Question - C59A Oil Pressure Relief in Lifter Valley

[Ziggster]

Did a little checking on the two pressure relief springs. I’m sure one is from the spare pump I had which I believe was a aftermarket piece. They are almost identical except for the following:

Overall length:

Orig - 2.204”
Aftermarket - 2.253”

Number of turns:

Orig - 16
Aftermarket - 16

Wire Dia:

Orig - 0.046”
Aftermarket - 0.044”

Force to open (compressed to 1.940”):

Orig - 3lb - 15 oz
Aftermarket - 4lb - 1 oz

Plunger head style:

Orig - bullnose with flat on chamfered edge
Aftermarket - pointed with no flat on chamfered edge

So, what this is telling me is that both springs are essentially the same (the one in the sump pump and the one in the oil gallery) and should “open” at the same pressure, but the one in the oil gallery is constantly bleeding off a bit of oil to feed the front timing gear area incl oil for the orig style water pumps. Now, Mac says (link below) the orig oil sump pump (32 - 48) did not have a built in pressure relief valve, but sump pumps built after that did. So, the “orig” sump pump I have is a later version, and likely has the 80 psi max pressure rating. I’ve now buttoned up the lower end of the engine, so I can’t check to see if the spring in there is the same as the one that goes into the gallery. So, what do the flathead gurus suggest? The options as I see it are as follows:

1. Install the bullnose plunger with the flat spot and hope it doesn’t open before the one in the sump pump. This spring will still bleed off oil to the front area of the block.
2. Install the pointed plunger so there is no bleed off as suggested by Ronnie. Still might have same issue with it opening as the two spring rates are essentially identical.
3. Shim the hex nut with a piece of 3/8” round stock x 3/16” high with either spring to ensure it does not open before the one in the sump pump.

https://www.fordbarn.com/forum/showt...1316&showall=1

[Mart]

1, 2 or 3. All will work. I think you're overthinking it. Nothing wrong with that, but at some point you just have to choose one way and give it a try.

I'd go with 1. Others will have their favourite.

As long as one valve opens when the pressure is too high you're good. Dicking with these valves will not magically restore pressure to a motor that has low oil pressure. If you have original type water pumps that require oil splash from the cam gear for lube, 1 might be favourite.

Mart.

[Ziggster]

For sure I’m over thinking it. I’m a mech Eng, and want to understand how things work. Lol!

[Bored&Stroked]

I usually just stretch the front spring, run the stock flat-spotted plunger and then run a 49-53 style pump in the rear. Has always worked for me - for 50 years! LOL

[Ziggster]

I just ended up using the spring/plunger (bullnose style with the flat for oil bypass) that came with the motor, but I did add one SS washer (0.039”) under the spring. This was actually recommended in one of the flathead books I have. I did install two washers originally, then came across them mentioning only installing one washer. Also cleaned out the inside of the nut with a small Dremel wire wheel. Was surprised at the crap that came out.

[Terry,OH]

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Zigg: It mentions the 80# pump not the relief pressure of the spring.

[Ziggster]

Thanks Terry!