Home » Public Forums » GMCnet » [GMCnet] lock up torque converter.
| [GMCnet] lock up torque converter. [message #122762] |
Fri, 22 April 2011 12:09  |
Gary Worobec
Messages: 867
Registered: May 2005
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Would anyone know if our standard garden variety GMC torque converters are "lock up converters". I'm asking because of a table in the EBL/EFI system that may be retarding the spark a little bit because it thinks we have a lock up converter.
Thanks
Gary and Joanne Worobec
1973 GMC Glacier
Anza, CA
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| Re: [GMCnet] lock up torque converter. [message #122825 is a reply to message #122765] |
Fri, 22 April 2011 20:01  |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
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| jimk wrote on Fri, 22 April 2011 12:26 |
Gary,
Our standard units do not have the lock up converters.
The switch pitch tends to be like a lock up.
If your goingto be at Western States, you can discuss that with Manny T.
Jim Kanomata
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Gary,
With all due respect to Jim, the Switch Pitch does not have a lock-up converter. The SP trans has a solenoid in the trans that when activated, hydraulically shifts the veins in the converter to a more severe angle to provide for more torque to the trans when extra power is needed. This also causes more slippage and consequently more heat buildup. Manny has used the valving of the SP trans to activate a developed lock-up converter. When doing this the trans is no longer a SP trans, but rather a standard 425 three speed with lockup. Instead of using the SP trans valving for SP, it uses the valving for lockup. Manny stopped development when it appeared that production cost would get out of line for the little gained by a lock-up.
Talk with Manny, makes for an interesting conversation.
Larry 
78 Royale w/500 Caddy
Menomonie, WI.
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| Re: [GMCnet] lock up torque converter. [message #122831 is a reply to message #122825] |
Fri, 22 April 2011 20:59 |
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I was about to ask this question, what was going to make it so expensive to make it a lockup? it sounds like the setup used on early ford AOD transmissions which used a hydrolic locking system. a locking converter would be great for reduction of heat and increased efficientcy...
| Larry wrote on Fri, 22 April 2011 20:01 |
| jimk wrote on Fri, 22 April 2011 12:26 |
Gary,
Our standard units do not have the lock up converters.
The switch pitch tends to be like a lock up.
If your goingto be at Western States, you can discuss that with Manny T.
Jim Kanomata
|
Gary,
With all due respect to Jim, the Switch Pitch does not have a lock-up converter. The SP trans has a solenoid in the trans that when activated, hydraulically shifts the veins in the converter to a more severe angle to provide for more torque to the trans when extra power is needed. This also causes more slippage and consequently more heat buildup. Manny has used the valving of the SP trans to activate a developed lock-up converter. When doing this the trans is no longer a SP trans, but rather a standard 425 three speed with lockup. Instead of using the SP trans valving for SP, it uses the valving for lockup. Manny stopped development when it appeared that production cost would get out of line for the little gained by a lock-up.
Talk with Manny, makes for an interesting conversation.
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73 Canyon Lands, (a.k.a. The Yellow Submarine) West Los Angeles CA
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| Re: [GMCnet] lock up torque converter. [message #122838 is a reply to message #122831] |
Fri, 22 April 2011 22:04 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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I've been lead to believe that the veins of a switch pitch converter are less angled than the standard converter which would create less slipping than the regular converter when at cruise. In this case it may be possible to have more advanced timing tables when the sp converter is the higher torque mode. Of course there are probably not that many running EBL and switch pitch.
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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| Re: [GMCnet] lock up torque converter. [message #122842 is a reply to message #122831] |
Fri, 22 April 2011 22:18 |
Kosier
Messages: 834
Registered: February 2008
Karma: 1
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Shan,
Don Brown of the Great Lakers used a switch-pitch and had the
converter modified to tighten up both the high and low stall.
He uses high stall for starting off and also when in town. He
says low stall is so close to lock-up that the motor stutters at
low speeds in low stall. Unfortunately, I can't find the notes
from when he told me all the details years ago and he can't
remember the details now. I'd still like to try it, though.
Gary Kosier
77EII & 77PB
Newark, Ohio
----- Original Message -----
From: "Shan Rose" <defconfx@gmail.com>
To: <gmclist@temp.gmcnet.org>
Sent: Friday, April 22, 2011 9:59 PM
Subject: Re: [GMCnet] lock up torque converter.
>
>
> I was about to ask this question, what was going to make it so
> expensive to make it a lockup? it sounds like the setup used on
> early ford AOD transmissions which used a hydrolic locking
> system. a locking converter would be great for reduction of
> heat and increased efficientcy...
>
>
> Larry wrote on Fri, 22 April 2011 20:01
>> jimk wrote on Fri, 22 April 2011 12:26
>> > Gary,
>> > Our standard units do not have the lock up converters.
>> > The switch pitch tends to be like a lock up.
>> > If your goingto be at Western States, you can discuss that
>> > with Manny T.
>> >
>> > Jim Kanomata
>>
>> Gary,
>> With all due respect to Jim, the Switch Pitch does not have
>> a lock-up converter. The SP trans has a solenoid in the trans
>> that when activated, hydraulically shifts the veins in the
>> converter to a more severe angle to provide for more torque to
>> the trans when extra power is needed. This also causes more
>> slippage and consequently more heat buildup. Manny has used
>> the valving of the SP trans to activate a developed lock-up
>> converter. When doing this the trans is no longer a SP trans,
>> but rather a standard 425 three speed with lockup. Instead of
>> using the SP trans valving for SP, it uses the valving for
>> lockup. Manny stopped development when it appeared that
>> production cost would get out of line for the little gained by
>> a lock-up.
>>
>> Talk with Manny, makes for an interesting conversation.
>
>
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| Re: [GMCnet] lock up torque converter. [message #122845 is a reply to message #122831] |
Fri, 22 April 2011 22:34 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
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Shan,
I reckon the only person that can answer that would be Manny and he does not
monitor the GMC net.
He's like Dave Lenzi, he's too busy!
Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Shan Rose
Sent: Friday, April 22, 2011 8:59 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] lock up torque converter.
I was about to ask this question, what was going to make it so expensive to
make it a lockup? it sounds like the setup used on early ford AOD
transmissions which used a hydrolic locking system. a locking converter
would be great for reduction of heat and increased efficientcy...
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: [GMCnet] lock up torque converter. [message #122849 is a reply to message #122845] |
Fri, 22 April 2011 23:24 |
LarryInSanDiego
Messages: 336
Registered: September 2006
Karma: 0
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Most full size car SP applications used the 13" converter and mid size were 12". They were used in 2 and 3 speed transmissions. The 13" converter had lower stall speeds than the 12", but companies like Kennedy had other variations. I remember one 12" they had was 1800/3000 I was considering for a street/strip car app, but I don't recall the lowest 13" stalls.
I would choose the 13" for the GMC with as low a stall speed as possible. High stall would still let you accelerate better than a non-SP.
I wondered about the feasibility of lockup for the TH425. The 4L80/85LE uses it of course, which is basically an electronically controlled TH400/475/Allison 540 with OD and lockup (TH425 is essentially a TH400 with a chain spliced in the input shaft and one way clutches installed in reverse).
I never saw a side by side of relevant parts, but I wonder what else would need to be changed...
Larry Engelbrecht
San Diego, CA
'73 26' ex-Glacier
TZE063V100319 03/07/73
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| Re: [GMCnet] lock up torque converter. [message #122854 is a reply to message #122762] |
Sat, 23 April 2011 01:28 |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma: 11
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| Gary Worobec wrote on Fri, 22 April 2011 10:09 |
Would anyone know if our standard garden variety GMC torque converters are "lock up converters". I'm asking because of a table in the EBL/EFI system that may be retarding the spark a little bit because it thinks we have a lock up converter.
Thanks
Gary and Joanne Worobec
1973 GMC Glacier
|
I had heard that Manny had used a switch-pitch case and put a lockup in it but did not like the way it handled in the GMC. Part of the trouble even with switch-pitch is that you have to pay attention. I could see him building one for someone and then them being all unhappy when they locked it too soon or forgot to unlock it and it caused trouble.
With EBL, all the safety features of modern cars could be put in place. As Gary noted, EBL wants to lock up the converter when certain criteria are met and slip otherwise. I, like Gary, would like to try it.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
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| Re: [GMCnet] lock up torque converter. [message #122871 is a reply to message #122762] |
Sat, 23 April 2011 09:15 |
Gary Casey
Messages: 448
Registered: September 2009
Karma: 0
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Senior Member |
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Adapting a lock-up converter to the GMC would certainly be a good thing, and
there is room to do it, As we did several of these back in the early 70's at
GM. But, I don't think the THM 400 ever had a production system built, so
unless someone has a good deal of money a converter from something else would
have to be adapted. The method we originally used to apply the clutch was to
reverse the direction of the converter charging/cooling flow, but using the
variable pitch front pump would allow a third fluid passage to be used. A
possible way to control it might be to just turn it on above a certain speed. I
suspect a lock-up clutch could improve fuel economy as much as 5%, so one would
have to ask if it was worth it.
Gary Casey
From: "Rob Mueller"Shan,
I reckon the only person that can answer that would be Manny and he does not
monitor the GMC net.
He's like Dave Lenzi, he's too busy!
Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
I was about to ask this question, what was going to make it so expensive to
make it a lockup? it sounds like the setup used on early ford AOD
transmissions which used a hydrolic locking system. a locking converter
would be great for reduction of heat and increased efficientcy...
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http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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