Home made heat exchanger

[kent olsen]

Anyone who has done something like this please chime in.

I'm thinking of taking some sheet steel and fabricating a round can using pop rivets. This will wrap around the straight pipe from my headers to the muffler, maybe 12 ". I'll fabricate an inlet and outlet to the top. I'll fabricate some mounting tangs that will use the header and muffler bolts to hold it in place. I have a twin plug distributor but I ran the bottom wires thru a hole drilled in the panel ahead of the original hole for the heater hose.

So I'll run the heater hosed from the fan down to the inlet to the little heat exchanger and out the outlet to the normal heater valve above the left axle.

I'm thinking this will give me a little heat/defrost, just enough to take the chill off in the morning.

I'm a nut about adding any weight, hence this idea vs SSI. Can anyone see anything wrong with this idea?

Thanks Kent

[faverymi]

Just a thought.

Where I live I need real heat. I like your idea but this in not an option here.

Has anyone tried anything like a plug-in electric heater. Any models, conversions, ideas?

How much draw would the alternator support?

Just another point of view for the same problem.

[kent olsen]

Actually my wife bought me something like that once. Plugged into the cigar lighter but didn't make enought heat to be worthwhile.

Kent

[daniel911T]

One really neat idea I took onboard was the addition of seat heaters. I haven't done it on my p-car yet, but I did install a set in my wife's Honda Fit. They were easy to put in, in a modern car the switches look stock, and they warm up quicker than the factory units in my 2010 Jetta. Cost was $70 a seat, and once installed you can't even tell they are there, except they're warm.

I know it does nothing for defrost, but it adds very little weight, and can make you a lot more comfortable.

As for your "fab up a can" idea... I bet you can find a bunch of people doing that over on the air cooled VW side. Probably pretty common there.

Good luck!
Dan

[faverymi]

Kent.

When I lived in Finland the cars had connected a small electric space heater that kept the car very warm in the morning. It was connected to a timer with the engine block heater. Obviously to a power outlet.

Nifty little thing. I always wonder if the alternator will support this draw. MallMArt has those power converters to go from 12volt to 110. I just never tried it.

I like your idea, but I'm not handy enough to build it. The electric way in my mind if possible seems easier and totally reversible on track days.

What do you think?

[daniel911T]

Originally Posted by faverymi

Kent.

When I lived in Finland the cars had connected a small electric space heater that kept the car very warm in the morning. It was connected to a timer with the engine block heater. Obviously to a power outlet.

Nifty little thing. I always wonder if the alternator will support this draw. MallMArt has those power converters to go from 12volt to 110. I just never tried it.

I like your idea, but I'm not handy enough to build it. The electric way in my mind if possible seems easier and totally reversible on track days.

What do you think?

I think the alternator should handle it, assuming it's the 75A variety. I don't think the accessory circuit will take it. Generally these are 10-15 amps. A normal electric heater is 600/900/or 1500W on 120VAC. I think the most powerful inverter I've ever seen was 1K watt, and I'm sure it needed MUCH MORE than 10-15 amps from the car.

Perhaps if you wired the inverter directly to the battery, then to a heater.... but really, that is complicated and potentially dangerous. I'd look for a better solution of it were my car.

-Dan

[Joe Bob]

Electric won't cut it. Webasto gas heater is the ticket.

[Quicksilver]

Making heat exchangers around a set of headers makes me instantly question What type of headers?

If the headers aren't good stainless steel you are making a pretty big gamble with carbon monoxide poisoning. Plain steel headers will rust through. It is a fact of life. Exhaust gases routed into the cabin is bad, bad, bad.

Either just get a set of heat exchangers or go the Webasto route.

[Wil Ferch]

In reading up on RUF's CTR Yellowbird....I think it too had a gas heater in the smugglers box...didn't mention if it was Webasto as some earlier 911's had.

I'm thinking of retaining headers on a 911 I'm looking at, and a minimum amount of heat ( actually...window defog/defrost capability) would be nice. Is Webasto still in business and what model heater is the proper one to use?

[Joe Bob]

Yep, still in business however they won't service the old school heaters. They have dealers throughout the US. I found them via Google.

They quoted me 4500 to buy and have installed a unit. They specialize in large trucks and RVs.

[cgarr]

Wrap the straight pipe with a big long spring (old screen door type) then cover it with the tin. This will help extract the heat from the pipe.

[kent olsen]

Good idea about the spring inside the heat exchanger. Also about the rust issue. Now I need to figure out how to build this with the ability to remove it and inspect/repaint the header pipe.

[911-32]

I have posted these before, but no matter. We made our own HEs on these stainless headers. In hindsight, making them even smaller and moving them back so they do not cover the collector would be an improvement from a maintenance stance. They make plenty of heat without anything inside them, though not quite SSI level heat.

[DanielDudley]

Very pretty !

[Geronimo '74]

+1 looks great, better than SSI's even.

Are they for sale, or are they a one off?

[sc_rufctr]

Originally Posted by kent olsen

Anyone who has done something like this please chime in.

I'm thinking of taking some sheet steel and fabricating a round can using pop rivets. This will wrap around the straight pipe from my headers to the muffler, maybe 12 ". I'll fabricate an inlet and outlet to the top. I'll fabricate some mounting tangs that will use the header and muffler bolts to hold it in place. I have a twin plug distributor but I ran the bottom wires thru a hole drilled in the panel ahead of the original hole for the heater hose.

So I'll run the heater hosed from the fan down to the inlet to the little heat exchanger and out the outlet to the normal heater valve above the left axle.

I'm thinking this will give me a little heat/defrost, just enough to take the chill off in the morning.

I'm a nut about adding any weight, hence this idea vs SSI. Can anyone see anything wrong with this idea?

Thanks Kent

This could work however it would best if you designed them to be easily removable. (two piece clam design)
That gives you the benefit of being able to clean any stray oil that may have found its way inside the exchangers. (stinky poo)
Also... You have to think about what you will be making these out of. Ideally Stainless Steel but that stuff is harder to work with.

Have a go and take some pictures. I've been living without heat in my 911 for about 8 years.

[911-32]

Originally Posted by Geronimo '74

+1 looks great, better than SSI's even.

Are they for sale, or are they a one off?

One off - but Turbo Thomas (near Birmingham in the UK) is making something similar and arguably better that will be for sale. Progress and pics can be found on impactbumpers.com.

[RarlyL8]

This is what you are describing. Don't recall who did it but typical aviation design.

[Wil Ferch]

Not quite sure what I'm looking at.....but I found this in the Aircraft Spruce catalogue....something like this maybe?--->

HOMEBUILDER'S HEAT MUFFS from Aircraft Spruce

.....maybe even this?---->

http://www.aircraftspruce.com/catalog/eppages/cessnatypeheatmuff.php

[Geronimo '74]

Originally Posted by 911-32

One off - but Turbo Thomas (near Birmingham in the UK) is making something similar and arguably better that will be for sale. Progress and pics can be found on impactbumpers.com.

Thanks for the tip!

Originally Posted by Wil Ferch

Not quite sure what I'm looking at.....but I found this in the Aircraft Spruce catalogue....something like this maybe?--->

HOMEBUILDER'S HEAT MUFFS from Aircraft Spruce

.....maybe even this?---->

CESSNA TYPE HEAT MUFF from Aircraft Spruce

Very interesting link!! Thanks for posting!