Calling Dr Clock!

Hey Alan... Help!
I'm looking for a project this winter and have just re-visited your "Cheap Heat" article in "knowledge". Since it's been almost 5 years since you penned the story, I'm wondering if you might have any up-dated insights into the tunnel to air duct modification.
Thanks, Ernie

Ernie, I presently have a '01 Vintage Speedster that has the "through the 2x4 box frame" heat which doesn't do much. I plan on doing the cheap heat sometime in the next month or so. The most difficult part of the project is accessing the chassis rear wishbones and making the hole cuts. Some feel that by cutting out the holes, the chassis is weakened but this is not the case.
By installing the pipe nipple it reinforces that area. ~Alan

I've gotten back into my "busy time" of the year but, if I were to come up with a Speedster heater design with the following specs, how many people would be interested?

1. Based on a small, late-model Asian water-cooled car heater

2. Replace the water heater core with a similar one running engine oil

3. Small enough to fit between the rear seat and the engine
(or in front of the engine in a Beck)

4. Retains existing heat output registers (floor outlets and defroster outlets.

5. Retains the existing external oil cooler (client car must have Full Flow external oil cooler)

6. Optional oil flow diverter valve (Summer/Winter)

7. Multi-speed air mover fan

8. heater air inlet from cockpit - air outlet to floor and defroster

9. Retains existing heater ducts along floor/under dash

10. Cost estimate at $450 or under per car (including AN Braided connecting hoses).

I guess it would depend on just how much heat it would produce, how simple it was to install and how it looks after installation, but I am definitely interested.
Troy

What about a simple aftermarker street rod type ( approx.7"x7") square heater core box w/ fan and change out that core?
This could be mounted at the forward bulkhead on the tunnel. For summer all that would need to be added is an in line valve to eliminate the flow through the core. ~Alan

Rather than mount the heater unit in the front and have to run those looooooooooong hoses to it, I would rather mount it in the rear for shorter hoses and then just use the existing air-flow conduits (frame rails) along the sides and also not need to modify the heater/defroster outlets. Nes pa??? All that would be needed is an air return from the rear of the cockpit (a nice grill over a hole and some flexible duct from a clothes dryer woould do).

On heat output, think about this: A Water-based heater is working with approx 180 degree water. This one would be working with about 175 degree oil, maybe 160 on cold days. Relative heat output should be very slightly less than a Subaru.

I'm wondering about the diverter valve if this and a "normal" external heater were installed in series. Just don't turn on the blower in the summer and let the regular cooler do it's job. We'll see......

I'm super-busy til about Thursday, but I'll try to hit a couple of junk yards and see what I can find for a suitable heater unit (they're cheap) and go from there......... The toughest part of this installation might be finding and fitting a correct-looking multi-speed dash switch.

gn
(Oh, I'm back in,
the Junkyard,
again........)

Won't using the frame rails as the heat tube path, revisit the old CMC problem of loosing the heat as it carries through the cold steel mass of the frame rails.... ya ? Just my investigating .02

You gotta insulate those looooooong tubes. There must be a good way. Put a tube in side the tube. Or do like the originals, and cover the exposed tube along the car sides w/ sheet metal. My plan would be to do that, AND use urethane spray foam inside. The sheet metal would be about 1/4 round, seems to me. Not sure of fastener details, but it is a concept on my mind. I believe there is a lot of heat lost along thet long expanse of ducting, even if it is mad eof plastic (the JPS technique) which will be better than steel for heat transfer, but even better still if insulated properly.

IMHO.

1-1/2" -- 2" white PVC thinwall (DWV) tubing right off the rack at any bigbox homeimprov store. Less than $.50/ft
90,45, tee fittings all available, and tubing is bendable too

Dave's got a good idea, but consider this: What you might get out of a new, perfect, VW OEM heater box might be 90-100 degrees F or so. And THEN it flowed through the heat channels along the sides.

As an aside, the original VW Sedan heater channels were a single layer of sheet metal formed into a tube, which also served as the stiffeners for the body/pan. Ingenious design there, and it loses surprisingly little heat along the way - you didn't get much heat up front because there wasn't much heat put into the pipe in the first place. The amount of heat loss has to do with the internal surface area AND the velocity of the air through the channel. I'll leave it up to Kelly to explain it, but believe me, the loss isn't as much as you all think.

What I'm proposing is almost twice the air temerature entering the channels along the side and if even only 90 degrees exits at the front, that's about the same temp as that coming out of a heat register in your hot air house. (g measure it if you don't believe me).

This thing WILL work with minimal (if any) modifications to a current full flowed CMC, VS, IM, Beck or original 356 (but the Registry folks will NEVER consider one) and should provide almost as much heat output as a gas heater with far better heat control and modulation.

gn

I don't think I'd substitute a water heater core "radiator" designed for 15-30 PSI for an oil cooler radiator capable of 60-90 PSI. Seems oil ones have smaller diameter passages to slow flow and diffuse heat. I've heard of stock oil coolers being blown out on high oil pressure (thick oil) on cold start up.

Well, I mentioned up above that I would replace the water core with one for running oil through it, but maybe I wasn't clear enough, so:

I would replace the OEM water heater core with something like an appropriately sized DeRale or Setrab that can handle 150 lbs. of oil pressure. If you're running more pressure than that, you either need a Berg pressure regulator oil pump cover or a new pressure regulator in your case.

So I guess I'll just go off on my own for a while, develop the thing, debug it in my own car, publish the results (I could show me naked and sweating in the cockpit in 20 degree weather, I guess), patent the thing and then make them available (at a sizeable markup to cover development costs).

I think I'm on to something here.........but don't look for it THIS winter...Maybe next. It'll probably be developed in conjunction with my new kit, although THAT one will be water-cooled from the get-go. I honestly don't care what liquid goes through the heater - water, oil, perfume...as long as it brings 170+ degrees into the heater box and it's all designed to handle the environment, who cares?

gn

Sounds like an interesting project, Gordo, but please, PLEASE skip the "naked and sweating" part - or at least the pictures.

Gordon.
Do you envision this as a DIY project, once the kit is purchased from you, that most any of us would be capable of completing? Would it be basically a bolt in with a hole cut in the rear of the interior? Would that hole add any significant engine or road noise to the already loud interior when the top is up and would it be visible or hidden behind a seat?
Troy

Troy wrote in Italics:

Do you envision this as a DIY project, once the kit is purchased from you, that most any of us would be capable of completing?

I see it as a DIY for a moderately capable kit builder/maintainer.
If I can spec it right, either I'll find an after-market blowered heater unit as Alan suggested that will fit the specs, or I'll find something interesting in a junk yard that's readily available anywhere. Either way, it would be easy to do a DIY project showing how to replace the core and how to mount the unit behind the rear seat. After that, it would be about the same as connecting the hoses on an external oil cooler. THAT is actually the most costly part - if you run stainless braided hoses with AN fittings it may run you *$150 just for the hoses!!

Would it be basically a bolt in with a hole cut in the rear of the interior?

That's what I'm thinking: The big goal here is very minimal modifications to the existing heater system; i.e.; use the side channels, floor heater sliders, defroster outlets, etc, so it wouldn't look like anything has been changed, but vastly increase the heat output (that'sd why I'm wondering where to put the switch and what it might look like).
I would mount the unit behind the rear seat somewhere convenient and then either have an inlet hole with a short duct pipe or (ideally) mount it right up against the back of the rear seatback with a rubber collar between the fiberglass and the unit (although that may be noisy in the cockpit - like an AC unit on "recirculate").
The air output can be ducted through appropriate-size flexible hose (like dryer hose or VW heater box hoses) from the unit outlet to the left and right heater channel connections on the car (just as you do now with the output of the left and right heater boxes).

Would that hole add any significant engine or road noise to the already loud interior when the top is up?

Don't know yet. Probably not a lot of engine or road noise, but some increase in blower noise, depending on where/how the unit is mounted. Having an inlet duct with a couple of bends in it will reduce the blower noise somewhat if needed - we'll see.

Would it be visible or hidden behind a seat?

Hidden behind the rear seat. Caveat here: I know what I'm dealing with on VS and CMC's, but would have to commandeer Lane's Beck and someone's IM to see how to mount it in those. At worst, it might be visible in the engine compartment, behind the engine shroud (I'm thinking Beck, here).

Another goal, thinking of Stan's many warnings that it's the cockpit air leaks that will kill you, is to produce SO MUCH heat output that you can more than live with the many air leaks sure to exist in most Speedsters and still be comfortable.

gn

Gordon - I had the same thought about placement in a Beck. The shelf in front of the engine - where my heater blower currently resides - would be the best spot. That way you would have to make no changes whatsoever to the car. The existing ducting could be used, as could blower wiring. Routing the hoses would be easy as they would not have to go into the passenger compartment. Some money could be saved by using the push-loc hoses instead of steel-braided ones. That's what I replumbed with, and they will handle the same pressures, but cost much less.

I've attached a picture that shows the blower in the upper right in front of the carb. The breather could also be moved elsewhere. There's plenty of room for what you have in mind. Under the blower is a hole for air input. That could also be used with your system.

Just wonderin', would a BN-2 gas heater fit on the shelf in the Beck engine bay?

~WB

Actually, it probably would. I toyed with the idea of making a built-in tool box before I mounted the breather there. I would have had to move the ducting, but that would have been no problem.

Doesn't the Beck have the empty space above the trans - between the rear seat back and the engine (front) firewall --- like the CMC? There's lots of room there in a CMC - even for the larger BN4 heater.

It has some, but there is a shelf in there. Rather than two bulkheads - one for the interior, and one for the engine compartment - the Beck has one. Look closely at the picture I posted. I'll see if I can find one that's more clear about the arrangement. If you could see the bulkheads through the side of the car, they would look like an 'h' rather than two parallel lines.

If I remember right from when Chris and I were prepping the engine compartment in Lane's car, the space of the "shelf" is something like 12"X12"X32"long (left to right) Plenty of room for a BN4 or most compact water/oil-based heaters.

Dr Clock............ You ROCK!
While I'm not quite done with my "cheap heat" project, I did do a road test this cloudy 45* afternoon. At this point, I'm done with the under-car work, but have only cut in the passenger side tunnel heater out-let.
As the sun was going down, I just had to take a spin around the 'hood and... The bottom line: I could not believe the heat!

Photos and thermometer readings coming soon!

Ernie,
Glad the project was an easy one for you, post your thoughts and any improvments you made to my heat project, pics will be great too so others can do this. I am doing this mod to my current VS speedster this weekend. ~Alan

Al, Snap a few pics too if you can.

~WB

Here are a couple of pictures of the "shelf" area in a Beck. These were rejects from the owner's manual.

OK here it is....
The first 2 pics show the heat duct prior to insulation, the last features 1" foil backed fiberglass blanket duct wrap.

The bottom line is that I made a errand run today where I achieved 70* in the cabin while the ambient was 45*. At this point, my challenge (this is a work in progress) is to manage the intense heat coming from just one 2" out-let hole on the passenger side of the tunnel.

At this point:::: I'm very pleased!

Ernie or anyone else who knows. Where is the rubber bumper on your rear suspension? I don't see it in that 3rd picture you posted.

Ernie.
Can I give you a call about what you did to get heat into your cabin? Contact me off list at vanatic99@yahoo.com Thanks.
Troy

Troy,
Check my post under "knowledge" improving speedster heat. ~Alan

Troy - you seem to have a "rear end" fetish. Two out of three shots and at different locales. Not that the view is objectionable - I personally like it a lot - but this may not be healthy. You need to examine your motives here. A you wanting to leave? Are you wanting us to follow? Are there some "problems" to be addressed up front? I'm sure someone can post some freudian pictures to better illustrate.

Ooops - forgot to take my meds @#$%^@#%^

Hmmmmm? I never really thought about it from a freudian perspective, but I guess I have always appreciated a nice rear end!
Troy