1968 L-36 Thermostat Housing Color

[Charles F.]

Hi:

I have a 1968 L-36 with A/C, 4 speed. The AIM shows the thermostat housing that sits on the aluminum intake as being painted orange. Is this correct ? All the 1968's I have seen did not have it painted orange. I searched the archives under several different search criteria and found nothing on the subject.

Second question: the judging guide (most current) shows only casting #3919849 as correct for the manifold. The archives have several threads on this and indicate that in mid-March 1968 #3937793 came into use. I am told that the older judging manual (about twice as thick as the current one) shows both. My car has #3937793 (correct for an April 1968 build date). Why doesn't the new judging guide show this and am I going to have a problem on the judging field ? I plan on bringing the print-outs of the Archived threads and photocopies of the older judging guide sections. Is this enough ?

Chuck Faillace

[Joe L.]

Re: 1968 L-36 Thermostat Housing Color

Chuck-----

I don't understand how the AIM could show the thermostat housing as being painted orange. The thermostat housing was installed at the engine plant and, even if it had been painted, it would not be shown on the vehicle AIM. In any event, the housing was definitely NOT painted orange. It was either natural aluminum or it was painted with aluminum paint. Sometimes, the aluminum manifolds, themselves, were partially or fully painted with aluminum paint.

As far as the manifold goes, I believe that the 3937793 was used for later 1968 L-36's such as your car. Configuration-wise, the biggest difference between the 2 manifolds is the casting number.

[Charles F.]

Re: 1968 L-36 Thermostat Housing Color

Joe:

Thanks. You are right...it is not the AIM but the JG that has the information on the thermostat housing. I'm paraphrasing (don't have access to the JG at the moment), but the JG says that all 68 had a cast iron thermostat housing and 69 was aluminum; that all the aluminum ones should be either natural or aluminum paint; that the rest are engine color (orange, I presume). Mine is definately cast iron. Should it be left alone or painted orange ?

Thanks

Chuck Faillace

[Dick W.]

Re: 1968 L-36 Thermostat Housing Color

Orange

[Joe L.]

Re: 1968 L-36 Thermostat Housing Color

Chuck-----

I am unaware of ANY 1968 Corvettes, except L-88, using any thermostat housing other than the aluminum GM #3877660. I have never seen a known-original 1968 or 1969 L-36 with a cast iron thermostat housing.

I do find it curious, though, that there were 2 different upper radiator hoses used for 1968 Corvette with L-36. This MIGHT imply that there was a change of thermostat housings somewhere along the way. Or, the change in radiator hoses might have been for completely different reasons.

[Lyndon S.]

Re: 1968 L-36 Thermostat Housing Color

So who is right? Joe L says no orange Dick W says orange.

[Charles F.]

Re: 1968 L-36 Thermostat Housing Color

Joe/Dick/Kelly:

I'm confused...orange or not ?

Chuck Faillace

[Lyndon S.]

Re: 1968 L-36 Thermostat Housing Color

From what I can gather the thing should NOT be ORANGE. Good luck

Kelly

[Joe L.]

Re: 1968 L-36 Thermostat Housing Color

Chuck------

To my knowledge they were not painted orange. Actually, this applies to all Corvette engines with aluminum manifolds and not just 1968 L-36. With respect to installation on aluminum manifolds, if the thermostat housing was aluminum, it was left just natural aluminum. If it was cast iron, it was painted with aluminum paint.

Also, I've never seen a 1968-69 L-36 with a cast iron thermostat housing. That doesn't mean that none were made, just that I've never seen one.

However, Dick has looked at a lot more 1968 Corvettes than I have. If he's confident that there are original 1968's with L-36 that have a cast iron thermostat housing and/or painted engine orange I defer to him.

[Dick W.]

Re: 1968 L-36 Thermostat Housing Color

What I am saying that if the housing is cast and is on a cast iron intake it should be engine color, but if the housing is aluminum on an aluminum intake, it should be silver.

[Charles F.]

Re: 1968 L-36 Thermostat Housing Color

Dick:

To make matters more confusing, the intake it sits on is aluminum and the thermostat housing is cast iron. Under this situation, should the housing be orange or something else ?

Thanks

Chuck

[Dick W.]

Re: 1968 L-36 Thermostat Housing Color

Chuck in your senario the cast iron thermostat housing would be silver. This is all explained in the 1968-1969 Technical Information Manual and Judging Guide

[Charles F.]

Re: 1968 L-36 Thermostat Housing Color

Dick:

Thanks. I have the JG (p. 65) in front of me now:

"Thermostat housings are cast iron for all 1968s. ...The thermostat housings are either painted engine color or unpainted aluminum according to the intake manifold used. ..."

From your last response, it seems that the intake manifold being aluminum means that the cast iron housing should be painted aluminum, not orange. Have I got this right now (I know I'm dense) ?

Chuck Faillace