Queston about honing a cylinder

[jp1961]

Hello,

There is a local company (Labarons power sports in Almont MI - labaronspowersports.com) that offers Nikasil re-plating services. I will call them tomorrow to ask them if it is possible to plate a Lawn-Boy engine. Seems like you'd want to plate a Lawn-Boy engine that has a separate cylinder head like the Duraforce, but it may be possible to plate a jug style engine like the D series. I have an old Duraforce engine, that I could use as a guinea pig. Hmmmm sounds like I've found my next 'winter project',,,lol.

If feasible, sounds like a way to restore an engine, where the cylinder is no longer available from Toro.

Jeff

 

[jp1961]

Hi All,

I called Labaron power sports, they use Millennium Technologies (out of WI) for the actual plating, so I called them. The tech said any cylinder (aluminum or steel sleeved) can be plated, but can't be damaged. He said the plating is about .004 to .005" thick, so you would have to bore out the cylinder that much. The process takes 7 to 10 business days and the cost is 209.95. They diamond hone the cylinder after plating. He did say you have to use chrome moly rings with this plating. I'm not sure what standard Lawn-Boy rings are made from.

So there you have it,,,be the first kid on your block with a Nikasil plated Duraforce,,,lol.

Jeff

 

[javjacob]

Thanks for finding that out for us! I wonder if it can be done to a F engine?
Then the next thing would be finding chrome rings. Is it chrome or chromoly?

 

[jp1961]

You're welcome. The tech said chrome moly, not chrome. Standard iron rings would probably wear out very fast against the Nikasil plating. I see no reason why an F cylinder couldn't be plated, remember though you'd need to have the cylinder bored out about .005".


Jeff

 

[javjacob]

I guess the hard part will be finding chromoly rings. If I can find a set I would think about doing it since I have a F engine short block I am going to tear down and rebuild sometime in the future. Just depends on the condition of the cylinder. I would imagine a F engine with a Nikisil cylinder and chromoly rings would never wear out.

 

[fabricgator]

There is another plating technology (of at least brand name) that I have heard in aviation called Cermanil like ceramic.

I would think that Millennium would mill the bore the 5 thou, build it up with deposit plating and then cut it true to size. A one stop cylinder shop.

We also have Millennium brand cylinders in aviation. I wonder if it is the same outfit?
It is not uncommon for the Millennium cylinder to pass compression test beyond wildest dreams. My first time, I got another technician to find out what I was doing wrong to get so high a differential pressure reading (leak down compression test)

 

[fabricgator]

A few posts back, there was a statement about rings.

Just a little knowledge nugget for some.

When we install new rings on and aircraft engine, there is a procedure about filing the ring gap. We put the individual ring (lets say the number one [or top]) into the cylinder bore and use the piston to push them in to the place where they would be at TDC if wrapped around the piston. Then we slide the piston out and use a feeler gauge to check that ring's gap.
We file fit to a engine manufacturer specification. so that when the assembled engine is at operating temperature, that the gap is just right. Then we repeat for each ring, keeping track of each rings intended position and orientation.

We don't want the gap so big that it is a large passage for pressure to escape, nor do we want it so tight that when the engine heats up and the individual metal parts expand, that the gap closes too tight and possibly applies mechanical pressure to the ring and/or cylinder walls.

In spec is just right.

I've not done a mower nor a lawnboy, but I'd imagine there is a procedure similar to this.

I have a dream, a dream of a home built, scale Junkers_JU-390 or a Focke-Wulf Ta 400 two seat airplane that has six air cooled lawnboy engines powering it...
My friends think I am crazy.

 

[javjacob]

A few posts back, there was a statement about rings.

Just a little knowledge nugget for some.

When we install new rings on and aircraft engine, there is a procedure about filing the ring gap. We put the individual ring (lets say the number one [or top]) into the cylinder bore and use the piston to push them in to the place where they would be at TDC if wrapped around the piston. Then we slide the piston out and use a feeler gauge to check that ring's gap.
We file fit to a engine manufacturer specification. so that when the assembled engine is at operating temperature, that the gap is just right. Then we repeat for each ring, keeping track of each rings intended position and orientation.

We don't want the gap so big that it is a large passage for pressure to escape, nor do we want it so tight that when the engine heats up and the individual metal parts expand, that the gap closes too tight and possibly applies mechanical pressure to the ring and/or cylinder walls.

In spec is just right.

I've not done a mower nor a lawnboy, but I'd imagine there is a procedure similar to this.

I have a dream, a dream of a home built, scale Junkers_JU-390 or a Focke-Wulf Ta 400 two seat airplane that has six air cooled lawnboy engines powering it...
My friends think I am crazy.

I like that idea lol I have a dream of a garden tractor with a detuned triple cylinder 2 stroke snowmobile motor powering it.