastic one you could try an aluminum one (search the Howe Radiator Fan Shroud HRE-3407 at summit) and make brackets (have them welded onto the shroud to line up to the holes where the rad bolts to the spacer against the rad cradle)...

for a fan, use a factory gm 7 blade clutch fan... fan should be about 1/2 into the shroud...

changing to a 160 stat shouldnt make a difference (only if your 180 is malfunctioning)... try it without a stat first and see if it heats up... good coolant/air flow is the most important thing

ak

Good to hear that the Beaumont is running good. Are meeting us for the all Pontiac show?