11hp Briggs & Stratton Rebuild

[Fordlords]

With a nikasil bore, the nikasil (which is a coating on the aluminum) typically wears down off the bore at a rate equal to that of the wear on the rings. You obviously can't overbore the block, and attempting to hone it will just wear off even more of the nikasil. Unless there is a cast iron liner in the block that will take well to a hone, such as on the I/C engines, I wouldn't bother doing anything to try to help a nikasil block. By pulling off the cylinder head, you can usually tell immidiately if the block has an iron cylinder liner.

It is not even typical to overbore an aluminum small engine block with iron liners, for tolerance reasons it is a safer and more economical bet to just replace the short block with a new one.

-Fordlords-

 

[Big Al]

Right. However, since my engine isn't showing signs of knock or oil consumption (just oil leaking), I'm going to give new gaskets & seals a try. I'm not looking for another 10 years out of this engine, just 1 or 2.

After that, I'll swap in another engine.

FYI - I just read an article online about honing that goes into detail on diamond honing. Apparantly it is possible to hone nikasil cylinders using new, high-pressure diamond hones.

Probably a bit of overkill for an 11hp lawnmower engine, tho. ;D

 

[Fordlords]

It is a lot of fun and its easy just to tear the engine down and put the seals and gaskets in, and you'll likely get another year or two out of it. I just wouldn't invest in a major overhaul on it

They are mainly developing the honing techniques for nikasil blocks because they were used on some exotic sports car engines, Porsche was especially successful with getting nikasil to work well. On those engines you are talking thousands of bucks to replace the block, thus it's worth it to try to refurbish it.

We had a neighbor back in the late 70's who was all proud of himself snubbing his nose in our faces because he bought a new John Deere rider mower about the same time my dad bought a Craftsman. Well, three years later we noticed someone else was cutting his grass for him, this being as he smoked the little nikasil Briggs in his JD, while the iron sleeved Tecumseh in our Craftsman lasted 10 years.

Just about all small engines above 10-12 HP today have iron sleeves and full pressure lubrication.

-Fordlords-

 

[Kyle_in_Tex]

The manual says my 10HP is aluminum. I guess I can pull the head and look. If the cylinder looks good, I'm guessing my knock is the rod. There is a spec to check the crank for excess wear. If too worn, then the cost to repair will be too much.

Yamaha used nikasil in the cylinders for the old TT600's. Saved 3 lbs weight. They were extremely durable. They rings for TT' s were made from soft ductile cast iron.

 

[Big Al]

We had a neighbor back in the late 70's who was all proud of himself snubbing his nose in our faces because he bought a new John Deere rider mower about the same time my dad bought a Craftsman. Well, three years later we noticed someone else was cutting his grass for him, this being as he smoked the little nikasil Briggs in his JD, while the iron sleeved Tecumseh in our Craftsman lasted 10 years.

Funny you mention Tecumseh -- I was taught to not trust Tecumseh engines. "They run too fast." is what I was always told. From what I can tell, when it comes time to replace my engine (B&S L-head which it seems they made for ages), my choices are either Tecumseh OHV engines or a B&S Intek. Unless I happen to find an L-head, but Briggs finally quit making them a few years ago and supplies are getting short on new engines...

Anyways, any thoughts on the merits of either brand?

 

[Big Al]

briggs and stratton small engine parts, briggs & stratton lawnmower motor,

Thanks for the link, Kyle. I ordered a rebuild kit, service manual and a Gator blade from them. I hope to have it all by next week. In the meantime, I'm going to add oil & Bar's leak and mow the lawn.

 

[jonwheelhorseb112]

do you know what the max bore size is in the 11hp B&s because im restoring mine and its got some pretty good scaring on the inside sleeve and the piston to i think the guy who had it befor me over heated it . and my friend
rod thinks that it had dirt in the motor all i know is its pretty much screwed right know

 

[The Toolman]

Al, if its just leaking oil, I'd just buy the seals an gaskets an replace them an forget about any rebuild.


Ronnie-The Toolman