I need some Ideas

mtndew342 · 08-12-2002, 12:35 AM

Ok, I need all the imagination you guys can muster here. Right now I'm working on making a heater for the teen so that I can get some headers later but still use the defroster when things get chilly. The current Idea is to modify the front impeller housing to take a stock type IV oil cooler and then use the impeller to draw air through it and into the passenger compartment through the stock ducting. Also I am getting an RX-& oil cooler for the front and was planning on running the oil lines through the origional heater ducts back into the engine compartment...Whew...Anyways if anyone has ANY ideas that would be easier or you think would work better or if you just have an idea I want to hear it! Thanks

~Steven

SummerSledSix · 08-12-2002, 07:11 AM

Hey Steven, I've been nursing an alternate heat scheme myself for a number of years, ever since I tried to remanufacture a set of heater boxes for an old VW Squareback back in the 80's.

First off, I'd be VERY careful putting anything in the existing airstream of that impeller. Anything you put there will reduce the net airflow to the engine either thru backpressure or outright blockage, risking overheating your engine.

I've ruminated over two approaches. One, build a flapper valve and duct adapter to pick up the waste heat from the existing engine oil cooler. Risk there would be backpressure (poor engine cooling) and reduced ground clearance. Other one, use copper tube, and encase the header pipe(s), blow air into one end of the pipes, build a plenum around the other end, and let the air return through the spaces between the pipes. The copper should provide real good heat conduction and a lot of surface area, the challenge would be fabricating the plenums and entry / exit ducts into the stock flapper boxes. About a half mile of metal muffler tape might do the trick. Might be able to use flex tube and coil it around the header; that's as far as I got. Good luck, and let us know what you come up with.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Actually, I think (or at least I really hope!) that he is talking about the blower fan (for "cool air") up under the front cowl, not the engine cooling fan. Both are "impellers"--squirrel-cage fans. But the word "impeller" in a 914 is most often associated with the engine cooling fan...

--DD

jabb · 08-12-2002, 08:01 AM

How about these

http://forums.pelicanparts.com/showthread.php?threadid=76397

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Tom Bussler of Memphis TN had, last I talked to him, built a small box out of aluminum. The box contained a flapper valve, some ducting, and an oil cooler. (Not sure exactly which cooler, but it was some sort of small aftermarket one.) It had ~2.5" inlet and outlet fittings for air hoses, one on each side of the cooler. The whole box was sized to fit up in the right-rear fender.

The inlet was going to be hooked up to the heater blower from a 73-74 914, and the outlet was going to either one or both of the heater ducts. This was all in a 914-6 conversion with headers. Sounded like a pretty neat idea, all in all.

One small problem--it takes the oil 5-10 minutes to get warm, so you're without any heat for that long... And you generally don't want oil running through an external cooler when the oil is cool anyway.

--DD

mtndew342 · 08-12-2002, 08:17 AM

Sorry about the confusion. DD was right about the cool air impeller. I want to route the oil hose to the external oil cooler through the existing heating ducts and so I'm thinking of options in the front area. But I've heard some really good ideas so far. Kepp it up! Thanks

~Steven

SummerSledSix · 08-12-2002, 08:36 AM

Uh - my mistake. Only read every other word in your original post, a bad habit of mine.

I wondered about doing an external oil-cooler-as-heater-core when I was doing my conversion and commited to oil plumbing anyway. Came to the conclusion the less connectors in my oil circuit, the less likely I'd be puking oil all over some pavement somewhere, especially during a DE.

Also, in those domestic water cooled monsters, don't they valve the water flow to bypass the core when not wanted? Wouldn't you have to do the same thing with your oil system to keep from toasting the core and its surrounding area, and oil cooling systems run a lot hotter than water, no?

karlp · 08-12-2002, 02:44 PM

Not sure about all this.........
In a water cooled car, the water temp. is in the 180-200 range. Your oil temp will be similar, maybe a bit hotter. In a water cooled car, the water typically flows like gangbusters through a 5/8 id hose to heat a 4-6 passenger car. How much oil can you flow through a "core" that is probably half the size of a passenger car heater core? Who cares, you're only trying to heat a 2 seat cabin.
I think I've just become convinced it may work.
I've been planning to get a second fan and mount it on the passenger side in the engine compartment and use it for defrost only. This would put two levers on the floor: one for the drivers side fan for face and foot heat, and one for the passenger side fan for defrost. The Fresh air blower is gone, the two defrost control valves under the windshield are connected together.
Heat source is from the heat exchangers.
Those exhaust pipes are hot! Great source of heat. I do not want to use the engine cooling fan to push hot air and have blocked both fan shrould outlets that went to the heat exchangers.
Karl

Joe Ricard · Joe Ricard's Garage

Ya know I think that is a good Idea. Once I figure out where the power is laking to the fresh air blower in the engine compartment I will do the same thing. Wonder if it is going to get as cold down here as last year?
Top off and currently getting a pretty good tan

mtndew342 · 08-12-2002, 10:37 PM

Ok, So the current plan is to make my own box out of tin to house a type IV oil cooler and mount to the impeller fan found in the front trunck to pull in the fresh air. Then all of the ducting will go together without modifications. Then I can run the oil line to my (now two) external oil coolers through the existing ducting origionally used to channel heat from the heat exchangers to the front trunk ducting. The box I'm making will be out of metal so I'm not too worried about too much heat. Ayone see any major bombshells here or should I give it a shot. The only thing I really care about is defrosting since I will be living in the L.A. area. Party on! Thanks :-)

~Steven

Special K · 08-12-2002, 11:04 PM

Mtndew,

How about a combination of your idea and karlp's. Make your box out of metal with the oil cooler in it, except mount it in the rear part of the engine compartment. Then get ahold of a couple of 914 heater blowers and mount one on each side of your box and run the heat ducts down to the original heat (J) pipes (because you want headers, run them down to the flapper valves). This way you'd get a little (probably very little without heat exchangers) heat, cool your oil a bit, and when you don't need any supplemental heat close the flapper valves and blow the excess heat from the oil cooler out the bottom of the car. There'd be alot less oil line to run and electric for the fans shouldn't be a problem. A T-stat on the oil lines probably wouldn't be a bad idea either.

Well, it looked good on paper

Dave at Pelican Parts · Dave at Pelican Parts's Garage

I would not use a Type IV cooler. This cooler does not have inlets and outlets that lend themselves easily to any setup other than on the engine. I would suggest a small aftermarket-type external cooler--you can screw the lines directly into that.

Also, make sure that you provide a path for any oil leaks that occur that gets the oil out of the passenger compartment. 220-degree oil is not something you want dripping down on your legs, or your passenger's. Make sure that the path of least resistance is one that goes out of the car.

--DD

Rog914 · 08-13-2002, 11:13 AM

Not on the market yet but, something to look forward to hopefully in the near future is a new AC system from www.kelix.com which you can use for both AC & heat. It has no compressor, runs off an electric motor. Check out the site. May if we could an auto AC company interrested in making some for the older car market?