Question - C59A Oil Pressure Relief in Lifter Valley

[Ziggster]

Hope you all donÂ’t mind all these questions, but since it has been so long since this engine was rebuilt my memory is a little faded. As I was working on it, J noticed a threaded hole in the lifter valley at the front of the . Took me a few minutes to realize that this was the location for the pressure relief valve. Panic set in as I wondered where the original parts were, but luckily I found two sets of parts. IÂ’m guessing one set (spring, plunger, and nut) are from the extra oil pump assy I had acquired. Again, no info from what I could see in the flathead books I have which is frustrating as this is exactly why I purchased them. So, I have a few questions pertaining to this relief valve:

1. Is it necessary as there is one already in the sump pump assembly? I seem to recall reading that some folks just plug it.
2. Can I reuse the original spring or do you think a new spring should be used?
3. The contours of the two plungers I have are slightly different. Does it matter which I use?
4. There seems to be gasket used to seal the nut. It appears to be the same used for the one in the oil sump pump. Is this correct?
5. I don’t have this gasket. I seem to recall having an “extra” at some point, but can”t find it. Any suggestions as to what I can use to seal it instead of using the gasket or should I just order another one?

[Ziggster]

Pics of the different contours on the plungers.

[Ziggster]

The location of the oil relief valve in the lifter valley.

[Mart]

The correct plunger has a flat on it to allow a controlled leak. I have not seen a gasket or copper washer or anything on the retainer. The area under the retainer has a hole leading into the timing gear area therefore is not pressurised so there is no real need for a seal.

[Ziggster]

Thanks again Mart. Very much appreciated! Between the two plungers which of the two would you think is the better? One seems to be more tapered with a smaller flat on top. It also has a slight ridge from wear. The other is more rounded with a larger flat on top, but also has a flat deformation on the surface.

[Ol' Ron]

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Always thought this was the right place to put the relief valve, This controld the pressure at the eng of the run, not the beginning .
Gramps

[Ziggster]

So I was wondering what is point of having another in the sump pump?

[Mart]

There isn't. 8BA type motors don't have that valve in the block. They rely on the one in the pump (as do French by the way).

[Ziggster]

My engine has/had both. Are you saying if a I have one in the sump pump I don’t need the one in the lifter valley?

[tubman]

Originally Posted by Ziggster

My engine has/had both. Are you saying if a I have one in the sump pump I don’t need the one in the lifter valley?

The function of the pressure relief valve is to remove undo load on the pump (and therefore unnecessary heating the oil) in cases of extremely high oil pressure. I believe it's best to relieve it right at the pump rather than allow it to go almost all the way through the engine, which would defeat the purpose of the relief system.

[Ziggster]

Ok. Thanks. Seems a bit odd to me, but I’ll read up on it now as I’m curious. IIRC the one in the sump opens at 80PSI and the one in the valley I’m not sure about. The two springs I have look identical though.

[tubman]

The 8BA pumps have a factory specification of 57 psi. I would expect the relief valve to open at that pressure. After my debacle with a Speedway pump https://www.fordbarn.com/forum/showt...light=Speedway in a fresh engine, I sent 3 original Ford pumps to "flatjack9" here on the barn for testing. All three came back with a positive result, with the relief valves opening right around 57 psi. The use of 8BA pumps in early engines has become almost SOP.

The 80 psi you are referencing is the maximum output from the pump, not the regulated output.

[Mart]

Leave them both in. The front of the motor needs the controlled bleed off from the front valve.

That's what I would do, and do do, if that makes sense.

[Ronnieroadster]

Originally Posted by Mart

Leave them both in. The front of the motor needs the controlled bleed off from the front valve.

That's what I would do, and do do, if that makes sense.

Actually Mart the front of the engine gets plenty of oil bleed from the clearances of front cam bearing and front main bearing this oil leakage lubricates the crank and cam gears perfectly. Proof of how well that design works is the success of the 8BA design which eliminates the front bypass flat spot on ball design.

As to the bypass on the early blocks the reason there's a flat spot on the bypass ball is so that there's extra oil splashing around in the front timing cover area. This additional oil splashing around eventually gets into the small oil holes located in the face of the early block these holes lines up with the oil hole in the rear of the early water pumps. The oil from this hole is now lubricating the bushings in the early water pumps.

Todays reproduction early water pumps now come with sealed bearings similar to how the latter water pumps are designed thus no need for that additional oil splashing around in the earlier engine's if the newer type pumps are being used.

Any early engine I build I always close off that front bypass if newer style water pumps are being used. This eliminates a bleed on the oil system.
Ronnieroadster

[Ziggster]

Originally Posted by tubman

The 8BA pumps have a factory specification of 57 psi. I would expect the relief valve to open at that pressure. After my debacle with a Speedway pump https://www.fordbarn.com/forum/showt...light=Speedway in a fresh engine, I sent 3 original Ford pumps to "flatjack9" here on the barn for testing. All three came back with a positive result, with the relief valves opening right around 57 psi. The use of 8BA pumps in early engines has become almost SOP.

The 80 psi you are referencing is the maximum output from the pump, not the regulated output.

Thanks. Much appreciated. Now I remember why I recalled the figure.

[Ziggster]

Originally Posted by Ronnieroadster

Actually Mart the front of the engine gets plenty of oil bleed from the clearances of front cam bearing and front main bearing this oil leakage lubricates the crank and cam gears perfectly. Proof of how well that design works is the success of the 8BA design which eliminates the front bypass flat spot on ball design.

As to the bypass on the early blocks the reason there's a flat spot on the bypass ball is so that there's extra oil splashing around in the front timing cover area. This additional oil splashing around eventually gets into the small oil holes located in the face of the early block these holes lines up with the oil hole in the rear of the early water pumps. The oil from this hole is now lubricating the bushings in the early water pumps.

Todays reproduction early water pumps now come with sealed bearings similar to how the latter water pumps are designed thus no need for that additional oil splashing around in the earlier engine's if the newer type pumps are being used.

Any early engine I build I always close off that front bypass if newer style water pumps are being used. This eliminates a bleed on the oil system.
Ronnieroadster

Funny you mention that as I saw the lubrication hole in the gasket supplied with the pump while I was applying sealant. IIRC they are Speedway pumps. I assume they are sealed bearings, so why would Speedway supply gaskets with a hole that is not needed?

[Ronnieroadster]

Originally Posted by Ziggster

Funny you mention that as I saw the lubrication hole in the gasket supplied with the pump while I was applying sealant. IIRC they are Speedway pumps. I assume they are sealed bearings, so why would Speedway supply gaskets with a hole that is not needed?

Your correct the Speedway pumps have the sealed bearing's. The gaskets are universal made for the bushing pumps as well so there's no reason to make a gasket for each application.
Ronnieroadster

[mike in tucson]

We have hands on experience with the valley relief... we left it off our last motor and had a bit of trouble figuring out why the motor had zero oil pressure. New parts (the 3 pieces) are available from Mike at Third Gen Auto in TN.

[jimTN]

RR has it correct I just finished a engine using a late oil pump with both regulators in. Once the engine got hot, I had very little pressure. I read old posts from GM who suggested hard shimming the front relief valve down so I put a ground off 1/4" nut in the front cap. Problem solved. Pressure is 40 or better while driving and 10 or so idling. Those two valves were fighting each other.

[Ziggster]

From the interweebs. Says pressure relief spring for cylinder block - 80 PSI. WTH?

[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!