DougM

I have researched but have not found a definitive answer. My Euro '84 S currently has the motor out for a refresh. I have purchased another '84 Euro S as a donor car mostly for a later model 5-spd G28/10 that it has. The donor also has aftermarket headers. My motor easily came out with the headers installed. From what I read, the aftermarket headers cannot be installed before the motor is dropped back in. I have also read that the lower bellhousing cannot be installed/removed with aftermarket header installed without lifting the motor a bit. I am trying to decide if it is worth the change to accrue extra headaches in future service with the header swap. My current setup has no cats and my lower bellhousing takes minutes to remove.
Sometime there is almost too much info here when searching for research.
Is it true that you cannot remove/install the motor with the aftermarket headers on?
Can you not remove/install the bellhousing with the aftermarket headers?
If you cant do either of these 2 items, is it worth the hassle for the gain(if there is any) over stock Euro S headers?

Jadz928

Cue Chris (Landseer). He just went thru problems related to MSDS headers.

Generally, they are a PITA, and for not much gain... though they yield a great sound.

85-86 32V Tubular manifolds are the way to go, really.

PS, I believe they need to be loosened to lower the bell housing, and assembled after engine is in situ with the engine elevated off the mounts.

GlenL

I'm confused by your statement about "stock Euro S" headers. The stock parts aren't headers at all, just manifolds. They look a bit like a lima bean and are pretty crappy.

There are a number of true headers that have been made. Following along, and not having them, some do not allow the lower bellhousing cover to be removed. That'd be a problem if you need clutch work.

The improvement may be around 20 hp over a stock Euro S exhaust system. You may not have that if the car was correctly federalized. Maybe 30 or 40 going from restrictive cats to headers and free-flowing or no cats.

Landseer

I don't know if you can pull the donor engine with (assumed) MSDS headers.
Hacker might know.

I do know that to loosen my set a couple weeks ago, and ultimately remove them, it was easier to remove the crossmember and motor mounts.
(my engine was staying in)

The MSDS headers prevented removal of the bell housing cover.
Loosening the drivers side pipe did indeed provide clearance.
But I couldn't reach two bolts to get that drivers side pipe loose. Might have got them laying across the engine --- didn't try, removed the crossmember instead. Once I got it loose, I took it off. Removed the bell housing cover. Then removed the right MSDS pipe.
So, to access the clutch area with MSDS, I literally had to remove the rack, crossmember and mounts.
For that reason they will not be going back on this car.


Each of the MSDS pipes measure 3mm diam smaller than the 85/6 tubular SS manifold/header pipes at the outlet of the heads. That's a big difference.

I have elected to jetison the MSDS in favor of 85/6. I installed them last week with the crossmember and mounts out. The cross member support brackets on each side had to be loosened and pivoted. (Flying Dog reported about that a few years ago) I think I could have installed them with the motor mounts in place due to better configuration than MSDS. (The volvo mounts are now installed and it appears I can access all bolts on the 85/6 units)

I think the 85/6 tubulars could be installed/removed with the engine, but am not certain if those brackets need to be moved. Probably not.

Others have considered the 85/6 tubulars to provide equivalent HP gain to MSDS and that seems logical.


I intend to run 87 factory cats. To do this, I am buying an adapter from Dave Lomas at Motorsports SLC in Utah. With stock 84 manifolds the 85 and later 32V factory cat pipes mount perfectly. But going to 85/6tubulars creates an offset due to head spacing differences. It takes an adapter to bridge the gap on the right side of the car.

Later, should I decide to go with an X-pipe and freeflow cats, or some other S4 aftermarket exhaust, it should bolt right up.

I have converted other 84 cars to 32V cats and true duals.

This Euro here will get 85/6 tubulars, 87 cats, 87 resonators and the last muffler is TBD, probably S4 pumpkin. There may be slight routing issues at the battery box and the need for a hanger or two.

The car needs to be emissions compliant and I prefer it quiet.

If you also go the route of 85/6 for flow, and to avoid MSDS, there are 2 nuances.

The stud holes on the 85/6 units need slight enlarging. I used a 27/64 drillbit and ran it through the mount holes. This provides just the right clearance to fit over the 84 studs at the heads.

Secondly, use normal metal / fiber sandwich gaskets. PET shows a metal ring or crush ring for mounting tubulars to the 32V head. Fiber gaskets are adequate and much less costly.

tilac999

Chris, I think I'll be doing this to my '85 Euro as well. 85-86 factory 'headers' and an X pipe. I'll need the adapter from Lomas Motorsports, how much does it run? I kinda like the sound of my stock Euro setup, might just do the manifolds and keep the Euro silencer. I've heard it has a built in crossover, no?

GlenL

This is the set-up I've got: '85 shorty headers onto a bone stock Euro S dual exhaust. Sounds really nice. I'm figuring 10-15 hp gain. Estimating as I put them in with other performance mods.

I had a piece of pipe welded on the "Y" right side after doing the installation myself. Cut the right-side exhaust pipe a foot or so back from the flange, added some flexi-pipe for a trip to any-old exhaust shop. Like $60 to have a piece welded in.

123quattro

MSDS headers do cover the bellhousing. I doubt you could pull/install the engine with them attached. I suppose anything is possible, but it would be tough. Even if the 86 manifolds have slightly bigger ports I'd still be willing to bet the MSDS headers will make more power. I have the 300hp Euro heads/cams , but not the intake or throttle on a US 4.7 bottom end. My car is still making ~320 crank hp with a full exhaust and MSDS headers.