Bore Honing Without Engine Removal

[a64pilot]

Honestly try running it down a little on oil level.
Or try sucking out every drop you can, then adding exactly what the book says it will hold, including oil filter and seeing where that is on the stick, it’s very possible that up to the full mark due to engine angle is a little overfilled.
Then honestly even though they ought to all be identical, some engines will burn a little oil if it topped off.
Mine will burn down to about half way to the halfway to the add oil mark in ten hours and if I don’t add any, it won’t burn another drop in the next 90 hours, if I keep topping it up, it will keep burning it down.
It took me awhile to figure that out, I initially thought I had a 1 gt in 50 to 100 hours burn rate, which is minuscule by the way.

I know I’m an airplane guy, but this is some decent reading.
Just for curiosity do the max engine oil burn rate and you will be astonished, an engine can burn that much oil and it’s acceptable, that means you take no action, it’s safe to fly.
https://www.lycoming.com/sites/defau...onsumption.pdf

[a64pilot]

Please don’t do the dingle berry hone, those things are really, really Mickey Mouse, even as glaze breakers, may as well feed Bon-Ami into the suck side.

[Lepke]

I've been doing engines since to 1960s. When I was young and didn't have a lot of money to spend, I'd pull the pistons, hone the cylinder and install original pistons with .002" oversize rings. And I got good results, always better, near new compression. With diesels I could just about double the life.
Later with turbo Detroit Diesels, I honed the sleeves at about 6-7000 hours, new rings, and went to above 12,000 before a normal rebuild.
Now I'm old and any overhaul will last the rest of my life, so I figure it's worth a total rebuild so I won't have to do it again.
If you're paying a mechanic, it's usually better to just do a full rebuild. It's almost always close to the same labor cost. More expensive if done in the boat.
I originally learned on aircraft radials. I can't see someone signing off on Bon Ami.

[Dockhead]

Originally Posted by a64pilot

Honestly try running it down a little on oil level.
Or try sucking out every drop you can, then adding exactly what the book says it will hold, including oil filter and seeing where that is on the stick, it’s very possible that up to the full mark due to engine angle is a little overfilled.
Then honestly even though they ought to all be identical, some engines will burn a little oil if it topped off.
Mine will burn down to about half way to the halfway to the add oil mark in ten hours and if I don’t add any, it won’t burn another drop in the next 90 hours, if I keep topping it up, it will keep burning it down.
It took me awhile to figure that out, I initially thought I had a 1 gt in 50 to 100 hours burn rate, which is minuscule by the way.

I know I’m an airplane guy, but this is some decent reading.
Just for curiosity do the max engine oil burn rate and you will be astonished, an engine can burn that much oil and it’s acceptable, that means you take no action, it’s safe to fly.
https://www.lycoming.com/sites/defau...onsumption.pdf

Well, the oil consumption is not excessive -- maybe 0.5 to 1 liter in 100 hours. That doesn't bother me -- but obvious signs of blow-by do -- oil dribbling from the breather, etc. And of course the smoke.


As to a possible overfill condition -- I've owned this engine for 9 years and put 2500 hours on it -- I've definitely used it with oil down near the minimum a time or two. It doesn't make any difference. But of course it was a good question (like all of yours).

[Ramona]

I would leave the engine alone. Probably not run in yet or run in properly. Could be glazed bores and gummed up rings caused by idling for long periods with no load.
I would suggest a snake oil remedy like FTC.
https://costeffective.com.au/product/ftc-decarbonizer/
It is expensive but makes a dramatic improvement in a short time. My Gardner was burning 2 litres of oil a day. After one dose and a hard run dropped to virtually nothing and the exhaust smoke to nothing [dry exhaust]. Very impressive in a fishing vessel engine of only 65 years of age. Similar results from friends yacht auxiliary engines. You may have to find the equivalent product in your country.

[Bruce K]

Originally Posted by Ramona

I would leave the engine alone. Probably not run in yet or run in properly. Could be glazed bores and gummed up rings caused by idling for long periods with no load.
I would suggest a snake oil remedy like FTC.
https://costeffective.com.au/product/ftc-decarbonizer/
It is expensive but makes a dramatic improvement in a short time. My Gardner was burning 2 litres of oil a day. After one dose and a hard run dropped to virtually nothing and the exhaust smoke to nothing [dry exhaust]. Very impressive in a fishing vessel engine of only 65 years of age. Similar results from friends yacht auxiliary engines. You may have to find the equivalent product in your country.

I have also used this stuff, works some of the time, esp on engines that have been use as chargers running under light load, sometimes does not work. A friend used it in a pair of old horizontal ~200hp Volvos with very dramatic improvement, went from being unable to see the boat on start up to a little bit smokey. Heaps cheaper than a rebuild, and worth a try I think.

[Dave_S]

We used to laugh about a mythical company called RAG engineering. They would hone cylinders with the crankshaft in, then tell you they have done it all their lives "no problem" as they rattle off down the road.

We had one guy make a spectacular entry into a finish control with a con rod making its way out through the starter motor, clouds of smoke and flames. He then announced that he couldn't understand it, he had only just rebuilt the motor last night and everything was perfect.

Truth is the harder you try to get rid of the cutting oil and gritt the more likely it is to find its way into every nook and cranny only to come out and circulate through your engine latter.

Don't do it. Step one is, you have to know for sure what is causing the smoke. Step two, is it worth fixing now. Step three, fix it properly when you do, no half arsed measures.

RAG engineering = Rough As Guts Engineering.

[pedro b]

FWIW we had a very smoky Ford diesel in a Roberts 45. Low hours but far too much freezer and battery charging. The local diesel expert gave it 2 table spoons of AJAX, slowly, into the air intake while at fast idle. After a very smoky full throttle flogging into a head wind we had a clean exhaust after 1/2 an hour. Oil pressure and temperature were normal from then on and needed no oil added between 100hr services.

[a64pilot]

It’s a Diesel, it’s supposed to smoke, stink and rattle.
Half a liter to 1 liter every 100 hours is nothing.
It cranks easily, makes good power, has good oil pressure. There is nothing to fix, trust me, I used to do this engine stuff for a living.

There is a lot of evidence that once an engine begins to burn a little oil that it’s upper cylinder wear drops quite a lot. The Brits did testing before WWII to confirm this, back in the day, they were likely the best engine builders / designers there was.
Anyway the paper I read a hundred years ago said that their theory was that once an engine began to consume some oil, the the compression rings were being properly lubricated, and before that they weren’t.

Now a lot has changed since then, but I see engines that use a little oil regularly outlasting ones that don’t still to this day.

By the way if you ran the formula that Lycoming publishes for their aircraft engines, you discovered that a modern 300 HP engine is allowed to burn .97 quart of oil per HOUR and it’s acceptable.
I know, these are not aircraft engines, aren’t air cooled etc. but 1qt every 100 hours is nothing.

I had an old VW Golf Diesel that I bought new for years, it burned down to the half way mark on the stick between every oil change, until about 50,000 miles, then it suddenly stopped burning any oil.
That was about the time we started driving it back and forth between Tx and Ga. I pulled a small trailer and would set the cruise control going downhill at about 65 mph, the car would plane out running wide open about 55 to 60, and I would run it wide open for 12 hours at which point it needed fuel.
I think I finally seated the rings is what happened.

[model 10]

[QUOTE=a64pilot;26978
By the way if you ran the formula that Lycoming publishes for their aircraft engines, you discovered that a modern 300 HP engine is allowed to burn .97 quart of oil per HOUR and it’s acceptable.


That's just a stupid warranty thing. Who cares how much oil it uses as long as you don't run out. Nobody would fly that engine if it used a quart an hour, that would be stupid.

[Kenomac]

I have the same Yanmar engine on our 53 which doesn’t smoke or burn oil. Leave it alone, you’d be burning a lot more than one liter per 100 hours if there was a piston ring issue. The issue is more likely fuel related.

[Compass790]

Without knowing this particular engine & your access to it, can you pull the liners ( if it has them) in situ? Obviously the blowby is making you grind your teeth so can see yr wish to hone. If you get the liners out that would solve the cleaning worries.You need to mic the bores & check ring gaps/piston dia.

[a64pilot]

[QUOTE=Ecos;2697877][QUOTE=a64pilot;26978

By the way if you ran the formula that Lycoming publishes for their aircraft engines, you discovered that a modern 300 HP engine is allowed to burn .97 quart of oil per HOUR and it’s acceptable.





That's just a stupid warranty thing. Who cares how much oil it uses as long as you don't run out. [/QUOTE]



That is actually where the max oil consumption number comes from, FAR’s require an engine to hold enough oil so that at max oil consumption, when it has flown in the airframe it’s certified in, that it will run dry of fuel before getting to the min bearing safe oil level.
Then along come STC’s that increase fuel capacity, and that isn’t accounted for. Flint tanks on a C-210 for example.
Point I was trying to make is that an engine can burn quite a lot of oil and still make good power, be safe and even still live a long life.
So long as you still have good compression, oil consumption isn’t really an issue.
Of course if it gets to the point that you look like a Smoker on the Water World move, yeah you need to fix that.

Apparently the big ole radials of days gone by the R-2800’s etc. would have a 50 gl or so oil tank and burn a lot of that on each flight.

[Nineteen]

Originally Posted by alaskaflyfish

The old time aircraft mechanics (circa.1950's) up here in Alaska used to take a handful of Bon-Ami powder cleaner (like Ajax) and stuff it into the intake while the engine was running high rpm. They said it was the best way to de-glase the cylinder walls if the break in process was done inappropriately. I would never do it, but on a old lawnmower,,(humm).. If you do try to hone your cylinder walls, piston and crank out of the block is best. Get a good quality rigid hone that is adjustable to .001 of and inch.

Hi Alaskflyfish

You made me laugh out loud (haven't heard of this in over 30yrs) - I have seen this done on 2 stroke Detroit diesels as an apprentice. I can verify it was approved in the maintenance manual and it worked in de-glazing.

Just be sure that you change the oil afterwards if you go this way as some of the grit will make its way into the oil.

Cheers
Tom

[Milko Berben]

Out of experience I would go with captloyd's advice and pull the full engine because you can do a much better job on the work bench instead of being a contortionist in the engine room. good luck!