We are completing a major rebuild of our 914 with new longs and other structural elements. Our restored car will not have need for heat, why not simply save the $$ and move on to other more pressing repairs. It's probably a couple hundred bucks plus the labor.

If you are doing a 4 cly build I have cover plates that neatly cover the J tube holes in the cylinder tin. I woyld block off the openings to the longs in the engine compartment to keet out rodents. I would not weld them shut as the next owner mmn ay want heat.
Curious as to why you do not need heat in Buffolo NY?

Just soooo tempting to get cute here....

So are you saying no heat plumbing in the longs or just not adding heat exchangers etc. Please clarify

I would put them in if only for future use. You never know if you might want to drive to Ellicotteville on a crisp fall morning and not wear a parka, gloves and a toque.

Having a little heat helps keep the windshield clear on cool damp days and with heat, you can drive comfortably with the windows up and top off in temps down in the 40s or less.

Deleting all the heating items external to the longs is no big deal, but if you delete the tubes inside the longs and you or a future owner later decide you want heat, you are kind of screwed.

True, true and true. Napa has 2 1/4" straight pipe and 2 1/4 fittings. I might go that route for simplicity.

Have been without heat since converting my car to a six on a budget…wondering if I can live with just headers.

The answer, years later, is not really. While I can live without heat, freezing toes and concerns about fogging up the windows—as well as mandatory top in place in anything less than wonderful weather—means the 914 sits more often than it might otherwise.

YMMV, but for anything other than a race car, I'd definitely want to put the tubes back into those longitudinals before sealing them up.

Why not use this opportunity to install a tube in the long that could serve both for heat and chassis stiffening?

Tried biting my tongue but I'm not good at it.

Before deleting parts the 1st question to ask is why whouldn't VW/Porsche simply use metal tube the whole way in the 1st place.

You can save a couple bucks with 2 1/4 tube but what you're missing is:


The OEM tubes serve 3 purposes.

1) They are insulators to prevent heat loss as the air moves though the tube. Othewise you have a heat tube that is a welded to a giant heat sink (the chassis) and the heat from the hot air will be cooled as it tires to heat the chassis before it gets upfront to the control vents.

2) They also absorb high freqeuncy engine and exhaust sounds that would otherwise resonate down a metallic tube acting like a microphone. A metal tube is going to be great at carrying all the engine clatters, exhaust pings, and other rattles right up into the cabin.

3) They decouple the rear end of the tube at the bulkhead from the front J-pipes that enter the cabin further reducing NVH.

No OEM puts parts in cars that are "extra" and not serving a useful purpose.

I put off having heat for quite a while, but now that I have it hooked back up, I would never go back. Julie and I have done several tours and it would have been difficult to see out of the windshield without that warm air.

I considered doing this by using a tube down the long with bulkheads welded in about every 10 - 12 inches. It would be a nice stiffness both increase in both vertical and torsional bending.

In the end, I didn't do it for the reasons posted above. Easier ways to obtain the stiffness either via clamshell doubler on external long or Mad Dog on internal longitudinal. However, I think these stiffners come at more of a weight penatly than could be achieved within the long. The plus side is that they are very easily added after the fact.

My goal was to keep weight as low as possible. Don't forsee adding those stiffners until I get to a /6 conversion and even then, I'll drive it 1st and evaluate where I'm at before adding the weight.

I was considering this as an option, but am not sure how it would all work? Where is the flex in our 914's? Within the longs or at either end. somewhere there is a weak link

If I was running a front oil cooler and replacing the heater tubes I'd likely run my cooler lines in the heat tubes, you might get enough heat to defog the windscreen.

Mine are plugged with rattle can tops clamped on.

I would think there is a modern insulation that would work. For sound and heat retention. Wrap the pipe with Roxul insulation a couple of times and zip ties. Doesn't attract vermin either.

Exactly that! ^^
The inner or outer shell will do a good job but they don’t quite close the loop and are not as optimal in torsion as the round tube. They are definitely easier to install though

Googling for center section images I came across zyyz.com. Pretty comp write up with excellent photos. It's the 72' link.

Was considering deleting the entire system, at least a couple pounds of weight savings

I would at least put the heat tubes back in.. You just never know what you or the next person may want to do in the future.

Adding to Superhawk's comments is the differential thermal expansion that will exist with a hot solid metal tube firmly fixed at either end into a cold long. Even with a 100 Deg temp delta over about 5' yields about .05" of differential expansion for steel. Depending on how rigidly the ends are attached, somethings gotta give.
Barefoot

Great insight.

That one didn't even cross my mind.

This specimen will be a rat rod at best and will never see rain or cold. It does make sense to install the tubes at least while we are in there for the next guy. I will use 2 1/4" straight pipe with fittings from Napa and build in some room for expansion. We have a few sporting cars in the stable, most do not have working wipers/heaters and other non essential accessories.
thanks for the input's

Bottom line, it's your car. You should do what you want.

The rest is just an engineering excercise from the peanut gallery (myself included).

Don't delete your eater tubes. I know you probably cut them to ribbons fixing your longs. But you will want those later on. I've been driving my car without heat since I did my resto-mod a decade ago and it was a poor choice. I'm now trying to source all the stuff I need to make the heaters work.

These cars are flat out dangerous to drive on cool mornings when the windshield starts to fog. There have been events I wanted to go to that I had to skip due to not having a way to defog the windshield, and drives I've made where I was not able to see much of anything.

Zach

The center piece is a slip fit to allow for expansion? I noted AA has NOS weld in end tubing on eBay.

I have sourced straight exhaust pipe and fittings from Napa, the 45 degree fitting at the rear needed to be reduced to about 37 degrees, other than that it is pretty straight forward. I will couple male to male at the front end with a Furnco type flexible fitting leaving room for expansion. I am not planning on insulating the pipe.

Edit: Furnco type flexible fitting not required. Front connection is male to male welded, rear connection is male to female. Female engagement is 2" potential, I fit the pieces with 1 1/4" engagement. Plenty of room for expansion. I will fab a few clips to hold the pipe in the clamshell, paint the insides and install the cover.Click to view attachment

My thanks to the peanut gallery

Hollow pipe? If so, it will be an acoustic waveguide & you'll hear a bunch of shit. FYI.

I noticed the stock pipes are corrugated, sound dampening?

Once it's closed up it's closed up. This may not be the time to cheap out.
Thanks

The corrugation probably does provide some sound dampening, but it also makes them flexible so they can be compressed to install. It's just a spring fit between the two end tubes so they move easily with expansion/contraction. They are an inner corrugated paper foil tube wrapped in a thick layer of insulation, and an out wall of paper corrugated tube. Complicated enough that some engineering has obviously gone into them.

BTW, it has to be said, "my what a large pipe you have there."

The rusted hulk had no heater tubes when I brought her home. I was brought up with VW bugs in Buffalo and was (50 years ago) used to having a small ice scraper in my left hand while driving. I recall hooking up a metal flex pipe to one of the heat exchangers and directing it to where ever heat was needed. All my friends wanted the same modification done on their bugs. Where did that 50 years go?

Go to Home Depot and get some 3 inch foil dryer vent the all alum type. Leave some holes in strategically to inject foam insulation in after you have spot welded up the clamshells and the pan in. Inject the insulating foam in...plug the holes up with a screw...done. 35 bucks per long.

I'm rooting for Summer like you said.

The OEM tubes have insulation inside them. It's loose so it doesn't overly prevent heat flow.

Alright my last post on this topic. I swear.

You have $450+ for the inner long. Then $125 ish for the outer side long close out and you're trying to avoid buying a $122 dollar heater tube? I honestly don't get it. a WTB ad would likey turn up two serviceable used parts shipped to you for around $125.

I'm not even counting your labor becuase we all know thats free.

As you said once you button it up, it's done forever.

But I'll finish on it's your car -- doesn't have to make sense to me.

Ditto.

Completed passenger side. Click to view attachment Click to view attachment

I am happy with this install, concerns of expansion, insulation, ... are secondary. I am sure many of us have worked on the 356 heat system. I half considered cutting an opening to provide heat with a sliding door arrangement per 356 standard install. painted with Rustoleum ready for the other half of the clam shell. Doors are fitting well, progress is moving.

Happy New Year to all!!