Engine lost all oil, some pistons grabbed

[Jarturin]

Devil put its tail in my cylinders...

Devil put its tail in my cylinders...

After one hour cruising in my 73 hardtop, with 302 engine upgraded 300 miles back with a top end engine kit for 300 HP, hearing loud music and talking to angels, suddenly music changed to an engine noise, and two seconds later engine stopped. This was my second rally after the upgrade.

Finding was that all oil had gone through the teared tubing to the oil pressure gauge, tubing that was ripped, just out of the connecting fitting tip, and also ripped some 5 inches after, see photos .





Radiator was expelling boiling water through the cap bypass, and level was good as could see later.

If there were idiot lights on, I could not tell, did not look there.

Result, after opening the engine: two or three pistons with signs of brushing the cylinders. Will need to replace all pistons, rectify all cylinder walls (030), put new rings, new metal bearings, and polish crankshaft, at least. So far inspection of cylinder heads has showed no damages there.

Why this oil tubing failed? See photos attached. No rubbing in that area...Seems tubing ripped by hot temperature. Why oil heated that much? I checked with a thermometer the thermostat operation and it works/open normal at 83-85ºC (183ºF). Cruising speed was between 100 to 120 kph (69 mph), so lots of air, ambient air temperature was around 30ªC (86ªF), not too much, engine rpms were around 3000 (have a T-5 transmission), clutch fan has only 60 miles, and was checked Ok after installation. It shows today to be clean, no leaks, spins with some force, as should be, so I discard it. Now checking the radiator, may be water tubes are partially plugged, will see after opening it. The air passages look clean.

What else to check?

What can be possible causes? Please your comments.

Thanks

 

[72HCODE]

WOW

 

[Mikes73]

Oh my, sorry to hear that.

 

[RacerX]

You didn't notice anything wrong on gauges or lights ?

What does that tube go to ? It's not original.

Looks like it was weakened by the bends or not rated for the pressure it was being used for.

 

[rocket366]

Looks like a a steel or aluminum line with an added insulating outside rubber hose

or some kind of insulation that had split NOT the line IMO from photo.

Paul

 

[mjlan]

If the black line is in fact the line supplying oil to an add-on gauge it looks to be of a very questionable material, and if it is plastic, it is risky to use. I would use at the minimum a copper line kit, or most preferable braided steel.

Is this the supply line for an auxiliary oil pressure gauge?

 

[basstrix]

That tube used for your pressure gauge doesn't look like any tubing I've ever seen in an engine oil application. Where did you get it, what is it made of, and how did it come to be used in this application? To me, that looks like cheap ABS tube used for backyard irrigation systems!

Anyway, sorry to hear about your situation and hope you get it resolved quickly so you can get back to enjoying your ride.

 

[Carolina_Mountain_Mustangs]

Most aftermarket gauges have tiny little tubes so the area of pressure is small.

I might suspect something hung in the oil pressure by pass valve in the oil pump. The 302 and any ford engine using the hat type valve stem seals are know for this happening. The oil filter is usually what explodes but that line was your weak link. The pieces from the seals gets into the oil pan and when there is enough the oil pump screen gets clogged and pulls up to open a hole to prevent engine from starving from oil. That lets chunks into the pump and can lock it up causing the drive in the distributor to break or hold the pressure relief closed and just pump until something gives. Check the oil pump and screen for black pieces of old seals or trash. Get rid of the line in the picture and go with something better. Idiot lights are a great thing if bright enough to get your attention. NASCAR has them on the dash you don't have time to check the gauges while racing other than a glance now and then. The BIG RED light right in front of you comes on if you loose oil pressure. That is the reason tachs have a shift light so you don't have to read the rpm. Lights are better than gauges any IDIOT can understand them. Gauges look cool and are great but a light will save you lots of money.

David

 

[Tnfastbk]

To me this looks pretty simple to explain. If you look at each of the splits they are located in a bend. When you use benders to bend tubing it stretches the metal to achieve the bend ultimately thinning the walls of the tubing. Over time or to thin to star with this is what happens. Still sucks no matter how you see it.

 

[basstrix]

Looks like a a steel or aluminum line with an added insulating outside rubber hose

or some kind of insulation that had split NOT the line IMO from photo.

Paul

If you're right, then I want to see the compression nut that fits the insulation and compresses a ferrule to the inner line. That's a big OD ferrule with a small OD for the inner line, right?

 

[rocket366]

Hard to tell what is going on from the photo.

Paul

 

[basstrix]

Agreed.

 

[rocket366]

The 70's Chevy truck fleet I was in charge of in the

80's had mech. oil guages and the line was 1/8 copper

with the brass nut and the line had a rubber or neoprene

hose or covering on it that protected it from rubbing on

things. The photo reminds me of that type.

Paul

 

[Jarturin]

Thanks all for valued comments, specially thanks to David from Carolina_Mountains, will check if oil pump could habe been clogged.

The broken plastic line comes with standard mechanical gauges, and my mechanic says have seen these working well since many many years. He says may be oil temperature went extremely hot for some unknown reason or pressure went wrong, or a combination causing the burst, so will check David's theory.

or simply the plastic lines today are not as strong as in the past.

For sure next added pressure or temp gauge will be electric!!

Will tell more later....

 

[Tnfastbk]

Plastic???? Well there went my theory. O'well least I know my eye sight is not getting any better.

 

[barnett468]

it wouldnt hurt to run a ball hone in your bypass valve bore andd snd the valve lightly with 600 thru 1200 sand paper and water or wd40 . loose is better than tight.

 

[MeZapU]

Maybe it's the plastic that has changed over the years, maybe it is the oil formulation, or a combination of both. You could try a copper capillary tube. Much more durable but it also can have some issues.

http://www.summitracing.com/parts/atm-3224

Sounds like you are going electric but I thought I'd show you this option.

 

[Don C]

I've always used 1/8" copper for mechanical gauges, the plastic stuff that came with some gauges went directly into the trash can. I've been using electric gauges in the last few installations, though. I kept one old SW mechanical gauge and copper tubing for testing.

 

[digithead]

Just my 2 cents but years ago I had a Firebird with oil pressure with copper tubing and live oil in it. Leaked all over and made a mess. I said never again. I will only go for electronic sender. Hell even if that plug/sensor leaked it would warn you with some tiny drips first and youd notice.