[mdbomstad]

I am looking for a illustration or picture of the pipe routing for the dual exhaust with the crossover pipe option for the Fuel Injected 347. Any information about this option will be much appreciated.

mdbomstad

[Bill Eveland]

This was for a 56 dual exhaust option, not sure but should be real close to the 56?

http://www.pontiacsafari.com/MPC/Pages/page_0176.jpg

If your looking to add dual exhaust, I know at one time Kanter said theirs didn't require the elbow on the driver side.

[Teej]

I bought a dual setup for my '58 370 from a guy in Ohio that doesn't require the elbow on the drivers side. (Duals that eliminate the cross over) Unfortunately I haven't had time to install it so I can't speak to it's fit yet. But I've also got an elbow I probably won't be needing.

[RamAirIV28]

elbow is being reproduced

late 55 and 56 are the same, 57 is unique and 58 is unique, only in detail but that matters some times,

[mdbomstad]

Thanks for the info on the dual exhaust. The optional exhaust I am talking about combined both dual exhaust pipes and a crossover pipe. I have the adaptor but do not know just what the crossover pipe looked like. I have been told it is different from the single exhaust system. I was hoping someone may have a picture or a recollection of what the crossover looks like and how it is routed. I have attached a picture of the driver side manifold and adaptor.

mdbomstad

[Safari Larry]

The '57 FI exhaust is unique and quite different than other models. See attached for photo I have, captured by Rick Gonser on ebay about 5 years ago. The crossover was used on the FI engine and was called "Crossover exh. equalizer" in the MPC, Group 3.609. It is not an option but is standard equipment on the FI engine, they all had dual exhausts and the crossover. As I understand it, the crossover was used for exhaust equalization between left and right because there is no crossover through the intake manifold as on carburetor equipped engines. The exhaust manifold adaptors are unique to the FI engine and the passenger's side exhaust manifold is unique to the FI engine. I hope you have the adaptor for the other side.

If you don't get the answers you need, I suggest you log into the POCI site (I saw your post there), search for owners of Bonnevilles and contact them with your question. I suspect they would all be happy to help another Bonnie owner. Bill Vance has a mostly original 57 Bonnie. Here's what he said about the crossover:

"My 57 Bonneville has a crossover pipe, probably because there is no intake manifold exhaust crossover to equalize exhaust pressures. As far as I can determine, both the left and right adapters are unique to Bonnevilles. Both adapters have three holes. One hole in each bolts to the manifold, one to the left or right exhaust and the last bolts to the crossover pipe.

My crossover pipe developed a hole and I wanted to use the car before I could have one made. I removed the pipe and capped the holes with home made plugs. It made the engine sound like it was missing even though it was running fine."

That was 5 years ago and he may have replaced his crossover and possibly have the original with holes in it.

[mdbomstad]

Thank You Larry, The information is very helpful. The picture is just what I needed.

mdbomstad

[Safari Larry]

Glad to help. Do you have a photo of the passenger's side exhaust manifold and adapter. It would be interesting to see what it looks like. The exhaust manifold surely doesn't have the heat riser as on the "normal" manifold.

[Baron Von Zeppelin]

i have a 57 passenger side F.I. manifold with cast iron elbow
and a 58 passenger side F.I. manifold with cast iron elbow

Could post pictures in the next few days if they would help anything.

Best i can recall - neither of them have a heat riser flap
and both elbows only have 1 port

[Safari Larry]

Originally Posted by Baron Von Zeppelin

i have a 57 passenger side F.I. manifold with cast iron elbow
and a 58 passenger side F.I. manifold with cast iron elbow

Could post pictures in the next few days if they would help anything.

Best i can recall - neither of them have a heat riser flap
and both elbows only have 1 port

Those are some rare items. They wouldn't really help me but I would sure be interested in seeing what they look like. I'm pretty sure manifolds won't have the heat riser but if the elbows have only one port then they surely aren't for the FI engine. The casting numbers will probably tell what they are.

[mdbomstad]

[ATTACH][/ATTACH]Larry, I have put this system together from information I have gathered from many sources including our local P.O.C.I. club. I have been told the passenger side is the same as for single exhaust with out the heat riser. I removed the heat riser tapped and plugged the holes with steel pipe plugs. The drivers side adaptor I purchased on EBAY. I needed more info about the crossover and the picture you posted gave me that. I have found a place in NC (Kepich exhaust) that has dimensions and can make the crossover. I plan to go their with the picture to be sure the pipe is correct.

Thanks for all the help
mdbomstad 365586

[Safari Larry]

Thanks for the photos, I've wondered what those exhaust adapters looked like. Another difference in the passenger's side exhaust manifold is the "standard" manifold and FI manifold have different casting numbers. The number is easily visible looking under the hood. See this link. That might matter if you are trying to restore to original for shows. But if you don't have the correct manifold, sounds like you have a good solution.

[mdbomstad]

Larry, I have looked at the manifolds and P/Ns on your web site and maybe I will find the correct P/N some day but for now what I have should work. Thanks for the help when I get this project done I will post pictures.

mdbomstad

[Baron Von Zeppelin]

The manifold numbers were verified about 20 years ago by a friend who has the Pete McCarthy book. Hopefully that was good info.
Have never tried to verify the elbow numbers.

Will try to get them out and post some pictures in next few days.

[Baron Von Zeppelin]

Broken Dreams
and probably mis-communications years ago.

Found where i had the numbers written down -
and checked them on pontiacsafari-com

Both are Driver Side (common side)

Manifold #523539
Elbow #523771
57

Manifold #528598
Elbow #52982 (something about like that)
58

shet

[Safari Larry]

Bummer!!!