Heat Exchanger Hell

[Howie149]

1970 914-6 All original. Factory exchangers full of holes.

First set of Dansk are horrible and don't really fit.

Second set fit pretty well except that the outlets are about 5cm wider than muffler inlet (picture showing the outlets relative to the support bracket below). Can this be fixed? How? Should I just crank on them and make them fit? Seems like they would break. Have a muffler guy modify them and/or the original muffler?

Also there is one bolt on the passenger side flange that is basically impossible to reach. (Pic attached). How the heck do people tighten that thing?

[Dave at Pelican Parts]

If you just pull the ends of the tubes, you put a lot more stress on the exhaust studs. It seems like those break if you look at them sideways, so you probably don't want to do that.

I would try putting them on with the fasteners loose, then pushing them as close to the correct alignment as possible, then tightening the fasteners. If they still don't line up, remove them and bend the pipes to line them up. You may want to fabricate a jig to hold the three pipes so you can bend them correctly. If you still have the original exchangers, you can use them as a template.

The exhaust nut I see in the pic does not look like the correct type. It looks like the type we use on the 4-cylinder engines, which have more room for access. (Not that access is easy, mind you.) The correct ones are 911 "barrel nuts", which have an Allen head on the end. that lets you use an L-shaped hex key to tighten or loosen them. It may wind up being necessary to cut down an oversize L to fit the space available, but that is easier than trying to fit a wrench in that space.

--DD

[mb911]

I would do 2 things. 1st I would checking alingmnet of the flanges.. If they don't line up use a dead blow rubber mallet to tap them into position. This can be done pretty easily..

The second thing is to enlarge the holes in the flanges by a couple of sizes this will allow for more flexibility.

[Bruce 914]

Aside note : Your large cupped washers of the trans mount bolts are on upside down. The cup should face downward do water will not accumulate in it.

Dave is right about loosening the nuts at the heads to see how much that gives.
Use the muffler holes as the guide for how much they need to be bent if needed. You do not have much of a window of error.

[mepstein]

Where there are acccess holes, use barrel nuts. In the blind areas, use a 12mm exhaust nut (more room than a 13mm) and use a SSI / distributor wrench to reach the nut.