Vilhuer

Since RHD headers are different you might run into problems. As rest of the exhaust is same X-pipe should fit when little over 2" piece is added on one pipe.

I sold ROW '86 S3 manifolds from engine I bought at German eBay about year ago and they are now installed into local LHD '84 S2. If you are lucky you might find similar engine somewhere in continent. Best option would be to get entire dead S3 engine and modify its cams to fit '87+ heads. Maybe year ago Van Zweeden in Holland didn't have any S3 engines when I asked so they probably will not have manifolds either but it doesn't hurt to ask.

Cheburator

No one answered my question whether the 3-bolt S4 pattern can be modified to fit the two bolt pattern of the S2 heads by cutting the extra bolt hole. The S4 manifolds are surplus to requirements, thus I don't mind butchering them...

Thanks,

Alex

Vilhuer

Its possible to at least make 2 bolt plates and put them in place of 3 bolts in S4. Shouldn't bee difficult job for anyone who can weld properly.

Mike Simard

The 2 bolt holes you'll need are in a different place. They would likely break through the edge of the manifold if you drilled new ones.

Cheburator

Thanks Mike,

I have not seen my S2 engine for 14mths Picking up the car tomorrow...

It seems that it is worth playing around with the stock cast manifolds given that the chances of finding a S3 engine are pretty slim to say the least.

Alex

mark kibort

Im still not clear of the differenes. would be nice to see some pics to see what you guys are talking about. I remember when i got the devek leve 2 headers for my 2 valve, it came with a universal flange, where we just cut off the top and it fit perfectly. now, from what Jim says, it sounds like the 85 heads are different from the 87 heads. I thougth they were the same.

so, is it near impossible to use the 87 manifolds on the 2 valvers? they sure do look less restrictive, but thats at first glance.

mk

Mike Simard

Here's what the Devek Level 2 headers look like with their dual bolt pattern:

The 2nd sets of holes is close but the flange is large enough to accomdate them.
It's very convenient having both sets of holes. I'm using these headers with a 16V engine until the 7L engine is ready. They'll be interchangable but instead of cutting off the top part that interferes on a 16v head, I'm using a spacer.

PorKen

Nick,

I ground the manifold outlet, only, while under the car. From ~51mm to the ~55mm ID of the 32V gasket. Then I put in 2" (stock 1¾") head pipes from an '86 cat, made into a Y-pipe. If I had the engine out, I might look at englarging the head ports and manifolds to the ID of the 2-bolt 32V gasket.

I'm pretty sure all year cats, and X-pipes are interchangeable. The 32V manifolds are offset because the ports on the head are spaced differently than 16V, but the manifold outlets are in the same location as the 16V.

It doesn't affect your monster engine, but I reckon the stock 4.5's probably will lose power with the usual X-pipe sized 2½" head pipes. It was tough for me to get over the idea of going big, but I've realized now how critical sizing the pipes to the engine is. Not sizing to what I'd like it to be!

Jim bailey - 928 International

The 16 valve and the 85-86 32 valve use the two which are centered on the port. The 1987> uses the triangular bolt pattern with three bolts. And 85-86 heads are very different than the 1987> cam journals, valve size ,pent roof shape , number of studs for exhaust...

mark kibort

so, there is no way the 87 exhaust will work on the early 2 valve cars, unless some major mods are made?

I knew about the valve sizes and cam bearing setup, as i did the 85 to 87 conversion with the cams, but was unclear of the bolt pattern different on the exhaust manifold.

thanks,

Mk

drnick

ken, thats an interesting thought on the x pipe size - i wonder if thats simply to do with the diameter of the manifold being less than 2.5" ie there wont be any gain going from 2" in the manifold up to 2.5" in the down pipe?? what size is the manifold outlet for the 32v cars? the ott x really had an effect on my euro S2 4.7 litre.

PorKen

Nick,

Oops, I looked at my notes, and the Ott-X has 2¼" ID down pipes.

The euro 4.7 with big intake and valves can easily handle the Ott-X, but AFAIK, it would be better to match the cast iron outlet, or use a 32V manifold. Anyway, I was talking about the 4.5, which have small intakes and valves.

The 32V manifold has ~55mm opening, the same size as the gasket. The stock US and euro cast iron manifolds have 51mm openings, at least until '83 euro. I wonder if the LH manifolds are larger?

Landseer

Forgive me for drawing this side-bar to the original question from England, but being as its being discussed, its probably worth confirming here.

What I'm hearing is that, in 3-D space, the x-y-z location of standard cast iron outlet pipes for a LH 4.7 is identical to the x-y-z location of the standard outlet pipes for the LH 85/6 32 valve.

Jim has said this before. Dr. Porken noted it above.

I tested it by buying a direct-fit US LH 85-86 pipe&cat and bolting it to a US LH 4.7. It almost fit perfectly, except I had to spread the pipes apart about 3/16 inch. This was probably mfg error in the aftermarket cat pipes. No spacer was needed. So, an X made for a 85-86 should fit the cast iron pipe flanges of a US 4.7. This question has been asked many times over time, but the answer is not that clear in the archived posts and I think some folks can benefit. Anybody with contrary information, please share.
(again, this is all LH drive data)


Please forgive the sidebar, Mr. Cheburator.