Auto Tranny Line PSI?

Does anybody know what the presssure is running through the auto tranny lines and into the factory cooler in the radiator?

I tried a quick search but I didnt see any numbers.

Thanks,

AARON

Very little since the return runs into the pan.

Residual. It's just enough to keep the stuff flowing - the pressure has already been bled off in doing the work. It's low enough that a non-beaded hardline and a slip-fit hose won't leak with a single clamp (but I use two anyhow.)

Why for do you want to know?

So I guess the tank in the radiator wont hold say 70psi max?

I have been reading about oil and oil temps in the research about oil not having the needed additives to keep a performance flat tappet cam alive. I was looking into a oil cooler/warmer similar to what Hesco offers to get the motor oil up to temp and keep it there. For motor oil to be most effective it needs to hit at least 180 degrees and no more than 250 for standard non synthetic. Synthetic can hit temps as high as 280 but with reduced life. The oil temp gauge I have typically reads 150 to 180 degrees and it takes the reading right out of the pan. I feel that is too cool and I really want the new 4.6L stroker I built to last this time and not blow up like the Crane cam just did in it several months back.

I run a manual tranny so that leaves the tranny cooler in the end tank of the radiator free so I was hoping I could run the oil through there and then back into the filter. I am looking for a cheap and effective way to heat and cool the oil. Hesco sells a kit but its $180. Maybe I will just fork out the cash for it and call it done. Get what you pay for right?

AARON

Well, I've taken a couple of radiators apart (threw them in the scrap bin - cut them down so they'd fit easier...) and that cooler is a simple shape, and should be brazed rather well - since it's got to NOT leak in a hot water environment while containing rather warm and low-viscosity oil.

I've not pressure-tested one, but the idea is interesting... Perhaps you could try it, and let us know?

The upper connection is a standard flare (I don't recall the size,) and the lower connection should use a QD fitting - but will probably accept a rubber hose. Else, it's also a standard flare.

You'll be wanting a "sandwich" adapter to go under the oil filter - it will route the fluid through the cooler/warmer before it gets filtered, so it would warm the oil before it's circulated through the engine.

The additive you're referring to is ZDDP, and it's not used in the API SL-series "Energy Saving" oils. Flip the oil over, and read the API ratings - if you see something like "SL/CD" (I don't know what the current Diesel rating is offhand...) then the oil is rated for use in Diesel engines, and will contain ZDDP (since Diesels don't live long without EP lubricating oils.) If it has the API "Energy Saving" sunburst on the front, chances are it only has an API "S" rating, and isn't fit for use in Diesels. The "S" refers to "spark ignition" - the typical gasoline engine - while the "C" refers to "compression ignition" - what makes a Diesel work.

As I recall, the "cooler" for the ATF is in the "hot" tank of the radiator (the upper hose goes into it,) which means it's going to be exposed (via a copper barrier) to hot coolant - which should help keep your oil at operating temperatures. An interesting idea, and I'd like to see your field report after you've run it for a little while...

What happened to your engine when it blew up? I'm pretty new to Jeeps but know that there are LOTS of guys running built small block Chevies with flat tappet lifters and regular oil and they last for years. Maybe your valve springs are too stiff or you just have too much ramp rate on the cam for your lifters? Coil bind? Improper valve train geometry? Are you using hydraulic lifters or solid?

The two cams that have blown up on me were Crane Cams. The first one, the lobes went flat after they sold me the wrong spring and retainers which eventually wiped the cam lobes flat. The second Crane cam failed due to a soft distributer gear. I know of at least 5 other people who have had the lobes go flat or the distributer gear get eaten in their 4.0L or stroked 4.6L motor. CRANE CAMS JUST SUCK AT LIFE!

I am hoping the Hesco cam holds up better. I got everything that touches the cam from Hesco and plus they have been building Jeep 4.0L motors for a very long time and I have yet to hear anything bad about Hesco execpt for the price. You get what you pay for.... I hope

This is the link for the Hesco product and what gave me the idea: http://www.hescosc.com/shop.asp?action=details&inventoryID=60385&catId=7936

AARON

That warmer looks to be like good insurance but if that's the "make it or break it" part for your engine then I think you might have other issues that need to be addressed. Good luck, hope it all works out this time around.

Arron, I have seen that tried before....and the thing came apart at the seams....better to get a specifically designed cooler...

Wait, are you thinking you can use the hot coolant to warm up the oil? The oil is generally hotter than the coolant, right? Just add an oil cooler and be done with it.

I don't understand how people think they are going to get warm water from a radiator that is cold. Until the motor warms up (ie oil is warm, trans oil is warm (if driving) then the water that is in the motor to cool it get warm) then the water in the motor geta hot enough to open the thermostat and the water is quickly exchanged and the thermostat closes again and the water in the radiator cools again. The radiator goes thru 2 or three cyles befor ethe water in there will be any where near what the oil is already heated too. When you first start your XJ and turn on the heater, is it hot, no not until the thermostat cylce starts.

There is no way that the oil heats up faster than the water. Its the other way around, the water heats up first, followed by the oil. I have both a water temp gauge and an oil temp gauge and I can tell you now water gets to temp way faster than the oil temp. Even with that said, the oil is too cool a majority of the time, so that is why I want to use the engine coolent as a way to warm/cool the motor oil that it is up to temp and working at its peak performance. The radiator will always be somewhere between 180 and 220 degrees, which is exactly where the motor oil needs to be.

Thanks Muddawg that was what I was thinking was going to happen. Guess its time to shell out the cash for the Hesco unit.

AARON

Ok, I can see the water in the block heating up faster since it flows around the cylinder sleeves. But the water in the radiator doesn't get warm until the thermostat opens, so you would be cooling the oil until the point that the thermostat opens. I'm still having trouble seeing much of a benefit.

The benefit is that the radiator still opens before the oil reaches operating temp, at least for me. Thats the whole reason why I was looking at this mod. The only time I have ever seen my oil temp get warmer than 220 is after a long slow hill climb in 4lo that required lots of heavy throttle use and even then the oil temp never went above 230 degrees. For the majority of people, this mod is not needed, but for thoes of us who are running a high performance cam with more lift than stock, and also with stiffer than stock valve springs, we need the most performance out of the oil to keep everything alive, specifically the flat tappet cam and lifters.

AARON

Well let us know what you get, I also have a Hesco stroker with cam and don't like the sound of it in the morning, but hope it is not doing any damage, about 16 months and 18,000 miles so far. But it does sound much beter after about 10 min run time.

XJJack said:

Well let us know what you get, I also have a Hesco stroker with cam and don't like the sound of it in the morning, but hope it is not doing any damage, about 16 months and 18,000 miles so far. But it does sound much beter after about 10 min run time.

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Do you have the standard rockers or roller rockers? On my old stroker I had the factory stamped steel rockers and they made a lot of noise, more so when cold but even after it warmed up, it was still pretty loud. If you dont already have them, toss on a set of roller rockers. They are so worth the money, I wish I had done them sooner.

AARON

lawsoncl said:

Ok, I can see the water in the block heating up faster since it flows around the cylinder sleeves. But the water in the radiator doesn't get warm until the thermostat opens, so you would be cooling the oil until the point that the thermostat opens. I'm still having trouble seeing much of a benefit.

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Your coolant definitely gets warmer long before the oil does. Unless you don't have a oil pressure gauge it is obvious from just watching it. Go on a short trip and you will notice that at idle your oil pressure is still up around 20/25psi (cold oil). Now if you go on a long trip idle oil pressure will be down around 13 psi.

Aaron,

Did you ever find out for sure what psi runs thru tranny cooler lines? Half the people I talk to say next to nothing, but several (transmission techs and jeep dealership mechanics) are telling me 200+ PSI.

cal said:

Aaron,

Did you ever find out for sure what psi runs thru tranny cooler lines? Half the people I talk to say next to nothing, but several (transmission techs and jeep dealership mechanics) are telling me 200+ PSI.

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Internal pressures can run up to 300psi in some gear ranges, but I've cut apart OEM hoses, and I doubt they're rated for more than, say, 30psi or so. I've also had occasion to have a transmission cooler line blow all over me - it was hot, it was oil - but it didn't do me any physical damage like HPoil would.

I still say it's "residual" - 15psi or less. Chew on it for a minute - it's already done the work it needs to do, so most of the pressure is already shot...

5-90 said:

Internal pressures can run up to 300psi in some gear ranges, but I've cut apart OEM hoses, and I doubt they're rated for more than, say, 30psi or so. I've also had occasion to have a transmission cooler line blow all over me - it was hot, it was oil - but it didn't do me any physical damage like HPoil would.

I still say it's "residual" - 15psi or less. Chew on it for a minute - it's already done the work it needs to do, so most of the pressure is already shot...

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What I've been trying to figure out is if say, a 1.5 quart radiator (with fans and shroud) that came off of my old honda interceptor would take the pressure of the trans lines..