70 SB Non-AC Heater Hose Clamps

[Pat M.]

Hi everyone. I was surprised to see that my JM seems to indicate that only my 1 & 1/16 heater hose clamps should be dated Wittek tower clamps, and that my 1 & 3/16 clamps should be DMC tower clamps without a date.

Is this correct? I thought I'd seen other sources indicate that all my heater hose clamps should be dated Wittek clamps.

Any help would be appreciated.

Patrick Moresi #45581

[Terry M.]

Re: 70 SB Non-AC Heater Hose Clamps

"I thought I'd seen other sources indicate that all my heater hose clamps should be dated Wittek clamps."

Patrick you may have seen that from other sources -- they are wrong.

[Pat M.]

Thank You Terry *NM*

[Geoff C.]

What is "DMC"? *NM*

[Terry M.]

"DMC" is a typo

The clamps say DCM. The TIM&JG should say the same. The judging manual explains the meaning of the abbreviation -- or at least the versions of the manual I was responsible for did -- I would have to look in the new manual to see if the explaination is still there.

[Pat M.]

Re: "DMC" is a typo

Terry - as I recall the latest version of the JM lists "DMC", which is a typo as you say, and there is no explanation other than to say it represents the manufacturer.

[Dick W.]

Re: "DMC" is a typo

Copy of manual I have says DCM

[Pat M.]

Re: "DMC" is a typo

Dick - page 86 of my Fourth Edition 70-72 JM clearly says DMC, in bold caps.

[Dick W.]

Re: "DMC" is a typo

Hmm, that is interesting. I wounder how it got changed. I have the master copy of the manual on disc with the DCM.

[Dick W.]

Re: "DMC" is a typo

I guess we start on revision 1.01 or the 4th edition. It is a never ending process, the more you learn, the less you know

[Pat M.]

Re: "DMC" is a typo

Dick, you all do great work on a thankless job on the JMs.

And this is a pretty insignificant typo, but for whatever reason mine has it. Send me your email address if you'd like to see a picture of it.

Best regards, Patrick Moresi #45581

[Terry M.]

Re: "DMC" is a typo

Someone was thinking of the music (if one can call their style music) group: Run DMC

[Terry M.]

What is "DCM"?

DCM is Wittek's abbreviation for "dichromate"

There were two sizes of heater hose tower clamps to go along with the two different size heater hoses.

One size of tower clamps had the size designation and date stamped in them and the finish was the as-cut galvanized surface.

The other size tower clamp, stamped DCM, got a dichromate wash after assembly, which lift a slightly yellow finish. This was done so that the installers could tell the different sizes at a glance. Both Wittek and Chevrolet believed it was important to use the proper size clamp for the diameter of the hose.

As an added piece of information: The folks I talked to at Wittek stated that their largest difficulty with tower clamps was excess torque used in installation. The diameter of the screw used on these (heater hose and AIR hose) tower clamps was designed so that if too much torque was applied the screw would sheer before the clamp broke or the nipple deformed. The reproductions I often see use a larger diameter screw than the originals, and thus this "safety" feature is defeated.