Jan Peter Stahl posted:

CSP offers the heavy duty quality also in bigger diameters

Thanks- I didn't know that.


Jan Peter Stahl posted:

CSP offers the heavy duty quality also in bigger diameters

I know you are aware, Jan Peter, but for posterity: so does CB Performance, SoCal, and a lot of other places. They have aluminium heat sinks and a true 1-5/8" tube inside, which should be good up to a decent 2276, depending on the state of tune.

EMPI has carried the Dansk 1-1/2" heater boxes since the paleolithic period, but they have no heat sinks (they're just a tube in a box).

I don't think I'd run stock boxes unless I had a 1600- (mild) 1776.

Last edited by Stan Galat

this is, what I wanted to say!

Before I would start thinking about an electric additional heater or something like that;

I would think about, how to improve the existing system. And there are ways to heat up the interior until the legs are roasted with a higher quality heater with the Aluminium block inside.

Also isolating the heater tubes from the back to the front will improve a lot.



Last edited by Jan Peter Stahl

Jan Peter. I think you mean "insulating"

Speedsters are much easier to use heater boxes, not the same on Spyders, no heater channels at all. That's my reasoning for the gas heater and carbon fiber seat heaters.


I never had heater boxes on my 2,110 because I didn’t think I needed heat AND the larger-tube boxes were something like $600 USD each!  Lived without heat for 15 years and thought it was OK, but had a home in a warm state and drove there all winter.  To avoid $1,200 in heater boxes I spent $400K for a house instead!  

Danny’s post of the gas heater farther up this thread is right on.  For about the cost of a pair of larger heater boxes you can get more reliable heat than you’ll ever need AND with true working defrosters.  I have an Eberspascher BN2 that I have throttled back to about 25% of full output and it is perfect for cockpit heat down to about 35°F outside.  If I were to turn it up it would drive me out.

From what I learned on several gas heater forums as well as from some truck heater techs I spoke with, all of the inexpensive Chinese copies of Webasto, Eberspacher and others are poor quality and should be avoided.  Like buying Speedster parts, you may like the low, low price, but you won’t like the product when it dies!

Lastly, any heat you can get, whether from heater boxes or a gas or electric heater, will be wasted if you don’t find and eliminate any cockpit air leaks (and there are usually lots).  If I could totally seal my cockpit (almost impossible on a CMC) I could get by with a lot less heat so I compensate by making more heat than I should need - That works.

Last edited by Gordon Nichols

so I don't know, just guess:

If you put two of these blowers (each has 30 watt) inline between airbox and heater I  can imagine, it will pull out the hair rapidly out of the air box. I don't know if then is enough air left for cooling the engine or it might cause a engine overheating. ...just thinking out loud.

the other thing is, do you really want to see them each time you open the engine lid? hm

Michael McKelvey posted:

Has anyone here added bilge fans, like Atwood  Turbo 3000, in front of the heater boxes?

My Beck had such a fan, but all it did was blow tepid air.  Luckily winter isn't much of a thing where I live.

The T4 engine used an OEM electric bilge pump-like blower to increase the hot airflow.  I had a 914 with it and the VW bus did too.  Not a great photo below as the other end of the hose to fan is broken in half! (I can't recall if it only came on with defrost switch or any time the heat was on?)  The 914 also had a fan booster up under the dash like a modern car. 

I don't think the bilge-type blowers will affect engine cooling since they are being used in the winter.  I would put them between the heat exchanger and body connection hose - so it pulled hot air from the fins on the heat exchanger. (You wouldn't see them there).

Others have moved the external oil filter to the back seat area and used a fan to blow over it heating the interior. It sounds like a lot of work though for the limited benefit.


Images (1)

Yeah, if you put the oil cooler in the cabin it becomes quite the unwelcome heat source in the summer. And imagine if it or the hoses burst?

Many years ago there was a kit sold that put something like an oil cooler inside the car below the rear window.  It may have had a method to bypass it in warm weather.

The current gas heaters are very small.  I still think about trying to put one up over the transmission and hooking it into the existing system with y-connections.  Then I could use heater boxes only or heater boxes plus gas heater.

Mike, honestly you won't need to use heater boxes if you install a gas heater. I do like the fact that you'll be using the existing ductwork for heat and defrost. And the combustion intake and exhaust can be neatly routed under the car if you install over the trans. Good on you if you take the plunge. It's a lot of fabrication, but from the work I've seen you do, you're up to it.

I recommend that anyone with a gas heater only start them when the engine is running. The glowplugs draw a lot of current, and the alternator really helps with that by boosting the voltage a bit. Heater startup is a lot faster when the engine is running.

Mike, that is essentially how the factory installed VW Bus gas heater worked - the engine heater boxes outputted right to a blower that outputted into the gas heater input.  Don’t feel it is warm enough with just engine heat?  Turn on the gas heater from the dash and the heat would drive you out.  No new ducting needed.  The buses I’ve seen had a BN/BA-6 heater (a BIG bugger) which was hung amidships under the floor and just sat in the middle of the heat ducts. 

I did the heat system mods bypassing the frame and connecting the heat exchangers directly to the heat tubes running along the door rails. It produces a decent amount of heat and a lot of engine noise. The only issue is when the outside temp drops below 35f the engine runs so cold there is almost no heat. When it is around 40f I actually have to turn the heat down. 

If you run the hear into any part of the chassis the metal mass quickly reduces the air temp. I have tried a few  way including  direct into the center tunnel via the rear wishbones ( have to weld in a thick wall pipe as a round gusset) Problem was the shifter and E Brake hot really hot to touch. The other way is from the heater box directly to the base of rearward vertical door jamb..this makes for some serious heat but as mentioned engine noise. One way to reduce the noise is to make up a piece of plastic pipe with alternation half moon shaped pieces in the pipe this makes the heated air travel in a lazy S' path and helps to reduce the engine noise..

Last edited by Alan Merklin
12 V electric blanket was the best idea I love it it’s great for what I

Over two years ago I bought a brand new Speedster from Justin in Scottsdale
Arizona. He sold the company to Matt T. Who took over on the liabilities
and he’s done an excellent job and he’s very honorable

As you know the last two years I’ve been complaining about gas mileage
performance and a below average assembly of my car.

I took my car to the best Volkswagen Porsche mechanic in Phoenix call
Competitive engineering. DAN LAWSON works on many real 356 models that are
almost concourse.

I went from two bad carburetors to one EMPI 34 PIC CARBURETOR.

My performance is more than I need and I don’t have to screw around with
two carburetors anymore , the mileage on the highway is about 21 which I’m
happy with cruising at 65 to 73
The new owner of Arizona vintage WROTE me out a check for $2000 to take
care of all my repairs

Matt was very businesslike and generous.

On Fri, Feb 28, 2020.

at 12:03 PM SpeedsterOwners.com <alerts@crowdstack.com> wrote:
majorkahuna posted:  ...The only issue is when the outside temp drops below 35f the engine runs so cold there is almost no heat. When it is around 40f I actually have to turn the heat down. 

When it's below 40F have you tried taking off the rear engine sheetmetal (the piece over the exhaust) so the engine can ingest pre-heated air? You'll find it will get up to proper operating parameters and make heat.


JPC.  Your Speedster was built by Vintage in Arizona so I don't know how they routed your heat exchanger tubing.  Improving heat flow has been discussed many times on here and below are some links and video that may help you out. 

The problem was that the hot air coming out of both heat exchangers was being forced through the cars box steel frame, which was too small to handle all the volume.  The fix is to route the tubing directly to the tubes running under the rocker panels that are connected to the floor vents.

Video of increased air flow. https://youtu.be/IhnvnspQ-TE





I originally had the Attwood Bilge blowers between my stock VW heater boxes and the body and they did a pretty good job, the cabin would get pretty warm, (Northern California Winter, maybe 40-45 deg!). The problem is, the blowers got very hot being so close to the heater boxes and the PVC fan blade melted and the body warped. I may try this again but only if the blowers are on the inlet side of the heater box.

I forgot I have a temp sensitive valve that stops oil flow into the oil cooler until the engine is warm. I also have the original VW thermostat and flaps. However I also have the low profile oil sump. Between the cooler and sump I think I carry 5 quarts of oil. Good news my car has never overheated. Bad news it simple does not get very warm when is is below 35F. 


I would think that a blower would be better served by blowing air into the heat exchangers, as the 914 does, and sucking air from above the engine tin or a fresh air inlet.  You could even duct it so that the fan sucks air from the cockpit to recirculate it.

If you put the blower after the heat exchangers, the heat exchangers will be in a vacuum, possibly drawing air from under the car. They aren't perfectly air tight.  Not so good as you could suck in fumes from oil dripping on the exchangers or other nasty smells.

Just an idea.

I had a type 2 bus and a 912E and they both had the blower in the engine before the heat exchanger. My bus also had a BN6 gas heater mounted under the bus that would melt steel in 10 minutes. 


I agree.  If you're going to use a blower it needs to blow into the heat exchangers, but I'm not so sure it's really necessary.

The volume of air being blown by the fan through the heat exchangers is pretty significant as you can see in the video I posted earlier.  Is it possible that a blower seems to be necessary due to the extreme restriction caused by the air flow being forced through the box steel frame?

Also, if the flow is currently being directed through the box steel frame there will still be restriction at the frame even with a blower.

Video of increased air flow at vent after bypassing the box steel frame. 


After this expert mechanic did everything right he missed a step by failing
to put the connector on that makes the flow very efficient. If there’s a 1
inch gap between the muffler and the heat exchanger that’s not too good

I had some great aluminum 3M tape that covered up the gap beautifully. I’m
sure there’s something that I should’ve use

what is the VW connector called. Is it a staovked item
It works and the airflow is great so is my electric blanket

But warmer weather is here who cares

👍I’ll be ready for next winter

On Sun, Mar 15, 2020 at 4:31 PM SpeedsterOwners.com <alerts@crowdstack.com>
@Robert M posted:

This will get you driving down into the teens. Just don't stop at a 7-11 for anything. It tends to freak them out the clerks a little bit.


Actually, given the current circumstances, you can't get in to 7-11, or any store for that matter, without similar attire! That's required here in Pennsylvania, and in NJ and NY!

Actually, given the current circumstances, you can't get in to 7-11, or any store for that matter, without similar attire! That's required here in Pennsylvania, and in NJ and NY!

I was COVID compliant before COVID was a problem. Lol

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