C2 By Pass and Expansion Tanks Hose Camps

[John F.]

I have an early 66 L79 Coupe that a previous owner frame off restored nicely, but with quite a few aftermarket parts. I am currently sorting through it and trying to correct judged parts as is practical. Right now I am fixated on hose clamps, specifically for the bypass hose and the expansion tank hoses. Between the Tech Board & Archives, TIMJG and AIM, a couple of experienced judges, sellers of alleged correct parts, and photos of supposed original cars, I am confused on correct clamps and which ones had what specific screw/screw head. Has there ever been a technical article or survey of C2 hose clamps that I'm missing?

Can anyone offer difinitive insight into the correct brand and stamped # for the hose clamps and the correct screws/head types for the L79 bypass hose, the Expansion Tank short hose to the heater hose T (pn 111607), and the balance hose (pn 274337)? Which slotted fillister head clamps screws should have the washer/shouldered heads?

Thanks

[David B.]

111607 Type B hose clamp, steel rust proof - regular band, 10-24 Fill. HD slotted screw, clamp size 1-1/32, .38 gap screw length 1.00,
band width .50, Dia. open 1.111, closed .96
274337 Type D hose clamp, fillister washer head screw, size #23, screw length 1.12, band thickness .028/.024, gap .38

[John F.]

Thanks David. Great info!

John

[T P.]

I have found 3 different L79 bypass clamps that were produced: pictured here as Clamp A, Clamp B, & Clamp C.
The 1965 AIM doesn't appear to denote a part number for the bypass clamp. Doc Rebuild claims there was a 1st design [Clamp B] and a 2nd design [Clamp C]. Can anyone comment on Clamp A? Which is correct for a '65 L79, and will here be point deduction for using one of the other two clamps?
Clamp A.jpg Clamp B.jpg Clamp C.jpg

[Don H.]

Roland, the 65 JG calls for either the closed A 4 3/4 clamp or the open style clamp, WITH 1" flilster head screw. And, the hose and clamps are worth 2 Orig points.. Whichever clamps of those shown in your post will not reach the level of 1 point deduction.

[T P.]

Don, thanks for responding. Just to better understand, my '65 TIM&JG 6th ed., p. 159 says hose is secured by "side-screw type clamps with 1" Fillister slotted screws"; and image M13-9 shows a clamp like the 'Clamp A' that I posted. So then, do you mean that any of the clamps I posted in addition to Clamp A will pass judging with out deduction and if Fillister screws are used?

[James W.]

John,

Here are my Wittek Mfg. Co. #2 expansion tank to radiator hose clamps from my mid-July built 1965 Corvette equipped with it's original L79 engine. I do not have a 1966 AIM, but the 1964 and 1965 AIM shows these two clamps as GM p/n 274337. The '65 TIMJG also calls out these clamps.

Hope this is of some help for you.

James

[T P.]

Thanks James for that info as well. But I'm asking about the clamps for the water pump bypass hose that goes from the top of the pump to the engine.

[Don H.]

Roland- I'm saying that any of the clamps you show, with Filister head screw, are identified as typical in the 65 JG.. And, that only 2 points are available to deduct if warranted for hose and clamps. Will those clamps "pass judging" without deduction? They should. But, different judges have different ideas. I'm saying that if you split the points between the hose, and the two clamps, you only have 1 point to deal with.. Using CDCIF in judging Originality, it should be impossible to take a point for the clamps if any of the three are used.. drop me a pm if you care to dig down deeper on this. I'm happy to help. good luck,

[Tony S.]

John,

Here are my Wittek Mfg. Co. #2 expansion tank to radiator hose clamps from my mid-July built 1965 Corvette equipped with it's original L79 engine. I do not have a 1966 AIM, but the 1964 and 1965 AIM shows these two clamps as GM p/n 274337. The '65 TIMJG also calls out these clamps.

Hope this is of some help for you.

James

James, great examples of the radiator-to-expansion tank hose clamps!