Well I'm pratically building my car like a giant Lego puzzle without directions since it was in peices when I got it. I had to swap Engines as the old one wasn't worth fooling with. (IMO) I went from an 83 carb to an 86 TPI. (Car is an 85)

I was hoping that the exhaust that was hanging under my car would fit up to the 86 engine. Manifolds looked the same. (Pretty sure they were) I even have the little block thing for the passenger side. When I slid under there the other day to start hanging it I ran into nothing but trouble. I couldn't get the passenger side flange to totally seal to the manifold what-so-ever. It looked as if I would pull the block thingy out it might fit better. (not really) But it(Block thingy) has to be there. I started modifying the y pipe to no avail, when I noticed that even If I managed to get the Flanges to seal that the exhaust going back to where the Cat is supposed to be would be hanging WAY down. Like 3 inches below the bottom of my GFX. I figured something has to be wrong with the Y pipe. I should just get a new one.

So this morning I called my local parts place and got one on order (to fit the 86 engine) and picked it up this evening. The bends going to the manifolds looked the same as what I had and I wasn't sure if it was going to line up either. Much smaller tubing for the cross over as well. I wasn't happy with this Y pipe. They let me take it to test fit it since I have to go back for a power steering line tomarrow. Well, I get home with it and under the car it went. I snug everything up and it seems to fit rather well to the flanges. BUT!!!, Its still hanging WAY down at the area the CAT mounts. At this point I decided that I can modify my old one, save myself 120 bucks and maybe even get it closer to the car.

Can someone tell me why the heck the Y-Pipe hangs so low? There is plenty of clearence above it. I talked to my mechanic buddy today and asked him if he had run into this before and he said "Ya, all of the camaros/F-Birds he's worked on were like that. It makes it a Bitc# to get the lift arms underneath it."

It looks as though it would drag the ground if you went over a speed bump...

Well, I went to modifying it and actually succeeded on all fronts. I got it to mate up pretty well to the flanges and it sits much closer the the car. I think I still have plenty of room between the starter and the pipe. I thought I would have to put some header wrap on the Y pipe below the starter when I started welding it but after I bolted it up it was perfect.

I just don't know why they would set it that low. Come to think of it, I think that my 85 berlinetta's Y pipe might have sat low like that as well. I can't quite remember though.

Just venting seeings how I had to re-work a factory GM pipe to get it right since the manufacturer couldn't.

 

Hi,
I hope its ok to jump in with a question since You have messed with the y-pipe and know about clearance etc. Could You please check out this thread?
https://www.thirdgen.org/forums/exha...pipe-work.html Maybe You can point me in the right direction? Ill fabricate most of the system so no need for exact stock routing..

thanks and regards
Hasse

 

If the 83 was an L69, the manifolds on the 86 TPI would have had the same outlet diameter. If the 83 was an LG4, the manifolds would be different, which might explain your Y pipe dilemma. Both the L69 and LG4 have the EFE valve (vac operated butterfly valve), the 86 TPI would have a spacer in place of the valve.

JamesC

 

I don't know anymore what engine the 83 actually was. I believe it was a L69. I still have the EFE Valve from the old manifolds and its outlet is identical to the spacer for the 86. I actually got the engine going last thursday and it turns out that I still have an exhaust leak. I also have a Clutch issue. I think I've got my friend talked into helping me to get things buttoned up on those two major issues. First things first though I need to get all of the sensors hooked back up since the previous owner of the 86 engine/harness butcherd some of the harness. Sounds pretty good though for an engine that hasn't ran in 4 years.

 

The L69 Y is on the right in the following pic (the LG4 on the left):

https://www.thirdgen.org/forums/atta...tion-ypipe.jpg

JamesC

 

Replace your sagging rubber engine mount inserts with polyurethane.

 

Rubber engine mounts are brand new. And theres no way that the engine would hang down 6 inches anyhow.

 

such a ridiculous difference.