1.7 heat flaps

[porsche930dude]

I rebuilt my 1.7 getting ready to put on the cooling tins and I did away with the warm up heat flaps but i kept the one for the oil cooler on and will permanently affix it in the down position so it diverts 1/2 of the air on that side over the cooler. does this sound good? or should i eliminate that flap entirely

[luskesq]

No, you should not eliminate the passenger side flap because it directs cooling air over the oil cooler. In a perfect world you should have both flaps operational via the thermostat. That aids in initial warm up as well as cooling after the engine gets up to operating temp.

Keith

[Joe Ricard]

Agreed is a bad idea. I think I have a thermostate bellows in a box. make me an offer.

I also have the entire heater ducting parts. J tubes, y duct, S duct and the control boxes if you are interested.

[porsche930dude]

thanks guys. i have all the stuff for it just thought id eliminate the potential for overheating.
Also I probrobly wont reinstall any of the original cabin heating parts. atleast not in their orignal configuation

[TheCabinetmaker]

sorry but you really need to go back and hook up all the stuff, else the air will not be directed to the right spots on the engine, resulting in hot areas. they are an important part of the system, they also aid warm up, which is very important. Would you run a Ford, Honda, or Toyota with the thermostat disconected? Probably not, same for the 914, long cold warm up periods really wear the engine and waste gasoline.

you also need to hook up the air ducts for the heat exchangers, the exchangers are designed to always have cool ing air blow thru them when engine fan is turning. even when the heater is turned off, air still flows thru the exchangers, heater off, and theair is dumped under the car, heater on, and the air is directed to teh cabin. In both cases the air passes thru the exchangers.

The exchangers need this air to keep the adjacent cylinder heads cooler,and to prevent damage to the exhuast system. Even if you dont want cabin heat, you at least need to hook up the ducts that take fan housing air and blow it thru the exchangers, you can leave off the heater valve, adn just let teh exchanger air dump out under the car.

this same thing is true on VW Bugs and their heaters.

[porsche930dude]

no heat exchangers im probrobly using bus manifolds. If the quick warm up is so important why dont the 6 cyl have such a device? Or the standard vw engine.

[Dave at Pelican Parts]

I don't know why the six-cylinder motors don't have an external warm-up mechanism. Possibly because they dump enough heat into the heads quickly enough that they decided the complexity was not needed?

The standard VW lumps do indeed have a warm-up mechanism. They all have some type of thermostat and thermostat-actuated flaps that direct cooling air. And the single-carb versions all have exhaust "heat risers" to warm up the intake.

Oh, and the bus manifolds probably won't work that well. They're very short and they point the wrong direction for a 914. The late 914s used something very similar or identical to the F-shaped bus exhaust manifolds, but their exhaust was the worst of the 914 versions. The 1.7 or (73-74) 2.0 exhaust is far preferred. Or real racing headers, but those are generally quite expensive.

--DD

[jhora]

Originally Posted by porsche930dude

no heat exchangers im probrobly using bus manifolds. If the quick warm up is so important why dont the 6 cyl have such a device? Or the standard vw engine.

the six does.....it's the oil thermostat....

[91fourgt]

as far as the heater parts?????hmmmm, never knew air blew through them. not downing anyones advice but i dont see a problem with not hooking up the heater parts. no extra heat will remain to make any difference but you wont have heat or defrost for windshield. my first take on it would be that im a pefectionist that likes to repair the car using manufacturers design, meaning put it back the way it was. but i also like modifications on custom rides too. 914's is what feeds the family and my love for the cars tends to like the original configuration. if a system is non functioning, i repair not eliminate it but thats just me...good luck

[91fourgt]

i agree with Dave on the manifolds, chuck those 2 pieces systems in the trash. keep your exhaust flowing in the right direction and opt for a good set of either performance headers or a set of 73-74 heat exchangers. the 75-76 he's are the worst design thinkable and over time the f shaped manifolds warp making a seal near impossable even with new gaskets. ( ive come accross this very issue 2 times this year on customers cars) over torqueing the nuts does not solve the issue but you chance pulling the studs or having them snap when engine heats up.
again,
just my 2 cents on a car that pays my bills.