Sourcing TV Limit Spring

[77 cruiser]

If you have a chance, measure the valves from say a KC & BR that is the main difference I think.
I did that with 4 or different VB's have them wrote down I'll have to dig it up now that we're on that topic.

 

[INEEDAGN]

Oh boy. Should we start a database thread with fully documented vb's? I have a KC in the shelf and a cq on the bench right now. Only problem is that this shits all 30 years old. And finding a 30 year old trans that no ones ever been fooling around in is like finding a 30 year old woman of the same criteria. "If no ones been in it, it's probably not a very desirable one in the first place".

 

[RmvBfrFlght]

OK, so the spring is nearly 100% part throttle shift RPM. This does make sense, I studied the valve line ups again and see that detent oil is also fed in. This oil is from the WOT position of the TV plunger, so this is how the WOT shift point is set.

With the valve(s) having governor oil on one end and detent oil on the other, the valves/bushing dimensions set the WOT shift points.

I can see that to increase the shift point, need to increase the surface area of the valve affected by detent oil. Which it appears to be able to be done by reducing the stem diameter which makes the flange area larger. Or, use a larger ID bushing with a larger diameter flange on the valve.

Jim, the measurements of the 1-2 and 2-3 shift valves would tell us something. I wish I had the BQ3 VB on the bench rather then in the car. I'd pull those two valve line ups and measure them. But as the guy who needs a GN posted, who knows if the BQ valves are still in it. The case is an AA and am fairly sure that an AA TV plunger spring was in this VB when I pulled it from the car.

RemoveBeforeFlight

 

[larrym]

OK, so the spring is nearly 100% part throttle shift RPM. This does make sense, I studied the valve line ups again and see that detent oil is also fed in. This oil is from the WOT position of the TV plunger, so this is how the WOT shift point is set.

With the valve(s) having governor oil on one end and detent oil on the other, the valves/bushing dimensions set the WOT shift points.

I can see that to increase the shift point, need to increase the surface area of the valve affected by detent oil. Which it appears to be able to be done by reducing the stem diameter which makes the flange area larger. Or, use a larger ID bushing with a larger diameter flange on the valve.

Jim, the measurements of the 1-2 and 2-3 shift valves would tell us something. I wish I had the BQ3 VB on the bench rather then in the car. I'd pull those two valve line ups and measure them. But as the guy who needs a GN posted, who knows if the BQ valves are still in it. The case is an AA and am fairly sure that an AA TV plunger spring was in this VB when I pulled it from the car.

RemoveBeforeFlight

Hmmm I wondered about this when I was playing with my valve body, I had a stock 305 olds valve body I was pulling things out looking for springs trying to get the shift points closer together, the springs changes affected the part throttle shifts .
If I recall correctly the shift valve was larger and would not fit in the BRF sleeve. so if I had installed that sleeve and valve I would have raised the WOT shift point on that circuit?

 

[RmvBfrFlght]

Hmmm I wondered about this when I was playing with my valve body, I had a stock 305 olds valve body I was pulling things out looking for springs trying to get the shift points closer together, the springs changes affected the part throttle shifts .
If I recall correctly the shift valve was larger and would not fit in the BRF sleeve. so if I had installed that sleeve and valve I would have raised the WOT shift point on that circuit?

If this is the 2-3 shift valve line up, likely yes, a higher RPM shift point with the larger 2-3 TV valve. This does depend upon what area of the TV valve was larger.

RemoveBeforeFlight

 

[BEATAV8]

OK, so the spring is nearly 100% part throttle shift RPM. This does make sense, I studied the valve line ups again and see that detent oil is also fed in. This oil is from the WOT position of the TV plunger, so this is how the WOT shift point is set.

With the valve(s) having governor oil on one end and detent oil on the other, the valves/bushing dimensions set the WOT shift points.

I can see that to increase the shift point, need to increase the surface area of the valve affected by detent oil. Which it appears to be able to be done by reducing the stem diameter which makes the flange area larger. Or, use a larger ID bushing with a larger diameter flange on the valve.

Jim, the measurements of the 1-2 and 2-3 shift valves would tell us something. I wish I had the BQ3 VB on the bench rather then in the car. I'd pull those two valve line ups and measure them. But as the guy who needs a GN posted, who knows if the BQ valves are still in it. The case is an AA and am fairly sure that an AA TV plunger spring was in this VB when I pulled it from the car.

RemoveBeforeFlight

I suspect that you are right on the money.

 

[chris718]

The thing to remember here is that the tv plunger is fed whatever the tv limit valve regulates line to.This is a fixed rate and usually @ 80 to 90 psi, regardless of line pressure,whether it is 75 or 300. The plunger /tv valve combo then regulates this pressure from 0 to 80 or 90 .Zero being closed throttle, 80 or 90 being wot. It is the full understanding of this concept that will allow one to gain the knowledge necessary to master the countless calibration changes that can be put into play thru fine tuning.

 

[INEEDAGN]

Hey Chris!!

Not hatin, but I put a couple calls in to you this week and haven't heard back from you. I want to spend some money with you lol. I Fully understand that you are probably busy and it's easier to field all your calls at once vs walking from the bench multiple times a day. Call me any hour.

Bob Koch.

 

[BEATAV8]

Haha I'll throw in a plug for Chris! I called this week just for tech and he called me back in about a 1/2 hour. Very much appreciated, thanks Chris!

 

[BEATAV8]

I have a KC vb on the bench and a BR vb that I can remove from a trans I have on the floor. If I can find time to take the BR out this weekend I'll start measuring....

some good info here:
http://www.atraonline.com/gears/1999/1999-07/gjul99p16.htm

 

[INEEDAGN]

I'm tearing into a br as soon as I get this budget bomb cq off my bench. I can measure it all.

The br is the reason I want to talk to Chris.

 

[77 cruiser]

OK been working on putting the VB measurements together. So study it till your eyes hurt.
For some reason I couldn't upload the files, I'm working on it. Maybe I can email them to some one.

 

[77 cruiser]

OK been working on putting the VB measurements together. So study it till your eyes hurt.
For some reason I couldn't upload the files, I'm working on it. Maybe I can email them to some one.

 

[larrym]

Thank you!

 

[INEEDAGN]

I'll add a bunch of data when I get caught up with life. We'll probably want to start a thread or a sticky with this. Might note if it's a kc4 kc5 etc cause there ARE differences between them. Now I wish I'd done the NOS KC vb I had before I sold it to Husek.

10 years from now we might be glad to have finally started on this.

 

[77 cruiser]

KC2

 

[RmvBfrFlght]

OK been working on putting the VB measurements together. So study it till your eyes hurt.

Thank you '77, lots of info to digest. Just glancing through it there are interesting differences.

RemoveBeforeFlight

 

[77 cruiser]

The only VB that for sure had anything done to it was the OG that's why I didn't have specs for some of the springs.
I got lucky one time & found the rest on Ebay, except the KC. So I can't be sure if they are untouched.

 

[INEEDAGN]

ill be adding another cq shortly and then another KC and eventually a br (or 2) in the coming weeks. also have a ct, cr, 2 bq's, and cz but they're inside whole cores

 

[INEEDAGN]

Might as well make the most of being home with an ill child