Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

What is the purpose of sleeving the bore of a new engine with cast iron? The ohv Snow King Tecumsehs still have the sleeve while according to my dealer the Briggs Snow Intek does not.

I am aware of sleeving being used to keep in service engines that have been bored to the point that the cylinder walls are too thin. Again,why on a new engine?

Marc 

                                                             
                                                         

Marc,
It is my understanding that both are aluminium engines if less than 9 HP like would be in the 860, that Simplicity would have an aluminium bore.

If however you are looking at a 1060 and it said Intek Snow it should have a cast iron bore. The 960, I have no idea.

I am not positve about any of this, it was what I have been told.                                                       


 

Hi Guys!

Just back from the Simplicity dealer. He is closed on Saturday. Winter hours don't ya know!

Yours in total frustration,

Marc

I wonder if a cast iron sleeve is any kind of an advantage in a snow motor.    None of my walk-behind mowers had cast iron sleeves and I've never had a cylinder wear problem. They saw many more hours of use per year than a snow blower would - and in much hotter conditions.   I think the main advantage of cast iron is better resistance high temperature. 

One advantage of an aluminum bore is better corrosion resistance - a big plus for a motor that might see just a few hours use in the winter and be idle otherwise.   I doubt an aluminum bore would ever be a factor in the life of a snow motor especially with modern synthetic oils.    -Bob

 Mark,

The Simp 860 blower has an 8HP Intek, which has an cast iron sleeve.

Go to Small Engine Warehouse and check out their snow engines and read the specs.

                                                              Hope this helps

                                                                          Fred         

Small engines starting at -40C and getting warmer needs those cast iron  Cylinder Sleeves why?

Because they have aluminium blocks and it's very important that the piston runs in a iron enviromment.

boblloyd wrote:
I would agree with this.

Throwing more iron into the fire...

I don't have any answers to the issue at hand, but I am throwing in information that may have been used in the companies decision.

Aluminum and steel expand and contract at different rates.  Steel expands/contracts less per degree than aluminum does.  If one had an aluminum piston that gets hot, within a steel bore, the seal/ gap between them might become better as the engine is warmed (assuming tolerances would never allow siezing of the piston).  If one had a steel piston inside an aluminum housing, and subjected it to temp extremes, the seal could be great at startup, but get worse as it is goes 

Also, the rings on a piston are usually steel.  As long as there is no foriegn matter in the upper or lower part of the piston, abrasion wouldn't be an issue; but if foriegn matter got stuck near the rings it would tend to scratch the aluminum housing first.

Depending on the process that was used to create the housing, a cast aluminum may have a porous surface, in turn a machined steel liner would assure a good finish inside the bore.  The Aluminum does disipate heat far faster than would a steel housing.

FWIW,

Walt 

jubol wrote:
Fred,
The only things that are odd are that the information I relayed is from Briggs tech support from a call made late last year, and if you go to the Briggs website Dura-Bore cast iron liner used to be the first thing listed for all the Inteks. Now there is no mention of Dura-bore for the Intek Snow.

Commercial Intek

Residential Intek site

Rob,

Read above, where I refered Mark to the Engine Warehouse.

At their  site, Intek engines spec sheets refer to a cast iron liner, at least 7.5 HP and up.

                                                      Fred

look  at the price for  a short block cast iron sleeve or alum. bore .Big diff  in price .Heat  is inside from combustion  as far as thermel  exspansion  it travels in all directions . Bottom line cheaper to produce.No cast iron sleeve stay away. Just my opinion. and you no what they say about opinions,there like a xxxxx holes every one has one.

millwright