Help me identify this exhaust manifold

[daughters-car]

I've spent hours searching trying to figure out what I've got here. I've came to the conclusion it must be some type of aftermarket replacement. At first glance it appears to be a 1G manifold, except it is larger in every way than my 2G manifold. When I first thought it was a stock 1G manifold I was going to replace it with the 2G manifold, except it is cracked all to heck as you'll see in the pictures. I thought the 1G manifolds were supposed to be the ones that cracked so bad? There isn't a crack in this "1G" style manifold!

I'm trying to decide if I'm better off to re-weld the cracks in my 2G manifold and run it or if this uncracked mystery manifold would be the better option. I'm going to be mounting a 16G turbo on this car to be used as a quick daily driven street car.

In this picture the manifold I'm trying to identify is the top one, my cracked 2G manifold is on the bottom:

The mystery manifold has a thicker head mounting flange and a taller/thicker overall profile as seen in these pictures. In the picture of the overall thickness/height, I measured the mystery manifold with the calipers and then held the calipers up to the same area on the 2G manifold - you can see there is a significant difference.

In these pictures you can see where it appears the identification markings have been intentionally ground off, both top side and bottom side.

Last picture, here's the bottom side - 2G manifold is on the right, mystery manifold on the left.

The overall casting of this mystery manifold has thicker walls, seems heavier duty. The internal ports also measure larger than the 2G manifold, so I think it would actually flow better than the 2G manifold. Whichever one I use, I'll end up porting the turbo outlet. This just seems so weird from all of the research I've done, the 2g manifold is supposed to be larger, thicker, and flow better than the 1G. My comparison of these 2 manifolds does not jive with that information - any ideas what is going on here?

 

[RamenPride]

Probably a Dorman aftermarket stock replacement

 

[Turbo2g]

This may be irrelevant but I once bought a 4g64 turbo kit for my 3rd gen GS. The kit came with the same style manifold you have in question and the same exact place had the grinding marks. I believe it is because the sellers of various kits source their pieces from various manufacturers and do not want them to find out that they are using their products to make profit. There could be legal issues. You likely have a stock replacement manifold that was sold in a kit in which the name brand could not be used.

 

[pauleyman]

The turbo opening is larger. It isn't for USDM. Possible evo3 manifold or some knockoff of it. and please no orange RTV.

 

[JusMX141]

Chinese copy of a 1G manifold...so Dorman, etc.

 

[pauleyman]

Chinese copy of a 1G manifold...so Dorman, etc.

Doesnt look like a 1g to me. Opening is too big. Even dorman wouldnt do that.

 

[pksystems]

Evo 1 or 2? I got a mystery manifold with an evo3 turbo I purchased awhile ago. O2 housing part number was one digit higher then evo 2. The exhaust manifold had the large evo size port and looked similar to 1G. It was cracked so I never used it.

 

[daughters-car]

I think I'm going to run it since my 2G mani is cracked so bad. I started porting the turbo outlet to remove the step and found more weirdness. While the port openings are larger at each end than my 2G, I think the ports get narrower in the middle. Since the casting is so much thicker, the dividing wall between cyl 1 and 2 is also thicker, which seems to reduce the runner size in those two cylinders. I'm not sure since I can't get any measuring tools in there, I'm just going by feel. I also don't have any carbide burs long enough to get in that deep to attempt to open them up any.

 

[JusMX141]

Doesnt look like a 1g to me. Opening is too big. Even dorman wouldnt do that.

Both manifolds in that photo have the 54mm collector which is "stock" for a manual 1G and all 2G's. The lack of reinforcement "webbing" between the runners ended in 1994, so at best it's an aftermarket 1G copy with all the "China" badging ground off.

 

[pauleyman]

Both manifolds in that photo have the 54mm collector which is "stock" for a manual 1G and all 2G's. The lack of reinforcement "webbing" between the runners ended in 1994, so at best it's an aftermarket 1G copy with all the "China" badging ground off.

Wow that's hard to spot. One with all the orange RTV on it looks to have a bigger opening. Guess not.

 

[PlanZero]

I think I found it. Same markings if you look close. AM autoparts sells their own stuff as well as a bunch of aftermarket (nothing special, usually the equivalent of rock auto "economy" parts) so it could be dorman. As mentioned, you'll see this pop up in conjunction with "eBay" turbos.
https://m.ebay.com/itm/Turbo-Exhaust-Manifold-for-Eagle-Talon-Mitsubishi-Eclipse-Galant-Laser-2-0L/130872386104?fits=Model:Eclipse&hash=item1e789a2238:g:ws8AAOSwq1JZMm1v

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At $45 I'd rather pick up a used 2g for the same price.

 

[daughters-car]

Yep, that sure looks like it. Their description of "Strengthened and redesigned in the vulnerable areas of failure" sounds like this one too with the thicker flanges and casting walls. You'd think they would have used a better example for their pictures though - look how off center those bolt holes are vs the bosses!

I'm going to run it since I already have it, it's not cracked like the 2g, and other expenses are adding up quickly on this car! I don't like the fact that I'm probably loosing some power vs the 2g manifold, but this build is more about reliability than power anyway. Thanks for the help!

 

[PlanZero]

I'm sure it will be fine. Honestly I didn't even really notice much difference when I went from 2G to FP manifolds. As long as it's not cracked and the mating surfaces are good (use two gaskets if not sure) you'll be OK. Make sure you use new hardware, I got my manifold to turbo bolts from fastenal and new exhaust studs from MAP (OEM style, seem to be holding up fine for $20) if your not going SS.

 

[daughters-car]

Yeah, the hardware is going to be my next issue. I had fairly new turbo stud/bolts along with the special crush washers on the old 2G manifold, so I was going to rob those. But the increased thickness of the aftermarket manifold makes those too short. On top of that, I hadn't realized until recently that the 16g exhaust housing (and this manifold) I have has already been drilled for oversize hardware and those oversize threads are damaged needing repair. I'm going to have to wait and see what has to be done to repair the exhaust housing before I get the hardware, hopefully I can stay with the stronger oversize stuff. I think I'm going to go with the Extreme PSI heavy duty 6 ply MLS 7cm turbo to manifold gasket.