| Author | Message | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 476 Registered: 10-2004 Posted From: 173.77.206.183  Rating: N/A |
Well the cooler is next on the hit parade. Jack Conrad had a great article in CBB and also in the bus mag. He used 3/4 inch lines and 1/2 tubes in his cooler. I am pretty sure my lines to the OEM engine mount cooler are 1". I have a 644 Allison coupled to a 6V71. I dont want to drain the trans down till i have the parts and there is a significant price difference in the coolers. My main concern is i dont want to go to small or large on my lines. Is this a case of larger lines less pressure (good or bad?) and smaller lines better pressure but restricted? And if anyone has done this what did the temps drop? Jack stated 10-15 degree drop without even turning on the fan to cooler. We run fine normally but heat up slowly in the hills and especilly towing in the hills. Cant believe i might get 3 days in a row working on the bus!!! Happy Independence Day. Thanks in advance | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 1056 Registered: 8-2006 Posted From: 99.184.9.29 Rating: N/A |
Dave, Smaller lines mean less flow, period. (Smaller lines require more pressure from somewhere else to get the same amount of flow as a larger line.) No such thing as too large a line, the only thing a larger line can damage is your pocketbook. The rumor that too fast flow thru a radiator won't let fluid cool as well is also wrong! With slow flow, the temperature drop is greater than with faster flow, but with faster flow, the total amount of heat removed is greater. G | ||
| james dean boggs (Jd_boggs)
Registered Member Username: Jd_boggs Post Number: 158 Registered: 11-2004 Posted From: 75.80.255.164 Rating: N/A |
I installed a tranny heat exchanger that's about 24"x24" using 3/4 inch lines and a temperature gage to measure temp. Works fine as long as my speed stays at 35-40 MPH or better. I rely on speed for air flow but when climbing Tejon or Tehachapi pass in Southern California my speed drops to 20-25 MPH and tranny temp reaches 200+ degrees after about 20-30 minutes of climbing. However this year I installed water misters and the temp problems disappeared. PS I have very good air flow because I installed an air scoop just for the heat exchanger. | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 910 Registered: 8-2006 Posted From: 74.32.84.228 Rating: N/A |
The Allison does fine at 160 to 220 F and 250 F for short periods is not a problem. Me I would stay with the 1 inch lines and install a double cooler on the engine if there is not one now and you can gain a little more cooling with a extra filter one on the suction and one on the return line.oops sorry I see you have the engine mounted cooler. A trick I always used on my MCI was to pull the thermostat on the left bank in the summer time good luck (Message edited by luvrbus on July 05, 2010) (Message edited by luvrbus on July 05, 2010) | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 477 Registered: 10-2004 Posted From: 173.77.206.183 Rating: N/A |
Thanks for the replies. I have a perfect place for a 24X18 with the one inch lines and has the fan and shroud attached. George, thanks for the line/pressure info. I think we are going with 1" lines. James i was thinking the same thing with the air scoop. It is going to end up onthe drivers side of the engine bay with outside air pulling/pushing inward. Luvrbus, the problem now is that the extra temp from the trans in the summer on hard pulls goes right into the cooler and puts too much heat into the cooling system. the plan is to route to the new cooler first and then to the engine mounted cooler for winter warm up. On the other hand, the new black/grey tank is in, shower,sinks, and toliet plus vents are installed and i am hooking up the new waterlines as well as the 4" toliet bowl platform. Seems like i should have more done on a long weekend. By the way it is hot out! Thanks again. | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 478 Registered: 10-2004 Posted From: 173.77.236.138 Rating: N/A |
As an update I contacted Matco distributing in Alabama ( www.transmissioncoolers.us ) and gave my specs to Jared and he looked up the 644 and reccomended the larger 1" model altho the flow rate for the 3/4 was also acceptable. The units with the fans attachted were actually the same price. You can also purchase the fittings and hose by the foot as well as thermostats etc. I am sure if i did some fooling around i could beat their prices but i think i have left my fooling around days behind me (!) well not in everything, but at least is trying to cheep out! I also found a web site looking for dump valves that wasent bad, Dupree products .com. got a manual one from them. The air operated valve is tempting tho! Tailgators? no problem! |