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jlaird

jlaird

Great Pumpkin
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Oil high pressure pop off valves.

I put a new spring, Moss, in Miss Agatha when I did the rebuild, however I only have 50 lbs of press when cold and 40 when hot. Now I know that is with in limits...........

I looked in my box of stuff and have a home made adjustable tensoner for the spring and several different spring lengths.

What is the length of this spring supose to be?

Now to the seat, I have several of the plungers that go on the end of the spring as well that I could try. Hopeing for a better fit?

Lets talk, this is a bit out of my experience area I am afraid.
 
Jack,

Racers usually use a means of adjusting the oil pressure. The general rule seems to be ten psi per thousand rpm.

Go to Spridgetmania and search for part # C-SRP001 for a fancy cap with an adjustable screw that lets one vary the spring tension. You can even make the adjustment with the engine running if you want. This item, though pricey, also comes with a new spring.

As I'm sure you can imagine, this kind of set up can easily be made at home if one desires. Reading your message, it sounds like you may have one of these already.

Spridgetmania also has the seat for the plunger if you decide you need one. See part # 2A797. The bad thing here is the engine would likely have to come out and make a trip to a machine shop to do the removal and installation.

Tim

PS: Another way to raise the oil pressure is add a shim between the spring and the cap. It takes some time as you may have to make a couple of attempts to get what you want but for a one time shot, it is cheap and effective.
 
The seat will pop out pretty easily if the inner hole is threaded (5/16"?) and a bolt is used as a puller, the obvious problem with this is the shavings in the engine so it is better not done.
Another avenue to explore is to replace the plunger at the end of the spring with a ball bearing (1/2"?). The ball will press against a different area of the seat which isn't currently worn and will seal very well- as well as release properly. This is a common trick done in Mini's in the 70's and probably still.
Bill
 
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