'66 Big Block Heat Riser Position w/ Images

[David P.]

I have two questions:

1. From the photos, which is the correct heat riser for my application? The top one is from GM, part #3887034, and the other appears to be a Long Island part. The primary difference is that the counter weight is configured on opposite sides. This causes some positioning options, which is my next question.

2. From the photos, which appears to be the correct position of the heat riser? The AIM is not clear for the L72 option and no one seems to post pictures in all the threads that try to describe the correct position. The descriptions that I can find are difficult to interpret because it all depends on the persons frame of reference. As they say, a picture is worth a thousand words.

Thanks for the help.

[Richard M.]

Re: '66 Big Block Heat Riser Position Question w/ Images

David, Did your photo get reversed when it uploaded? It sure looks like the Top is the repro as it has the clean flap and blue welds.

Coincidentally, just yesterday we installed one on a 1967 BB, and according to what I've been told the counterweight points inward toward the starter. This is also what is stated in the 1967 JG(my 5th Ed but I don't have the 6th). Not sure about 1966 BB if similar.

The 1967 AIM is also missing ANY reference to the BB heat riser. I always thought one follows the standard engine AIM section and thus also applies to BB if not differentiated..... But in this case, the JG does not depict it in a similar way. 1967 AIM UPC 6 C1 shows SB engine with the 3888024 VALVE ASSY riser weight at the Rear position. I cannot find 3887024 listed anywhere for Corvette so the AIM may be wrong or superseded part #.

3888034 VALVE ASSY Applications follow...(June 1979 P&A)

http://www.gmpartswiki.com/getpage?pageid=93552

Rich

[David P.]

Re: '66 Big Block Heat Riser Position Question w/ Images

Rich,

The top one is a recent purchase from GM, not a 1966 original part. If you go through a GM dealer and get part #3887034, that's what you get, which according to the '66 AIM is the correct part number. If you go to Long Island Corvette, the bottom heat riser in the picture is what you get.

As far as installation, the GM part can only be installed like the center picture. Rotating the GM part to any other position causes interference with the frame or starter. The "Long Island" part can be installed like the last picture or like the picture I've attached here.

[David P.]

Re: '66 Big Block Heat Riser Position Question w/ Images

Rich,

The part number is 3887034. It's listed in your GM parts wiki link for 427 and 454 applications. The big question is which configured part is correct? Each one dictates the position(s) it can be installed.

[Richard M.]

Re: '66 Big Block Heat Riser Position Question w/ Images

David, Here is my only photo of the riser installed on a recent 67 BB. It points inward, the end of the weight that is. Unfortunately I can't find other photos.

I just checked the Judging Sheets from last years Winter Regional, and it got no deduct whatsoever.

[Peter M.]

Re: '66 Big Block Heat Riser Position Question w/ Images

David and Rich,
If you look in Noland's book on page 387 there is a photo of the underside of a 1967 427 showing the counterweight pointing at the starter. There is a similar photo on page 324 of a 1966 427 and on page 259 of a 1965 396.
Kind Regards,
Pete

[David P.]

Re: '66 Big Block Heat Riser Position Question w/ Images

Pete - I ordered the book, but don't have it yet. Any chance you could take a picture of the pages and post it?

[Jim D.]

Re: '66 Big Block Heat Riser Position Question w/ Images

David and Rich,
If you look in Noland's book on page 387 there is a photo of the underside of a 1967 427 showing the counterweight pointing at the starter. There is a similar photo on page 324 of a 1966 427 and on page 259 of a 1965 396.
Kind Regards,
Pete

Regarding the 1965 396, the Judging Guide states the weight should be in the front, pointing inward. That agrees with Noland's picture and my 65.

[Richard M.]

Re: '66 Big Block Heat Riser Position Question w/ Images

David, I just clicked on "Similar Threads" at the bottom of this page. The GM service part is NOT configured as original. I'll trudge out to the shop in the rain and get my Noland book and shoot a few pics. I'm confused now too.

[David P.]

Re: '66 Big Block Heat Riser Position Question w/ Images

Rich,

I've attached a photo, which should be identical to the Noland installation picture. If this position is correct, you cannot see the counter weight from the top of the car. Is that right? Let me know what you think.

[Richard M.]

Re: '66 Big Block Heat Riser Position Question w/ Images

....wiping rainwater off my keyboard as I write this......nyuk nyuk.....

It appears you're good. Is that the LIC part? Here are the Noland photos. First 2 1966, last 2 1967.

edit.... The 1967 photo I posted earlier is clearly showing it at the rear, which is NTP, which proves the riser was likely a service part, which proves the eyes that looked at it last year must have blinked when it was viewed.

[David P.]

Re: '66 Big Block Heat Riser Position Question w/ Images

Rich,

This would have the counter weight positioned to the front of the car and pointed at rear of starter, if that makes sense.

[David P.]

Re: '66 Big Block Heat Riser Position Question w/ Images

Rich,

Those pictures are worth a thousand words! Thanks for doing that. The last picture I posted now matches the Noland pictures. That is the "Long Island" part. The GM service replacement, even though the correct part number, cannot be installed in that manner. Thanks for helping me clear that up!

[Richard M.]

Re: '66 Big Block Heat Riser Position Question w/ Images

Rich,

This would have the counter weight positioned to the front of the car and pointed at rear of starter, if that makes sense.

Yes, Correct, as shown in the Noland references. Mine was wrong. I edited my last post.

Rich

[Richard M.]

Re: '66 Big Block Heat Riser Position Question w/ Images

Rich,

Those pictures are worth a thousand words! Thanks for doing that. The last picture I posted now matches the Noland pictures. That is the "Long Island" part. The GM service replacement, even though the correct part number, cannot be installed in that manner. Thanks for helping me clear that up!

David,

I was curious too so it was good timing. Pete gets credit for the Noland book idea, I just opened it up and there it was. After I saw them I recall I already had those pages saved from a previous thread regarding front valence details.

I'm glad you asked. I'm glad it helped.

Rich