6 heat exchangers,, anybody built 'em? Options

[goose2]

Has anyone built their own heat exchangers for a six conversion? It would be so nice to have a little heat for those cold mornings with the top off...and some defrost for rainy days...but I can't see laying out over a thousand bucks for manufactured exchangers. I have a friend who is a master stainless fabricator but we need a plan and some guidance...what works and what doesn't. I'd like to retain as much access to lower valve covers as possible and I don't need tons of heat. Engine is a 2.4...headers are pictured below. Thanks for any insights offered. (IMG:http://www.914world.com/bbs2/html/emoticons/welder.gif)

[Steve]

I have been involved in 914's since the 70's and I have never seen anybody make a home made heat exchanger.
Of course I have been wrong from time to time so who knows....
GHL and B&B are the only company's that I know of that make aftermarket 914-6 heat exchangers.
Both company's are in AZ.
You might be able to look at there web sites and try to copy it....

[brant]

Dan on this site has a prototype set he is working on.
I believe he is starting out with a different set of 911 headers...

this thread comes at a good time, as I'd love to see an update on Dan's set.. and am trying to figure out what to buy to make a set for myself.

Dan??????
are you out there?????

[Dr Evil]

Dan was just welding a pipe to the outside of the headers. Then he would run air through them. Simple, and practical. I agree, I would like to see more on it.

[brant]

Hey Mike,

hope you had a good weekend.
I'll write out my bills tonight and get some money in the mail to you!!!!!!! (pay day is tomorrow)

hope the packing is going well!

brant

[Dr Evil]

Brant,
Your dash was done, but then.........I kinda had an accident that caused a small tear in the new vinyl. It will be done tomarrow. (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif)

I aint packing yet. I got too many damn parts/projects to deal with (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

[brant]

QUOTE (Dr Evil @ May 30 2005, 11:26 AM)

Brant, Your dash was done, but then.........I kinda had an accident that caused a small tear in the new vinyl. It will be done tomarrow. (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif) I aint packing yet. I got too many damn parts/projects to deal with (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

Hey...
I'm in no rush for it.
don't make a special trip down there or anything for me.

------------------------------------

(IMG:http://www.914world.com/bbs2/html/emoticons/icon_bump.gif)

Dan, jump in here about your heaters!

brant

[IronHillRestorations]

QUOTE (Dr Evil @ May 30 2005, 10:17 AM)

Simple, and practical

Oh and DEADLY too! (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif)

Here we go again on this topic. I hope 'ol Back Yard Bob has good product liabiltiy insurance, as home-made heat exchangers from mild steel is a lethal combination.

Porsche learned a long time ago how deadly heat exchangers can be. Ever since the early sixties all Porsche exhaust systems have exhaust tubing made of a low grade stainless, and heat collectors of mild steel. Ever wonder why the heat collectors on 914 h/e's rot away, but the pipes look ok? Also there aren't ever any welds inside the heat collectors.

This is penny wise and pound foolish bull!

But look at it this way, all that money you save will go towards a great casket!

[brant]

Perry,

I believe the 2nd generation set (the one I'm interested in learnnig about)...

actually uses a set of early 911 STOCK heat exchangers..
then the ducting is modified to bring heat into the 914.
but this relieves some of the concern about the exhaust gasses killing you.

brant

[goose2]

Thanks Perry....hadn't really thought of the CO danger. Definitely not to be ignored! A couple ideas come to mind...use stainless headers and mild steel heat boxes so the box rusts before the header pipe? The factory plan, right? How about steel headers with stainless boxes that incorporate a stainless sleeve inside isolating them from any potential leaks? Would probably need some material between header and sleeve to insure good heat transfer. Also perhaps there exists some kind of CO monitor/warning device that could be installed in the cockpit....seems like a good idea for any manifold heat system. On the other hand, 90% of my driving is done with top off...but there's still that other 10%...and the possibility of exposing the unwary or future owner to the danger.
Thoughts?

[mudfoot76]

CO exposure is always a bad thing. Even with the roof off. I was out for a cruise a while back after reconnecting all the heat ducts. Roof off, heat on. My girlfriend is with me, and starts complaining about feeling dizzy. I later stopped by the local fire station and asked one of them if I could borrow a CO detector. Turns out I had a nice leak, 60 PPM, and they said that exposure to that level, even with all the fresh air, could cause a person to lose consciousness over 30-60 minutes.

Always avoid CO. Talk to your local FD if you want brand recommendations for good in-home CO detectors. It is at least as important as having working smoke detectors!

[Dr Evil]

It doesn't seem to hard to rectify the problems mentioned. Weld a stainless pipe like structure to the outside of the headers. This way there is no exhaust running throught the box. If the exhaust rusts, oh well. You could have the air drawn in from some where other than around the exhaust so a breach in the exhaust system would be inconsequential regarding CO getting into the cabin air system. Also, a solid pipe/tube would have no seam inside the exhaust system to worry about rusting out. just the weld between the pipe and the header. From the old post, the only problem that I remember was where the air intake was coming from, and how. Pushing air through was reasoned to be better becasue you would have less worry of sucking exhaust gas into the system andyou could pick where you were getting air from. A suction system would draw air from any leak in the system leaving a weak point by the exhaust link potentially.
What in this line of thinking strikes any of you as incorrect, or dangerous? What concerns are left to address?

[ss6]

I was one of those few who bought the B&B headers, they were the most expensive purchase in my conversion project. I don't recommend them, the fitment was poor, the boxes block access to the header studs, and there are air leaks between the tubes and the boxes.

Have been toying with the notion of putting a BF aftermarket alternator where the AC compressor used to be on my 3.2 and using it exclusively to power heating elements for cabin heat, butt warmers, defrost, etc. Haven't yet checked if the firewall will let me do this though...

[maf914]

You might want to take a look at the heat exchanger Racer Chris offers for his Type 4 header systems. There are some photos on his site. He makes some beatiful headers. (IMG:http://www.914world.com/bbs2/html/emoticons/wub.gif)

http://www.tangerineracing.com/Super_Heade...EAT%20EXCHANGER

[goose2]

portable CO detectors: http://www.detectorsandalarms.com and http://testproducts.com/safecart/index.php...37d657a9e91ed92

some specifically for use in vehicles: http://www.safehomeproducts.com/SHP/SM/Cos..._Alarms.asp#P-1

[Root_Werks]

The system I made was a 2" exhaust pipe welded to the header pipes. Not around them, just to them. So I don't think fumes would be an issue since the pipe was so thick and never split. It worked great, just cooled off too much when you hit the freeway.

But luke warm air was much better than nothing. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

In town, they worked great. (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

[lapuwali]

When I had a 6 conversion, I toyed with the idea of running an oil cooler as a heater core, just like a water cooled car. Mount it low in the engine bay with ducting to blow air through the cooler and into the stock heater tubing seems like the best way to do this. Never pursued it, and I don't know of anyone else who did, either. No possibility of CO poisoning, and you gain a bit of cooling in the deal.

[jd74914]

QUOTE (lapuwali @ May 31 2005, 01:04 PM)

When I had a 6 conversion, I toyed with the idea of running an oil cooler as a heater core, just like a water cooled car. Mount it low in the engine bay with ducting to blow air through the cooler and into the stock heater tubing seems like the best way to do this. Never pursued it, and I don't know of anyone else who did, either. No possibility of CO poisoning, and you gain a bit of cooling in the deal.

Thats a very interesting idea. I wonder if you would get enough heat?

[goose2]

If you had a thermostat on the external cooler, it would probably be closed in cold weather when you need heat the most....but you'd have lots of heat on hot days. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

[brant]

Dan,

care to elaborate about version 2 and the other type?

or if that is a development secret then I understand.

brant