Smokstak

By Staff
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Arecent topic on the EnginAds SmokStak bulletin board at
http://www.smokstak.com/ involved seating new piston rings in old
engines. The thread’s head? Expert Advice Needed.

I just rebuilt the engine in my 1914 12-25 Avery. The sleeves
are new and I re-grooved the pistons for new, over-width step-cut
rings. I also installed new wrist pin bushings, new valve stems and
guides, everything. But I have a problem: The rings will not seat,
and it’s pumping oil like a pig even though it runs like a
Swiss watch.

I started with 20/50 weight oil, switched to 10 weight
non-detergent, and now straight 50 weight. I don’t have the
pulley mounted, but when I press a plank against the flywheel it
clears right up. I’ve resigned myself to the fact that it’s
just going to take a long, heavy load to do the trick. Does anyone
know of any shortcuts? – Craig

I have seen this happen in a pressure-fed engine when rod
bearings are running excessive clearance, which causes excess oil
to be slung from the crank onto the cylinder. I’m not familiar
with your engine, and if you don’t have pressure feed to your
rod bearings then everything I’m saying is hog-wash. But if you
do, try tightening your rod bearing clearance.

I don’t know what of oil ring you are using, but if it’s
a simple gapped ring, make sure the gap faces the wall of the
cylinder opposite from the wall that gets all the oil. If it’s
a compound ring, make sure you stagger all of the gaps
appropriately. – Harvey

Craig, a friend of mine overhauled a Farmall H and his tractor
ran great, but it pumped oil worse than before he overhauled it. I
helped him tear it down and found he had put the oil ring in upside
down. There were no marks on the rings, so he just put them in the
way they came out of the package. It turned out the rings had a
groove on the inside that had to face towards the top of the
piston. After we did this it cleared right up. – Justin

An old tractor engine man told me he would quick seat a
difficult engine by putting a fair amount of Bon Ami in a cloth and
dusting it in front of the carb. He claimed just enough abrasive
going in would seat the rings and not hurt the engine. I have never
done this, but found it an interesting idea. – Randy

You guys are right on the ball. As to the oiling system, two
solid streams of oil delivered through a 3/8-inch pipe are shot out
over the connecting rods. Talk about overkill. That’s probably
why all the journals are nearly perfect. And that’s not the
first time I’ve heard of using Bon Ami, or baking soda,
delivered through the carb. – Craig

Please go easy with the Bon Ami stuff, guys. While this used to
be an accepted way of quickly seating in an engine, it is also a
very quick way to destroy an engine and should only be used as a
last resort. In older engines with low piston speeds it was
marginally workable. The abrasives were typically used to resolve
compression issues, not oil consumption issues. It sounds like you
have plenty of compression – oil wiping is the prevailing issue.
Remember that abrasives counteract the lubricants in the engine. If
you have never done the Bon Ami thing, try it first on an engine
you don’t care about. – Harvey

I have seen an engine ruined beyond repair with the Bon Ami
trick. – Dan

Caterpillar used to have some stuff they called ‘Break in
Powder’ that was used to seat rings in the manner described
here. I tried the Ajax thing on my 16-30 Rumely, but the results
were inconclusive. Now, with more time on it, it seems a lot
better.

I wonder if there wasn’t something special about the
original Avery bottom rings. What type of rings did you put in the
bottom groove? I did a little checking in a reprint catalog and
would think with five rings there wouldn’t be much oil getting
by. If my 25-45 has too much oil in the crankcase everything within
50 feet is covered with black spots – including the operator. –
Ken

These are five ring pistons: three compression, one that holds
the wrist pin to keep it from damaging the cylinder should it get
loose and a fifth ring below that. Immediately below that ring is a
chamfered groove with drill holes for oil escapement, sort of a
substitute for a real oil ring. A friend said he has heard some
rings are harder than normal and very difficult to run in. Could
this be my problem? – Craig

Craig, because of the rotation of the Averys and their oiling
system, all the oil goes to the front cylinders. Averys smoked when
new because of what they called their oil control ring, the holes
drilled in the piston next to the last ring – it never worked. I
have seen bushings put in the oil lines to help with this, but
that’s not a good idea. Put a real oil control ring in the
fifth and third land on the front cylinder and in just the fifth on
the rear – and don’t forget to drill the pistons under the
rings. – Ed

I think Ed has the answer. These old engines were made to work
with a wide open butterfly, so there wouldn’t be much suction
drawing oil past the rings. The first Model T’s had no oil
rings, but that soon changed. Break in powder probably wouldn’t
get to the bottom rings, where it is needed most, and I don’t
think a regular ring will ever control oil as well as a scraper or
oil ring. Some people recommend putting an oil ring in Rumelys, but
most seem to control their oil level well enough without them. –
Ken

It could be the rings never seated. A long time ago I rebuilt
the engine in my 1954 Ford. I put in a set of chrome rings, and
after 500 miles of carefully breaking the engine in, it was smoking
like crazy. The shop that did the boring job told me to really
stand on it a few times to get the rings to seat. They said if I
was lucky the bores hadn’t glazed and this would work.

I was going to Kentucky from California the next week, so I
drove over Donner Pass with my foot in it. Remarkably, going down
the other side there was no more smoke. Maybe you need to hook up
to a Baker fan and just load the heck out of it. Be sure to vary
the engine speed and give it a rest every minute or so. – Elden

I still think I’ve got hard rings. Ed’s rotation note
makes sense. If you could see the stream of oil pouring over the
rods you would not believe it! But I don’t think there’s an
oil ring made that would cure the problem. I might lift the timing
cover again and put a shield inside the crankcase to reduce the
amount of oil getting thrown onto the front piston, or modify the
oil delivery elbow to shoot a wider, less concentrated oil stream.
– Craig

Craig, let’s straighten this out. Ed and Ken hit it square
on the head – until you put an oil ring in a closed crankcase
multi-cylinder engine it will smoke and burn oil, period. You are
looking at a prime example of early technology before they knew
what oil rings were. Ever watch a silent movie and see the cloud of
smoke following the old cars? They didn’t have oil rings in
most cases.

Rumelys without oil rings are sloppy pigs. You need an oil ring
in the bottom groove and holes through the bottom of the groove to
let the oil through. Do not use Bon Ami or dirt or any other
abrasive unless you want to ruin the engine. There is no substitute
for break-in running time. My assumption from reading the thread is
that your compression is acceptable and the oil slobbers
everywhere. Is this correct? I consider the lack of oil rings in
closed crankcase, four-cycle, multi-cylinder engines to be a design
defect. You can live with it, or fix it -.Dave

Ed is correct regarding the rotation of the engine. I had the
timing cover off today and modified the oil feed to the front
piston connecting rod and things have improved considerably. As I
explained before, just below the bottom ring is another groove with
numerous holes through the skirt. In my humble opinion an oil ring
above that would be superfluous. It’s strictly a matter of too
much oil all the time. The rings will break in eventually when I
can get it on a constant load for a while. It has great
compression. – Craig

Even with the oil groove, if you want it to be dry you need an
oil ring in the bottom groove with holes at the bottom of the
groove, at least on the front cylinders. As I stated before, these
early engines were lacking in oil ring technology. You wouldn’t
dream of using such a lame system as a groove with holes in it
below the bottom compression ring and no oil ring in a modern
engine. It does not work, period. If it did, those cost-cutting car
makers would all be doing it to save 15 cents per car. You need a
wide, double scraping edge that scrapes both ways.

Look at flathead Fords -same problem, but caused by too narrow
an oil ring. Henry Ford insisted that 5/32-inch was wide enough for
an oil ring. Well, he was wrong. When Henry got out of the shop
Ford started using 3/16 inch oil rings, and they still do to this
day. If you want to stop the oil burning, oil rings are the only
way unless you mess with the oil flow inside the engine. Be careful
that you don’t cut the oil down so much that you cause
damage.

Talk to Rumely owners. Without oil rings a Rumely slobbers and
spits unless run full bore and under load. This despite the
cylinders being angled down at the back. Early John Deere engines
had the same problems. Deere had a scraper compression ring that
actually came out of the cylinder a little at the back. They
insisted this would scrape the oil down. It did not. I have piles
of useless new-old-stock oil scrapers that will not do the job.
Rumely never did wise up, and there aren’t enough Averys around
to make a decision on them. I think that they were doing the best
that they could with what they knew at the time. – Dave

SmokStak is an engine conversation bulletin board with over
39,000 messages on file and is part of the Old Engine series of web
sites that started in 1995 as ‘Harry’s Old Engine.’
Harry Matthews is a retired electronic engineer and gas engine
collector from Oswego, N.Y., now residing in Sarasota,
Fla.

‘Do not use Bon Ami dirt or any other abrasive unless you
want to ruin the engine.’

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