Hydroboost/oil cooler question

[bonose]

Need input from the experts.

Will be building hydroboost roadster in N Texas. I have seen some use the auto tranny circuit in the radiator for Hydroboost fluid cooling. Proposed usage is mostly street with occnl autocross/track day outings. Is the hydro/radiator option a good use of my assets and will an aux oil cooler/thermostat in the chin be worth the trouble? I'm really wanting to control fuid temp in the heat here.

Thx

Bonose

[Greg_M]

I used a Mocal cooler in the chin for mine. Stock Mustang just has the loop.

Greg

[tad240]

I used the trans cooler built into the radiator. Cheap, easy, and its already there. I do some track days at high revs so I thought it was a good idea. Also put an oil cooler in the chin so that was no longer an option for the hydroboost cooler.

[dukegrad98]

I have an independent trans cooler plumbed into my hydroboost setup. I don't monitor the temperature, so I have no idea whether it is really necessary or not. That fluid does move with considerable velocity. My engine has a finned aluminum oil pan, so I do not have an engine oil cooler -- never had anything even close to an oil temp problem, judging by the gauge.

For point of reference, my car has spent its life in street use in Houston and here in deep East Texas.

Cheers, John

[Bob Cowan]

What's built in to the radiator is not a cooler, it's a heat exchanger. There's a big difference. The heat exchanger works by moving heat energy from an area of high concentration to an area of low concentration - kind of like osmosis.

When the oil is cold (like winter driving) it will help to warm the fluid to operating temp. When the oil is hot, it transfers the heat to the coolant. If your cooling system is marginal, that could be a problem in the summer.

I'v seen some radiators with the heat exchanger on the left side, with the inlet on the right. That's a bad thing. It takes the excess heat from the oil, and feeds it directly to the engine. The heat exchanger should be below the inlet, so the coolant has a chance to dump the energy to the environment before going back to the engine.

[canuck1]

Originally Posted by Bob Cowan

...When the oil is cold (like winter driving) it will help to warm the fluid to operating temp. When the oil is hot, it transfers the heat to the coolant. If your cooling system is marginal, that could be a problem in the summer...

I have no data to indicate it, but I believe the above to be true as well. If it is an actual 'stock' type radiator, adding heat via the trans fluid tubes may be the straw that breaks the camels back in tems of coolant temp.

Are they necessary? I know PS systems build a fair bit of heat by design and heat is generally what kills pumps in the end. I added one in the oil cooler position because it fit and it seemed logical to have some type of cooler.

If adding an engine oil cooler was required, I would consider stacking one behind the other. I see it all the time in heavy equipment and don't see why it wouldn't work (one cooler behind the other in the oil cooler opening or one behind the rad) provided you could find the real estate to mount it?

Sean

[bonose]

Bob,

You're absolutely right about the heat exchanger vs radiator terminology. I am very familiar with them and just latched on to easy terminology. Thx for correcting me. No sense being sloppy here. What should the normal PS fluid temp be? For an engine with 190-210 ish temp, would that be an adequate heat sink?

Anyone in Texas see high oil temps and under what conditions? A finned oil pan would seem to offer a simple yet weight effective answer. Anyone using these and what are the results? Vendors?

Thx

Bonose

[Bob Cowan]

Originally Posted by bonose

Bob,

What should the normal PS fluid temp be? For an engine with 190-210 ish temp, would that be an adequate heat sink?

Thx
Bonose

That's a good question. I have never been able to find real data that tells me what the temp should or shouldn't be. But, PS is a lot like AT fluid. So I use those numbers.

Minimum operating temp - 150*. Max sustained temp 200*.

I plan on adding PS this winter (yes, I'm officially Old now). I do not plan on adding a cooler. But I'll watch the temps closely at the track and at various operating conditions to see if I need one.

[Greg_M]

I would estimate temp of PS fluid is around 110-130* using an oil cooler of some type. The cooled flood returns to the reservoir and you can easily dip your finger in it without a burn after a long run.

Greg

[itzdapig]

My set up.Afco power steering cooler. $50 +hoses.

[Bob Cowan]

Originally Posted by itzdapig

My set up.Afco power steering cooler. $50 +hoses.

That's actually a heat sink. In theory, the ho fluid passes through the chamber, and then transmits the heat energy to the aluminum housing and fins. The fins then transfers the heat energy to the air.

However, they are notoriously inefficient. What really happens is as the fluid moves through the tube, it forms a stagnant boundary layer around the walls of the tube. The rest of the fluid simply passes through the tube with very little cooling effect.

There are products available that use a "turbulater", to break up the boundary layer and allow it to work properly. Better, but not nearly as good as a stacked plate cooler, or and oil/water heat exchanger.

http://www.harley-davidson.com/en_US...ator_Chart.pdf