| Author |
Message |
Michael J Ryan (Mjryan) (67.41.243.42)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 22, 2003 - 6:00 pm: | |
I bought a 1978 AM General with a 8v71 turbo and a Allison V-730 automatic transmission to use as a heart transplant for my 4104. You can see it on eBay on BNO under my new ride. I understand most of what I got but what is a lockup converter?
Michael4104-4008 |
Bill Gerrie (216.185.73.251)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 22, 2003 - 6:37 pm: | |
Michael
When you first take off with the V730 it is using the torque convertor to allow slippage because you do not have a manual clutch. It is a series of vanes with oil between them and the faster the one set of vanes that are driven by the engine turn the vanes that are coupled to the tranny start to turn because of the oil between them. As you get going faster the tranny senses the speed and there is a clutch that locks the engine to the tranny so there is no slippage. In the V730 the sequence of operation is as follows;
torque convertor and 1st gear;
torque convertor and 2nd gear;
lock up and 2nd gear;
lock up and 3rd gear.
It is like having 4 gears forward but the V730 really only has 3 gears. If the lock up clutch doesn't let go when you are slowing down to about 5 mph the engine will actually stall just like you had a manual tranny. This is rather a simpfied explanation but it is basiclly how it works. The 8V71T and the V730 will make a powerful engine package. Becarful you don't jack up the HP on the engine as the V730 is limited to a net 275 HP on the input to it. That is after you deduct 20 HP for the fan, some for the generator and everything else that turns and requires power to drive. I'm not sure what size injectors you could use but maybe somebody else can answer that. You would hate to ruin the tranny due to too much power. Bill |
Geoff (Geoff) (66.238.120.231)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 22, 2003 - 6:49 pm: | |
A lot of us run 350 HP 6V92TA's with the V730 and have never had a problem with the extra horsepower.
--Geoff
'82 RTS CA |
BrianMCI96A3 (65.40.145.6)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 22, 2003 - 8:53 pm: | |
Lock-up converters in automatic transmissions give the advantage of direct engine lockup through the otherwise fluid-coupled transmission.
The advantage of a lock-up converter is increased fuel economy and decreased heat at cruising speeds.
Inside of a torque converter are two opposing turbines, in operation it works somewhat like sticking a pinwheel in front of a room fan.
Start the engine and the turbine attached to the engine (the room fan) drives the turbine attached to the tranny (the pinwheel) by "blowing" tranny fluid over the vanes of the turbine on the tranny.
Because of this function, NON-lockup converters will have some slippage at all times. This causes a loss of some fuel effiency and approximately 5% of top speed for any given platform vs a manual tranny.
Lockup converters eliminate these losses... as cruising speed is reached and sensed by the tranny, a clutch will physically couple the engine to the transmission. As a side benefit, when locked, such a converter will generate less heat inside the transmission.
Brian |
Richard Bowyer (Drivingmisslazy) (24.196.191.70)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 22, 2003 - 8:58 pm: | |
Sounds like the fluid drives of some of the 40's and 50's autos, without the lockups.
Richard |
Michael J Ryan (Mjryan) (67.41.243.42)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 22, 2003 - 9:44 pm: | |
Does this help in engine braking, like going down a hill or slowing down for a stop. Does down shifting work in these conditions?
Michael |
Jim Stacy (12.75.53.185)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 22, 2003 - 9:56 pm: | |
The torque converter will stay locked up when slowing, even down into 1st gear. Before you come to a complete stop it will unlock. It works fine with a Jake brake. I too am running 350 hp in a V730. Over 60,000 miles pulling a toad over the 48 and to Alaska with no problems.
Jim Stacy |