BSA B25 relief ball valve questions

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madsundaysurvivor
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BSA B25 relief ball valve questions

Post by madsundaysurvivor » Thu Feb 21, 2019 6:47 pm

Hello,

After E&V crankcase mods with the oil pump conduits, I'm testing the release ball valve.

My engine did not have the 5/16 ball and the spring. Then I brought it, but I have some doubts.

The first sprng that I brought is more wide in a side (surely to seat better the ball), but it is too much wider because don't pass through the plug, and the ball blocks in half race, and It doesn't allow open the conduit.

The second that I brought is in cylindrical shape, the same wire (0,7mm), and the same lenght (about 15mm) and works well through the plug.

I can not measure to what pressure opens the valve, I use a oil gun and block the pump hole with the finger and it seems to me that open with low press and I think that this valve will be almost always open.....
20190221_132606.jpg
20190221_132725.jpg
Someone knows the correct load for this spring in Kgf?
where can I buy good oem springs?

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ampshire-og
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Re: BSA B25 relief ball valve questions

Post by ampshire-og » Fri Feb 22, 2019 7:07 am

If I'm correct the spring with the enlargement one end is for the oil feed side of the timing cover not for the blow off pressure valve. A straight spring is correct. :thumb
From memory and without consulting BSA reference books I think the overall length of the straight spring should be 5/8" (16mm).
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madsundaysurvivor
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Re: BSA B25 relief ball valve questions

Post by madsundaysurvivor » Tue Feb 26, 2019 9:25 am

Thankyou ampshire,
Yes,the straight spring should be the correct according to the seller.
I have heard that the load of this ball valve is 40 or 50 psi, and without can mesasure it, only looking the spring I think that it will be about 10 or 20 psi as much

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