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Oil Pressure Regulator Questions

Alpine 1789

SAOCA President
Diamond Level Sponsor
I'm running a OPR valve modified by the inestimable Mr. Stone, along the lines of the mod shown in this article.
That valve was modified c1982, shortly after Tiger Tom first published his modification in the TEAE newsletter. It is nice to see that it is still working! FWIW, I am currently using the later valve, modified along the lines Jarrid recommended, courtesy of Rocco/Mototron's shop.
 

hartmandm

Moderator
Diamond Level Sponsor
I agree material choice is key.
...
This morning, I found this thread on a machinist site concerning material choice:
http://www.practicalmachinist.com/v...l-choice-brass-steel-1018-steel-12l14-270863/

That is funny. The original poster, Karl, is my machinist friend who I worked with to create my replacement OPRV tube. I didn't know he was posting online about the material choice! FYI, I didn't melt the original brass tube as Karl indicated, I deformed it when re-soldering. I had a bad setup...

In an earlier post, I indicated the replacement tube was made from stainless steel. That was wrong. The new tube is steel, not stainless.

Mike
 
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zack

Donation Time
OK...so if I get this right...they started with two .25 diam holes for a total dump area of .098175 in^2. Then they went to two square .25 holes for a total dump area of 0.125 in^2. Then they went to two .316 diam holes for a total dump area of 0.156853 in^2. I am assuming that throughout this process the feed end hole was .370 diam for an area of 0.107521 in^2 because that's really as big as they could reasonably get away with given the piston size.

Thanks for the measurements! I'll set to redesigning this...I have a couple heavy days ahead but I think I should have enough to spec out a prototype before the weekend, before monday at the latest.
 

hartmandm

Moderator
Diamond Level Sponsor
I'm not sure where the square hole OPRVs fit into the picture, given I haven't been able to connect the parts manual info to where a square hole OPRV would have been used.

Anyways,

- Pre-series V was the larger steel tube with the .316" dump holes.
- Then at the start of series V they came out with the smaller brass (or bronze) tube with .250" dump holes.
- About 2/3rds into the series V run they went back to the earlier larger steel tube design with the larger dump holes.

If "feed end" means where the oil enters the OPRV, then the feed end size on the two tube designs is different. The larger tube OPRV has a larger feed end.

My opinion, for whatever little it is worth - if you are producing a smaller tube OPRV, then go with .250" holes. If producing a larger tube OPRV, go with the larger holes. Both are proven designs for dumping oil sufficiently. The issue to address is sticking!

Mike
 
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Ken Ellis

Donation Time
Checked Mossmotors and Rootes Parts over in Netherlands and didn't find anything of benefit on this topic. One of the Moss Motors valves listed was a ball (or at least rounded plungers) and had an aluminum body and brass plunger.

From a manufacturing standpoint, round holes are much easier/cheaper than square. So there must have been a really good reason to try square holes, even if they didn't live out production. Or, they went back to round as a cost-control measure. Or the square version didn't provide enough of a benefit to offset the costs.

I wonder if there's any correlation between the dates of 'round hole valves' (if that's even knowable at this point) and Chrysler's takeover. At that time, didn't Chrysler have a 5-year/50,000 mile powertrain warranty?

Always possible it was aftermarket, but that would mean high enough failure rates of OEM to sustain an aftermarket for that part.

An early post by TomH noted that on the occasions when his stuck, he found grit in it. If a ball valve is used, or the edges of a piston are chamfered, I'm wondering if that design may serve to wedge grit in the gap pretty hard. And the angle or ball radius may tend to admit and trap bigger chunks than would be possible with a straight, non-chamfered piston.
 

zack

Donation Time
Checked Mossmotors and Rootes Parts over in Netherlands and didn't find anything of benefit on this topic. One of the Moss Motors valves listed was a ball (or at least rounded plungers) and had an aluminum body and brass plunger.

From a manufacturing standpoint, round holes are much easier/cheaper than square. So there must have been a really good reason to try square holes, even if they didn't live out production. Or, they went back to round as a cost-control measure. Or the square version didn't provide enough of a benefit to offset the costs.

I wonder if there's any correlation between the dates of 'round hole valves' (if that's even knowable at this point) and Chrysler's takeover. At that time, didn't Chrysler have a 5-year/50,000 mile powertrain warranty?

Always possible it was aftermarket, but that would mean high enough failure rates of OEM to sustain an aftermarket for that part.

An early post by TomH noted that on the occasions when his stuck, he found grit in it. If a ball valve is used, or the edges of a piston are chamfered, I'm wondering if that design may serve to wedge grit in the gap pretty hard. And the angle or ball radius may tend to admit and trap bigger chunks than would be possible with a straight, non-chamfered piston.

I'm pretty sure that the scratches caused by the non-chamfered design are most of the reason grit can stick in the first place. Of course there is still an edge with a chamfer so the final might be radiused...with modern CNC lathes is is just a matter of replacing a couple of G1 commands with a G3 and a G2. That way we get the good part of a ball with the good parts of a piston.

On the "reasons why they did a square port", I had a theory. Originally the dumps were larger, then they went to the smaller tube and circular holes that size would have been rather large compared to the tube itself. In a car where the bearings and shafts were on the large end of spec in winter with thick oil this could have caused excessively high pressure even when the valve was full-open. The square ports may have been a response to this. Just a theory.

Not sure if anyone knows this...but are all the bodies interchangeable? Since the final version of the valve is still available from Speedy, would it be theoretically possible for someone with a thin version to just buy a new body? Or are the bodies even rarer than the valves?
 
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65beam

Donation Time
questions

Not sure if anyone knows this...but are all the bodies interchangeable? Since the final version of the valve is still available from Speedy, would it be theoretically possible for someone with a thin version to just buy a new body? Or are the bodies even rarer than the valves?[/QUOTE]

refer back to the photo I posted of the valves. You'll notice that the early valves had the threads on the base that the tube solders to. On later versions the threads are on the end of the tube. You can change the filter base to a unit that uses the late style valve.
 

Ken Ellis

Donation Time
Looking at Mike's pic #3 in post #3, it may be possible to re-drill a 'small' oil filter base to accommodate the larger diameter/end-thread setup of the larger OPR valve. Sitting down at a bench with all parts in-hand would tell you for sure. It might be slightly difficult, in that the larger hole may need to be non-concentric with the smaller -- meaning you can't just drill it, you'd need to mill it. And it looks like there could be some bumping into casting walls to be expected. Also, threading down in the bottom of the hole is slightly more difficult -- but by no means impossible. And if it is just a matter of milling and tapping the right size hole in the right, non-conflicting space, that's easier than making a new valve.

Maybe the way to approach it is offer a repair service, reaming existing tube of either size, and installing new piston of compatible material with (or without) chamfer, and with or without adjustability?
 

65beam

Donation Time
questions

Filter bases are cheap and plentiful. I'll sell one cheap. No need to reinvent.
 

zack

Donation Time
Filter bases are cheap and plentiful. I'll sell one cheap. No need to reinvent.

I'll take you up on that...and before I install it I'll set it down next to the original and see if they can be converted easily. I guess my current plan is to get a newer (larger) style filter base and a newer (larger) style valve from speedy. I may continue the design project so it is available to others when the stock that Speedy has runs out but it appears I won't be making one from scratch, at least not soon.
 

zack

Donation Time
Here's a PDF with the measurements of the Series V brass/bronze OPRV.

http://mhartman.net/files/sunbeam/Series V OPRV.pdf

Mike

Nice! I might have to model that up and post some proper blueprints so when some random guy is pulling his hair out in 20 years he can take them to a machinist.

[edit] Spoke to Speedy again and now they don't have the valves...lovely. So I guess now I am making a newer style valve once the new housing shows up...should be a lot easier to make something that will last forever and a day given the larger diameter at least.
 
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Ken Ellis

Donation Time
Zack, if you could include in your drawing what you learned about the spring, its measurements, strength, and material, that would be of benefit as well.

Across the pond they have all the available Rootes factory drawings and information, but it looks like they're still sorting through it all since it's a huge task. I don't know if it's "all" the drawings, or just "all that's available" -- and they may not know yet either. Here's a link:
http://www.rootesarchivecentre.org.uk

One of their stated missions is to provide drawings for parts reproduction. I don't know if Speedy was selling OEM or repro items -- if repro, they could just be out of stock. If they were OEM or "the last they're likely to see", then an opportunity may exist...
 

zack

Donation Time
Zack, if you could include in your drawing what you learned about the spring, its measurements, strength, and material, that would be of benefit as well.

Across the pond they have all the available Rootes factory drawings and information, but it looks like they're still sorting through it all since it's a huge task. I don't know if it's "all" the drawings, or just "all that's available" -- and they may not know yet either. Here's a link:
http://www.rootesarchivecentre.org.uk

One of their stated missions is to provide drawings for parts reproduction. I don't know if Speedy was selling OEM or repro items -- if repro, they could just be out of stock. If they were OEM or "the last they're likely to see", then an opportunity may exist...

Unfortunately, I know little about what the spring originally was (maximum travel before buckle and k rate can't be gotten from a failed 50 year old spring). But I'll toss in what I have.

Talking to speedy, they don't expect to get any more regulators at any point in the future; they are not backordered...there is no one to backorder from.
 

Ken Ellis

Donation Time
Ok. I can measure the spring force on the ones I have, using Bill Blue's Tried and True Drill Press Magic Method™®.

Basically, put the assembled unit on a drill press, with a scale under it. Zero the scale. Push down on spring with a upside-down drill in the not-running drill press. Increase in weight on scale=force necessary to compress spring.

But yeah, they're 50 years old.
 

zack

Donation Time
Ok. I can measure the spring force on the ones I have, using Bill Blue's Tried and True Drill Press Magic Method™®.

Basically, put the assembled unit on a drill press, with a scale under it. Zero the scale. Push down on spring with a upside-down drill in the not-running drill press. Increase in weight on scale=force necessary to compress spring.

But yeah, they're 50 years old.

Sounds good. I can calculate the K from those numbers and just give a minimum maximum load before buckle number. I designed the stock square port in solidworks in about 5 minutes...now to make drawings; that will probably take a couple hours that I don't have right now so I'll do it another time.

Please get at least 4 sets of readings so I can get a good average.
 

hartmandm

Moderator
Diamond Level Sponsor
...
[edit] Spoke to Speedy again and now they don't have the valves...lovely. So I guess now I am making a newer style valve once the new housing shows up...should be a lot easier to make something that will last forever and a day given the larger diameter at least.

Zack,

If you are intent on making a version of the larger steel OPRV, I can send you my spare steel OPRV for you to use as a pattern. I'd prefer you not disassemble it though. I like to trash my own parts. :) Private Message me your info.

Mike
 

zack

Donation Time
Zack,

If you are intent on making a version of the larger steel OPRV, I can send you my spare steel OPRV for you to use as a pattern. I'd prefer you not disassemble it though. I like to trash my own parts. :) Private Message me your info.

Mike

Maybe I can save some shipping. The main thing I need is the thread type; the pitch, the outer diameter of the threads, and the inner diameter of the threads. You probably have a thread pitch gauge, the OD can be gotten using calipers. The depth of the thread can be gotten using a razor blade or something plus a calipers. It might even be a standard thread, although there's no reason to think that it is; that would be too easy.

Everything else I can calculate from the housing once I get it.
 

Ken Ellis

Donation Time
I'm bettin' on non-tapered BSP (British Standard Pipe).
If you want to go full-McGuyver, Google up three-wire thread measurement method.

Chip
 

hartmandm

Moderator
Diamond Level Sponsor
Maybe I can save some shipping. The main thing I need is the thread type; the pitch, the outer diameter of the threads, and the inner diameter of the threads. You probably have a thread pitch gauge, the OD can be gotten using calipers. The depth of the thread can be gotten using a razor blade or something plus a calipers. It might even be a standard thread, although there's no reason to think that it is; that would be too easy.

Everything else I can calculate from the housing once I get it.

I don't have a thread pitch gauge. I've gotten by with matching up TPI and thread OD against charts.

Mike
 
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