Boring Chromed Aluminum Cylinders

[Ryker Carruthers]

Its not exactly "modeling" but it does involve machining and you guys are some of the smartest I could think of so here goes;
December 27th I purchased a 1980 john deere 440 trailfire snowmobile, rough shape but nothing I couldnt fix. The last time it ran it burned both pistons and scored the cylinder walls real bad. Long story short I got it to run in 16 days and now just waiting for snow. I got lucky and found some resleeeved cylinders on ebay and got a set for myself and a set for my dad (he has the same sled just a year newer). How does one go about boring chromed cylinders? It looks like it is sleeved at the top but on the bottom its a different story. I dont want to press on what I think is the liner and screw anying up. Would I have to take a deep cut first to get under the chrome?
Thanks in advance,
Ryker Carruthers

 

[canadianhorsepower]

Its not exactly "modeling" but it does involve machining and you guys are some of the smartest I could think of so here goes;
December 27th I purchased a 1980 john deere 440 trailfire snowmobile, rough shape but nothing I couldnt fix. The last time it ran it burned both pistons and scored the cylinder walls real bad. Long story short I got it to run in 16 days and now just waiting for snow. I got lucky and found some resleeeved cylinders on ebay and got a set for myself and a set for my dad (he has the same sled just a year newer). How does one go about boring chromed cylinders? It looks like it is sleeved at the top but on the bottom its a different story. I dont want to press on what I think is the liner and screw anying up. Would I have to take a deep cut first to get under the chrome?
Thanks in advance,
Ryker Carruthers

HEY RYKER,
don't touch these cylinders, they are perfect.
they are coated with NI-CA-SIL and alu (piston) want damage them.
Just get a bottle of |sulfuric acid]cement or concreat cleaner, this will swallow
aluminium alive.
BE CAREFULL TAKE ACVID USE A QTIPS AND SLIGHTLY PUT SOME ON THE DAMAGE PARTS OF YOYR
CYLINDER SOME SMOKE WILL APEAR"IT'S SHEWING ALU" RINCE OFTEN AFTER A COUPLE OF SECONDS NOT MINUTES
IT'S AL GOING TO BE PERFECT
SPARY SOME OIL RUB IT KISS IT, IT'S LIKE NEW

 

[Ryker Carruthers]

That will disolve the chrome or the aluminum?
Thanks

 

[MuellerNick]

That will disolve the chrome or the aluminum?

NaOH will dissolve the aluminium. Only helps, if the piston seized and left some ali behind.
Don't try to bore the chrome, it won't work at all. The only way is grinding or stripping it at a plating company.

Re-sleved and chromed is a contradiction. The cylinders are either sleved or chromed. Two-strokes are commonly chromed. Re-chroming (Nicasil) is quite expensive (at least here). Starts at about 200 € (roughly $250).

Nick

 

[jack620]

Hi,
Etching the aluminium with Hydrochloric (muriatic) acid is quite a common fix for go kart engines:

http://www.ekartingnews.com/viewtopic.php?t=108330&sid=fd834c397c80d9bf9a6044da30069231

 

[Ryker Carruthers]

I see what you mean now, no the pistons arent stuck or seized. The ones I got on ebay were bored out and had cast iron liners pressed in. Not chromed after that just left as cast. I just need to know how I can take that chrome layer out on my old ones without ruining a few boring bars... When the pistons burned the rings broke up and there is a major gouge in the wall in both cylinders that is past the chroming.

 

[va4ngo]

The concrete cleaner I have seen here in Australia is Hydrochloric acid. and referred to as Muriatic acid not Sulphuric acid. Sulphuric acid is used in batteries.
phil

 

[aonemarine]

Having built hundreds of outboards that are nicacel bores your only option to save the jug is to install a cylinder sleeve. Wiseco should make one for your application.
Never had a problem cutting thhru the plating, usually took .020 off the first pass then .010 as a finish pass. If I didnt quite hit the mark for the press fit I would use a rigid hone on the aluminum to finish size it then press in the sleeve. The cylinder was heated to 400 deg and the sleeve stuck in the freezer, then it was an aluminum disc placed on to por the cylinder and a 3 pound hammer to send it home as quickly as possible.

 

[Ryker Carruthers]

Having built hundreds of outboards that are nicacel bores your only option to save the jug is to install a cylinder sleeve. Wiseco should make one for your application.
Never had a problem cutting thhru the plating, usually took .020 off the first pass then .010 as a finish pass. If I didnt quite hit the mark for the press fit I would use a rigid hone on the aluminum to finish size it then press in the sleeve. The cylinder was heated to 400 deg and the sleeve stuck in the freezer, then it was an aluminum disc placed on to por the cylinder and a 3 pound hammer to send it home as quickly as possible.

Thanks!
I think I will buy a sleeve from mcmaster carr and do the porting myself.
Thanks again,
Ryker Carruthers