Surprise on the new 2152 Johny

[Tony Snyder]

The new 2152 Jonsered has the removable transfer covers like the 2159. The way the covers are shaped, it looks almost like quad ports.

Kenn, is that the way the 2159 was?

I haven't run it yet. It is a little muddy here to get to where we cut.

 

[glens]

Hi Tony,

Not having ever seen one I can only speculate, but I wonder if the covers don't make it possible to die-cast the jugs, if you catch my drift.  What do you think?  Is it possible?  The added step of machining the surface and what, drilling and tapping 4 holes, might be cheaper in the long run than shaking out disposable sand shapes.

Just me habitually thinking out loud again...

It looks like it'll be even muddier tomorrow, but by Friday morning it should be stiff enough again.  Did you catch any of that earthquake the other day?

Glen

 

[Tony Snyder]

I can think of no more practical reason for them to do this than to be able to die cast it without cores. In other words do closed loop transfers in a relatively simple mold. Looks like a good idea to me. It may become very popular; probably nothing patentable about it.

Also lends itself to at least semi automated assembly.

If you do a search you can see the 2159 that Kenn Dunn worked over.

I firmly believe that e-lux in at the front of the pack on technology.

 

[glens]

Yeah, I recall seeing Ken's post, where he'd speculated about air injection while decelerating or something (EPA).  I immediately thought "Well, they might do that too, but I bet it's so they can die cast", but you know me, I hate to suggest anything to the experts

I'd like to like Husky better, but there's something Microsoftesque about them; and I don't mean that in a good way, if it's even possible.

My mother says Husqvarna makes wonderful sewing equipment.

Yamaha is probably a better comparison.&nbsp; For the same reason that I dislike Lowes, Home Depot, et al., I have a hard time with a company that has to try to make and sell <i>something</i> to everybody.&nbsp; Yamaha makes good motorcycles, snowmobiles, electronics, pianos, ad infinitum.&nbsp; Sure, the products are each good, but the whole big picture just leaves a funny aftertaste.

Glen

 

[mikek711]

Glen,
What does "die casting" the head mean?
Also,I hear Mobil is coming out with a 0w50 premix.......................................
just kidding!
Mike.

 

[glens]

Mike,

This is not intended to be anything more than a very general overview.

There're basically two ways to make a mold to contain and form the molten metal.&nbsp; One is where several objects, which represent the places where metal will <i>not</i> be (like the transfer port passages), are made ahead of time and intricately placed prior to filling the mold with the metal.&nbsp; The process involves several steps and the mold is only used one time.

The other is die casting, where the mold is a multi-part reusable mechanism.

The freeze plugs (more properly "core" plugs) on your cast iron engine block are places where the sand molds ("cores") to form the water jacket passageways are suspended and through which the sand is later removed.&nbsp; I think that people who don't know that think they're there to allow some "give" to protect the block from freezing situations.

I once put an extremely healthy 351 Windsor together with an Edelbrock manifold which still had some of it's core in place in the front crossover - it really pissed me off and I always look for such conditions now.

Anyway, with die casting, you can go into production in a very automated, cost-effective way.&nbsp; It's just that it's usually not possible to get quite so intricate with the mold, so maybe you have to put an extra cover on here and there to seal an opening you needed to stick a part of the die through.&nbsp; It will undoubtedly cause a bit of extra weight since you now need enough material to form a sufficient sealing area, not to mention the fasteners, but the production cost will drop significantly in the long run.&nbsp; There are also other benefits to the process.

I was able to locate this quick comparison: http://class.et.byu.edu/mfg130/processes/HTML/D13S007C.htm

Glen

 

[mikek711]

Glen,
Thanks for the quick overview.Completly cleared up my questions.
Mike.

 

[glens]

I had at one time searched out all posts made by kdhotsaw, and in <a href="http://www.arboristsite.com/showthread.php?threadid=4798">2159 jonsered</a> had only read the ones he'd made.&nbsp; If I'd taken the time to read the whole thread, I'd have readily seen most excellent posts by Tony Snyder and jsikkema1.&nbsp; My idea that the purpose of the cover plates was for ease of die casting was totally independent and immediate, but by no means unique or early.

That thread is well worth review.

Glen

 

[woodsjunkie]

I wonder if they used the same jug as the 2149 and changed the bore and stroke.
the 2149 has the removable transfer covers also.
Great saw

 

[Tzed250]

Die-casting

The biggest problem with die-casting is that precision molds can cost hundreds of thousands of dollars. It takes very high production to make up for the buy in cost.

 

[Tony Snyder]

Tzed250

I spent 35 years in tooling work with the old Western Electric Co. and then TRW. I both designed and purchased tooling, including die cast moulds. Cost figures can indeed be astounding, but one thing rang thru pretty near all along, and that is that foriegn sources can produce such tooling at fractions of what it can be done for in the advanced economies; U.S., Germany, etc.

We were once inquiring about tooling for a new housing for an air bag control module. I spoke to an Asian vendor. He was back in a little over two weeks, pulled an actual bag of parts out of a box and handed me a quote. He had done that before the other potential vendors had responded. He had amortized the tool cost and was still half the competitors price. Point is, you can get die cast tooling at a fraction of what you might think.