OIL (i know)...

[racerrad8]

i think the previous post about oil not really making that much difference is true.
i just didnt want to give any more reason why i should change to a better clutch!

See my previous post about the oil, since you have a turbo...synthetic is what you should use.

All you will need to do is double spring the clutch if you have the stock pressure plate. If that configuration can drag around my 1500+ pound race car with at least ten times more traction contact patch than the bike has, you will have no problems with any oil you choose to run.

Randy - RPM

[backstreetheros]

just to confuse everyone more...
i took your advice randy and made the oil cooler hoses in an-6
the turbo cooling system is IN NO WAY connected to the engine cooling system
i have a completely seperate resivoir, pump and oil cooler just for the turbo.
also seperate water resivoir, water pump and radiator for the water cooling of the turbocharger.
see pictures. one oil cooler on the front of the bike and one at the rear (the rear cooler is for the turbo)

i am using castrol power 1 synthetic for the engine cooling
and castrol magnatec 10-40 for the turbo cooling as this was specified for the subaru impreza.

[backstreetheros]

rear cooler for turbocharger.


front cooler for engine...

[Dan Filetti]

We are talking about large coolers on the race car, 12"x12". The size of the cooler requires the pump to be large enough to create pressure within the cooler and cause the oil to rise to the top due to the restriction. When big hose & fitting are sued on the lower volume secondary pump of the FJ once it leaves the pump and there is no back pressure, the oil will only flow the path of least resistance.

I know that this is probably an obvious question but I still don't get it.  I am certain I am stumbling into oil cooling theory without proper knowledge to begin with.  Be that as it may, I am still curious.  In your above statement you talked about a 'path of least resistance'.  My question is why is there a path of least resistance in the first place?  Why will the oil just not snake through all the rows, like an efficient use of a Tron light cycle, one row at a time until it comes out the other side. You seem to be indirectly answering this but saying the oil needs to flow up to the top of the cooler once the engine is running and producing enough pressure.  I get that pressure can be too low, and cause issues, as above, but if the cooler can be empty for a period of time while the bike is running, while pressure builds, then why not have it be empty while the oil is snaking through the labyrinth?  Too much time?  A design like this would certainly ensure that the oil passes through the cooler in an orderly, an optimized fashion -No?  would it make the engine run too cold in some cases? It is so obvious that I am beyond certain it's been tried and discarded for some reason, I just can't wrap my mind around why it was discarded from a design perspective. 

Any input would be helpful.

Dan     

[racerrad8]

I know that this is probably an obvious question but I still don't get it.  I am certain I am stumbling into oil cooling theory without proper knowledge to begin with.  Be that as it may, I am still curious.  In your above statement you talked about a 'path of least resistance'.  My question is why is there a path of least resistance in the first place?  Why will the oil just not snake through all the rows, like an efficient use of a Tron light cycle, one row at a time until it comes out the other side. You seem to be indirectly answering this but saying the oil needs to flow up to the top of the cooler once the engine is running and producing enough pressure.  I get that pressure can be too low, and cause issues, as above, but if the cooler can be empty for a period of time while the bike is running, while pressure builds, then why not have it be empty while the oil is snaking through the labyrinth?  Too much time?  A design like this would certainly ensure that the oil passes through the cooler in an orderly, an optimized fashion -No?  would it make the engine run too cold in some cases? It is so obvious that I am beyond certain it's been tried and discarded for some reason, I just can't wrap my mind around why it was discarded from a design perspective. 

Any input would be helpful.

Dan     

There are two types of oil coolers, oil coolers & transmission coolers.

Oil coolers are referenced many different ways, full flow, single pass, dual pass, three pass...

These coolers have an inlet to a row of cooling tubes that flow to the outlet side. There is nothing controlling the oil flow inside the cooler other than the flow & pressure of the supply side. An oil cooler is like a radiator more or less. If the oil pressure system does not have enough flow and/or pressure it will allow the oil  to travel the path of least resistance within the cooler. Sure, the cooler will be full of oil, but if it falls to the bottom, flows to the other side and out then the upper tubes will not flow as much oil and the viscosity will stay higher and the flow will be decreased. I am not saying the oil only flows across the bottom of the cooler, but the large cooler with -8 fittings & hoses and a large cooler can see as much a 30* difference of the cooler temp from top to bottom.

You can see the inlet and the edges of each cooling tube/fin in the photo below.


Transmission coolers are direct flow with no option to choose which way it flows. So, the oil has a direct flow and not option of least resistance.


These types of coolers do not provide adequate surface area for cooling. The only expose the oil to the direct oil flow path through the limited amount of cooling area. Also, this type of coolers are designed to be used in conjunction with the radiator heat exchanger dropping the initial temp of the trans fluid to radiator temp and then being further cooled by the cooler. I cannot imagine how big a cooler of this design would have to be to obtain the oil cooling surface of the full flow style cooler.

Randy - RPM

[ribbert]

Noel
WHAT do you think you're doing?  You can't use that kind of logic in this topic!

Somebody get a rope.

He's a Witch, BURN HIM!!!!

If the world wasn't flat, I'd sail over there teach you a lesson.  :-)

DavidR.

My apologies, a serious breach of forum protocol, I don't know what came over me, a moments sanity perhaps, or sniffing the wrong oil.  It won't happen again.

I promise all future opinions will be divisive and provocative.

Noel

[andyb]

Oil will always take the path of least resistance, just like any liquid or gas.  Balancing the pressure and rate against the cooler size/shape is another matter!

Sorry, was bothering me to read that.  Understand what Randy meant though.

[ribbert]

I'm just curious where you get a new FJ for ($150*5)  or even ($150*10).
You must be a great shopper.

I paid $500 for my second bike and there's one on ebay at the moment with a buy it now price of $750 (76,000 k's)
Noel