Spin-on oil filter base for 1592 engine

[greenbeam]

Happy New Year all,
I have found an oil filter base to convert my early 1592 engine from canister to spin-on filter.

I recall there being a 1592 and a 1725 spec for these oil filter bases and a warning about some pressure relief valves sticking, so before I swap them over, just want to make sure I have the right one for my engine and how to check the valve is OK.

I *think* the type with the thread at the head of the PRV is the one for 1592 engines - correct?

However, I also seem to recall brass PRV is bad. Is that correct?

See photo attached.

Cheers,
Paul.

 

[hartmandm]

A good thread on this topic: https://forum.sunbeamalpine.org/index.php?threads/different-oil-pressure-problem.29343/

My conclusions from the thread:

• Brass OPRVs are more likely to stick open than the steel OPRVs.
  
• The series 5 brass OPRV is more likely to stick open than the series 4 brass OPRV.

I think you can distinguish the series 4 and 5 brass OPRVs by the bolt head. The series 5 has a center bump in the bolt head.



Mike

 

[greenbeam]

Thanks Mike,
This is more convoluted than I thought.

It seems like I have an early SV base and OPRV then - it has the thread the the head of the valve, and the bump in the bolt head of the valve.

So my options are to find a brass SIV valve (no bump on the head of the valve) or to find a late SV base. I see that new steel valves are available from on of the UK supplier, should I need one.

One question, I read somewhere that the filter base changed for 1725 engines. I have a 1592. Can I use the 1725 base on my engine? Does it need to modified at all? (not sure if this 'change' refers to the the location of the thread on the OPRV or the within filter base elsewhere).

 

[hartmandm]

I think the series 3 spin on filter bases might have used the steel OPRV as well.

The filter base would have changed during the series V production when they went from the brass OPRV back to the earlier steel OPRV. The base needed to change due to the different size and thread location of the steel OPRV.

From the Parts Manual for 1725:


If you check the Sunbeam Specialties catalog, the gasket for the oil filter base to the block is the same part # for series 3, 4, and 5. But it doesn't show the same gasket being used for series 2.
The Parts Manual shows different gasket parts numbers for the canister oil filters and the spin on oil filter bases:



So I don't know if a 1592 block that came with a canister oil filter will properly accept the spin on oil filter bases. Someone on the forum should be able to confirm that.

Here's a picture of a brass OPRV base next to a steel OPRV base.



Mike

 

[greenbeam]

Thanks Mike, that is most helpful. I only have a parts list up to SIV, so hadn't seen the SV changeover.

Good to know then that a late S3 base - spin-on filter with steel valve would be OK too.

I did find the page below, where someone says that any 1725 will work on a 1592 - even a later 'slant' 1725 one from eg Fastback Rapier/Alpine or Hillman Hunter. That would open up the field of possible sources.

https://www.sa.hillman.org.au/TT_OilFilterBase.htm

Cheers,
Paul.

 

[alpine_64]

The late spin on filter bases 5 main motors fit the 3 main motors without modification. The gasket IS DIFFERENT make sure you get the matching gasket AND make sure you mount it the correct orientation. The gaskets will fit each block but will BLOCK the oil passages... Same goes for mounting them in the wrong orientation...they will go on but block the passages.

 

[greenbeam]

Thanks for confirming that Michael, also for the warning re gaskets.

I have put the word out among the Oz folk looking for a late SV/Hunter base. Let's see how that goes.
Cheers,
Paul.

 

[alpine_64]

Thanks for confirming that Michael, also for the warning re gaskets.

I have put the word out among the Oz folk looking for a late SV/Hunter base. Let's see how that goes.
Cheers,
Paul.

Contact the rootes club or jim withers or simon noukse in melbourne... Should be easy to find one...both should have the gaskets too

 

[Tim R]

Mike,
This is a bit more convoluted. The pip on the end of the PRV was not just 'all Series Vs'. It is explained somewhere in the service bulletins. I seem to remember that they added the pip than realised that there was an issue with the PRVs, changed the PRV and removed the pip again.

To make it more complicated they then put the pip back on again for late model, post Alpine PRVs but with a different pressure setting. This makes it extremely difficult to identify what you have if you pick up a PRV that is not in packaging showing the part number. I'll try and find my notes to give you the definitive answer and the classic numbers here the changes were made but what I've described is close to what happened.

Tim R

 

[greenbeam]

Hi again,
Success! A kind club member has come through with a later type base.

Next question, should I replace the steel relief valve (no 'pip' on the head) with one of the new ones available? The one in this base was stuck closed and gummed up when removed, but with a good shove it is now moving.

Reminder - it's going on a 1592 alloy head engine.
Cheers,
Paul.

 

[hartmandm]

If you think the plunger was stuck due to rust you can soak the valve assembly in distilled white vinegar for a couple of days. If gummed up due to some other reason, then you could try other solvents. When installed it will have constant oiling. It wouldn't be bad to purchase a new replacement. Then you'd have a spare.

Mike

 

[greenbeam]

Thanks Mike,
It's not rusty, it was sitting in a box for about 30 years, so oil has thickened and solidified.
I've soaked it in petrol overnight and a lot of the hardened oil has come off. It seems to be opening and closing more smoothly. I think I'll still buy a new one in case this one does anything weird when the engine is started.
Cheers,
Paul.

 

[alpine_64]

Thanks Mike,
It's not rusty, it was sitting in a box for about 30 years, so oil has thickened and solidified.
I've soaked it in petrol overnight and a lot of the hardened oil has come off. It seems to be opening and closing more smoothly. I think I'll still buy a new one in case this one does anything weird when the engine is started.
Cheers,
Paul.

Soak it in paint thinners for a few days and plunge it up and down periodically

 

[RootesRooter]

IIRC, the mid-SV Service Bulletin advised dealers to replace the PRV with the earlier, SIV part #, which I think would have been brass.

Someone mentioned that new PRV's were available from the U.K. What company?

 

[Scotty]

Bought one recently, this is who sells new steel PRV ones. Working wonderfully.