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More power from a Dynaflow??


1955super

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I'm finally at the point where my transmission is out of my car, and the rebuild starts this week. I ran across this on another Buick forum. Anyone ever heard of such? Does it sound like a good idea?

"It's an old hop up trick that makes the Dynaflow perform better, by increasing the high accumulator's LONG spring pressure.......To increase the power and decrease slippage in the trans... I did it on my old 55 and the results were pretty sweet.

Procedure is as follows: Firstly ensure the trans is in good condition, bands correctly tightened - Find the High accumulator - Remove the original spring (long one) and replaced it with 1982 Chevy 2.5 oil pump spring (available in Chevy oil pump rebuild kit). The accumulator does not have to be taken off the car...

Improves power transfer through the trans and helps get these big ol' barges hustling"

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Giving the Buick Dynaflow trans more punch

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I'll bet all those engineers and tranny designers at Buick are all slapping themselves in the foreheads and saying " A bigger spring!!!!!!!!!!!!!!!!! Why didn't we think of that????????? "...........Bob

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I saw that same article, and could not find the kit with the spring. Looked for the cheapest priced pump, bought the whole thing. Carefully took it apart, and there was no way I could see that spring working. It was way too short and the wrong diameter. Reassembled the pump and mailed it back.

Maybe I had the wrong one. If you find the spring and try it post the part number and the results. Be curious if it works. Also, when you look at the hydraulic circuit for the dynaflow, seemed to me that the condition of the steel clutches with good pump pressure would do more to reduce takeoff slip than a change in the high accumulator spring rate, but I'm no expert.

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I'm finally at the point where my transmission is out of my car, and the rebuild starts this week. I ran across this on another Buick forum. Anyone ever heard of such? Does it sound like a good idea?

"It's an old hop up trick that makes the Dynaflow perform better, by increasing the high accumulator's LONG spring pressure.......To increase the power and decrease slippage in the trans... I did it on my old 55 and the results were pretty sweet.

Procedure is as follows: Firstly ensure the trans is in good condition, bands correctly tightened - Find the High accumulator - Remove the original spring (long one) and replaced it with 1982 Chevy 2.5 oil pump spring (available in Chevy oil pump rebuild kit). The accumulator does not have to be taken off the car...

Improves power transfer through the trans and helps get these big ol' barges hustling"

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Giving the Buick Dynaflow trans more punch

That will have no effect on performance. The accumulator is a cushioning device to alleviate harsh engagement of the the clutches. Page 156 of your shop manual gives a good description of the operation.

Willie

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Yes, "accumulators" are there to cushion "apply" pressure pulses in the trans fluid circuit. A stiffer spring will make "less cushion". If you want to eat up some more horsepower, but have possibly better efficiency (or clamping force for the bands), then slightly raise the basic line pressure. That might make those accumulators work a little harder, too!

The main "efficiency" issue in a transmission is the "torque converting device". That, plus "friction and power absorption" inside the trans, are the main determiners of how much power gets to the driveshaft from the engine. Plus how "stout" the guts of the trans might be with respect to the power of the engine.

Just some thoughts . . .

NTX5467

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I wonder if you could perk up a dynaflow from 55 by making an adjustment to the stator linkage.

I am somewhat embarassed to say this but I just discovered that this is indeed adjustable, and has been negatively impacting my 56 for close to 25 years.

My 56 was originally equiped with a Carter carb. Due to youthful impatience ( back in 1975 or 6 ) I swapped the Super's engine for the 70K engine from my rusted to death 56 Roadmaster. That engine ran great and had the Rochester carb. I did not adjust or even look at the linkage however. Now, after this latest carb rebuild, I discovered that the linkage was actuating the stator linkage so early that at best the secondaries would only open 1/3 of their distance. ( I also found that the secondaries linkage on the carb was disconnected, so they didn't open at all regardless of the linkage misadjustment. )

But thats only part of the story. The main point is; even though I was essentially running the car as a two barrel, you could feel the pickup when the stator was actuated. So I wonder if it's possible to adjust the stator to it's power position earlier in the accereration process, and thereby improve on the general pickup off the line and in passing?

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Guest Koala

Yes, I explored the operation of the stator control on my 56 and with a bit of fiddling managed to liven up the power delivery. The main problem with mine was that the external linkage looked to be adjusted and working mechanically correctly but the car was still like a slug. After removing the valve on the side of the transmission I discovered that the internal linkage was loose and was not pushing the spool much at all. After tightening things up, adjusting and removing the wear in the linkage the car came to life. It is faster off the line and the transmission is more active especially when overtaking on the highway.

Don't know if it is recommended to do this but the quickest way off the line in my 56 is to select low and floor the accelerator and hold it there to about 35mph then ease off a little and the trans will feel like it changes gear into a higher range but keep accelerating. :):)Then shift the lever into D and floor the accelerator again untill you are not brave enough to go any faster. :D

Koala

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John

There is a screw and lock-nut in the linkage on the back side of the drivers side head that is used to adjust the stator control apply time. I have one of my 55's adjusted so that the stator control is actuated at 1/2 throttle...the others at near full throttle. It is still a kind of wimpy passing gear. I have been known to use the technique outlined by Koala.:D

Willie

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I have been known to use the technique outlined by Koala.:D

Willie

[NOW, the "secret" is out?]

Sounds kind of like adding a little more "preload" into a kick-down linkage adjustment to elevate basic shift points a little, for better performance with less throttle needed. Or to get part-throttle kickdown a little earlier.

Enjoy!

NTX5467

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John

There is a screw and lock-nut in the linkage on the back side of the drivers side head that is used to adjust the stator control apply time. I have one of my 55's adjusted so that the stator control is actuated at 1/2 throttle...the others at near full throttle. It is still a kind of wimpy passing gear. I have been known to use the technique outlined by Koala.:D

Willie

In the process of doing the initial adjustments to my throttle linkage I found that that screw you mentioned was set around that level Willie. This stopped my secondaries from opening more than 1/3rd of the way. I have it set now so that the stator linkage is all in at WOT, but I have not had much chance to get the car out on the open road yet. Bad weather week in my area.

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  • 1 year later...
Great info in this thread. I will be adjusting mine this weekend. I don't have my manual on me at the moment - does it outline this adjustment in detail? Is there a sweet spot I should be aiming for?

No 'detail' is needed...just find the rod that goes to the stator control on the tranny and be sure it is hooked up at both ends. There is an adjustable bolt with a lock nut in the linkage behind and above the left cylinder head. Just observe what and when opening the throttle does to the stator control rod, adjust as needed and road test.

Willie

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In high school I hooked my 55 stator lever up to a solenoid with an on/off switch. (Stop sign racing) We would race from stop sign to stop sign. (You had to stop!) It worked great; the thing would launch real good. I won a couple. I would have done better if I could stop the dang thing!

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Just a side note here: The '55 only shifted the stator angle in Drive, the '56 would switch pitch in low and reverse also..

Interesting...............how is that achieved John? If the operation of the stator lever is mechanical and actuated from the throttle linkages how is it disabled in Low?

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Interesting...............how is that achieved John? If the operation of the stator lever is mechanical and actuated from the throttle linkages how is it disabled in Low?

The high accumulator lever is not linked to the torque converter, it is a hydraulic control. The valve body is the control center of the trans. The 56 has a different valve body.

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It appears my post may be misleading about shifting the stator. My 55 shop manual states that the stator is normally in low angle for cruise when at normal throttle positions and is shifted to high angle at full throttle for acceleration WHEN IN DRIVE. When in Low or reverse, the stator angle is at high angle at ALL THROTTLE POSITIONS.

I still believe it to be true that the '56 is different but I don't have a 56 manual to confirm exactly what is different. It may be that the 56 allows low angle in Low and Reverse but shifts to high angle at full throttle. That would explain Koala's post about easing up in Low and feeling the stator shift. I need to do some more research on that.

PS I tried uploading a pdf file from my shop manual but the uploader will not show the file after going thru the motions, something wrong with the website's uploader?? When I switched off Enhanced Uploader, it simply broke connection and showed as IE lost connection when I clicked on upload.

Edited by TexasJohn55 (see edit history)
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The tip in the first post doesn't seem logical when you consider how bands work with a planetary gear set. But, like the Hudson guy said when I told him he didn't need an engine rebuild "I don't care what you say, I'm not going to let you talk any sense into me!".

Bernie

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The tip in the first post doesn't seem logical when you consider how bands work with a planetary gear set. But, like the Hudson guy said when I told him he didn't need an engine rebuild "I don't care what you say, I'm not going to let you talk any sense into me!".

Bernie

The only way a stiffer spring 'might' work would be to engage the clutches slightly sooner and firmer in a shift from L to D...the way you did it in stop light drag racing.

John is right about the stator 55 vs 56. I used to regularly spank 54 and 55 big series cars with my 55 Special. Then I got waxed by a big ol' 56 Super.

Willie

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