Aluminum cylinder

[Scrubcadet10]

I was told (from a member on the Jack's small engines forum) that you can only hone aluminum cylinders to oversize, not bore them with a boring machine, but I also heard otherwise. I need the Briggs aluminum cylinder bigger to 20 thousandth s, I'm sure the machine shop would know what to do, but for the sake of me knowing. Can you bore an aluminum cylinder to oversize, or hone or to oversize.
?

 

[jp1961]

Hello,

Honing doesn't remove that much material. I think the general theory behind honing is to put the cross hatch pattern in the cylinder walls, go get the piston rings to seat.

If pistons are available oversize, your best bet would be to bore oversize and hone to final factory recommended dimensions.

There is a YouTube video of a guy boring a Briggs Quantum engine to the next oversize (using a boring head on a Bridgeport).

Regards

Jeff

 

[Walt 2002]

My recommendation if you have a B&S engine with an aluminum bore is don't waste your money on it. They do or did make a special set of auto type cylinder hones for over-sizing aluminum bores but the success level is very low. Original bore has a special coating which will be removed in oversize process.

I have used an automobile type hone to over size several cast iron bore blocks - not just for deglazing. These are often pictured in the back of Service Manuals. Note that 2 or 3 graduated grits of stones compose the set for doing this job with the first, coarse set, being very aggressive in removing metal as opposed to above statement.

Walt Conner

 

[SidecarFlip]

Boring will depend on wall thickness of the cylinder and know Briggs, I'd say toss the engine and buy a mew one. Cylinder walls are as thin as the can pressure die cast them to allow for a one time machining.

 

[Scrubcadet10]

they offer a .020 over piston for it.
I'm doing this for a longtime friend, who is in a financial pit right now and i told him i'd do what i could.

Or i could mow his yard for some extra :2cents::2cents: he he he he

 

[SidecarFlip]

Mike the cylinder wall thickness and you'll know right away. After boring you need at leas .030 wall thickness. Tell him to buy a cheap goat and can the lawnmower.

 

[Scrubcadet10]

Goats, good lawnmower, and when the teeth fall out eat em! lol.

 

[SidecarFlip]

Reason I mention that (not on thread) is, I have a good friend who leases out his goats for grounds maintenance here in Michigan. They eat everything including poison ivy and fertilize as they munch which is 24/7. I hear they like Kudzu too. No maintenance needed and they make 'new mowers' by themselves. I mow 7 acres myself and I'm considering mowing less and getting a pair of goats.

 

[Scrubcadet10]

Goats are very expensive down here, at least more than they used to be. A 2 YO nanny runs around $250.

i remember when we had goats, 6 nannys and 1 billy named Sampson. We'd go out there at night (well lit area) with a big thick trash can and one of us would get in the trash can with 2 wheels, while the other pulled and the billy goat chased us, and butted us. those were the days. And we had one billy before him, Lightning, he was a mean little dude, horns grew behind his head about 2 feet. He was tame most of the part, but if you got him riled up, he was literally a pain in the rear!lol

 

[Walt 2002]

they offer a .020 over piston for it.
I'm doing this for a longtime friend, who is in a financial pit right now and i told him i'd do what i could.

Or i could mow his yard for some extra :2cents::2cents: he he he he

Cylinder wall thickness is NOT your problem but the very high risk of failure is. You will get a bunch of time and money in this then be plagued to make good when it fails. Better pick up an equivalent engine with cast iron cylinder liner and rebuild it, good chance of getting by with just new rings or even just a decent used running engine. You likely are working with an old 11 hp, 25-- series engine??

Walt Conner