Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

[Larry M.]

The attached pic may not be a correct clamp but it serves to ask a question. There is a slot on the lower side(left side in pic) where the tab is sheared out and then bent up. That is fine but my question is the slot on the top side(right in the the pic) where the end of the tab feeds as the clamp is tightened. On this pic and on the clamps I just bought from a supplier this top slot is long(like the pic), maybe a half inch or so. For the ones on my car, which I'm fairly sure are not original, this top hole is not really a slot. It is more of an oval or slightly elongated round hole. I've been looking at picture books....Adams and VetteVues....and I see both I think, although there are not many clear pics. Is one of these configurations or both correct...or neither one. The by pass clamps are 11s and the expansion tank are 10 1/2s. This is consistent between the two. The screw heads are fillister. I've noticed that on my clamps with the elongated hole that the tabs are not reliably feeding through the hole but may just force their way under the clamp band as tightened.

[Page C.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

Hi Larry,
I have these clamps on 2 of my 1965's and have seen them on many others. These are on the short hose between the expanison tank and the Tee. There are probably other manufactors as well.1963-67 Expansion Tank to Tee Clamps.jpg

[Gene M.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

Larry,
I found two types of clamps used in this application. One is like what Page shows in his photo. But most of the originals I've looked at have a flanged fillister head screw. The other type is a Whittlock made clamp. Totally different in appearance but both just as common. Originals as far as my experience goes were not hex head screws. The square nut on the two types are not interchangeable (same thread but different size).

[Larry M.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

Page and Gene....thanks for your input...I went back and found a picture Bill Mock posted which show the ones like Page's on an original 64....but Gene, for the Wittek,versus the other pic I posted, did they have a longer slot, maybe 1/2 inch, or a barely elongated hole to the right or were they for all intents like Page's which I don't think are Wittek?














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[Larry M.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

I've posted a picture of the clamps I have on my car, same type in both locations, just different sizes. This illustrates what I mean by an elongated hole in the clamp. It is clearly not a 1/2 inch slot as my first picture depicted. So the question restated is this. Even though a repro, is the style of clamp in this picture right for a midyear bypass or expansion tank? Or is this just an incorrect clamp?

[Bob J.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

Incorrect clamp for your 64.

[Larry M.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

OK. So the original Wittek clamps, similar to the first pic I posted, are 10 1/2 and 11 respectively. I don't know the maker on the ones like Page and Bill have in their pics but it appears the numbers are A4 1/2 and A4 3/4 respectively. I'm guessing about the 4 3/4 but it seems you can almost read it in Bill's motor pic. Is A4 3/4 correct?

[Bob J.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

OK. So the original Wittek clamps, similar to the first pic I posted, are 10 1/2 and 11 respectively. I don't know the maker on the ones like Page and Bill have in their pics but it appears the numbers are A4 1/2 and A4 3/4 respectively. I'm guessing about the 4 3/4 but it seems you can almost read it in Bill's motor pic. Is A4 3/4 correct?

A 4 1/2 = original expansion tank clamp
A 4 3/4 = original thermostat by-pass clamp 63-65 SP/HI PERF & FI

[Larry M.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

Ok- I have a firm line to buy both of these clamps but I need some guidance. The A4 3/4s have slotted pan head screws which are wrong so I'll have to change them but for the A4 1/2s I have two options. One is the slotted fillister which would be exactly like the picture Page posted above. The other is a "flanged fillister". The seller, who is a low number NCRS guy, says the flanged is correct for the "majority" of cars with usage from 1960 through all C2 SHP. He thinks that American Stamping went through a progression of the heads: Flanged Slotted Fillister to Plain Slotted Fillister to Flanged Slotted Hex to Slotted Pan. My car is November 63. Does anyone know what is right other than Page saying that two of his 65s have the plain fillister.

[Larry M.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

I wanted to re-open this, maybe to brag a little, but also to give others some encouragement. This thread is from over two years ago from which I learned that I had the wrong clamps on my car and what the right ones would look like. The source I thought I had above really did not know what was correct. Since that time I've looked at essentially every clamp posted on ebay and I finally got lucky. Over time I've bought five A4 1/2, one A4 3/4 and about ten 4 1/2's, all used, some in decent condition. But the crown jewel finally came. I bought the four NOS A4 3/4's pictured along with some other NOS non Corvette clamps for $9 delivered. Sometimes you just get lucky. The screws are wrong per the picture Bill Mock sent me but that is easy to fix.

Maybe there are plenty of these at Carlisle or other places but I don't think so. To me it was like winning the lottery.

[Larry M.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

Hopefully a better picture

[Tony S.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

Here are a couple good photos of an original '65 clamp. Notice the shouldered bolt head. Hope this helps. Tony

[Michael J.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

The original owner of one of my '64s sent me a bag full of all the original clamps, some like this, that he had taken off when he updated the car about 40 years ago to modern clamps and fasteners, as some of the originals were leaking. I kept that bag and have been slowly restoring them and putting them back on. It is like winning the lottery, he was amazed I wanted them, I was amazed he saved them.

[Joe R.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

ALL the pictures above Tony Stein's pics are wrong in some way. Mostly the screws are incorrect. Tony's clamps are correct in every aspect. If you got them, use them. All the others are just repos or reproductions.

JR

[Larry M.]

Re: Expansion Tank and By Pass Clamp Configuration-C2 SHP(64 FI)

Joe, read the thread. Tony's are for the radiator to expansion tank. They are correct; I have the originals replated and four NOS originals for my car, but they are not the subject of this thread. All of the other pics are either from the expansion tank to the Tee or on the water pump bypass, A4 1/2 and A 4 3/4 respectively. The pic in post #4 above is from Bill Mock of an unmolested 64 fuel car. It is an A4 3/4 clamp. The NOS clamps I just bought are EXACTLY like his pic except the screw and the stamping is in the reverse direction (which i think is inconsequential).