We just lost oil pressure

[Thruster88]

This guy intentionally induces a loss of oil pressure in a lyc 0-320. The engine ran at full throttle for 17 minutes producing good power until almost the end. It greatly exceeded my expectations. Would a fresh overhaul do as well ?

 

[bexrbetter]

have blown up a few old engines on the past, never less than about 10 minutes with no oil or water, and Subaru EA81s just keep going for at least 20 theres a few Youtube vids around, people are always surprised how long they last.

[Bruce Tuncks]

I knew this guy who took off from Parafield in a Cessna. Only a few km away, he lost all his oil pressure and turned back but the engine got hot and stopped quite quickly. He force-landed but the rollout took him into a vineyard near Yatala prison.

17 mins would have got him home but he sure had less than that.

On the other hand, the advertising for a teflon oil additive described a car which drove from Sydney to Melbourne with no oil.

[Thruster88]

have blown up a few old engines on the past, never less than about 10 minutes with no oil or water, and Subaru EA81s just keep going for at least 20 theres a few Youtube vids around, people are always surprised how long they last.

This engine did have the propeller load, 2200rpm static would be about 65% power.

[JG3]

I watched a country show when they emptied all the oil from an old Vanguard and then took bets as how long it would last. It drove around and around the race track while the evening show, complete with fireworks, took all evening, but the Vanguard was still going well.... Finally it was getting late and everyone wanted to go home but the engine giving no sign of seizing. Finally they drained the radiator and then it only lasted another half hour....

[Bruce Tuncks]

The reason he lost all his oil was that the sump-plug was only finger tight when he took off. A classic case of maintenance induced failure.

[bexrbetter]

one thing i know from wrecking engines intentionally, if you are ever in a demolition derby, used to be populat on Speedway nights, have a rope tied to one of your pre loosened radiator hoses.

 

A main goal in the derbies is to wreck your competitors radiator causing them to overheat and die. If you get hit and lose all your water, pull the hose off with the rope so you will pump cool air instead, your engine will last longer.

 

I should write a book ....

[Yenn]

One of the things that a certified engine has to do is be demonstrated that it will run without oil for a certain amount of time. I can't remember the actual wording of the requirement. If one failed quickly it wold probably be because there were other problems.

[Bruce Tuncks]

You are right Yenn, I remember some test they had to do with a Jabiru engine along the lines of running it without oil.

[pmccarthy]

There used to be a Holden engine at the annual show that they would run without oil. Had STP or similar in it. They claimed it had been running all year at shows and still OK>

[facthunter]

Worn out engines do it much better and your bearing metal will vary the result. The older Babbitt coated bearings go much better than copper-lead or Alutin.There's some oil left along the oilways to help stop it squeeking but the heat build up should kill it eventually. In some motors only a momentary amount of air being allowed in the suction side of the pump is enough to cause a blow up . Nev

[jackc]

One of these could be handy:-)

 

http://infinityaerospace.com/product/other/pre-oiler-and-back-up-engine-oil-pump/

[Bruce Tuncks]

For years I have wondered why not have an electric oil pump to use before starting. It is interesting to see there is such a thing. My desire was fuelled by the claim that most engine wear was before oil pressure arrived to separate the crankshaft bearing faces.

In my imagination, the pump could even be a manual thing. But these stories about engines going without oil are evidence that the auxiliary oil pump is not really needed.

[facthunter]

It's recommended to pre-pressurise a lot of motors including aviation ones after an overhaul prior to running it. Also to fill a screw on oil filter when it's replaced..Caterpillar graders had a 2 cyl Delco auxiliary engine that warmed the manifold and pressures the oil before firing it up. Where you have metal to metal completely dry you risk metal welding (scoring) of the surfaces. Pressured oil doesn't do the whole job, it's relative movement of the two surfaces that generates the very high pressures in a film of oil that keeps the friction down, separates the parts and reduces wear in PLAIN bearings. Nev

[kgwilson]

Pre oilers have been around for a very long time. The complexity of the Merlin engine meant that the electric pre oiler pump was used to fill the galleries prior to startup. It wasn't on the earlier versions but apparently added 3 hours to the overhaul time which was only 240 hours originally. By 1951 this had increased to 650 - 800 hours depending on use.

[facthunter]

The cam followers in a Merlin don't have rollers. They did scuff out the followers on some starts. This could happen on a new motor as easily as a tired one so the 3 hours added is not a convincing statistic. as it's occurrence is not in any way related to engine hours. Most other "brands" of similar types had roller followers. Engines are not usually" worn out" at TBO. It could be better regarded as a "prudent time" to strip and check the motor to Prevent failures that might increasingly happen for various reasons. Many of these engines were overstressed and were shot down long before any engine was out of hours. The early "state of the Art" French rotaries in WW1 used to fail the little springs in the piston crowns and they were lucky to go 5 hours which could still be OK for front line fighters whose job it was to get off the ground quickly and shoot the enemy down without spending a lot of time in the air.. Nev

[onetrack]

One of the major causes for loss of oil pressure is having external hoses that can burst, or external oil lines that can fracture. Minimise them, and you have a much lesser chance of losing oil pressure.

 

Nev - The Caterpillar diesels 2 cyl starting engine was built as an integral part of the engine by Caterpillar, not Delco. It was fitted to nearly all Cat diesels as standard up to the early 1950's, regardless of application.

The only Cat diesel application that had a standard Delco-Remy electric starter were the Cat Marine diesels, because engine starting conditions on the water meant that very low temperatures were rarely encountered.

 

The 2 cyl starting engines were initially crankhandle start, or started with a pull rope around the flywheel. In the 1940's, electric start was offered for the 2 cyl starting engines.

Some later model Cat diesels from the mid-1950's had a standard starter opening in the flywheel housing, with a Delco-Remy electric starter offered as an option - whereby the 2 cyl starting engine was eliminated.

 

Many big industrial diesels utilise a Delco-Remy or equivalent starter, with a prelube pump attached, as an extension of the starter motor. As soon as the starting motor is cranking, lube oil pressure is raised by the attached prelube pump.

 

https://www.dfjauto.com/product/dfj020300-starter-motor/

Edited May 9, 2020 by onetrack

[facthunter]

I think it's based on the GM copy of the R 38 BMW offered as a warbike engine for Harley but with cooling jackets. Flat twins are not very widely used in any American Industrial design. Harley briefly produced the W model Sport twin 1919 to 1923 600cc horizontal twin of their own design using an integral gear box and clutch. It was not successful in the US but more accepted in Europe.. The crankshafts "One piece and forged" were made in Germany..Nev

[onetrack]

Nev - If you're still talking with regard to the Cat starting engines, they were all solid cast-iron watercooled twins, and shared the cooling system coolant with the main engine.

The smaller Cat diesels utilised a horizontally opposed side valve twin, laid across the rear of the engine above the flywheel housing - the larger Cat diesels utilised a vertical 2 cyl water-cooled starting engine placed alongside the left rear of the block.

The bloke with the slideshow below has good photos of the Cat diesel horizontal starting engine. The Americans referred to them as the "pony" engine, Aussies generally refer to them as the "donkey" engine.

They ran at about 5000RPM for starting the main engine, and they were a constant source of trouble. One of the biggest problems came from operators leaving the starting engine fuel tank tap turned on.

 

Vibration of the main engine would make the carburettor float bounce and let petrol flood the starting engine.

This would run through to the starting engine sump and dilute the oil so badly, the starting engine wouldn't get adequate bearing lubrication. The next result was a huge BANG, as the little engine "threw a leg out of bed"!

 

https://www.mervbergman.net/wp-content/uploads/ss2caterpillar/#IMG_0099.JPG

Edited May 9, 2020 by onetrack

[jackc]

Nev - If you're still talking with regard to the Cat starting engines, they were all solid cast-iron watercooled twins, and shared the cooling system coolant with the main engine.

The smaller Cat diesels utilised a horizontally opposed side valve twin, laid across the rear of the engine above the flywheel housing - the larger Cat diesels utilised a vertical 2 cyl water-cooled starting engine placed alongside the left rear of the block.

The bloke with the slideshow below has good photos of the Cat diesel starting engine. The Americans referred to them as the "pony" engine, Aussies generally refer to them as the "donkey" engine.

 

https://www.mervbergman.net/wp-content/uploads/ss2caterpillar/#IMG_0099.JPG

Also referred to as ‘pilot motors’

[facthunter]

The only ones I've seen were on Cat graders and the motor was rope started. They ran it for a number of minutes and then engaged it and started the 6 cyl motor. Be in the 50s. Usual council grader medium+ size. Where I worked we rebuilt many graders right through and then leased them to Councils for about 3 years. I think most of them were Allis Chalmers. Maybe they had GM 2 strokes. We did many of them and to be frank it was just another job to bring in the shekels. We didn't get any failures as they were done properly right through. Nev

[jackc]

Centurion Tanks had the 650hp Meteor V12 motor where we had to start the Morris Minor side valve motor with generator before you cranked the Meteor up. Always hard to start and the wooden case batteries would not stand the strain on their own.

[facthunter]

They had a crank handle in the series MM car. What's wrong with you guys? No Weeties for breakfast? Nev

[craig scott]

A bit of topic I know but, on a cross country several years ago in a constant speed machine I suddenly lost oil pressure - it was reading zero by the time it was noticed. I reduced power, bought the pitch back to full fine and started looking for a suitable field. Every 15 - 20 seconds the oil pressure flickered and rose to about normal and then dropped back to zero just as quickly as it came up. I turned for home and nursed the engine at low rpm heading back to the closest airfield, all the time looking for a more suitable forced landing area. Although I lost some altitude, I managed to make it back the the departure airfied and landed safely. The aircraft flew for over 20 mins in this state. On the ground, the covers came off and we discovered a broken flare on the propeller governor oil line running from the rear to the front of the engine. In this case an IO-360 Lycoming.

It seems that with the prop in full fine (on this engine at least), there is no pressure in the governor line, so no more oil was lost after full fine was selected. There must have been just enough oil left in the sump to intermittently allow the pump to push a bit out as it returned from the engine.

I know that some constant speed prop's will go to feather when they lose oil pressure, but some don't - check your machine, know your machine and this little tip might save your engine or your life one day.

[facthunter]

Pt 6's start and stop in feather and have auto feather, but that's not what Pistons do. The ones that use oil pressure from the engine will end up on the fine pitch stop like they are when you start. Selecting fine will control the governor which ports the oil to the prop to force it into a coarser position at the appropriate RPM.. That IS something that's worth remembering. Centrifugal forces acting on the prop blades make it want to go to FINE. That's it's "fail to" position. The fine pitch stops should be set so as to permit flight comfortably above stall speed. Good post Craig. While not every ultralight has in flight adjustable or C/S props the principles should be understood. Nev