Can I just hone this cylinder?

[953 nut 55,261]

Seem like this question is asked nearly every week on here. The answers given quite often include buying expensive Bore Gauges or Inside Micrometers. I have an inexpensive down and dirty method of evaluating the cylinder's wear that uses a tool nearly everyone has or could buy for around $ 5.00. A set of feeler gauges and a ring from the piston you just removed will let you know without any other equipment. It won't tell you how much it should be bored (though you can get close) but it will tell you if it is beyond the point of being successfully honed.

In the photo below you can see the first step, placing a ring at the very top of the cylinder above the ridge. The piston ring end gap in this case is 0.080. The cylinder at the ridge measured standard at 3.25" and the cylinder walls and ring edges were worn smooth.

Next I used the piston to move the ring down to a point just below the ridge. The piston helps keep the ring square to the cylinder wall.

At this point the piston ring end gap increased to 0.110"

This step was repeated three more times at 3/4 inch intervals. The results were 0.117", 0.118" and 0.117"

Next the ring was moved to the bottom of the cylinder where the piton rings would not have contacted the cylinder walls. The piston ring end gap returned to 0.080".

The greatest deviation of the ring end gap was 0.038". Now we can do a little fuzzy math to figure out how much the cylinder need to be bored. Changes in the ring end gap will be a change to the circumference. Bore changes would be a change in diameter.

    So, 0.038" divided by 3.14159 will show that the greatest wear in the cylinder is 0.012" larger in diameter than standard and should be bored 0.020".

This is a quick easy way to get the job done without spending a bunch of money on tools you will never use again. You are going to need the feeler gauges when you put the engine back together anyway.

[JAinVA 4,619]

I think you have come up with a simple way for the average person to get an idea of cylinder wear.As a machinist I have the tools you mention to get a more precise measurement but I am well aware of their cost and limited use to most folks.Your method is all most people need to know what they have.You have my vote!

Edited May 31, 2020 by JAinVA

[Pullstart 62,902]

Great post Richard!  When you started, I didn’t quite see the end of the tunnel... then started thinking about what you were getting to, then the rest confirmed my speculation.  Awesome job!

[ebinmaine 67,535]

Excellent write-up of basic and very important information.

 

Perhaps this should be pinned.

 

 

[oliver2-44 9,756]

@stevasaurus As EB said it would be great to pin this

 

[Stormin 9,981]

 Quick, simple, cheap and an excellent idea.

[ri702bill 8,327]

I agree that this is a good process - the only thing it does not take into account is an out-of-round cylinder condition. The ring will maintain its round shape even in an egg shaped hole. I had been given a K161S that was removed from a TroyBilt tiller due to excessive piston slap noise. That bore was .004 out of round - wider where the piston skirts touch the wall. The short version is if you came up very close to the .020 desires bore number, you should either check for out of roundness or be safe and go up to .030 oversize to avoid boring to a size that would not completely clean up.

 

Bill

[Tuneup 1,433]

"mmmmmmmmm, pi..."

 

Seriously, ring travel measures are a deviation of .008 - very nice. Above and below (where it doesn't matter???) adds your .03. Yeah, I'd hone it and move on. I like your method!

[SylvanLakeWH 25,577]

Thank you for an excellent tutorial!

 

Agree this should be pinned.

[Stormin 9,981]

Any doubts about ovality can be checked by checking bore once, then turning the ring 90 degrees. Check again.

[Tractorhead 9,064]

That‘s a perfect quick field qualification method of the cylindre to see if it‘s further useful

or a Bore must be done oversized.

 

did this on my old Mercedes Engine before finally decide to keep the bore.

Another thing could be checked that Way, you can verify if the round is one side washed out or good enough

to keep. With a light behind the piston ring.

 

While you repeat ( i did it 4 times) each pass with a 90 degree rotated ring.

so that measurements give feedback on roundness of the Cylindrewalls.

👍

[formariz 11,987]

 What else can I say?

[ohiofarmer 3,276]

I don't quite understand the out of round thing, but then I have the perfect engine to check it with so I do understand---a seriously out of round 14 HP k series  It is so bad that you can see the rings expanding out from the groove and shake the piston in the bore Not running that engine because I do not want it to blow up

 

 Thanks for that seat of the pants engineering . That is Farmer Gold right there

Edited October 4, 2020 by ohiofarmer

[Tuneup 1,433]

Just a New Year's KUDOS to 953 Nut. Thanks! The P216 is on the bench and is an oil burner. No idea of the hours but the 20 or so I put on her since purchase and cleaning of the the chamber certainly demonstrate wear. Pistons look good and are STD. Top ring on each gapped in spec top to bottom, though just in spec at .019 - .020. Considering wear, a new set of rings and a hone may do the trick. Anyway, the procedure added confidence without having to purchase costly 'unitasker' tools. The 516 will rise again.

[Maxwell-8 4,276]

People who have REAL Yanmar engines, you don't have to hone the cylinder-wall cause it's made out of there special metal that doesn't wear.

Just replace the rings and bearings.

[Wheelhorse#1 1,666]

Excellent write up.Thank for the info !

[seuadr 488]

On 1/3/2021 at 4:32 PM, Maxwell-8 said:

People who have REAL Yanmar engines, you don't have to hone the cylinder-wall cause it's made out of there special metal that doesn't wear.

Just replace the rings and bearings.

is that actually a thing?

[bc.gold 3,403]

4 hours ago, seuadr said:

is that actually a thing?

 

A pedigreed Yanmar proudly displays ISO 9002, show me your clones pedigree.

 

 

 

 

 

 

Edited March 19, 2021 by bcgold

[seuadr 488]

11 hours ago, bcgold said:

 

A pedigreed Yanmar proudly displays ISO 9002, show me your clones pedigree.

 

 

 

I don't have a clone - iso9002 is a standard for quality control and has nothing to do with magical materials that never wears.

 

Which is what i was asking about.

Edited March 20, 2021 by seuadr

[bc.gold 3,403]

2 hours ago, seuadr said:

I don't have a clone - iso9002 is a standard for quality control and has nothing to do with magical materials that never wears.

 

Which is what i was asking about.

 

Direct your question to the metallurgist recently hired by Yanmar.

 

[Maxwell-8 4,276]

On 3/19/2021 at 8:33 PM, seuadr said:

is that actually a thing?

Worn out yanmar's ( which i almost never see)  just need new rings and bearings. often you still see the original hooning marks

Edited March 21, 2021 by Maxwell-8

[bc.gold 3,403]

1 hour ago, Maxwell-8 said:

Worn out yanmar's ( which i almost never see)  just need new rings and bearings. often you still see the original hooning marks

 

I see honeing marks on Onan engines built in the mid 1970's, the secret is they added nickle into the cast iron alloy.

 

The Chevy high performance engines that were sought after displayed 010 or 020 cast into the engine block those numbers indicated the percentage of nickle used in the casting.

 

Nickle and chrome are expensive metals in order to keep production costs down on larger engines the manufacture installs cylinder liners made from metal alloy of a much superior quality than the parent block.

 

 

[bc.gold 3,403]

Henry Ford, used Vanadium in his Model T, frame, springs and the engine crankshaft.

 

Craftsman "Vanadium" Sub-Brand.

During the 1930s Sears used the "Vanadium" mark as a sub-brand on many of its Craftsman tools, including open-end wrenches, box wrenches, and pliers. This use of Vanadium as a sub-brand was undoubtedly intended to draw attention to the alloy steel used for the tools. The tool-buying public of that time had learned to associate the common alloying elements -- vanadium, chromium, and molybdenum -- with the higher quality tools preferred by professional mechanics. References to the "Craftsman Vanadium" sub-brand began appearing in catalogs in 1931 or earlier.

 

 

 

 

[bc.gold 3,403]

The modern 2 stroke is a much lighter engine to help keep the weight down the aluminum cylinder bore has been chrome plated.

 

 

 

[Maxwell-8 4,276]

Just now, bcgold said:

The modern 2 stroke is a much lighter engine to help keep the weight down the aluminum cylinder bore has been chrome plated.

 

 

 

didn't work well in the 686cc in my opinion, had one, never done much hard work and in the end used more engine oil then gas.