heat riser valve

[Robert K.]

I searched the archieves and found quite a bit of information on the above subject but needed a confirmation on something:

Is either part number 3887024 or 3746838 the correct part for a '67 (L71)- the AIM shows that this part number was changed in 6/66. I have a Jan. '67 car.

Thanks for your help!

[Joe L.]

Re: heat riser valve

Bob----

GM #3746838 was a predecessor part number for the GM #3887024. However, neither of these is correct for a 1967 L-71 (or, any big block, for that matter). These are 2" exhaust heat riser valves. The heat riser valve used with 1966-68 big blocks was GM #3887034, a 2-1/2" valve.

[Joe L.]

Re: heat riser valve

Bob----

GM #3746838 was a predecessor part number for the GM #3887024. However, neither of these is correct for a 1967 L-71 (or, any big block, for that matter). These are 2" exhaust heat riser valves. The heat riser valve used with 1966-68 big blocks was GM #3887034, a 2-1/2" valve.

[Robert K.]

Re: heat riser valve

Joe,

Thank you for the information! I looked again in the AIM but still am unable to find the part number that you provided (I'm sure you're correct however, I can't find it in the AIM)....Am I correct, or am I missing it? Also, on page 382 of the AIM (UPC N14) for a side exhaust car, there doesn't appear to be a heat riser valve installed. Is there one used in this application? Again, a '67 L71....

Thanks Joe......

[Robert K.]

Re: heat riser valve

Joe,

Thank you for the information! I looked again in the AIM but still am unable to find the part number that you provided (I'm sure you're correct however, I can't find it in the AIM)....Am I correct, or am I missing it? Also, on page 382 of the AIM (UPC N14) for a side exhaust car, there doesn't appear to be a heat riser valve installed. Is there one used in this application? Again, a '67 L71....

Thanks Joe......

[Joe L.]

Re: heat riser valve

Bob-------

The undercar exhaust system for L-36 or L-71 is not shown in the AIM. At least, it's not in the copy of the AIM that I have. Consequently, the heat riser valve for those applications is not shown in the AIM. So, I don't see where you're coming up with the part number that you mentioned previously. If it's from the exhaust system components shown on UPC 6, sheet C1, that's the base engine heat riser valve. It was the GM #3887024 since it's a 2" valve, same as used for L-79.

As far as a heat riser with N-14, as far as I know, a heat riser was used with N-14 just as it was with undercar exhaust. The page in the AIM which shows the manifold-to-pipe connection shows only the LEFT side. The heat riser is on the RIGHT side and is not shown.

[Joe L.]

Re: heat riser valve

Bob-------

The undercar exhaust system for L-36 or L-71 is not shown in the AIM. At least, it's not in the copy of the AIM that I have. Consequently, the heat riser valve for those applications is not shown in the AIM. So, I don't see where you're coming up with the part number that you mentioned previously. If it's from the exhaust system components shown on UPC 6, sheet C1, that's the base engine heat riser valve. It was the GM #3887024 since it's a 2" valve, same as used for L-79.

As far as a heat riser with N-14, as far as I know, a heat riser was used with N-14 just as it was with undercar exhaust. The page in the AIM which shows the manifold-to-pipe connection shows only the LEFT side. The heat riser is on the RIGHT side and is not shown.

[Duke W.]

Re: heat riser valve

Be sure to look in the L-71 section of the AIM. It should have a parts list labeled "install same as regular prodution" or similar verbiage. The main body of the AIM only covers base equipment.

If options used different parts than the base configuration, but they looked essentially the same, they are often not illustrated, but just referenced as above in a list in the appropriate option section.

Duke

[Duke W.]

Re: heat riser valve

Be sure to look in the L-71 section of the AIM. It should have a parts list labeled "install same as regular prodution" or similar verbiage. The main body of the AIM only covers base equipment.

If options used different parts than the base configuration, but they looked essentially the same, they are often not illustrated, but just referenced as above in a list in the appropriate option section.

Duke

[Robert K.]

Re: heat riser valve

Joe & Duke,

Thanks for your responses - I now underestand about the AIM........

Joe,
Just one more quick question.....You referenced a part # 3887034 for a L71 '67, but in looking in the archives for a L71 - '67 there is a part # 3746844 referenced...Any thought what that might fit? I didn't see that number in the AIM either.....

Sorry for all the questions about this but I just want to be sure.....

[Robert K.]

Re: heat riser valve

Joe & Duke,

Thanks for your responses - I now underestand about the AIM........

Joe,
Just one more quick question.....You referenced a part # 3887034 for a L71 '67, but in looking in the archives for a L71 - '67 there is a part # 3746844 referenced...Any thought what that might fit? I didn't see that number in the AIM either.....

Sorry for all the questions about this but I just want to be sure.....