oil cooler, your thoughts Options

[brant]

Rich,

for the sake of it, since you obviously know how to use paint brush and I don't...

draw out the "series" diagram also please.
brant

[TimT]

i suspect the website was built by someone who doesn't know Porsche oiling systems - lists 10mm, 12mm, and 30mm. that's gotta be AN-10, AN-12, and 30mm ..

Perhaps... they have advertised the other (smaller sized) thermostats for years, perhaps for other applications..I think the print add reads 10an and 12 an

[ArtechnikA]

draw out the "series" diagram also please.

hot from engine
connector line
cool oil to engine

sorry - there is no 'brown' textcolor...

note how ALL the oil goes through BOTH coolers.

[brant]

Ok...
not that it matters but I have to one final time correct myself....

I am running my coolers in series.


When I planned it out with the fluidyne engineer, they were very technical and were using not only PSI, but other info about my cooling needs....

They were very concerned about restrictions (for example you must use smooth 90's and not sharp 90's fittings)..

They wanted my total pumping lengths and factored in their cooler restrictions.

They were very concerned about the angle that I mounted the coolers and wanted them stood up straight with no lay back...

but they did not mention the series - parellel argument...

The reason I bring this up is do you fluid dynamics minded souls see a volume or pressure problem with the parallel design?

brant

[TimT]

The reason I bring this up is do you fluid dynamics minded souls see a volume or pressure problem with the parallel design?

I do... You can plumb the coolers in parallel, and have only one cooler working.. Fluid will find the path of leat resistance...If one of the coolers has restrictions ( some gunk, a snot of teflon tape, trapped air) the fluid will flow to only one of the coolers.. You wont have and problems with pressure or flow, but you may only be using one of the two coolers you paid for.... a quick touch test will confirm this (IMG:style_emoticons/default/wink.gif)

Fluidyne coolers are the shizzle... the reason the want you to mount them straight up is again to not trap any air. if the cooler is layed over at an extreme angle, you may only get fluid flow through one or two of the passages..

Ill have to shoot some pics of the install on my 911... I have the cooler layed down at about a 45 deg angle, but it is don in such a fashion that there can be no trapped air..

Also ponder this... the front cooler in a 911 is plumbed in series ( stock from the factory)

[brant]

Tim,

when I talked with the engineers they explained that they wanted the cooler stood up for maximum air flow reasons and not trapped air inside the cooler...

The guy had a percentage chart and told me that If I bought the larger cooler I was looking at and then laid it back at such and such angle, it would be less efficient than the smaller cooler I did buy and stood straight up.

Maybe its all bunk.. but they were insistent that there would be more restriction and less air flow if I laid it back.....

dunno, but I can say I was totally blown away from spending 45minutes on the phone with the guy and having him go over my whole oiling plans..

I may be way over cooled, but we choose to run 2 (a pair in series) of model # DB- 30617 coolers. They were also able to custom make them with the AN fittings on them instead of the NPT fittings (saves weight don't ya know, to not have an extra adapter in there)

brant

[ArtechnikA]

... You wont have and problems with pressure or flow, but you may only be using one of the two coolers you paid for.... a quick touch test will confirm this (IMG:style_emoticons/default/wink.gif)

Fluidyne coolers are the shizzle... the reason the want you to mount them straight up is again to not trap any air.

Also ponder this... the front cooler in a 911 is plumbed in series ( stock from the factory)

that's true, but your engine won't die because a single-point failure shut off all the flow.

fundamentally, you want coolers normal (perpendicular) to the airstream, especially if there are fins involved. fins (vanes) are just like shutters, and if you can't see through the cooler, the air will have a hard time getting through. the entrained air issue is also significant.

you're gonna hafta s'plain your last point, unless you're talking about coolers on 3,4's and up. on all 911's with engine-mounted coolers, the engine cooler is plumbed into the pressure circuit, and the front cooler is plumbed into the scavenge circuit. they're actually completely separate, neither parallel nor serial - each cooler has its own separate pump ...

3,4's and newer that have no engine-mounted cooler - typically have only one cooler...

(and i agree with the FluiDyne... i'll be running one big RS-sized one behind my RS bumper...)

[Trekkor]

Here's a little something to get the juices flowing!

Discussed this with a club member today.
Bear with me on this one. (IMG:style_emoticons/default/unsure.gif)

Put the cooler in the space between the fuel tank and the windshield , right under the fresh air intake grill.


Now, dig this...Use the existing air tubes to route the air out the back of the car where the hot air would normally come from the heat exchangers to the front of the car.

With careful planning, you can use this set-up as an alternate cabin heater by shifting the levers on the dash.

Another concept would involve using brass or copper pipe as oil lines to the front of the car in the rocker space.

Flexible hoses would thread onto each end. Using metal pipe would allow heat to escape freely the entire trip.

KT

[TimT]

The guy had a percentage chart and told me that If I bought the larger cooler I was looking at and then laid it back at such and such angle, it would be less efficient than the smaller cooler I did buy and stood straight up.

that all depends on how you get air to the cooler..you want the cooling air to enter the cooler dead on..if the cooler is at an angle to the airflow, it basically makes a high pressure area just before the cooler...ie less air passes through the cooler..

I will of course defer to the fluidyne techs.... they make a great product, and lots of big bucks race teams use fluidyne coolers...

also having the extra oil coolers gives the benefit of more oil capacity, which is a good thing

[SpecialK]

Okay, now I'm getting confused (IMG:style_emoticons/default/huh.gif)

If the only reason for running parallel HEs VS series HE's is restriction/back pressure, then crunch (IMG:style_emoticons/default/smash.gif) some numbers to figure out what line sizes to use to achieve the desired outlet pressure/volume. I still haven't seen anything to show me (pressure, volume, and airflow/temp across the HEs being equal) how a parallel system could be more efficient than a series system.

Sorry, it's a "Missouri" thang.

[ArtechnikA]

OK - if you guys -really- care about this stuff, go get "Tune To Win" and read Chapter 9. the edition i have is a bit dated and technology marches on - FluiDyne is now the Hot Setup for coolers. technology changes, but heat and air work pretty much the same way they did 30 years ago...

he actually doesn't elaborate much on the parallel setup, he just says do it - for efficiency.

since we're looking at total heat rejection, Delta-T is significant. assuming we're dealing with multiple coolers rather than one big one for packaging purposes, for a given Delta-T, two coolers in parallel will be smaller and lighter than if they're plumbed in series. put it another way - they'll reject more heat and "cool better".

that's my story and i'm sticking with it. (IMG:style_emoticons/default/smile.gif)

i wouldn't mind participating in a controlled test, but it has been done before...

now - that said, i will be plumbing the supplemental automatic transmission cooler in the Subaru (light-duty tow car) in series with the existing cooler. here's why: i will be adding a freestream air/oil heat exchanger upstream of the factory cooler that is actually part of the water radiator. by cooling the transmission oil when it is at its very hottest with air, i will be removing some of the heat rejection load from the engine's air/water heat exchanger ("radiator") under the conditions that it is also working at its hardest. in cold temperatures, if the trans fluid is cooled below its optimum by the airstream (which i will be able to block off), its trip through the engine radiator should actually warm it up a bit, since it is downstream.

[TimT]

that's true, but your engine won't die because a single-point failure shut off all the flow.

never said the engine would fail, just observed that by plumbing parallel you may not see the benefit of the plumbina second cooler this way....also trapped air can shut off some/part/much/all of an oil cooler benefit...

you're gonna hafta s'plain your last point, unless you're talking about coolers on 3,4's and up. on all 911's with engine-mounted coolers, the engine cooler is plumbed into the pressure circuit, and the front cooler is plumbed into the scavenge circuit. they're actually completely separate, neither parallel nor serial - each cooler has its own separate pump ...

oops point taken...... I was considering them as a system the oil goes out iof the pump...to cooler #1 then to filter etc... to the front cooler....

[ArtechnikA]

I still haven't seen anything to show me (pressure, volume, and airflow/temp across the HEs being equal) how a parallel system could be more efficient than a series system.

okay - imagine you have two identical, very efficient coolers. you have 250F oil and 100F freestream air.

since the coolers are very efficient, the first cooler reduces the temperature of the oil from 250 to 101. AT BEST the second cooler can cool the oil only one more degree. you have twice the cost, twice the weight, and yet you cooled the oil only one more degree. that's not efficient.

for the same Delta-T, you will be able to use smaller coolers in parallel.
or - two coolers in parallel will reject MORE HEAT than the same two coolers in series.

(serial coolers may eventually result in lower temperatures, but it is not efficient to do so.)

[TimT]

My copy of "Tune to Win" disintegrated years ago

Actually there is a GT3RSR at my friends shop now, ill have to take peek how the radiators are plumbed

[theol00]

Hi Trekkor - is your engine an "S" spec engine - if not you might get away without an oilcooler - I run a 2.2 ltr "e" spec without any additional oilcooler - and even on the track going fast the temperature remains perfectly fine - I was told by a very reliable source - my trusted Porsche Factory Race Engineer and Engine Builder - that unless you run an very hot "S" spec you don't have to go without all that plumming - that is good enough for me - I like to keep it simple - (IMG:style_emoticons/default/rolleyes.gif)

[Trekkor]

Nobody's biting at the oil cooler/heater, eh?

I will look at this a little closer later.

Good posts thus far, thanks for that.

Still have a few more a/x's and may have a DE in Nov before I tear it all down.

KT

[SpecialK]

Nobody's biting at the oil cooler/heater, eh?

I will look at this a little closer later.

Good posts thus far, thanks for that.

Still have a few more a/x's and may have a DE in Nov before I tear it all down.

KT

Actually did that with a '70 Baja Bug I owned 20 years ago in Colorado. I had two remote oil coolers, one mounted on the rear fiberglass, and one mounted in a box I made out of sheetmetal (HVAC stuff), an old blower motor out of the junk yard, and a couple of valves to switch between the two depending on the weather. It did keep the back window clear in the winter, but not much more than that.

Should've mounted them in "parallel", might have been more effective (IMG:style_emoticons/default/lol2.gif) (IMG:style_emoticons/default/wink.gif)

[redshift]

technology changes, but heat and air work pretty much the same way they did 30 years ago...

(IMG:style_emoticons/default/smilie_pokal.gif)

At least we aren't stupid!

(well... Rich isn't stupid..)

Group Hug!


M

[ArtechnikA]

Nobody's biting at the oil cooler/heater, eh?

for sure it had at least half a good idea - i have seen oil coolers mounted in the high-pressure area of the cowl where the ventilation plenum is, ducted through the structure and exhausting out the bottom of the car.

but i donno why you'd want a heater in an AX car, and most engines don't make enough oil temp in warmup and cruise to even open the thermostat, much less actually heat the car...

[Trekkor]

All those cones give me "the chills"! (IMG:style_emoticons/default/unsure.gif)

Really, this car is mainly street. I drive it several times a week.

Heating me is really not important at all. I never use the heater now.
I'm just thinking of having heat available for a very cold day or for the wife (IMG:style_emoticons/default/wub.gif)

Since the headers will knock out the heat, it'd be nice to offer *something*.
I like the idea of running the hot air out the back through the longs.

If I truly wanted a functioning oil heater, the copper pipe idea might cool the oil too much? Can you cool it too much?

Ten feet of thick wall 3/4 inch pipe exposed to the air might exchange a lot of heat.

KT