Oil Pressure Adjustment

[thatch]

"no, not you Hanley"!

Hanley,
I was certainly not referring to you or others who have a more normal "high at cold temp, decreasing at increasing temps" situation but there have been at least two recent entries that have the reverse condition that I described previously. Since the only accessible oil system service point (aside from the pumpout hole) on a stock A4 is the oil pressure adjuster I feel that Universal had no intention of having these little jems last forever as we are trying to make them do.
Tom

[hanleyclifford]

the oil issue

Tom - Although I do not have the specific problem you have been discussing, your reference to the oil pick up screen applies to all. I had not considered the possibility that since I now have a 1/4" npt pick up elbow, the screen may have become MY most restrictive component. That is the aspect of your post that gave me a little (positive) jolt. As long as I own these engines I will be looking for ways to improve circulation and flow of all vital systems. As for your allusion to "planned obsolescence", I see the A4 the same as the wooden boat - it IS going to outlast me. Regards, Hanley

[Mephisto, a C&C 29 Mk. 1]

Oil Pressure is Low on Start Up

My late model A4 registers 10-20 psi oil pressure on startup then climbs to the desired 30-40 psi when warm (which takes several minutes in the cold waters of British Columbia. I'm also prone to overheating, even though the heat exchanger is clean and both fresh-water and raw-water pumps are working well. This is the reverse of the usual problem with oil pressure and I wonder if anyone has advice to add other than Tom's suggestion of a clogged oil screen.

Thank you!

[hanleyclifford]

two issues

Mephisto - Your oil pressure issue is probably unrelated to the overheating. I would just keep clean oil in the engine, maybe a little thinner grade, temporarily, and enjoy that warmed up satisfactory oil pressure. Your cooling issue is more serious - see the thread by RobH2 - restrictions are at the heart of many such problems.

[sastanley]

Tom,
Thanks for that. My start up pressure is very low, less than 5 PSI. As the engine warms up, my pressure will eventually move to the 15-20 PSI range. Long runs (multiple hours) will let it get to 35 or so.

For now, I just try to baby it when it's cold, running 1,200-1,300 RPM or so, until the pressure begins to build, then I will move up my cruising speed a little bit.

Your explanation seems valid...although as you've noted a tear down is necessary to confirm.

[Jesse Delanoy]

Hanley, I would love to see what you have done about oil cooling. thanks.

[perchance]

Low oil P on startup

The reason your oil pressure is low on start up has to do with the low temp and the viscosity of the 30 w oil. The thickened oil forces the relief valve off its seat until the engine warms up

[Mephisto, a C&C 29 Mk. 1]

Oil Pressure is Low on Start Up

Thanks, Hanley: I'll treat the overheating and low oil pressure on start up as coincidental problems. I'll try a lower-viscosity oil at our next oil change. Overheating is not dangerously bad: both pumps and heat exchanger are clean and working well; and raw water flow quantities are satisfactory. I'll investigate the flow of coolant through the engine itself.

[hanleyclifford]

Oil cooling

Jesse - Thank you for your interest in this oil cooling matter which is still under development. I have the Indigo oil filter with external adjusting arrangement with which I'm sure you are familiar. My original foray into cooling was to use the oil bleed -off from the system to a Sendure exhanger and thence to a return hole in the location where the old oil change pumps used to be. This proved to be unsatisfactory because my engine required most of the "adjustment" simply to maintain sufficient oil pressure. Concurrently I realized that in fact very little oil was being filtered. My present effort involves an independent oil circuit drawing hot oil from the pan thru the old oil change pump hole into a series 809 March pump (www.marchpump.com), thence to a Sendure exhanger, thence to the Indigo oil filter, thence back to the pan via a hole drilled and tapped into the fuel pump block off plate. The Indigo adjuster has been moved to the oil hole just behind the flywheel housing. The bleed-off is now used to "prime" the 809 pump on the input side. The pump is listed in the McMaster catalogue. As I may have mentioned before, this system has a trip to Florida under it's belt. Sorry I cannot do drawings or pictures yet as I am new to computers. I just learned to upload pictures into the computer today, and I have pictures to post of my systems as soon as I learn that part. I would appreciate your comments on the above - and also the rest of the platoon. Regards, Hanley

[hanleyclifford]

another idea

Perchance - Your thought on low pressure on start up due to cold oil pushing the adjuster off its seat is new to me, and interesting. I wonder how it squares with Tom's theory regarding the oil screen. Tom?

[thatch]

Sorry, Perchance

Hanley,
I sincerely hope that you agree with me when I say that, that 3/8" ball comes off of it's seat after the oil galleys have been filled and pressurized and when the spring holding it down says it can (in my A4 it's about 5 seconds at 40 psi). I do suppose that it is possible with an extremely dirty pressure relief assembly that the ball could stick in the open position and start operating after it warmed up. Of course in that engine wear would probably be so high that the adjuster would have been bottomed out anyway preventing any ball movement at all.... On another note, I read with great interest your "upgrades" to your oil system. If we were to take this one step farther and use a Gilmer belt with a gear pump we could pretty much solve all of the A4's oil system's shortcomings. Sort of a modified "dry sump system".
Tom

[hanleyclifford]

ball and spring

Tom - Yes, I do agree with you, but I suppose if the spring were old and weak in a dirty environment it is possible it could stick until engine warm up "softened" the mess in the cylinder - but this does not address the LOW oil issue that concerns most of us. The spring should be able to control the ball in all conditions. I have become interested in other pressure regulating hardware, perhaps something from the McMaster catalog. You lost me with the reference to "Gilmer belt" - please elaborate. Hanley

[thatch]

Clarification

Hanley,
A "Gilmer" belt is a "cogged" type of belt that works good in situations where you want to provide a positive drive, without using a chain. Come to think of it, using one of these belts on our "oversized" alternators would probably be a good idea.
Tom

[David Masury]

Tom I finally read you theory on why oil pressure may increase as the engine warms up... I think that the internal screen plugging up over time idea may not hold up considering modern detergent oils and especially if people use MMO before winter layup... but having said that, it is as good of a theory as anything esle....

David

[thatch]

"Newfound Respect"

David,
I would really hope that you are correct in assumming that people would care for these great little engines the way that they deserve to be treated but I'm sure there are some A4's out there that have survived despite being for the most part neglected. I personally disassembled an automotive motor that had been fed a popular motor oil (which will remain nameless) for it's entire life and you would not believe how completely sludged up the entire motor was, even to the point that the oil would not drain from the heads back to the pan. When people finally woke up to the fact that this was an engine worth keeping around and thank's, in no small way, to Don Moyer we now have the resources to keep them alive.
Tom