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727 Over Heating Problem?
#1293752
08/29/12 02:58 PM
08/29/12 02:58 PM
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Joined: Jan 2005
Posts: 3,635
Oakland, MI
dizuster
OP
master
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OP
master
Joined: Jan 2005
Posts: 3,635
Oakland, MI
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Hey Guys…
Well now that I have my coolant overheating issue solved, now I'm on to the trans overheating issue. The combo has a lot going against it for cooling, but I'm still sort of stumped why this would happen.
Cruising down the road with decent air movement, the trans will get up to about 220 degree's. Anything with stop and go, will cause the trans to climb (I've had it up to 270, but I stopped at that point).
What's strange is that the few times I've been on the throttle hard, right when I slow down the trans will drop from 220 down to around ~195 or so. I would have thought that the temp would have gone up, but maybe the inrush of air and the higher fluid movement (from more RPM) actually cooled it? Very strange…
I get that it's got a 1/2 way loose converter, a trans blanket, and a 3.23 gear… but I am surprised that it overheats so badly. I can't be the only 3500 stall, 3.23 car running around. Maybe the blanket just puts it over the edge?
Anyway… combo is as follows… any help or ideas would be greatly appreciated.
Scott
-Push Button 727
-Tranzact Nitro Trans Brake (low band apply, reverse manual)
-9.5" PTC converter Stall is tough to tell, but seems to be around 32~3500 off boost, and flashes to about 5000rpm spooled up.
-Trans Blanket (not helping)
-3.23 gear w/ 255/60 radials (~27" tall)
-Deep Mopar Stamped Steel Pan
-Sending unit in the side of the pan
-13" x 13" "10 pass" trans cooler mounted on the front side of the radiator
-3/8" steel trans lines, with a few inches of rubber at each end.
-Wolfshead Synthetic Trans Fluid
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Re: 727 Over Heating Problem?
[Re: Moparnut426]
#1293755
08/29/12 04:28 PM
08/29/12 04:28 PM
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Joined: Dec 2006
Posts: 3,533
Indiana
Fury Fan
master
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master
Joined: Dec 2006
Posts: 3,533
Indiana
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Quote:
Ive seen a derby car with just ice in the cool can stay alive in a 100 degree hot day here in nebraska and here in nebraska the derby guys are not nice.
I do agree the coolcan idea would help but a derbycar is a whole different animal.
Most derby guys I've seen are running stock converters, which generate less heat than a high-stall. Derby guys are also usually running on dirt, so the wheelspin allows turbine and pump to get closer to speed-matched, which is when the least amount of heat is generated.
OP - if you're running 220+, I think tapping back into the radiator cooler would help a lot. Cheap and easy enough to try, anyway.
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Re: 727 Over Heating Problem?
[Re: Fury Fan]
#1293756
08/29/12 07:22 PM
08/29/12 07:22 PM
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Joined: Mar 2007
Posts: 12,013
Finally a HUSKER again
Moparnut426
I Live Here
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I Live Here
Joined: Mar 2007
Posts: 12,013
Finally a HUSKER again
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Quote:
Quote:
Ive seen a derby car with just ice in the cool can stay alive in a 100 degree hot day here in nebraska and here in nebraska the derby guys are not nice.
I do agree the coolcan idea would help but a derbycar is a whole different animal.
Most derby guys I've seen are running stock converters, which generate less heat than a high-stall. Derby guys are also usually running on dirt, so the wheelspin allows turbine and pump to get closer to speed-matched, which is when the least amount of heat is generated.
OP - if you're running 220+, I think tapping back into the radiator cooler would help a lot. Cheap and easy enough to try, anyway.
that is true about the wheel speed, and stock converter. I can see less heat generated there, but when the engine is 260 degrees, all that heat goes back to the tranny, and the temps get high.
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Re: 727 Over Heating Problem?
[Re: dizuster]
#1293759
08/30/12 09:40 AM
08/30/12 09:40 AM
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Joined: Jan 2003
Posts: 75,125
A Banana Republic near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,125
A Banana Republic near you.
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Quote:
I have an 8 x 10 cooler that was on it, so I think I'll try to add it as a second cooler under the car (out of room up front). My Dad has a small fan that I can try on it too to keep it cooler.
I called PTC and Tranzact today...
PTC thought it was strange the converter was overheating, but the loose converter with no gear isn't a great combo, and the trans blanket isn't helping.
Tranzact told me the same thing, and said that they weren't sure if more cooler would really even help it much. They actually suggested crusing the car in 2nd just to get the converter closer to lock up while driving down the road.
Neither sounded like the "explination" I was hoping for. Just speculation more then anything on either of their parts I think.
Are you still running the cooler circuit thru the radiator ?
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Re: 727 Over Heating Problem?
[Re: mopartoby]
#1293760
08/30/12 09:41 AM
08/30/12 09:41 AM
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Joined: Mar 2007
Posts: 12,013
Finally a HUSKER again
Moparnut426
I Live Here
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I Live Here
Joined: Mar 2007
Posts: 12,013
Finally a HUSKER again
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Quote:
Does derale still make a 727 pan? The one with tubes welded through it? I had one on my dart along with an external cooler and it never broke 185*
They still make it, and I almost bought it for my Ramcharger, but settled on the B&M pan.
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Re: 727 Over Heating Problem?
[Re: dizuster]
#1293762
08/31/12 12:28 PM
08/31/12 12:28 PM
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Joined: Jan 2003
Posts: 75,125
A Banana Republic near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,125
A Banana Republic near you.
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Quote:
No it's got a Griffin aluminum, so it's only using the aftermarket cooler for the trans.
You don't have enough cooling capacity with just the aftermarket cooler if the car is street driven
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Re: 727 Over Heating Problem?
[Re: JohnRR]
#1293763
09/01/12 11:05 AM
09/01/12 11:05 AM
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Joined: Jan 2006
Posts: 166
MINNESOTA
BRONZEBEE
member
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member
Joined: Jan 2006
Posts: 166
MINNESOTA
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The converter is too loose for 3:23's.You will overheat the fluid with the that converter or that gear ratio. With that set up you are causing a lot of turbulence in the converter and it is churning the fluid. I believe your stall range should be closer your cruising rpm so the converter isn't working against itself.The more you drive it down the hwy at 55 the worse it gets?Drop it down to 2nd gear and see if the fluid temp comes down. If your stall is 3500 rpm you should be closer to 3500 rpm cruising speed . 
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Re: 727 Over Heating Problem?
[Re: dizuster]
#1293765
09/01/12 12:59 PM
09/01/12 12:59 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
cruising it in 2nd is exactly what tranzact suggested too. I'll try it today when I go to grab the car from Mr p
I can't tighten up the converter any, or it won't spoil the turbo.
Just gonna need a massive cooler... maybe a fan on it....
I need to do the same thing... I'm gonna put 2 in
series... the one in front then the other under the
bed area with a fan and a air scoop to direct air
up into it
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Re: 727 Over Heating Problem?
[Re: MR_P_BODY]
#1293766
09/01/12 09:16 PM
09/01/12 09:16 PM
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Joined: Nov 2004
Posts: 4,330
Lynchburg, VA
Leon441
master
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master
Joined: Nov 2004
Posts: 4,330
Lynchburg, VA
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I know plenty of people who run a converter like that with a 3.23 gear. But, they have short tires. I do know one who runs 33's but, has a 2600 lb car.
DO NOT WAD UP YOUR BLANKET TO CLEAR THE PAN. The blanket is no where near as beneficial if it is not strapped tight. The safety guys frown on this. I did have to run a brace around the shifter cable to run the blanket tight. Blankets are bad for making heat. An aluminum sheild would be best for cooling but I would think a CSR may work also sense it simply has a strap around the pan.
You probably need a better cooler. I finally went with a very large B&M style cooler. Had trouble with people taking to long to stage with me on the brake causing some overheated transmisions.
Leon
Career best 8.02 @ 169 at 3050# and 10" tires small block power.
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Re: 727 Over Heating Problem?
[Re: Leon441]
#1293767
09/01/12 09:27 PM
09/01/12 09:27 PM
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Joined: Oct 2006
Posts: 4,590
Indy
joshking440
Lunch is on me!
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Lunch is on me!
Joined: Oct 2006
Posts: 4,590
Indy
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dizuster.... my car with 3:55s a looser convertor than yours and 30" tall tires had no problems at all with temp..... even when I would spool it against the foot brake on the street dickin around numerous times and then go cruising at 30-60 mph, never once did it get out of shape.
dont blame the combo, I think its something else
Last edited by joshking440; 09/01/12 09:28 PM.
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Re: 727 Over Heating Problem?
[Re: Leon441]
#1293768
09/01/12 09:28 PM
09/01/12 09:28 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Scott came over and picked up his car after I put a 8 point bar in it.... I was out looking in my pole barn for something and I came across some inner coolers and I offered Scott 1... maybe 2... I want to put 2 of them on my car... in series .. they are some what small... about 14" long, 6" tall and 3" deep... I would guess they might hold 2 qts each... I would have to weld on different inlets and outlets(necked down to 3/8")
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Re: 727 Over Heating Problem?
[Re: joshking440]
#1293770
09/01/12 10:00 PM
09/01/12 10:00 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
buy a b&m super cooler and put a fan on it.....
I've got one but no fan...its up front but in my case
I dont have ANY air flow across the trans... unless
I put a small scoop at the front of the trans... I
was gonna put both inner coolers at the back and maybe
a fan on them
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Re: 727 Over Heating Problem?
[Re: JohnRR]
#1293771
09/02/12 06:19 AM
09/02/12 06:19 AM
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Joined: Jan 2003
Posts: 2,937
A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,937
A shed in England
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Quote:
Are you still running the cooler circuit thru the radiator ?
This helped on mine for street duty, also helps to keep trans temp more consistant and stable. Good for bracket racing
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
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