Hi. I recently acquired a 1969 briggs and stratton engine model 130202 type 0283-01. While taking it appart i noticed cylinder scoring and some piston slap. When i run my fingernail over the scores i can feel them. I thought about boring out the cylinder to .10 oversize but the problem i am facing is that it is an aluminum bore. No sleve. A lot of sites say stuff like "boring an aluminum engine is a nightmare" and things like that. I wasnt sure what to do. In my opinion it is scored bad enough to just throw it back together. The rest of the engine is in really nice shape and would be really cool to get running again. Any thoughts?

 

If you have piston slap you probably have more than a .010 over bore to fix it. The point to start at would be measuring the out of round at the bottom of the cylinder. That may tell you what you can and can't do with the boring.

 

You are going on quite a few assumptions unless you actually get out an inside micrometer and check your cylinder bore, looking for out of round and comparing it with the original specs. Standard practice if the cylinder was still within tolerance was to crosshatch the cylinder with a hone to deglaze it, then install new rings on the original piston, assuming the piston also mic's out within specs.

This is not something you can tell visually or with a fingernail... it requires precision instruments.

My guess is that new points and condenser and some attention to the carburetor is probably more of a priority than anything mechanical.

 

Ok. Thanks for the information. I will see if i can rent/buy a micromerer to do investigation of the cylinder

 

If you don't already have an cylinder micrometer I'm assuming you also don't have the tools to bore out the cylinder. It may be less expensive to take it to someone experienced overhauling engines that already has the tools. They could offer professional advice and may be able to do the work cheaper than buying the tools and doing it yourself.

 

I was originally planning on just taking it to the small engine shop downtown. I was just wondering if it was worth doing it.

 

So aparently the shop doesnt bore out aluminum blocks👎🏻. Can i run a hone on the cylinder wall to oversize it or is this not a good idea for an aluminum engine?

 

You can, but as mentioned you would be better off finding a machinist to do it for you. I know you are probably feeling nostalgic about this engine but frankly its not worth the effort.

As mentioned, you don't even know if it needs to be bored oversize. The honing that I was talking about is simply deglazing, not boring oversize. Deglazing helps the new rings seat/seal.

 

Ok. Maybe i will just put it togeather and hope to get a few years out of it. Thanks everyone!

 

To bore it with a hone, the only way to get it uniform is to use a locking hone and do it incrementally and have the hone on a drill press and the block fixed so that the bore is exactly parallel with the stroke of the drill press. Do you only have one machine shop? Some small engine shops can do it, most automotive machine shops can do it.