My Heater Tubing Melted!

I have a Vintage Speedster and I took several steps to improve the heating. One of the steps was to purchase some plastic heater tubing from Vintage Speedstes and to bypass the frame. This is the same tubing that VS uses to bring heat into the interior and the system worked very well to improve airflow.

Then I put on original heater boxes and got much better heat. The heat was so much better that it melted the plastic heater tubing!

So now I'm searching for some sort of replacement tubing that is more heat resistant.

Any ideas?

Thanks. Cole

Flexible metal exhaust pipe

Or this. Rated to 225 degrees. http://dcthermal.com/catalog/2-12-high-temperature-hose

CAUTION. I have not run the car up to normal operating temperature yet, so I am not postive that the 225 degree rating will be high enough to avoid melting. I'll do that ASAP and post on here what I find. I know that there is higher rated hose available, but it gets very expensive.

I just used it on the ivory car that goes on eBay tonight. It's 2.5" and fits right on to the heat exchanger, but you may need to get an adapter to match it to the tube running under the rocker panel to the vents. Should be available from any hardware store.

Or this from Grainger. Rated to 250 degrees. http://www.grainger.com/Grainger/HITECH-DURAVENT-Industrial-Ducting-Hose-2RY21?Pid=search

And I hear so many complsints that these cars have poor heat!

When my Espar gas heater was installed "Scat" aircraft tubing was used.this is about 3" in diameter, a rubberized material with wire wrapping for strength. Bright orange colored. I had the same stuff in a couple of airplanes. High-dollar material but nothing like it available that can compete.

Outlet temp of my old Eberspacher is 150 F, so I think you should be ok with heater boxes.

Yup. I ran the car for about 30 minutes this evening and it seemed fine. The hose and clamp on the heat exchanger were warm, but not too hot to touch.

Here are some pictures.

Hi Cole,

Could you be more specific on by-passing the frame ? I ordered some by-pass tubes from Fibersteel back in Oct. (still haven't received them) see post under Vendors. Is this what you mean ?

Chuck

are you sure that tubing you bought from VS was for the heater output? it looks like the heater input (ie fresh air from fan shroud).

that does not look heat resistant, nor does it look like it would keep the heat in.

Chuck.
The pictures I posted are by passing the fram and that is what you are waiting for from Fibersteel. Do you see the white square metal with the round tube coming out of it? That is the frame and that tube is where the heat comes out and goes into the tubes that run up to the front of your car. Do you see the white tube directly across from the heat exchanger outlet that I circled in blue? That is where the heat goes into that square metal tube from the heat exchanger. The square metal tube goes all the way across the back og your car and the other heat exchanger connects connect to it on the other side. Do you see how big the heat exchanger outlet is compared to the smaller tube that the hot air is being forced into? Well that is where all the restriction is. Both sides are trying to force all that air into that smaller white frame tube. The black tubing in the pictures bypasses all of that on both sides and all of your hot can flow unrestricted.

Mango.
You said "it looks like the heater input." Where do you see pictures of the tubing he got from Vintage? The tubing you see in my pictures is from DC thermal and is sold for use with their quartz heaters. It's rated to 225 degrees.

Chuck, on a Vintage Speedster the heated air comes out of the heater boxes, then goes though the frame, then into plastic tubing and into the cab. Going through the frame both restricts the airflow and cools the air. once I made that one change, bypassing the frame, the airflow was much greater.

The bypass was done with tubing I purchased from VS, the same they use to run the air up the sides of the car and into the cab. I'm guessing that the air is so hot near the heater boxes that it's melted the tubing. I do not have the plastic tubing connected right to the heater box, but have a 6" buffer of that paper/ foil tubing that is used on the topside of the engine.

So I'm looking for some higher rated temp tubing.

That aircraft SCAT tubing is rated for 550 deg F. You might not like the price though. http://www.aircraftspruce.com/catalog/appages/scat.php

It takes about 3 feet per side or just a little more.

FYI: If you go with the aircraft type (GOOD STUFF)get the SKEET type it's a little more $ but a much better product. Using it on ours from the fan shroud to the heater boxes and from the heater boxes to the chassis.

Doug, are you using the 2-1/2 inch ID hose? I assume that's the size of the heater box connections?

Why are you running it to the frame, why not bypass it and improve your airflow and heat?

The SKEET has a reinforcing wire? How does that improve its function?

Thanks!

I'm using 2" SKEET. It has wire coils that are between the layers of the hose. I purchased (2) 2 1/2" ID to 2" OD exhaust adapters to go from the heater boxes to the chassis. I slotted the 2 1/2" area length wise about 1 1/4", put (1) layer of header wrap over the heater box outlet and used muffler clamps to secure the adapters to the heater boxes. The 2" SKEET hose is a good size to go from the fan shroud to the heates boxes. SKEET is a little pricey but it's what I use and recommend for aircraft since it's approved for these types of applications and holds up for a LONG time. The reinforcing wire keeps it from collapsing at any bends. With this mod I'm getting good airflow thru the standard Vintage setup.
As posted earlier Aircraft Spruce is a good source.