Heat Shields

[Bill L.]

Why do some heat shields have a hole?

[Wayne M.]

Re: Heat Shields

Why do some heat shields have a hole?

Billl --- could you give us the model year and what the heat shield is protecting ?

[Bill L.]

Re: Heat Shields

Oops! 70 L46 convertible spark plug wires under the exhaust manifolds.

[Joe L.]

Re: Heat Shields

Why do some heat shields have a hole?

Bill-----


If you're talking about SPARK PLUG HEAT SHIELDS, the left front heat shield for L1970-75 had a hole for the temperature sender.

[Terry M.]

Re: Heat Shields

And the right rear has clearance for the temperature sensor for the TCS system. In fact I think they are the same part, but Joe would know that better than I.

[Joe L.]

Re: Heat Shields

And the right rear has clearance for the temperature sensor for the TCS system. In fact I think they are the same part, but Joe would know that better than I.

Terry-----


Actually, I'm not sure if the same spark plug shield was used for the left rear position as for the right front, but I don't think it was. The information I have says that the GM #3919807 spark plug heat shield (the one with the hole in it) was used only for the right front position. However, it incorrectly states that this shield was used for 1968-75. There's NO WAY the heat shield with the hole in it could have been used for 68-E70. That's because those years used the RF shield at front and rear positions, both sides (for cars equipped with radios). There is NO WAY that the RF shield for the left front position, GM #3934833 (the one with the hole in it), will fit over the 3919807 heat shield with the hole in it---no possible way.

As a matter of fact, my 1969 small block was originally delivered with a left front heat shield that was the standard configuration (i.e. without hole and GM #3917664).

I believe the same thing would apply for the right rear heat shield for 1970-75. As far as I know, all 70-75 with radio used the RF spark plug shields at the rear positions on both sides. I'm virtually certain that the 70-75 right rear RF shield, GM #3980192 (with the hole in it), would not fit over the GM #3919807 heat shield (with the hole in it). However, I'm 100% certain the left front RF shield with the hole in it will not fit over the left front heat shield with the hole in it.

[Terry M.]

Re: Heat Shields

I shouldn't post this late at night.

I may have mixed up the heat shields and the noise supression shields. I'm going to have to think about that one in the light of day. Maybe it is the RF shield that is the same LF and RR.

I'm also beginning to think there were only three heat shields on my car originally. I had to add one to make the car look TFP --if my memory is right -- and the more I think about it the more I think the missing one was the left front. I may have to look at the fasteners to be sure of that. I know something had only three where most cars had four.

[Joe L.]

Re: Heat Shields

I shouldn't post this late at night.

I may have mixed up the heat shields and the noise supression shields. I'm going to have to think about that one in the light of day. Maybe it is the RF shield that is the same LF and RR.

I'm also beginning to think there were only three heat shields on my car originally. I had to add one to make the car look TFP --if my memory is right -- and the more I think about it the more I think the missing one was the left front. I may have to look at the fasteners to be sure of that. I know something had only three where most cars had four.

Terry-----


My car had the left front heat shield (standard configuration) in addition to the RF shield. However, the fitment was horrible and it was nearly impossible to get the RF shield back on over the heat shield. In fact, I had to slightly modify the RF shield to make it fit, at all. I imagine the factory was able to make it work because they likely installed it when the engine was not yet installed in the car. I would not be a bit surprised if the factory finally decided to remove the left front heat shield altogether for the left front position for cars which were radio-equipped and that may be what happened in your case.

For later 1970, the problem "went away" for the left front since the forward RF shields on both sides were eliminated. I don't know what they did for the right rear shield, though, since the TCS switch was added for 1970 to the right rear. However, as I mentioned, I really don't think the right rear RF shield would fit over the heat shield with the hole in it. The 70-75 right rear RF shield is different than the 68-E70 left front RF shield, though.

[Terry M.]

[Bill L.]

Re: Heat Shields

Okay this is great stuff.

Here is what I think I gleaned.

LF Heat Shield is PN-3919807 (Hole in it)
LR Heat Shield is PN-3817657
RF Heat Shield is PN-3817657
RR Heat Shield is PN-3917664

Does this sound about right for a L70 sb?

Thanks Terry and Joe.

[Jack H.]

[Joe L.]

Re: Heat Shields

Okay this is great stuff.

Here is what I think I gleaned.

LF Heat Shield is PN-3919807 (Hole in it)
LR Heat Shield is PN-3817657
RF Heat Shield is PN-3817657
RR Heat Shield is PN-3917664

Does this sound about right for a L70 sb?

Thanks Terry and Joe.

Bill-----


Yes, the part number/locations of the heat shields are just as you have listed. However, as I mentioned, there's no way the 3919807 can be used with the 1968-E70 left front RF shield.

[Alan S.]

Re: Heat Shields

I have a question about the right rear heat-shield on my 71.
The AIM calls for part # 3815084 in that location, but I can't find that # in my limited information resources. The original shield seems as though it fits and is properly used in the Right Rear and also could fit the Left Front in earlier years while there was still an RF-shield on the Left Front.
So... is that where the 084 came from?
Thanks Joe!
Regards,
Alan

[Joe L.]

Re: Heat Shields

I have a question about the right rear heat-shield on my 71.
The AIM calls for part # 3815084 in that location, but I can't find that # in my limited information resources. The original shield seems as though it fits and is properly used in the Right Rear and also could fit the Left Front in earlier years while there was still an RF-shield on the Left Front.
So... is that where the 084 came from?
Thanks Joe!
Regards,
Alan

Alan-----


GM #3815084 was a predecessor to the GM #3917664. The 3815084 was used in PRODUCTION for the left front and right rear positions for 1963-67 Corvettes. It may or may not have been used in PRODUCTION after 1967 as the AIM's seem to indicate. The 3815084 was discontinued from SERVICE in May, 1968 and replaced by the 3917664. I do not understand why the 3815084 would have been used for PRODUCTION after 1967 if its SERVICE availability ended after that time.

As I recall, the only difference between the 3815084 and the 3917664 is the raised, reinforcing "rib", but there may have been other differences. It's just been too long since I studied these. Anyone have HANDY a known original from a 63-67 left front or right rear they could provide photos of?

[Alan S.]

Re: Heat Shields

Hi Joe,
This is a picture of the right rear shield on my 71. I'm sure it's original to the car.
What part # it is I really don't know.
Thanks very much for looking.
Regards,
Alan