As other's have said, it won't make a difference good or bad on our motors. Either way the air is always flowing from the engine through the heat exchangers. The only difference is if it dumps to the atmosphere or the cabin.

The reason that it works on a water cooled car is that the heat comes from the heater core which is basically just a small radiator in the dash. When you turn the heat on hot coolant from the engine flows through the heater core and a fan blows air across it. It's like adding an extra radiator. The system is completely different in a 911.

+1

what masraum said..
ryan

500,000 hp eh? Damn. But.... is it air-cooled?! =)

If it makes anyone feel any less comfortable, last week I made water spontaneously run uphill...

Babak

PS the trick is to use the surface-tension of the water, still no free energy, alas

So, this thread is the guys who think you can cool the house by leaving the refrigerator door open, versus the guys who know you can't?

lol..pat.

jim, ever work with any liquids colder than liquid nitrogen? i know it's probably the standard for this kind of work..we used it regularly for storing various little critters when i worked research in molecular biology, etc.
ryan

are you saying that, for instance, driving at 65mph in 5th then shifting into 4th while maintaining 65mph saw your temps rise ?

if so it's not my experience.

Wacky out the box idea all the way from the UK:

Remove the A/C pump and fabricate a mounting for an alternator.
Then remove the original alternator from behind fan and replace it with an electric motor. You can then have very high fan speeds even at idle....

pretty handy..i always had to keep track of ordering a bunch of cylinders. not too many smiles around when you found you ran short. of course we'd play the occasional sophomoric games..dipping a rose in it to drop and shatter..:rolleyes: etc etc. hey, it was 20 years ago..i was young.. :)
ryan

yes..absolutely. i had a frequent 50-mile drive i'd make on the highway where i could maintain constant speed/rpm ranges for little 'tests'. i have no idea where that thread went, but grady was involved in it and i was reporting my observations. cruising at higher rpms resulted in higher oil temps at same ambient temps and speed.
ryan

Remove the A/C pump and fabricate a mounting for an alternator.
Then remove the original alternator from behind fan and replace it with an electric motor. You can then have very high fan speeds even at idle....

Yes, plus combine it with a variable pitch fan and control the motor speed and fan pitch thermostatically

ahh..i see. there would be no need for the 'normal' alternator belt either, as the motor would be powered by the newly-relocated, belt-driven alternator. you could have a variable-speed fan, based upon engine and/or driving conditions.
ryan

Oh!

Even better; have a one-way (or electric A/C) clutch for the fan/alternator and electronically spin the fan faster at idle and low RPM. That 3-Ø alternator will work just fine alternately as a motor and dynamo with the proper electronics. The data we need is the HP vs. RPM of the fan to see if this is feasible.

Best,
Grady

this might become interesting. can't you see this being a practical upgrade, sometime during the next 5-10 years, seen on more and more of our old 911's? electronically-controlled (or thermostatically?) electric-powered fans..higher-powered alternators that reflect 'today's loads' re-located to the site of the present a/c compressor. only thing is, the guy's who really need high fan speed at idle are the same guys who mainly drive in town..and they need a/c. the track guys are already hauling ass and may not benefit as much from increased electric fan speed..or am i wrong about that? guess we'd have to see how much speed we could reliably obtain from our electric motor..and maybe even design a better fan? perhaps one that borrows more from current jet aircraft technology and their systems of vanes..compressor section, etc. could there ever be too much airflow? a point where more airflow simply doesn't bring 'more to the table' in terms of cooling cylinder heads?
ryan

grady..i just happened to notice (our posts are adjacent)..that we have identical 'total posts'. guess that's pretty much where the similarities end, eh? lol. ;)
ryan

Ryan,

You are right on point. One of the issues not addressed with our air (air/oil) cooled 911s is warm-up. A controlled fan wasn’t economically feasible in ’65. Allowing the fan to run at part speed during warm-up and cold weather is desirable now that we have electric fans for the heaters. Having the ability to spin the fan faster than the engine RPM ratio at low RPM is also very desirable.

Today, with varying connection to the crankshaft and the sophisticated use of a 3Ø 1500W (2.0 HP) motor-generator some subtle improvements can be had. With temperature sensing and feedback that can be doubled for short periods.

In the early ‘80s I considered a 2-speed fan and using the alternator as a motor under certain conditions. The technology was too expensive and too heavy then.

We need to understand how recent electric fans are. Think of a pre-’50s ship and the funnels used to ventilate the ship or belt driven fans on early locomotives. When considering our 911s, every HP counts for something; the art is applying it when and where it is most effective.

Best,
Grady

I think I'm correct that higher oil temps are not caused by an oil cooler deficiency in cars above?

The more power the engine produces the hotter the heads. The hotter the heads the more oil cooling necessary? For instance my CHT, went up from 210F/CIS/stock cam To 230F/Carbs/E-cams in general during tame driving. The engine up-dates created more hp = higher CHT. The up-dates create A CHT of 275F at a constant 4k in 5th.

If I was running at a DE and I was able to read a CHT of 325F[safely doable imo] and my oil temps were getting too high I would assume I had an oil cooler deficency.

Disclamer: My CHTs are not the most representative readings of true CHT but the plug gasket is good enough for monitoring up to full race where it turns into another ball game imo.



Am I all correct ?

The idea to run a high tech elec Fan is a neat one - but would it work WITH the belt driven fan - or replace it entirely ?

Example, even though electric waterpumps are widely available today, no one uses them as an 'equal' swap with the belt driven pumps simply because an electric pump can go out in a heartbeat and you've had it ! The reliability of the belt driven pump is why it's such a good thing... however, I may have misread your idea above.

The increases in air may work alright for someone north of Mason Dixon line - but how will they work for guys in New Mexico, Arizona, Ca - July thru September ? You may get a tiny benefit if finding yourself snagged a few hours on a hot freeway, but that's it !

For ex, Say it's 3PM and mercury is pushing 95 degrees
Farenheit. An aircooled motor's CHT - even with 3 X's the volume of 95 degree air - again, (as you're inching along the freeway) is not gonna help you much on your temps. Guys who are crunching numbers may differ - so the results are unofficial. Say you can keep move along at 20 -35 mph and you have 3 X's the volume of air. At 85 - 95 degrees F you're likely to see your temp gauge with not very nice readings. :(

No mention thus far about reducing the motor's compression to produce less heat . The conclusion seems to be that all the fun will vanish out of the motor. How do we know that for sure ? If a few guys here with Steve Wong chips in their 3.2 were willing to give it a try - there may be a surprise in store. Is dropping the horses from 240 to 215 something that could be offset in other ways ? Granted, it's the opposite of what guys usually do with their porsches...bumping 'up' that aspect of the motor is the by far the usual practice.


Phil
_______

'80 928
'82 Targa - sold

I believe the 911 cylinder cooling airflow runs backwards. Heat rises. Seems it would be better to reverse the flow and draw air from underneath via inertial seperator, across the engine and out the lid. Would draw air from where you don't want it in the first place. Perhaps see some tangible negation of lift at speed or even downforce sans wing. Electric fans for use at slow speed. Nothing for high speed would seemingly be adequate. have to side mount the alternator among some other things.

:lol: a friend of mine used the engine heat to cook hotdogs when we passed by Arizona desert years ago :lol: Worked.

If it were 1975 right now, and Porsche had poured money into a prototype 3.0 litre motor - using an experimental water cooled cyl head - can anyone imagine how well, or not so well it might have worked ?

If millions $ had gone into the project insuring that the motor had a teutonic, professional look about it and plumbing done in a superb manner - it's a strange hypothetical of what 'might have been.'

Fan housing would be out altogether and alternator over to the side - as 911mot suggested. Lots of room at the center for the pump (belt driven)....

Let's get busy ! ..:eek:


Phil

.....hope you guys will stick around a bit longer - thread seemed to die with my last post.



Phil
_________

'80 928
'82 Targa - sold

You must be talking about the 959.:)

Off by six years?

http://en.wikipedia.org/wiki/Porsche_959

Can you still buy an air cooled Porsche at the dealer?

I'm going to have some hard info around by Tuesday concerning the 65mph, 5th gear, 4th gear posts above.

I can very accurately measure CHT on all 6cyl under all conditions using the plug gasket sender. The thing is the test will be low key to keep from getting arrested.

My current position is that those with high oil temps need bigger oil cooling. Achieving max hp combustion without detonation is partially related to low oil cooling.. imo so far.

ron..keep in my mind that for my test..there was no (still isn't) auxillary oil cooler..
ryan

oh.. I didn't know that.

A single engine oil cooler + the hoop fender cooler is maybe good for a 150hp engine, can't really say. A simple thought is the more hp the more oil cooling necessary. More added power than good stock means more wasted heat must be channeled away some how/one way or another if heat control was borderline before. Your combustion chamber is the center of the power universe. Heat control of this chamber is absolutely necessary when building more hp. Adding more fuel to control detonation at high hp levels without proper heat control is more of preventing the engine blowing up than proper operation. The conventional knowledge is that added fuel itself cools combustion just as throwing water on your face to cool down does. It's wrong imo. The added fuel is slowing down the speed of combustion and is a sort of ignition timing retard. Combustion speed varies not just with the piston pressure but with the A/F mix. That method may be safe but it doesn't allow the theoritical max hp.

what's that said !

ron..i'll still be interested to see what your result is with an auxillary cooler. i suspect the difference will be less dramatic than mine. in other words, i think your temps will increase cruising in 4th for an extended period, say 30-60 minutes, but not as much as in my car. we'll have to wait and see.
ryan

Originally posted by bigchillcar

auxillary cooler.
-------- I have the Lemke front right and I may have to do a front left cooler also. I missed a ride to the 4 Corners last May to find out. If I don't need a front left cooler these carbs are going to impress me again. Right now all I can figure it's a 50/50.

i think your temps will increase cruising in 4th for an extended period, say 30-60 minutes,
-------- that means my oil will be gathering increased heat from somewhere. Somewhere has to be my CHT. Greater heat from CHT has to come from excess heat of combustion. More combustion heat means I'm creating more power at the engine. I guess so until someone tells me I'm wrong.

More power = more heat.. so then If I downshift and create more CHT heat then it should eventually be reflected in oil temp heat. The oil temp heat lags maybe a minute or two behind CHT before you can actually get a clear idea that's it's starting to move. That was figured in summer Rockys, summer high deserts, etc, at around 3.5-4k in 5th.
Around here I'll figure oil temps within 20mi in each gear.

So then.. Am I making more power from the engine when downshifting?
I don't think so because of gearing? Without a log then all I can say now is that it don't happen. I should be able to spit out the hard #'s but I pay little attention to slight specific oil temps. I watch CHTs like a hawk w/oil secondary. It's one of those "it's good enough" things.

I kinda hit a brick wall now 'cause I'm sure the gearing affect on combustion power output is not linear. But it's only gonna be a series of 65mph straight pedal runs thru the wetlands. It's a 12mi straight with 7mi of HP freedom w/plenty of U turns available. It's where I jerk around with my testing. That's where i got the 5th gear, 4k CHT #'s from. Flat, straight, fixed rpm, consistant humidity, no cars, no HP.. perfect for baseline tuning imo. I'll know oil temps within 20mi in each gear.

Jim Sims also threw his thoughts in this mix which I think are unintended consequences concerning other issues. I think?

but not as much as in my car. we'll have to wait and see.
-------- a 2.7 is crippled unless it has a good front cooler. A start is a fender cooler. It's a glorified air cooled VW when naked.



I could be nuts on all of above and before?


ryan/ Ron [/B]

Good point Kach22i. But a 3.0 to 3.4 normally aspirated motor using a belt driven waterpump - rather than the shroud and fan assembly - would maintain simplicity and alleviate heat concerns. More than a Subaru motor - something that could function and appear as clean (or almost ) as an MFI 911 motor.

In other words a 'flat' motor that stays extremely flat - one without every supertrick item taking up every cubic foot of space, as in the 959...But water into those cyl heads and back again to the pump. Goal: 220 - 240 horsepower with no detonation and summer trips to Tuscon or Death Valley if desired.


Phil
____________

'80 928
'82 Targa - sold

well, as far as being 'crippled', ron, i'd bet you're right under hot track conditions..wouldn't doubt it for a second, in fact. high temps and humidity in arkansas sometimes make my car TEMPERATURE limited during summer highway cruising. in other words, i can't maintain 90 mph for too long without temps beginning to creep into the 230, 240 range, etc. if i keep it at 80 and under, i can stay close enough to the magic number 220. i'd love to add a cooler..until then, i can drive balls out until it gets close to 80+ degrees.. :(
ryan

you need cams.

i actually think i prefer the basic cams over the 's' cams available in '74, at least for street use i think they're fine..no doubt i'd have more breath in the upper ranges with the 's' cams. now, whenit comes time to break this puppy down..who knows what the devil i'll do.. ;) in the meantime, i need that front cooler more than anything..and you'd have to agree, ron! SmileWavy
ryan

There are thousands of you out there who have gone to some pretty great lengths to control temperatures.

...many of you are working engineers. My Dad was a successful engineer - I don't have as much training as you engineers. But my bet is there is a ton of engineering left in a 911.

The 928 of mine is a nice car but w/ more weight can never give the 'feel' of a 911. I would like another vintage 911, but with a motor that I can live with in any climate. In a previous thread Grady mentioned about his attempt years ago with a liquid cooled head....few seemed interested - regardless, that to me was a great idea.

My interest has always been long distance cruising - as opposed to track events. Cross country to me is the ultimate. So, water flowing thru the heads of a protoytype 911 engine would knock my socks off. If I had Seinfeld's banking - I would be modifying aircooled motors for liquid cooling. Rather than just purchasing and collecting millions of dollars worth of rare Porsches - and polishing them for 'concours'. But it's his money to do as he pleases.

Phil
________

'80 928
'82 Targa - sold

My oil temps rose.

45F ambient, 170F oil in 5th, 170F + 1/2 thickness of the needle in 4th.

I couldn't notice any increase in CHT although the group of cyls must have risen a bit.

yep..another data point that supports my experiment last summer. either with or without an aux oil cooler, all else being equal, oil temps rise switching from 5th to 4th gear for crusing in hot and even 'not so hot' weather..
ryan

it seems my rise would be more radical under more demanding ambient temps.

i'd intuitively agree..and even moreso without an aux oil cooler.. ;)
ryan

My neighborg 2004 supercharged Mustang Cobra with 659 hp use the a/c to cool the fuel into an homemade cool can. He is planing now to cool the water that recirculates thru the water-intercooler inside the intake manifold. I think that he is "thinking outside the box".