Cutting a cylinder base without a lathe?

[watsonr]

Have a few cylinders with squish in the not so squished category. Removing the base gasket only does so much and removing some material would solve the problem.

We all read about aftermarket cylinders or big bore kits with the compression reading of 120psi, reducing the squish would raise compression. Most of us don't have access to a lathe or the funds to have the machine work done.

Anybody do something to remove some of the base material to reduce the clearance effectively lowering squish without a lathe?

 

[polkat]

i.have taped sandpaper to a flat smooth serfice and took a smidge off, its time comsumeing not really knowing how much you took off but it did the trick

 

[nmurph]

Won't work on most Husky cylinders either.

 

[plumbcrazyjr]

i have used a belt sander a steadyhand and a set of calipers. just keep turning and measuring

 

[watsonr]

Nobody else? Looks disappointing.

 

[Justsaws]

Nobody else? Looks disappointing.

All I have ever used is some form of sand paper mounted to what ever it took to remove the material. On the Husky 350s I just mounted the paper to the crankcase adaptor, for other saws sometimes you have to make a different jig. I usually scribe the amount I want removed into the cylinder and sand away.

I do not do it very often but it has never taken very long and I have not had any issues with the results. You could always use a belt sander, router, wood lathe or cut it on the table saw if you were so inclined. If was doing a bunch of the same cylinder then putting together a jig for the router table or table saw might be of interest but for one cylinder a half hour to a hour worth of hand sanding is acceptable.

I probably would not try the joiner or the planer.

 

[Mastermind]

Are you sure you can't afford to have the jug cut on a lathe? I have most every size of mandrel already made so setup time is just a few minutes......

 

[Jim Timber]

The only other way I'd do it is on a mill with a boring head. Lathe is faster.

 

[BloodOnTheIce]

I was going to say there's a bunch of guys on here who own them and for about 10$ in shipping
and their labor would throw it on their lathe and do it for you.

 

[Eccentric]

Have a few cylinders with squish in the not so squished category. Removing the base gasket only does so much and removing some material would solve the problem.

We all read about aftermarket cylinders or big bore kits with the compression reading of 120psi, reducing the squish would raise compression. Most of us don't have access to a lathe or the funds to have the machine work done.

Anybody do something to remove some of the base material to reduce the clearance effectively lowering squish without a lathe?

Are you sure you can't afford to have the jug cut on a lathe? I have most every size of mandrel already made so setup time is just a few minutes......

There it is Randy. Send your jugs to Randy.:msp_thumbup:

 

[Justsaws]

I was going to say there's a bunch of guys on here who own them and for about 10$ in shipping
and their labor would throw it on their lathe and do it for you.

Hmmmm, still to much for a Husq 350 cylinder but maybe a 395,....


nah, probably still would not bother shipping it.

Hey folks I read BOTI's post wrong so I deleted the part were I said that $10.00 was a heck of deal, I have know idea what the people charge for their services. Contact them and find out.

 

[XPLRN]

I was going to say there's a bunch of guys on here who own them and for about 10$ in shipping
and their labor would throw it on their lathe and do it for you.

If I'm reading this correctly..........$10 is a approx. shipping cost..........however there would still be the labor charge of the person doing the work!??

 

[Justsaws]

If I'm reading this correctly..........$10 is a approx. shipping cost..........however there would still be the labor charge of the person doing the work!??

Good catch, I think that I misread the post.

 

[Jacob J.]

Are you sure you can't afford to have the jug cut on a lathe? I have most every size of mandrel already made so setup time is just a few minutes......

I can't afford you but I still want you working on my saws.

 

[watsonr]

I can't afford you but I still want you working on my saws.

Exactly!!

I don't have a bunch that need it, just an occasional jug... like the 7900 BBKit. Darn thing runs great but only has 120psi and the squish is a little out, near .048 without gasket. Disappointing to know that after spending a crisp $200 to get it running I'm going to send the jug for milling and an additional cost that I shouldn't really have to do. Asked to see what others were doing and it sounds like custom work required or live with it.

I'm not one stuck on numbers and believe that if the saw is running good, the compression number doesn't really matter but...

I tried to sell this saw several times and each time the buyer backed out because of the low number... it throws chips 20 feet! and I know that a BB kit is about torque not RPM or high compression. That said, a lot of people are hung up on a compression reading and if I am going to sell it, the number has to come down.

Thanks for the replies!! Looks like I'll need some work done to it, better save my money..:censored:

 

[Justsaws]

.048 =18 gage =1.270mm

Get all crazy with it and remove
.027=23gage=.711mm

Maybe a half hour worth of hand sanding on a glass plate, with some breaks for typing on the computer and eating pie.

Check it for square and use a feeler gage to scribe a mark and away you go.

 

[nmurph]

BB are not about torque. The hope is that they have more power than OEM which is usually not the case.
My BB7900's are above 150psi without a gasket. I will give you your $200 so that you can be rid of your problem child!!

 

[nmurph]

Randy, my son (8YO) picked out the emoticon. Sorry if it wasn't funny.

 

[steve316]

sanding

It dosen't matter how good you are it will not be flat and square; sand one then have it turened in a lathe, it will most likely take min. of.010 before a cut will clean the surface.If that works for you go for it.Steve

 

[BigDee]

Have a few cylinders with squish in the not so squished category. Removing the base gasket only does so much and removing some material would solve the problem.

We all read about aftermarket cylinders or big bore kits with the compression reading of 120psi, reducing the squish would raise compression. Most of us don't have access to a lathe or the funds to have the machine work done.

Anybody do something to remove some of the base material to reduce the clearance effectively lowering squish without a lathe?

How about a wood lathe? This tool to cut the base on an open-port Mahle cylinder for a Husqv 55 was made on a wood lathe with a scrap of maple, some 120 grit abrasive paper and some two-face tape.



I cut the mandrel and land, attached the paper, and used the tailstock to minimize wavering while I hand-held the cylinder against the tool, rotating at about 400 rpm.



With an $8 Huztl Farmer-Tech piston, the assembly had .039-inch squish. With no gasket.

I measure squish one side at a time and after the reduction, the squish was .021 on the recoil side and .019 on the clutch side, which is less variation than I usually find.



I still need an air filter mounting plate, and the three-bond is still setting, so I did not fire it yet. Left handed, compression feels strong. Don