Oil Pressure Relief Valve - This one is different???

[ashyers]

Wondering if anyone has seen one of these. It's what was in our spare motor and is not the usual relief valve.

The lettered portions are attached and there is a chamfer on the side that the pen is pointing to.

Oil Pressure Relief Valve.jpg (67.22 KiB) Viewed 1901 times

I did find some info on a valve that looks like this variety, but I have not seen one in the T245's I've seen.

[just me]

I've got a bag of them at the shop. I'll take a look at them this weekend and see if anything matches.

[ashyers]

The ones I've seen so far look like what's shown in the manuals. This one is different, maybe it's for a passenger car???? I'll have to post a diagram I found when I get home. I suspect it works OK as the engine bearings looked OK, it's just not what I'm familiar with. On the bright side, I don't think you can put it in backwards!

[ashyers]

Did some digging and this may be from a full flow filtering system. Not sure how it ended up in this engine, but I guess I'm not surprised! This thing's been around the block a few times.

Check this out:

https://www.youtube.com/watch?v=TRGLYUyEdCU

I think I may pick up a standard valve...

Andy

[NAM VET]

just started watching some of the '48 Chrysler mechanic video's about these motors. Already saw and learned a few new things about these old lumps of iron. Thanks for the link, I intend to watch all of them this week.

thanks,

NV

[ashyers]

Picked up a standard valve and new spring. Here's a comparison:

The old spring and new spring were essentially identical. The new one was a "green" spring which is supposed to be the "heavy" one. The valve on the right is the standard valve.

Pressure Relief Assy..jpg (103.08 KiB) Viewed 1784 times

Wonder what was going on with the oil pressure in the motor we used as a core. Yikes!

[just me]

The one on the left matches mine. Is the one on the right for a full flow engine?

[ashyers]

just me,
The one on the right is the standard valve. I think the one on the left was for a full flow engine. Of the 3 engines I've played with the one on the right is what I've seen in 2 of them. The one on the left was in the core we're rebuilding, but I'm swapping it out for the standard valve.

Andy

[RMS]

why would a full flow block require a different relief valve ?

[Elwood]

why would a full flow block require a different relief valve ?

Probably for the filter bypass circuit during engine start up.

This 1948 Chrysler publication explains it: http://www.imperialclub.com/Repair/Lit/ ... page14.htm

[Elwood]

Here's another variation on the oil pressure relief spool valve:



This one came out of a late (1967) T-245 engine with a bypass filter system.

It looks like a cross between the bypass and full flow designs. Perhaps a standardized valve that could be used in either system?

[NAM VET]

Perhaps it is essential that the proper plunger be used so that the relief pressure system works as designed. My motor, (I am not sure when it was cast) has two vertical holes in the relief pressure system. And my plunger looks like the one in the photo in the TM. Using the "wrong" plunger, the system may not work as designed. Here is a video explaining the general principles of straight 6 oiling.

https://www.youtube.com/watch?v=TRGLYUyEdCU

I ordered a new plunger/spring/gasket/cap from VPW just to have a spare, and it matches the one that came out of the engine, and the picture of the one in the TM. I chucked it in a drill, and used some ultra fine German metal polish (Wenol) to smooth it out, perhaps making it less likely to get "gunked" up and stick in some position. In my military experience, the Army tries to keep things simple, and uncomplicated. Which is why some mechanical systems are not to be touched by lower echelons of repair and maintenance. The last thing the Army wanted then, and even now, is for some trooper to stay "this one looks like it might work) when pulling maintenance or a repair on some mechanical thing. Plus, the Army has always, when possible, strived to have a commonality of parts.

While those of us rebuilding our motors strive for the most precise and balanced assembly possible, long ago, my dad had a '48 Chrysler, which he had for over a 100 K miles and a decade, until he one day replaced it with a '57 Imperial, with the 392 hemi. Early on in the 48's life, he told me later that one of the piston pin clips had come loose, scratching the bore in that cylinder, so that cylinder was bored and a replacement piston installed. I am sure it was out of balance, and yet we would drive coast to coast in that blue car. One day we were driving on a dirt road, and a back door came open, and a tree tore it off. It must have had suicide doors. Back seats in those days were narrow, but had lots of leg room so he would put suitcases and blankets there, so us kids could have a big play area.

putting my rings on the pistons now.

NV