trans. cooler ?

rsh4364

Dragway Regular
Aug 12, 2011
744
0
0
greensprings,ohio
I have a Hughes t/h350 #35-1HD trans. and 3600 stall T/C,I run trans.fluid thru built in cooler in radiator then a B&M 70264 cooler then a remote trans filter then back to trans,also installed a 3 qt.deeper pan on trans.(which I should have gone 2qt,because the 3 qt. pan hangs lower than my 7qt. oilpan) Amazed at how much more heat higher stall T/C produces.Trans temp never gets above 185 but it really transfers heat to my coolant and my elect. rad. fan runs much more,I now have a B&M 70266 cooler ready to install.Should I completely bypass rad. cooler?Can I use 1/2 npt to 3/8 barb 90s on cooler? Maybe my elect. pump is running coolant thru radiator to fast to cool! Its a proform and using moroso large restricter in thermostat housing. Any experience or advice?
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,847
1
38
North Jersey
If I'm understanding what you wrote, your engine temp is up after you installed a looser converter and you run a restrictor plate instead of a thermostat. You're asking if the electric water pump may be circulating too fast to give off the proper amount of heat. The pump isn't the problem. Take the restrictor plate out & install a good quality thermostat. At the very least, install a smaller restrictor plate. The "too much flow doesn't allow enough time for the coolant to transfer heat" theory is a myth. Even though if you ran your coolant through the radiator so fast that there was no decrease in temperature, you would obviously overheat, that's not what actually happens. Automotive coolant pumps are inducer style pumps with centrifugal impellers. Impeller style pumps must work against some head pressure to avoid cavitation. When the impeller cavitates, the flow drops off dramatically. Running without a thermostat doesn't provide enough head pressure, the pump cavitates & temps go up.

Tommy
 

rsh4364

Dragway Regular
Thread starter
Aug 12, 2011
744
0
0
greensprings,ohio
You cant,if you do water pump will deadhead against closed thermostat and burn up your waterpump,you can run a a thermo sending unit to keep pump from running below 160,which I have,but have not installed yet.My pump does not cavitate with large restricter plate at all.so don't see benefit of a smaller plate.Is it okay to run 90s in trans lines out of cooler?
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,847
1
38
North Jersey
rsh4364 said:
You cant,if you do water pump will deadhead against closed thermostat and burn up your waterpump.

Not to be argumentative or insulting to anyone, but whoever told you that has zero understanding of centrifugal pumps. Deadheading a centrifugal pump results in discharge pressure dropping to pretty much zero. It doesn't build pressure like a positive displacement pump. According to that logic, when the T-stat is closed with a stock belt driven water pump, the belts should fry. If you completely block the inlet or the outlet on a centrifugal pump nothing bad happens. The impeller more or less just free wheels. On an electric pump the amperage draw will actually decrease as there is no load on the pump.

Tommy
 

rsh4364

Dragway Regular
Thread starter
Aug 12, 2011
744
0
0
greensprings,ohio
No offense taken or implied,I was told a fact.type has a bypass built into it internally,and the elects don't.But I really don't know.
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,847
1
38
North Jersey
Cool. The purpose of the bypass is for faster warm up and to avoid pressure buildup behind the stat, not to protect the pump. I got too technical about one thing and I didn't get as technical as I should have about the bypass. If anything, blocking the bypass allows for better cooling, especially if you drill three or four 1/8" holes in the T-stat body.

Tommy
 

rsh4364

Dragway Regular
Thread starter
Aug 12, 2011
744
0
0
greensprings,ohio
Thanks Tommy,Guys do you think I should try bypassing fact.cooler built into radiator,and is it ok to use 1/2npt to 3/8 barb 90s on inlet/outlet on cooler? New cooler is 8x11 B&M plate type cooler.
 

SSedan64

Dragway Regular
Oct 5, 2009
948
0
0
MACON, GA.
If it's causing an overheating problem you can bypass the Internal cooler. Just keep an eye on the Trans temp.
Yes, you can use 45*-90* angle fittings on cooler lines.

The external B&M plate coolers are LPD/LowPressureDrop type, which are self regulating. Thick/cold fluid bypasses the cooler which helps the fluid warm up in cool/cold weather.
If the vehicle is used a lot in Winter the Internal cooler should be connected to cook off condensation & maintain proper fluid operating temp.
 

rsh4364

Dragway Regular
Thread starter
Aug 12, 2011
744
0
0
greensprings,ohio
Thanks guys,car not driven in cold,usually in storage by now,but draggin my feet this year? gonna be in 50s this week so she has to go to storage,gonna be in teens this coming weekend.
 

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