Exhaust Manifold Interchange - see photo

[B Jake Moran]

https://mankato.craigslist.org/pts/d/3800-exhaust-manifold-new/6826576889.html

 

I don't suppose by any chance this would fit Reatta era 3.8's??

 

 

New in package front (left) side exhaust manifold to fit a 3800 series II or III, most 1995-2005 Park Avenue, Bonneville, Regal, Lesabre, Riviera, 88, LSS, Monte Carlo, Impala, Grand Prix, Intrigue with a 3.8L. Includes gasket and flange hardware. Greywerks brand part number 101273.
$40 OBO
101273 674-540 2109-259583 961599

 

[2seater]

No,  it will not fit. The Series II ports are evenly spaced and the LN3/L27 are not. Pretty much why Series II heads won't work on the Series I also, the valves are in a different order, and the deck of the block is nearly 1" shorter.

[B Jake Moran]

Dang it, that seemed like a good deal.  I wonder? If Rock Auto or anywhere else might have some NOS Reatta LN3 / L27 exhaust manifolds for cheap. I'll have to go check.  It's not like they really go bad, it's more for appearance and like new fit and performance.   Thanks

[DAVES89]

You need to find a 5000 mile engine like I did in a salvage yard in Rhinelander Wisconsin...

  Engine was not sealed and was all corroded in the cylinders, but there was a lot of free parts for 2seater and me as the guy gave us the engine for free.

[2seater]

1 hour ago, B Jake Moran said:

Dang it, that seemed like a good deal.  I wonder? If Rock Auto or anywhere else might have some NOS Reatta LN3 / L27 exhaust manifolds for cheap. I'll have to go check.  It's not like they really go bad, it's more for appearance and like new fit and performance.   Thanks

No, they generally don't go bad, they are a low grade 400 series stainless steel. For appearances, just have the existing ones ceramic coated. I use satin black for turbo piping, which is pretty much a temperature requirement, or titanium gray for naturally aspirated, but lots of colors are available. If coated inside and out, the heat shields can be eliminated in some areas.

[Blue90]

Here's the same side exhaust manifold from a '90 Reatta.

[2seater]

This is a quick photo of a complete set done in about 2001 in titanium gray. The crossover pipe is somewhat obscured by the manifold on the left. The darker gray is the modern take on the same color and has not been installed or run yet. The dark gray one is heavily reworked in the area of the exhaust outlet to eliminate the turbulence where the exhaust from the front and rear exhaust ports run into each other at the outlet.

 

[Barney Eaton]

Can you show a top view of the modification to the dark grey header?   Looks like you greatly spread the opening where they intersect.

[2seater]

Not a lovely creation but should be better within the original design envelope, maybe sound a touch different?

 

 

[Barney Eaton]

Nice job,  looks like a lot of work.

[2seater]

2 hours ago, Barney Eaton said:

Nice job,  looks like a lot of work.

Thanks. Just done as an exercise for an obsolete engine family to see what could have been😐