Adding Heat to the Clown Car Options

[davebrossi]

Apologies for going quiet for months, but I'd burnt out trying to solve the overheat issue on the clown car. Turns out at 5k miles, the fan belt was stretched/heat damaged. no more overheating. (IMG:style_emoticons/default/beerchug.gif)

Now, in case you're wondering about the whole title/point of this thread, I have been bitten by the bug that whispers "what you really need is heating!" as I live in Idaho where they don't salt the roads, but where it's below freezing much of the year.

I'll be searching/educating myself in exactly what I need to do, but in the meantime I thought I'd offer a window/way for people to follow along in the adventure.

To recap; The Clown Car has a 3.2 from an 87 911, straight headers (which -will- be available once I'm done, hint hint) and it uses a custom engine mount/tin from Rich Johnson. I have opted to go for as close to a stock heat exchanger system as possible over an aux gas heater due to concerns over my ability to cause vehicles to catch fire (I lost an 81 Vanagon to fire.)

Based on what I've been able to piece together thus far, in addition to custom headers that mate up to the 3.2's larger diameter exhaust ports, I will need;
-flapper valves (I'm assuming the 'custom' part of the headers means I can utilize standard 914 flapper box assemblies.)
-aircraft grade fresh air ducting from flapper boxes to longitudinals
-the 'mystery manifold' that exits the bottom of the engine tin and goes to both exhaust headers, this part I'm still working through. (IMG:style_emoticons/default/chair.gif)

On the other side of the engine tin the standard 3.2 has a 'port' of sorts on one side of the fan shroud (currently capped,) a duct that terminates on an aux blower (still have the wiring harness on the motor), then duct work from the aux blower to the engine tin terminating just next to the distributor cap. There should be some form of flange in the tin that mates the upper and lower together.

I know because the engine bay is not the 3.2's native land there will be'customization' (IMG:style_emoticons/default/sawzall-smiley.gif) (to be fair I don't like customization, that's how you get terms like Mississippi'd or 'mickey mouse'd'

I hope to photograph the process here, and while advice is always appreciated, I -can- use the google search function too, so I'll be looking at everything else in the meantime.

[Justinp71]

(IMG:style_emoticons/default/popcorn[1].gif)

Cool project.

Where do you plan to get heat exchangers from? Heat would be nice this year in Ca, lots of cold days with no rain this year.

Also does your wife call your car a clown car too (IMG:style_emoticons/default/smile.gif) ?

[mb911]

Dave,

Please feel free to follow up with a phone call.

The simplest way is the 911 hot air ducts on each side of the fan. use the Scat tubing to connect through the engine sheet metal, Ditch the 911 blower, and go into a set of heat exchangers. Obviously I make the correct size heat exchangers for this set up but you could opt for smaller if you have a line a set cheap?

[mepstein]

Dave,

Please feel free to follow up with a phone call.

The simplest way is the 911 hot air ducts on each side of the fan. use the Scat tubing to connect through the engine sheet metal, Ditch the 911 blower, and go into a set of heat exchangers. Obviously I make the correct size heat exchangers for this set up but you could opt for smaller if you have a line a set cheap?

In the 911 world, they call it - backdating the heat. You just use the 3.2 engine fan to move the hot air through the heat exchangers, flapper valves, and into the cabin. Very simple and effective. Get a set of Ben's/MB911 heat exchangers if you want the best ones made for your 3.2

[davebrossi]

Hi All,
I thought about backdating the fan shroud, but I was concerned that the level of heat would be inadequate to stay warm/defrost the glass. Standard 914 interior and duct work in the longitudinals. My reason for considering the 'standard' approach stems from my Van experience where the interior relied only on the motor's fan. The results were almost non-functional.

[mepstein]

Hi All,
I thought about backdating the fan shroud, but I was concerned that the level of heat would be inadequate to stay warm/defrost the glass. Standard 914 interior and duct work in the longitudinals. My reason for considering the 'standard' approach stems from my Van experience where the interior relied only on the motor's fan. The results were almost non-functional.

Totally different for a 914. Ben’s headers are the right size for a 3.2 and his heater boxes (copy of the Porsche design) transmit plenty of heat. The 914 cabin is small in volume and it’s a pretty short path from the heat exchangers. The engine fan has plenty of volume and velocity. That’s why the backdate is popular on the 911’s.

I don’t use an auxiliary electric fan on either my 914-6 or 6. Both are too hot to leave on high, even during the coldest days.

There are some other makes of 914-6 heat exchangers but they are very heat deficient. Don’t bother unless you use the stock Porsche or Ben’s.

[porschetub]

Hi All,
I thought about backdating the fan shroud, but I was concerned that the level of heat would be inadequate to stay warm/defrost the glass. Standard 914 interior and duct work in the longitudinals. My reason for considering the 'standard' approach stems from my Van experience where the interior relied only on the motor's fan. The results were almost non-functional.

A 911 motors moves a HUGE amount of air so no concerns there,do you already have heat exchangers to fit on ?.

[davehg]

I just received Ben’s heat exchangers for my 2.7 and can attest to their being well made.

[mb911]

Making more heat exchangers next week and your in cue. Thanks everyone for the feedback..

[GeorgeRud]

You’ll love the amount of heat you’ll get through the heat exchangers with the 3.2engine. Backdating to the older style heat ducts should move as much air as you want, and you can fry yourself from all the heat that flows through the exchangers. Ben does amazing work!

[davebrossi]

You’ll love the amount of heat you’ll get through the heat exchangers with the 3.2engine. Backdating to the older style heat ducts should move as much air as you want, and you can fry yourself from all the heat that flows through the exchangers. Ben does amazing work!

I'm looking forward to it. I've purchased a set of Ben's custom headers, and in the meantime I've opted to backdate to the pre 73 set of 'snozzles' (Snozers? Snaussges? Warm air ducting) with warm air tubing through the engine tin. I've got part of the kit, planning on fitting the flapper valves to the heat exchangers from the comfort of my flat, I'm hoping someone's been camera friendly with their experience out there as getting that part in is new to me. More as I get bits and bobs in :-D

[Steve]

My 3.2 runs much better with Bens heat exchangers than the factory ones, due to them being the correct size for the motor. The heat is also as good as the factory heat exchangers. If you want a stock looking lightweight quiet muffler, than Bens muffler is also a nice addition to the heat exchangers.

[mepstein]

You’ll love the amount of heat you’ll get through the heat exchangers with the 3.2engine. Backdating to the older style heat ducts should move as much air as you want, and you can fry yourself from all the heat that flows through the exchangers. Ben does amazing work!

I'm looking forward to it. I've purchased a set of Ben's custom headers, and in the meantime I've opted to backdate to the pre 73 set of 'snozzles' (Snozers? Snaussges? Warm air ducting) with warm air tubing through the engine tin. I've got part of the kit, planning on fitting the flapper valves to the heat exchangers from the comfort of my flat, I'm hoping someone's been camera friendly with their experience out there as getting that part in is new to me. More as I get bits and bobs in :-D

I’m pretty sure you need a 914-6 heater cable. I believe it’s slightly longer than a 914-4 cable. 914rubber has them and the barrel nuts.

[GeorgeRud]

Don’t know the differences, but there are three separate part numbers for the heater cables in 914s and 914-6s.

[davebrossi]

I believe you’re right with the cable. Given I was a little concerned with the cable being original, I’ve ordered a 914-6 cable and new protective caps from 914 rubber. With my luck even if I managed to get the cable to ‘work’ it’d snap the first time :-)

[mb911]

Dave have you found a picture of the correct heat ducts off of the engine?

[mepstein]

Homemade six flappper valve

[mepstein]

Dave have you found a picture of the correct heat ducts off of the engine?

Ben - I could be wrong but it sounds like the correct ducts are there but capped. I’m not sure If the OP realized there is not a “special” lower duct but you use the fan shroud ducts and run the hose through the side engine tin. Down to the he’s.

[Steve]

Ive run the 4 banger flappers and cables for over 20 years. I did have to add bug pack throttle cable extenders. Some day I will replace the cables with six cables

[RickS]

Have original 6 HEs on the 3.0 with backdated heat using flappers. If you go something similar, you will have so much heat that even when it is in the 30s you will only have the vents partially open. That system will poach your feet.