Portable generators - cast iron cylinder liner or not ?

[3930dave]

It used to be that choosing a cast iron cylinder liner was always the better bet.

Is it still so, at least for light duty (residential in other words) applications ? This is an honest question on my part, as I don't know enough about current small engine metallurgy.

Cars - water cooled engines with aluminum blocks and NO liner seem to last pretty well, even given normal customer non-maintenance.

1) Metallurgically, is it hard to get the same lifespan on an air cooled aluminum block, w/o a cylinder liner ? (Thinking block expansion vs. water cooling).

2) If I accept that aluminum alloys exist that would work fine in an air-cooled engine, how to sort out what the manufacturers are using ? Anybody running high hours on an aluminum block (no-liner) air cooled motor ?

3) At the risk of starting a border skirmish - what is the best oil for air cooled aluminum only blocks ?

I'd prefer to talk tech on this, rather than brands, but where this came from is looking at recent portable generator offerings. Some North American "name brand" generators are aluminum only cylinders, and actually made in PRC.

At the same time, lesser name imported generators are also made in PRC, but use cast iron cylinder liners.

When brand distinctions start to get blurry, I like to go back to the technology base.

Comments ?

Rgds, D.

 

[aczlan]

3) At the risk of starting a border skirmish - what is the best oil for air cooled aluminum only blocks ?

Mobil1 (full synthetic) in the weight recommended by the engine manufacturer.

Aaron Z

 

[jonyyuma]

Mobil1 (full synthetic) in the weight recommended by the engine manufacturer.

Aaron Z

I don't see how you could go wrong with Mobil 1 motor oil. I use it in all my small engines and autos...The Iron sleeve in a Briggs engine usually means bearings on the crankshaft instead of a sleeve..light duty>,,Ic marked on top for Industrial/ commercial. Most are red in color, Black= alum sleeve..Briggs.

 

[Soundguy]

i have a near 15yr old rier mower with a cast iron liner. IMHO.. if notheing else.. you can guarantee that you can return to specs without machine shop with a new liner. piston and rings.

for oil.. run what the manufacturer specs.

in my old lawnmower I run a 15w40 C(s) rated oil.

soundguy

 

[3930dave]

Thanks for the feedback guys.

Mobil1 is good oil, I've used plenty of it in my 4 wheel gas road vehicles. I usually have Rotella T6 around for my diesel, would likely use that (5W40), as I have to deal with both Hi/Lo temps here.

Didn't start out by talking brands here, as that sometimes leads to rants too quickly, but here is what got me thinking about this:

B&S Elite generators:

Portable Generators by Briggs & Stratton

As far as I can determine on the B&S site, their 2100 series engine does not have a cast iron liner.

Champion:

41537 - Champion Power Equipment

While they don't seem to explicitly list their HD generators as having a cast iron liner, they do list it in their replacement engine listing:

61301 - Champion Power Equipment

Costco here does list the liner in their ad:

Costco - Champion

As I recall, Harbor Freight Predator engines are cast iron lined too, so it does seem to be common in the established Chinese lines.

I would be verifying the liner issue further myself, before pulling the trigger on buying the Champion, but essentially my question is this:

At around the $1000 price point, what would you buy - The B&S with NO cast iron liner, or the Champion with the cast iron liner ?

Both are made in PRC.

Rgds, D.

 

[Soundguy]

similar wattages.. or does the non liner one have more watts? i'd make the decision based on many factots.. not just presence of a liner or not.

 

[3930dave]

Nope, I'm not obsessed (OK, maybe my wife would argue the point) with cast iron liners, and am looking at all aspects of a generator, before I spend scarce $ upgrading the one I have.

For my application, I could live with something in the 6kw to 8kw range. Other than Low Oil shutdown, any other Bells/Whistles are just "nice to have". Larger kw rating is great, but I am willing to trade some watts away, to get a cast iron cylinder liner at a given price point.

(Geek confession - yes, a genny that has a 12vdc charging output on it does score points with me, but less so than a robust engine design).

Besides a reliable engine design, that does not use a stupid amount of fuel/oil, and stands a reasonable chance of me buying replacement parts in the future, I really have no strong preferences.

I realize that there are some differences between these 2 models/brands (ex. brush vs. brush-less), but for the purpose of this thread, assume I don't care. (Brushes I can handle changing, not sure I want to count on a PRC brush-less interface card to run right, 4.5 years from now, at -40C, regardless of what brand of genny it is. I "get" most of these issues, but just want to set them aside for the moment).

Correctly or not, I view cast iron cylinder liners and upgraded bearings as key factors in the heavy mechanical stuff sticking around for the long term. Partly I'm using this thread as a sanity check; I've been around long enough to understand that "safe bets" can change, over time. Remember the GM Vega ? Back then, aluminum car engine blocks didn't last very long - today, different story. Are we at/past the same inflection point with air-cooled aluminum engines ? I don't honestly know for sure; that is why I threw this out to the brain trust here.

The last generator I bought ('98) was a Briggs one. I've been happy with it, under light use. From what I see on the market at this time though, at around the $1,000 level the Champion product is at least competitive, and appears to have upgraded mechanicals, vs. the Briggs at/near the same price point.

My tech side would like a true Industrial generator, but if I spent that much, it would likely end up in an Asset's of the Marriage xls in a lawyer's office.

Thots ?

Rgds, D.

 

[Soundguy]

here's my view.

bundled stuff is nice.

the built in 12v dc would be cool.. if it's cheap. I can get a 6v/12v 2-10-50 charger from harbor freight for 30$ If the built in 12v is cheaper than 30$ bonus. if not.. I can hang it and plug in a charger..

another thing I'd like to point out. load.. it's an electrical and a mechanical thing.

if you have a 7kw genny.. it comes with an engine capable of making 6kw plus a small bit of leeway for surge... that means you will be running her flat out at high load. on the other hand, a genny capable of 8kw, being run to make 6kw is being run at a much lower load. lower load = lower stress.. to me.. that may mean longer lifespan.

of course if you can find one with repalceable bearings, carb rebuild kits, and valves and ci liner.. you should be set.

it's a trade off in all directions.


on the other hand.. you can aim low.. get a cheaper model and just run the fire out of it and not worry that it won't last 20ys.. because you got it cheap enough that the $$ you saved, 20ys down the line.. will get you another new cheap one. thus you would then be comapiring a 20yr old more expensive one to a brand new cheap one. there are actually times when disposable makes sense, money wise.. though it generally goes against my grain of likeing to rebuild things.. or having durable products..

 

[jonyyuma]

Soundguy, Your close on the cheap replacements, Hopefully the quality of the electronics is good enought to give you a few years of service....Cheap electronic boards are just that...maybe so and a crap shot at the best...I have the opportunity to buy and replace parts on a regular basis, at work....My choice is for the Brushless..I'm still out on the hunt for the replacement of my own unit? it only takes minutes of reading here, to put doubt in my mind about durability of some of the newer foreign units??

 

[joshuabardwell]

(Geek confession - yes, a genny that has a 12vdc charging output on it does score points with me, but less so than a robust engine design).

If you decide to get a genny with a 12v DC output, check your owner's manual carefully. I saw an oscilloscope trace of the 12v output from a Honda eu2000i, and it varied widely between 11 and 15 volts, or something like that. The conclusion was that it is fine for charging a battery, which will be fairly tolerant of variation in voltage, but if you were to try to run a 12v appliance off of it, it probably wouldn't be happy. This is what the owner's manual says, and why it's called a charging port, but a lot of people might miss that.