Power Steering Flow Control Valve used in GM type 1 pump. - sizing info necessary

[mcwho]

I have a factory build engine with a GM type power steering pump. To alleviate the high pressure these pumps produce I decided to install a Heidts valve.

I have only driven 40 miles as I am getting ready for paint.

I have had a complete front/rear align and 4 corner balancing.

The steering is still very light and I thought I would look into a Flow control Valve replacement, because I have the Heidts turned out as far as I feel safe (4 turns) from the end.

I removed the Flow control vlve that was in the PS unit and it seems to be the same as the two replacements that I have acquired.

there are two holes on the valves and I wonder if anyone KNOWS which one is the actual flow control.

The two valves on the left are ones I have acquired.

The one on the right is what was in the PS pump.

hole "A" seems to be the size of a 1/16 drill shank, hole "B" seems to be 7/64 in all three.

I am wondering if anyone has dealt with this knows actually knows which hole changes size as the flow is increased or decreased.

[totem]

On KRC valves, it is the venturi diameter that change with flow rating. The venturi is inline in the valve at the level of hole "A" on your image. It is not the hole seen on your image. The venturi diameter is the inside diameter when you look at the end of the valve.

Stock flow KRC 253080000 valve is 0.125" diameter for a flow of 2.91 GPM.
KRC #4 253040000 valve is 0.062" diameter for a flow of 1.66 GPM.

I don't know how you can reduce the inner diameter of the valve. Press fit a plug and drill through?

I suspect that cutting the spring might have a similar effect, reducing both flow and pressure.

[mcwho]

Totem,

You are absolutely correct, the one that was in the pump is a drill shank size of .012 (1/8) is the largest I have

the next one is in the middle is the smallest

the one on the left is somewhere between the other two.

I was reading somewhere on a KRC description and they said a #6 was the correct ofr a ford mustang rack on a GM type 1 pump.

I was thinking of ordering the KRC 4,5,6, 7 set because they are marked, but for now I think I'll put my smallest one in for now.

only my center valve is marked and it says "1P"

thanks for your help, I didn't really want to cut the spring.

Bob

Do yu happen to know the venture size for a KRC #6 ?

[totem]

Totem,

Do yu happen to know the venture size for a KRC #6 ?

No, sorry. Following advice on this forum, I bought KRC #4. Note that on a lightweight Cobra, you might want less flow than a typical recommanded Ford setup.

I'm not certain that KRC valves fits non-KRC pumps. You'll have to do research.

Using your smallest valve is a good start.

[DaleG]

Talk to the folks at Vintage Air; they helped me select the one that finally worked with my GM pump: http://www.vintageair.com/2017%20Catalog/2017%20Vintage%20Air%20Catalog%2065.pdf

[mcwho]

I have the valve like the one from vintage air and also one from speedway. they both have an 0-ring fitting on the side that connects to the -an6 adaptor. The one I took out of the pump had a inverted flare so I need a 0-ring to inverted flare ferrule too. There are 2 solutions. Both flow valves came with o-ring type fittings, not the inverted flare as with the one I took out.

1. a o-ring to inverted flare adaptor, see link

http://www.speedwaymotors.com/O-Ring-to-Inverted-Flare-Power-Steering-Adapter,24682.html

or

2. a adaptor fitting

http://www.speedwaymotors.com/Steel-Power-Steering-Box-Adapter-Fitting-16mm-1-5-IFM-6-AN-80-Up-GM,37128.html

Got one of each on order, hope one works

[mcwho]

The KRC Valves will NOT work in my GM/Saginaw type early pump, the threads are not long enough to engage.

see pic

69088