Dewitt's petcock; one point deduct

[Gary B.]

I was told by someone who bought a Dewitt's radiator for his small block '66 that he lost one point for originality at a regional judging event for the petcock on his Dewitt's radiator. He said the original petcock used a long, aluminum bolt as a drain plug, whereas the Dewitts uses a NPT draincock and that the original GM bolt will not thread into NPT fitting. Has anyone experienced this same issue during judging? If this is a common problem, has anyone come up with a way to solve it?

Thanks,

Gary

[Michael H.]

Re: Dewitt's petcock; one point deduct

Gary,

As far as I know, no original AL radiator ever came with anything other than the AL pedcock. I believe the judge was misinformed.

[Joe L.]

Re: Dewitt's petcock; one point deduct

Gary-----

No bolts, aluminum or of any other material, were used for any GM #3155316 radiator (used for all 1963-67 small blocks and some 1968-72 small blocks). For one thing, a bolt, being of straight thread, would not seal in this application. Theoretically, a pipe plug (rather than a bolt) could have been used. However, I'm virtually certain that none were. Instead, a special aluminum petcock (to ward off galvanic corrosion) was used.

[Gary B.]

Uniformed judge(s)?

Joe, Michael:

Maybe I'm not describing the parts correctly, but I'm a bit surprised that there would be a deduct on a Dewitt's radiator at a regional judging based on two judges being misinformed. Has no one else had any problem with the petcock area on a mid-year small block DeWitt's? If not, I'll have to conclude that it was a judging mistake, which I hope it turns out to be.

Gary

[Michael H.]

Re: Uniformed judge(s)?

From your description, I would have to assume it was a judging error.

[Peter L.]

Inquiring Minds Want to Know-C2 Rad Drain Asm

Gary - I think we have confirmed one thing about the mid-year sb radiator drain assembly, is it a
petcock(?) or plug(?). From the mid-year AIM it looks like the answer is YES!!!!!!! or we're not sure yet.

The 63-67 sb radiator drain assembly as described & shown in the RADIATOR & SHROUD ASSEMBLY drawing in the associated Corvette AIMs is as follows:

63 AIM (SECT 11-13, SHEET 8.00) identifies & points to a DRAIN ASM and shows what appears to be a

petcock handle but has no part number call out; but indicates a torque reading
64 AIM (SECT 11-13, SHEET A4.00) identifies & points to a DRAIN ASM and shows what appears to be a

petcock handle but has no part number call out; but indicates a torque reading;
65 AIM (SECT 11-13, SHEET A4.) identifies and points to a BUTTERFLY HANDLE DRAIN ASM and shows

what appears to be a petcock handle but has no part number call out; but indicates a torque

reading;
66 AIM (SECT 11-13, SHEET A4) shows & calls out as Item 3 part number 9428401 PLUG in the spot

where the 63-65 AIMs identified a DRAIN ASM;
67 AIM (SECT 11-13, SHEET A4) indicates 9248401 PLUG REMOVED in the REVISION RECORD on

7-28-66.

So, it looks like according to the 66 Corvette AIM that the judge did have some basis for the for his evaluation, now the question is does anyone have knowledge of what the 66 plug looks like and also what the 67 sb radiator is supposed to have in the hole at the bottom of the radiator. My early 67 sb which has the original radiator has what appears to be a hex head pipe plug in the hole. Is it aluminum, brass, or steel? I'll have to check but I do know for sure that between whatever it's made of and gavanic action, it's in the radiator drain hole for the long run.

Have fun.

Pete

[Gary B.]

Hmmm... Need to hear from some '66 SB owners

Pete,

Yet again, something that I thought would be a no-brainer turns out much more complicated. Unfortunately, I don't have the original radiator for my '66. The original was replaced in '68 and I have the '68 date coded radiator stored in my attic somewhere. I'm not sure I can find it easily however.

Are there any '66 small block owners with original radiators out there who could check to see if they have a petcock or a plug?

Gary

[Gary B.]

Joe Lucia: GM # 9424801

Do you know what GM # 9424801 referred to as a "PLUG" looks like?

Gary

[John Fowler]

[Dave K.]

Re: Joe Lucia: GM # 9424801

Gary/Joe,

My original 66 SB radiator had a petcock in it. I assumed that the plug was replaced with the petcock by previous owner. I now have a new DeWitt repro alum radiator in my car that came with a petcock. I replaced the petcock with a plug purchased from Long Island Corvette.

Regards,
Dave K.

[Henry J.]

Re: Hmmm... Need to hear from some '66 SB owners

My April-built 66 SB has the original radiator. It has a hex head plug. I can't remember the material of construction. The car is in winter storage now, so I can't check.

[Peter J.]

Re: Hmmm... Need to hear from some '66 SB owners

Gary,
June -66 car with an aluminum hex head plug in the original radiator.
Pete #25176

[Michael H.]

Re: Inquiring Minds Want to Know-C2 Rad Drain Asm

Thanks Peter. I thought they all had pedcocks. Amazing the things we can learn hanging around this discussion board.

[Tracy C.]

Re: Dewitt's petcock; one point deduct

I have 3 original radiators dated 64C 64E and 64M. All have petcocks.

tc

[Randy R.]

Re: Dewitt's petcock; one point deduct

Sorry to add to the confusion, but I have had my 67 sb for many years and it has a brass petcock. I don't recall ever having a problem that would have required a replacement.