85/86 Tubular Exhaust Manifolds on an OB
#16
Rennlist Member
Dan,
How have you confirmed the cats are heading straight back along the longitudinal center? And "leveled", if you will?
If your left downpipe it mounted tight to the manifold flange (with or without gasket), I'm concerned you may not be square.
I'm sure you are close, but your 2-axis adjustment may not be necessary.
Though this approach should work just fine if you can assure the correct location of the cat exits.
I propose you can only my this determination with everything mounted up in the car.
How have you confirmed the cats are heading straight back along the longitudinal center? And "leveled", if you will?
If your left downpipe it mounted tight to the manifold flange (with or without gasket), I'm concerned you may not be square.
I'm sure you are close, but your 2-axis adjustment may not be necessary.
Though this approach should work just fine if you can assure the correct location of the cat exits.
I propose you can only my this determination with everything mounted up in the car.
#17
Rennlist Member
Thread Starter
#18
Rennlist Member
Thread Starter
Dan,
How have you confirmed the cats are heading straight back along the longitudinal center? And "leveled", if you will?
If your left downpipe it mounted tight to the manifold flange (with or without gasket), I'm concerned you may not be square.
I'm sure you are close, but your 2-axis adjustment may not be necessary.
Though this approach should work just fine if you can assure the correct location of the cat exits.
I propose you can only my this determination with everything mounted up in the car.
How have you confirmed the cats are heading straight back along the longitudinal center? And "leveled", if you will?
If your left downpipe it mounted tight to the manifold flange (with or without gasket), I'm concerned you may not be square.
I'm sure you are close, but your 2-axis adjustment may not be necessary.
Though this approach should work just fine if you can assure the correct location of the cat exits.
I propose you can only my this determination with everything mounted up in the car.
With the left pipe attached, all looks lined up based on centerline and level with the ground. Will confirm with some measurements soon.
I was not able to confirm the height of the cat in relation to the engine.
Also, it seems that these have been installed with the left pipe attached and a "spacer" on the right. So, it makes sense based on other's feedback.
I think I need a 2 axis adjustment because the flanges are parallel. I think moving the flanges "together" 32mm and the exhaust pipe outboard 12mm will do the trick.
Maybe one pipe extension close to the flange doing both?
This weekend will tell.
#20
Rennlist Member
Elongate the holes...I purchased a pre-fabbed spacer from the folks in Utah. Heat relief to aid alignment is a good idea. Still bummed that someone else scored the Euro front muffler from 928 intl during half-off..I was looking for one of those for years (despite the drawbacks...)
After talking to Jim last year at Rick's, I may do the 32V manifolds too.
#21
Rennlist Member
Jim's 84 Euro is getting 32V manifolds and 87 S4 cat. Will probably then Y-down to his existing 3" single pipe exhaust with the spintech mid. Its what we had on-hand / should flow well, sound good and still be compliant.
#25
Rennlist Member
Thread Starter
I think I'm going to buy a simple arc welder and some stainless steel exhaust tubing tomorrow. Maybe a cutter. Why not? What's to lose?
I can drive to HF for the welding stuff. But can't find a place for mandrel bent and straight tubing. Maybe JC Whitney. And do it in a week.
I can drive to HF for the welding stuff. But can't find a place for mandrel bent and straight tubing. Maybe JC Whitney. And do it in a week.
#27
Rennlist Member
Thread Starter
Advice? Stainless, aluminized, mild steel.
What material to weld in to stock pipe?
I figure the stock is stainless just because it survived 33 years
What material to weld in to stock pipe?
I figure the stock is stainless just because it survived 33 years
#29
Rennlist Member
I had some downpipes replaced with SS.
Dan, here's a similar situation to what you found.
This is 84 car, 85 manifold, 87 cat --- bolted-up on the drivers side
Both pictures below show passenger side gap / misalignment.
Muffler is a little misaligned in the tunnel, too.
I'm going to have 2 things done.
First, in place, have exhaust guy heat drivers side pipe red hot, then twist hole muffler arrangement to center the discharge pipes in the tunnel. (Bends easy when hot)
Second, cut the cat input pipe on the passenger side. Bolt-up the flanges, add a joiner pipe (again, in-situ).
Dan, here's a similar situation to what you found.
This is 84 car, 85 manifold, 87 cat --- bolted-up on the drivers side
Both pictures below show passenger side gap / misalignment.
Muffler is a little misaligned in the tunnel, too.
I'm going to have 2 things done.
First, in place, have exhaust guy heat drivers side pipe red hot, then twist hole muffler arrangement to center the discharge pipes in the tunnel. (Bends easy when hot)
Second, cut the cat input pipe on the passenger side. Bolt-up the flanges, add a joiner pipe (again, in-situ).
#30
Rennlist Member
Thread Starter
Good luck Chris. Let us known how it goes.
I aligned the exhaust with the centerline of the engine today. It was pointed towards the right.
Used a wedge. The gap to get it centered is more like 40mm's.
Welding gear and tubing in the mail. I do think one strategically placed cut and one straight extension will do the trick.
Guess I'll bond on other little projects for the rest of the weekend.
I aligned the exhaust with the centerline of the engine today. It was pointed towards the right.
Used a wedge. The gap to get it centered is more like 40mm's.
Welding gear and tubing in the mail. I do think one strategically placed cut and one straight extension will do the trick.
Guess I'll bond on other little projects for the rest of the weekend.