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Posted by: Chris914n6 Mar 3 2023, 08:55 PM

I need to clock the steel tube to clear the trunk.

I'm guessing it's pressed into heated aluminum, maybe with a lube that turns into a glue?

Anyone know for sure? @http://www.914world.com/bbs2/index.php?showuser=22428 maybe?

I have a 1500F heat gun to work with.

Posted by: tazz9924 Mar 3 2023, 10:14 PM

You could remove it and tap it for pipe thread and install with what ever fitting and orientation you want.

Posted by: Superhawk996 Mar 3 2023, 11:58 PM

Not sure what part this is. Subaru coolant crossover pipe?

Without seeing the part from other angles or knowing exactly what it is I’ll take an educated guess.

Assumption:
Cast aluminum tube with steel elbow

I’m going to say the steel elbow is likely to be cast into the aluminum and probably has an anchoring and/or anti rotation feature within the casting.

Rationale:
Looking at the picture, it seems like there is no machine work visible to square off the aluminum casting right below the “bead” around the base of the steel elbow. I also don’t see any hint of a chamfer or machine work that would be wanted if the steel elbow were pressed into the aluminum after the aluminum was cast.

Heat shrinking and a press fit would leave some opportunity for difference in thermal expansion to cause a leak or to allow the fitting to slip. I suspect the steel elbow has some features like a knurled serration or multiple beads like the one you can see, around the steel tube to allow the casting to grip it permanently and to seal it.

Casting steel features into aluminum castings is pretty common. Example cast iron liners cast into an aluminum block. It’s certainly not uncommon to cast in metal sleeves and nipples into things like water pump housings.

Being limited to a heat gun probably means you are going to struggle to get the aluminum hot enough to even try to swivel the elbow. Aluminum is a great conductor of heat and it’s going to suck the heat away from the local area you’re trying to get hot. You can try - not likely to hurt anything.

I agree with post above. The easiest approach is to remove the elbow, drill out a remnants of the steel tube, and then tap it for a fitting.

You could also cut the elbow off, orient it as you need it, index the parts, and then have someone weld the reoriented elbow back together. This would be my approach if I were in your situation. I don’t like fittings that can leak if that can be avoided.

Posted by: Chris914n6 Mar 4 2023, 01:00 AM

I knew you would know some stuff @http://www.914world.com/bbs2/index.php?showuser=22428

The n in 914n6 stands for Nissan but yes it's a coolant crossover pipe.

The hole surface has radial machine grooves, as all the others (gauge & ecu temp senders, etc) like a special cut drill bit, then I would assume threaded after.

If I can clock this it would be much better than piecing together a bunch of NPT fittings. This is heater out @ 5/8" and feed to the VW coolant reservoir @ 5/16". Steel pipe is actually 19mm OD.

I thought a double banjo stack would be sweet but no luck finding all the pieces, plus I doubt I could get it threaded straight anyways.

I'll look into ORB fittings next.

Posted by: Krieger Mar 4 2023, 09:16 AM

You could just cut the steel pipe before it bends and put a rubber hose with a 90* bend on it. No barb on the pipe though.

Posted by: rick 918-S Mar 4 2023, 10:09 AM

Hey Chris, try the heat gun first working the tube right to left if all else fails cut it off with a small tubing cutter, rotate it where you need it and weld it back together.

Posted by: 76-914 Mar 4 2023, 10:21 AM

Loosen the hose clamp, remove engine, install Subaru EZ30, tighten hose clamp.

Posted by: Chris914n6 Mar 9 2023, 09:16 PM

Update: surprisingly easy. Used the old deteriorated pipe to experiment with.





FYI- steel tube is only .060 so too thin for me to MIG, plus without fresh plating it would rust apart in no time.

This mod and replacing the heater return pipe and removing the no-longer needed vacuum tubing spaghetti knocks 2" off the rear / trunk side.
Finally a reason to update my build thread

Posted by: Superhawk996 Mar 9 2023, 10:03 PM

So you were able to rotate it in place?

Posted by: Chris914n6 Mar 10 2023, 12:34 AM

Yep. Got the joint area about 180f per the temp gun, decided to try it and around it went. Cooled down to about 120f and it was stuck again. Kinda concerning because the engine likes to be at 215f....

Another one of those things it would have been nice to know 20 years ago

Posted by: Superhawk996 Mar 10 2023, 11:51 AM

Hmm - I’d have the same concern regarding thermal expansion and operating temp.

Wonder if it is riding on some sort of o-ring seal.

Can you see any hints of it being machined so that the elbow with a o-ring can be pushed into it?

Really interesting. Regardless, I’m glad I was wrong on my initial assessment and that it was easy to reorient without welding.

Posted by: rick 918-S Mar 10 2023, 01:14 PM

Reheat it, remove it reinstall with Locktite?