byrdman454

I need some advice on this.

I bought an Ott x-over from a fellow Rennlister and it is in great shape. I plan to use this on my '84 Euro. The Euro has dual pipes that go all the way to the rear muffler unlike the single piped US version.

I spent the weekend swapping the crappy cast exhaust manifolds for a set of 85-86 tubular style. I thought since I had changed the manifolds to 32v, the Ott X would bolt right up. Not!

It was way off on the passenger side. I guess I still need to make a spacer. How thick does this need to be? Is the reason it is not fitting because the 16V motor spacing is funky? I am a little confused. Can someone help me outand explain why this does not bolt right up and what I need to make this work?

Thanks

FlyingDog

If you'd left your stock manifolds it would've fit. To use the 85-86 manifolds you have to either extend the passenger side downpipe or make a spacer.

Richard S

The exhaust ports on the 16valve heads are not oriented the same (fore and aft) as the 32valve heads, thus the 85-86 manifolds do not end up in the same place as the stock 16valve manifolds. You will need to modify the x-pipe or make a spacer for it to work. Matt is correct, the x-over would have fit fine with the stock 16valve manifolds.

When you get it done, post a dyno run....many of us are interested in the actual gains from the 32valve manifolds.

Rich

Big Dave

I have an Ott on my 85 with the stock manifolds and no spacer. It fits fine.

FlyingDog

Dave, that's because you have 32V manifolds on a 32V engine. Mike is putting 32V manifolds on a 16V engine.

byrdman454

The only reason I changed them was because I got the manifolds for about $50 off eBay. It was too cheap to pass up. I talked with DR about it, since he is a Euro expert with his '85 and he said it was worth about 10 hp. 10 hp for $50 was way too good of a deal for me. It was a pain to change out, one of the studs was snapped off a long time ago, from someone. I was able to drill it out without any more problems.

Does anyone know how thick of a spacer I need? I bolted the pipe up on the drivers side, and even with a spacer, the pipe does not look like it it going to line up on the passenger side. It looks like the pipe need to be spread a bit. Is the 16v motor a bit wider than the 32v?

I thought to hook the Ott on the 16v stock manifolds, a spacer was needed. That is another plus for me to buy the '85-'86 manifolds. I must have read something wrong in the archives. When is the spacer needed? I cannot believe no one has ever used an Ott on a 16v Euro. Someone has to know the answer to exactly what I need to make this work.

Thanks

Ketchmi

An Ott (and our X-over for that matter) fit stock Euro 16 valve engines with the factory exhaust manifolds. If you install 85'/86' 32 valve headers on any 16 valve engine a spacer will need to be made for the passenger's side. We are considering doing a batch of X's and Y's that will compensate for the later headers on 16 valve cars.

byrdman454

Dave,
Have you researched this new pipe to know how much longer the passenger side needs to be to match up? I need to have a spacer made and need a thickness.

Thanks

Normy

Byrdman- when you come up with a spacer....please post measurments and pictures online so that others can copy it!! I want to install the 32v manifolds on my S2 as well, and any muffler shop should be able to fab a spacer- with plans.

Thanx/good luck!

N!

BeerFish

Amazing how Ketchmi, Flyingdog and I were just mulling over how to do this last Thurs/Friday to mine. I have been trying to work out all these issues BEFORE I do it.

Dave, Im seriously interested in the }{ that is built for the later model conversion!! Just wish I had someone close to me that could build the cats back cheaply!!

Imo000

You can just drive your car (with only the manifolds) to your local muffler shop. They can easily bolt the pipe up and extend the pasanger side. The easiest way would be to cut the passanger side flage off the X and install an extension. OR they can actually fabricate an extension using two collector flanges and a small piece of pipe.

The triangular collector gaskets are standard size and match up perfectly to several Nissan or Mazda gaskets. I replaced mine with gaskets matching to a Mazda engine. They cost around $5 each and most muffler shops would have them in stock.

byrdman454

Here's an update...
I made a tri-bolt 1" spacer out of wood last night. This takes care of extending the pipe, but the tri-bolt holes will not match up. They are about 1/2" short (Ott pipe is not wide enough). I cannot believe it. It looks like the Ott would have to be cut and extended. If it is cut in the straight section (Y section, not at the flange) and extended, the tri-bolt flange should move a little outboard since this pipe is at an angle and take up this 1/2".

I really do not want to cut my Ott. It would be useless for 32v cars and everything else except this particular setup. I am going to next look at a spacer that is offset a bit to account for the 1/2". I'll keep you guys posted.

Is everybody sure no one has done this before???

Thanks

SMTCapeCod

Oh its been done...but like people are saying the solution is typically to cut the short brach of the crossover pipe and have it modified. The angles are typically close, so your just talking about inserting some straight pipe. Cheap solutions never comes without a hassle, does it?

I did the same but wimped out on the 32V manifolds, they are still in my basement. Had the same motivation, socred the pair for $150. Can you post some more information about your work to swap them? Did you have to unbolt the motor mounts or elevate the engine? Remove components? I assume you had a lift at your disposal- wish I had such a resource!

byrdman454

SMTCapeCod,
A lift....HAHA, not here. I was on my back the whole time doing this job. I did have my jackstands raised pretty high, but I was still on my back.

It really was not as bad as I thought it was going to be. The first thing I did was unbolt the AC compressor and brackets. I supported it with some wood to take pressure off the AC lines. I then removed the air pump and all of its accessories since I was removing the cats and no longer needed the pump. This opened up the passenger side a bit, which seemes to have less room than the drivers side. I also needed access to drill out one exhaust stud that was broken by the PO on that side. I then supported the engine from above and removed the steering rack. I then removed the cross member and motor mounts. I had just replaced MMs a few months ago, so it was not such a big deal. I was also able to remove the exhaust nuts without breaking anymore studs. I used a 3/8" impact wrench and burped it back and forth. This is the best method I have found in removing rusted bolts/nuts. I had it done in a day and I was not working all that hard.

Good luck
Let me know if you have any more questions.

SMTCapeCod

thanks for the right up -- right-helpful!

Looks like I'll add that to the WYAIT list when I do motor mounts.. and hopefully someone will offer a run of 'spacers' in the interim. I really doubt I'll pony up for another pipe that spans the difference, and there are no decent custom exhaust shops around here.

Trouble is I'm finding that lumping in what I 'ought' to do or 'want' to do, with what i NEED to do is making projects daunting and very cost-prohibitive!!!