Paul,

I think your situation is close to normal. If Chip sees your post, he will weigh in. He knows the 4 cylinder engines pretty well.

Mike

Hi Paul

With your engine, the only thing that runs under oil pressure is the oil gauge.

That pressure is created by a valve solely for the purpose of showing pressure on a gauge so that you know the oil pump is actually pumping oil.

No part of the engine is oiled under pressure, but rather by a FLOW of pressure free oil, so I don't think you need to worry about that.

BUT

The only thing non-detergent straight 30 weight oil should be put in is an oil can, and maybe not even that.

A high quality 0W-20, 0W-30, or 10W-30 is a MUCH better alternative, unless you want to sludge your oil lines shut and starve your engine bearings of oil.

And a search of the old VCCA site will show that if Gene were here, he'd tell you the same thing.  🙂

Personally I would never, ever use non detergent oil. Detergent oil does not remove built up sludge making your engine smoke more. That would require a solvent. It prevents sludge from building up. You are actually damaging your engine by using it. I put 10W-30 in my 38 and 53 when I change oil. The 38 currently has synthetic in it. I grabbed the "wrong" can last time for the change and decided to use it anyway to test the old adage that putting synthetic in an old car will create leaks. So far the old adage is wrong. If anything, my seat of the pants feeling is it runs quieter and stronger with the synthetic. It's the Walmart house brand synthetic, cheaper than the brand name dino oil.

I've used 10-30W detergent oil for the last 30 years in my four-cylinder engines with no problems. When I rebuilt Lurch's engine in 2017, the innards were clean as a whistle! Just worn out.

As mentioned above, the only thing that these engines need from the oil pump is volume and flow, not high pressure. Also, I agree that the oil gauge's sole function is to let you know that the oil pump is working.

However, history shows that Chevrolet stopped servicing the vane-style pumps in the 1930s and offered the gear-style pumps as replacement parts.  With this in mind, I changed out the vane-style oil pumps for the newer gear-style oil pump for my peace of mind. The gear-style pumps move more oil and at a higher pressure than the vane-style pumps. They also don't lose their prime, as the vane pumps sometimes do when they sit unused for a while.

When I first start Justin (1928 Canopy Express) when cold, the oil pressure jumps up to around 16 psi. After the engine warms up, the oil pressure drops to around 5 psi.

I'm happy with that. 😉 Dean

@tiny 

I agree

There are a FEW oils that will lift significant amounts of old sludge and deposits as discussed here:

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

but you won't likely see them on the shelf at your local supply.

PS

ACTUALLY...

It looks like Valvoline Restore and Protect IS on the shelves at Walmart in the USA, but not in Canada.

However, I'm not seeing the old Valvoline Premium Blue Restore diesel oil, which was apparently a pretty aggressive cleaner.

As for seals... some of the early synthetics were formulated completely on PAO base stocks, which will shrink modern seal materials.

Other things such as a small amount of ester base stock are now added to swell or maintain seals, so the problem is now really non-existent.

A good explanation can be found here:

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

All that said, I can't stress it enough...

NEVER use a non-detergent oil in ANY engine.  🙂

PS above

@tiny 

A correction to my above post

Valvoline Restore and Protect IS on the shelves at Walmart in USA, but doesn't appear to be in Canada.

Since Mike mentioned me I feel obligated to comment. I can't add much to the posts that have already been made. I have never used non-detergent oil in my old Chevrolets. The original oil specified for most locations was 20 weight and only 30 weight for hot summers in the South. The lubrication to these engines is by oil can for the rockers and valves, oil reservoirs to gravity feed bearings and splash or mist for wrist pins, rings, etc. The mist lubrication is similar to all 2 cycle engines. Higher viscosity oils produce larger drops that do not lubricate as well as lighter oils.