Addressing low oil pressure

[rebuilder86]

Well, I'm back overseas in my jungle hut with my beloved jeepy and the mighty 4k is still going strong.
While in Perth, i got a cheap oil pressure gauge online, as i have no idiot light, or anything like that to warn me of something funny like a hole in my sump or a broken oil pump.
This gauge really only indicates from 10-70 PSI and i would laugh at anyone who tried to use it to accurately measure oil pressure.
However I trust the sender unit, so I'm just going to believe the readings it gives me within a ball park, lets say, within ~30-40 PSI.
I stuck it in, and had the gauge sitting earthed on the stainless steel bonnet, started the engine and the thing took about 10 seconds to register any oil pressure then went up to about  40PSI as indicated on the gauge. ( i know that could be completely wrong, but lets use it for comparisons between old and fresh oil)
"Sweet!" i said, but then i thought about that 10 seconds and was pissed off to remember that i forgot to buy a ryco oil filter with the anti drain.
So i spent a day going around wasting my time looking for a filter with an anti drain valve, only to come back and get on the net and find in one of Banjos posts that the anti drain is only one of the required 2 check valves in an inverted oil filter for any non return system to be of any use. apparently the second valve is called "anti siphon". that makes no Fuc -king sense. siphoning isnt involved at all here. I did wonder how the it managed to stop both inlet and outlet from draining.
Anyhow, my pressure is scaring me. 
I understand these motors are quite old, and pressures are generally low, and clearances are large, but after that first gauge test, after installing it really professionally (ziptied the gauge to the indicator stalk and just wound wires around the places they needed to go) it would never, ever, no matter how cold, start and idle above an indicated 20 PSI when cold.
I have checked all connections and they are tight, so oil pressure is possibly much worse than it was when i first tested the gauge., or the gauge burnt out and changed sensitivity because its so shit and cheap.
For now, I'm going to try sticking in some fresh oil, 20W-50 . Its frikn hot here, and the engine does run hot, and sometimes overheats when I try to drive over the hills. Perhaps this overheating is due to the oil thinning out so much due to gasoline dilution its just simply exiting at the pressure relief valve and then a piddle is leaking out the first journal.
The oil dilution is probably now less of a problem going forwards. I used to have a rich condition which fowled all my plugs and all that extra fuel around would have easily made its way down past the rings.
My question after all that dribble.

Why do people shim their oil pressure relief valves, claiming that it increases oil pressure?
My understanding is that it is spring loaded, which means, at a certain pressure (maximum alowed pressure) the spring is open at such a point that oil is allowed back into the sump.
So wouldn't shimming this, simply be changing the maximum allowed oil pressure, not the maximum pressure at any given time? i think shimming this thing would simply increase the likelihood of blowing a main seal at startup when the oil is cold and pressure is close to this maximum allowed. At all other times, the oil pressure is so low this relief valve is out of the picture.

Why do you all do it?

Edited September 20, 2017 by rebuilder86

[Banjo]

Hi Jeremy,

                  Good  oil filter manufacturers have several valves built into the filter, to safeguard the engine, under various operating conditions.

Cold Starts: can produce very high oil pressures, particularly in cold weather, when the oil is very viscous (thick).  This high pressure could damage seals etc. in the engine, so a Sump Bypass Valve between pump & filter membrane itself, opens & closes quickly to release oil back into the sump, to maintain a lower pressure, set by the spring behind the valve.

Blocked Filter: resulting from the oil filter not being changed regularly, with very dirty oil, can be catastrophic for an engine, due to partial or total oil starvation to the bearings. The Oil Filter Bypass Valve allows oil to bypass around the filter, and continue the oil feed to the engine, despite the filter being blocked. Unfiltered oil to the engine, is still better than no oil at all, but this type of valve usually requires some sort of indication to the driver, that the filter is blocked.

Dry Starts: are to be avoided at all costs. You produce more wear in your engine, for the few seconds, each time you cold start it, than the total wear produced in driving the car for the next few hours. That's why taxi engines last so long. They rarely get cold ! An Anti-Drain Valve stops the filter's internal oil reserve, from draining back into the sump, after the engine is switched off. It ensures that when you first start the engine, the filter is already full of oil, & primed to go.

Dry Starts:  can also occur in applications where the oil filter is installed horizontal, or in an inverted position. An Anti-Syphoning Valve is fitted to the filter at the outlet or downstream side, to prevent oil draining back to the engine via journal clearances etc.   "The anti-syphon valve performs a similar function to the anti drain-back valve by preventing oil from returning to the engine when switched off. The main difference between the two, is that the anti-syphon valve prevents oil from draining out from the filter outlet, whilst the anti drain-back valve prevents oil draining out from the filter’s inlet hole. The anti-syphon valve is located within the filter on the outlet side (otherwise referred to as the downstream side)"

P.S.  An empty oil filter is unavoidable when you change your oil filter & fit a brand new empty one.  It takes several seconds for the oil pump to fill up the filter, before oil flows through the galleries to the journals.  It is usually obvious from the rattles you get in olde engines after stating up after a filter & oil change. It rattles a bit,  then all of a sudden, goes quiet. I have always changed the oil & filter with the engine hot, after a run.  I have found that the oil is thin & empties more thoroughly & quickly, when hot & thin.   If the filter is then changed and new oil added straight after, there is enough oil left in the galleries & journals, to ease the start, & reduce the possibly of a dry bearing start.  Just my personal feeling, but maybe worth a thought, when next you are doing an oil & filter change.

Trust that clears up a few of your questions.

Cheers Banjo

 

Edited September 20, 2017 by Banjo

[rebuilder86]

OOOOOHH!
this sump bypass valve you speak of, is that not the one in the pump or are you definitely referring to one some filter companies design into the filter?

[rebuilder86]

ok, update,

i found the earth strap from the engine to the chassis (well its actually just a 240 volt lighting wire, not an actual earth strap) had snapped and the only way the battery was earthed to the body was through the gearbox mounts and the radiator haha

so after changing the oil, and reconnecting that earth, the apparent oil pressure is off the charts, above 100 PSI lol

just for interest sake i undid that earth again and tested with the new oil, and it was much the same as before. so it turns out i probably never had an oil pressure issue, just ANOTHER electrical issue, which is something i face daily on this fun piece of jungle junk.

[Banjo]

Hi Jeremy,

                 Glad you solved your issue oil pressure guage issue.  The olde earth strap issue.

Just to clarify your earlier question.

The Sump Bypass Valve or Pressure Relief Valve as it is sometimes known, can be in the oil pump itself, as it is in our K Series engines, or it can be in the filter proper.

This article explains why, better than I could.

https://www.quora.com/What-is-an-oil-bypass-valve

Cheers Banjo

 

Edited September 21, 2017 by Banjo

[rebuilder86]

ah ok i see. 
So, pressure relief valve, relieves pressure (oil) back into the sump. This is the one I am talking about.
Bypass valve by-passes the filter of course but the oil continues on through the system to build pressure. this would usually be in the filter.
That also clarifies what i suspected, that anyone shimming such a relief valve is doing there engine absolutely no good at all and is wasting a lot of effort and time and all instances of it giving any gains, posted anywhere on the interwebs really should be ignored.
Interesting that my shitty gauge indicates over 100 PSI when cold now haha.
Perhaps that might explain the oil that has forever been dripping from the gearbox mounting plate that i can't be bothered addressing.
 

Edited September 21, 2017 by rebuilder86

[Banjo]

Hi Jeremy,

                   Sorry if I confused you.  Yes, there are two bypass valves. One to the sump, & one around the filter.   Maybe we should just refer to the Sump Bypass, as the Pressure Relief Valve, which is its function.

Cheers Banjo

[rebuilder86]

another update, i was a bit upset when i got back to the villagr and found the oil filter is bigger than the old one. but i checked the net and it is the listed part, allbeit bigger than the smaller newer one.

however, for some reason, this one is filling up faster than the old one, judging by the almost immediate oil pressure I'm now getting on startup.

I'm certain the new filter doesnt have both the intake and outlet valves, just the outer ring one which i believe is the inlet anti drain valve which all filters have.

frikn wierd, but I'm not complaining, the filter cost 150 pesos, thats about 4 dollars.

[Banjo]

Hi Jeremy,

                   There are more than one size oil filters that suit or fit the K Series engines.  Most of us have used the good old Z68 / SCA068  in it's different formats & manufacturers. (They all have a 68 somewhere in the part number)  They are large, and I've used them, because I figure rightly or wrongly, that there is more filter material in there to filter the oil.

However, there are the quite small Osaka ones, which are usually black in colour, & from what I've read, are a very high quality Japanese oil filter.

I've also used these, when I wanted to mount some waste spark GMH coils on the K engine block, and the Z68 was too large, & blocked the area I need to mount the coils in.

 

The different sorts of valves I described earlier in this thread, are not necessarily in every oil filter.  That's why I prefaced my remarks by  . . . .  "Good  oil filter manufacturers have several valves built into the filter".

That's not to imply that all of those valves are actually needed in every engine.  In many other engines,  & the K series engine,  the oil pressure relief valve is built into the oil pump or engine itself, and therefore is not required in the filter proper.

The one that is a must is the anti-drain valve, to prevent "dry starts"  !

P.S.    Where are you living ATM, where you pay 150 pesos ($4.00) for an oil filter ?

Cheers Banjo

 

 

Edited September 21, 2017 by Banjo

[rebuilder86]

banjo, do u hust have a library of 4k pictures laying around?? haha

I'm in the philippines, in cebu island, in the remote jungle and i go into the town of toledo for parts.

The brand is VIC model c120.

id say on an inverted motor, the anti drain valve is useless on its own, u need both in and outlet blocked when the engine is off. or is that not correct and the outlet side is restricted enough and above the filter to stop oil exiting? maybe all that is required is the anti drain valve and perhaps the old filter had a faulty anti drain valve which was why i was always waiting 5 seconds for preasure.

 

[Banjo]

Hi Jeremy,

                  When flying Brisbane - Hong Kong, I know we passed over Cebu.   What do you do there ?   I noticed there was a big mine or something between Cebu City & Toledo.

According to the web, the VIC brand of oil filters are made in Japan, & have a good reputation.  Found a VIC  C115 oil filter on line here at a discount price of AUD 16.50.

Cheers Banjo

[rebuilder86]

hah what do i do here,... the only sensible thing to do in this country. add to the overpopulation of course.

full time sex with the missus, and part time engineering this 4k to last me my entire life to be honest.

that mine would be carmen copper, a primarily copper mine with gold byproduct credits which the operators use as offset against the copper production costs to make themselves look better. the reason u can see it so clearly from the aeroplane is because; "the environment",  in this country, to the people who have enough money to have any say, means sweet ʞ©$ɟ all.

they just dig, dig and dig. the labour is so cheap that a pitshel for a similar grade of copper anywhere else in the world, would be narrower by half.

all just for copper.

 

luxuries are expensive to the locals.

but there are more trucks per person here than any other populated place on earth, and for that reason, there is a market for stupidly cheap imported car parts which work on a mass throughput minimum profit margin system. being so close to the manufacturing hubs of china, japan, and thailand makes all car parts stupidly cheap here.

[Viterbo]

Regarding engine starts after a filter change, I always disconnect the plug from the ignition coil so it can't start due to no spark, and then I crank it until the oil pressure light goes off. Only then I start the engine.

[rebuilder86]

i used to do that, but never done it with this engine, although of all engines ive ever touched, this would be the one that would require it the most haha.
i say that because of the size of the filter.

i think i remember learning from someone not to run the coil without a place for the spark to go, or else it will just release the energy as heat into the coil body.
I guess a couple of seconds couldn't possibly hurt it tho.

I had a little bit more of a think about it yeswterday, perhaps the reason this bigger filter is priming quicker, is because there is more weight above the anti drain membrane on the inlet to hold the membrane sealeddown , and perhaps the old one didnt have enough weight to make a good seal.
its honestly a 1-2 second oil pressure delay now with the new bigger one, and the old one of the exact same brand with the same single anti drain membrane but of smaller volume took about 8 seconds.

[rebuilder86]

and perhaps the reason no one else experiences this, is because i get the worlds worst automotive parts.