066 Poly vs Metal

hautions11 · Nov 29, 2006

I wanted to raise this question and get some comments on the poly flywheel versus the metal version. I undrerstand that Stihl changed the crank and added the poly flywheeel to abate some crank breakage problems that they had experienced. Almost counter to that arguement, I have heard Dean at WHS talk about prefering the heavier metal flywheel for improved torque and inertia while cutting, even on modified saws.

As I am looking at used 066's, and there seem to be a lot of the older metal versions out there running just fine, should they be avoided in favor of the poly models? Is the problem with the old ones that bad? I like the idea of getting a fixer upper and putting the big bore kit on it. Does the big bore rule out the metal flywheeel versions? I would love to hear some opinions.

oldsaw · Nov 29, 2006

Metal owner and not losing any sleep over it.

Mark

Lakeside53 · Nov 29, 2006

There is a difference between manufacturing a large quantity of saws, having to warranty them, protect your good name,and a handful of guys modding saws.

The crank breakages had a lot to do with the operators also... but Stihl has to deal with that too.

Stihl had problems with cranks breaking so they changed the crank and flywheel. There problems were on a fraction of a % of the saws shipped, so that means over 99% didn't have any problems. Add a BB kit to that 99%, and you'd expect a few more problems, but that doesn't mean all of them will fail.

The is also a difference between a BB upgrade, and a PORTED BB upgrade...If you have the choice, get the Poly version.... better crank, bearings, etc.. but..

If you are talking 044, Stihl didn't go to poly, but they did change the flywheel on the 440 to increase the cooling efficiency. If I was BB'ing an 044, I'd be looking for a 440 crankcase, but that's me.

Freakingstang · Nov 29, 2006

Not too much helpful info, but My metal flywheel 066 red light runs stronger than my new 660. both have dual ports, but the older one seems to have had more grunt. It now has a woods port, but still runs great.

timberwolf · Nov 29, 2006

Here some of the latest 660 saws have very differnt port design, and don't produce the same umph the 066 or even early 660s did.

Lakeside53 · Nov 29, 2006

timberwolf said:
Here some of the latest 660 saws have very different port design, and don't produce the same umph the 066 or even early 660s did.

Yep.. It's called "optimized porting"... i.e. optimized for the EPA..Dual port muffler seems to make most of it go away

Cut4fun · Nov 29, 2006

My 066 red light has been converted to poly with a woods port. It cracks the rpm's quicker and I havent seen any cutting difference in the big stuff.

Lakeside53 · Nov 29, 2006

Did you put a new crank/bearings/flywheel or just use an later Crankcase? on your older saw?

wagonwheeler · Nov 29, 2006

Even more reasons to cherish my 1998 066 w/ poly flywheel and dual-port!

As though having Lake rebuild it wasn't already enough to make it a sho' nuff keeper! :rockn:

..

Lakeside53 · Nov 29, 2006

wagonwheeler said:
Even more reasons to cherish my 1998 066 w/ poly flywheel and dual-port!

As though having Lake rebuild it wasn't already enough to make it a sho' nuff keeper! :rockn:

..

Careful... or I'l show them the picture of your old flywheel:biggrinbounce2:

wagonwheeler · Nov 29, 2006

Lakeside53 said:
Careful... or I'l show them the picture of your old flywheel:biggrinbounce2:

Or the 440 crankcase that only served to increase shipping costs... :cry:

Or the fancy China starter handle...or...

Man did you ever work wonders on that thing! :cheers:

And yes, I'm planning on new plastic for it... filter cover and cylinder cover...I'll holler at 'cha.

Which reminds me...what's with the black filter cover doodads I see 'listed' for sale or attached to some new filter covers? Never seen one on a saw... I don't particularly like 'em.

Chaser

Lakeside53 · Nov 29, 2006

wagonwheeler said:
Which reminds me...what's with the black filter cover doodads I see 'listed' for sale or attached to some new filter covers? Never seen one on a saw... I don't particularly like 'em.

Chaser

Those are PART of an older cold weather package...

wagonwheeler · Nov 29, 2006

Lakeside53 said:
Those are PART of an older cold weather package...

I'm rather confident that wouldn't apply to equipment operation 18 miles north of the Florida/Georgia state line... :yoyo: :yoyo:

CrazyCarl · Nov 29, 2006

Flywheel

The theory behind a heavy flywheel tends to lean in the stronger horsepower,while a lighter flywheel helps torque. Also a flywheel is neede to "swing,(for lack of a better term),the motor thru to the next stage,ie;intake exhaust etc etc. without the flywheel the motor would not spin thru it's revolution and complete the cycle.Pull the blade off your mower and try to start it.So My question is, lighter flywheel for the torque(my preference)Or heavy for the horsepower.I would think with a big saw,light flywheel.Small saw heavier for the added grunt .Comments?????? This should get some debate goin in here.Another good reason for a chat room!!!HINT HINT! :rock:

klickitatsacket · Nov 29, 2006

HP is a function of RPM and Torque. A heavy flywheel is slower on the acceleration and holds the RPM back a little. A light flywheel has faster acceleration and higher RPM. The rotational mass helps determine the width of the torque band.

klickitatsacket · Nov 29, 2006

I forgot to put in..... if all things are equal.

just heading off a non arguement. :dizzy:

Lakeside53 · Nov 29, 2006

klickitatsacket said:
just heading off a non arguement.

Damn:biggrinbounce2:

bwalker · Nov 29, 2006

A change in flywheel weight doesnt increase or decrese torque. It does change the power charachteristics. IE more weigh = more resistance to changeing speed, less weight the opposite.

wagonwheeler · Nov 29, 2006

Heavy flywheel on a tractor...typically...and brush blade on a trimmer. Both help preserve RPM through intermittent increased load.

Neither are bolt-on's for HP or torque.

..

RiverRat2 · Nov 29, 2006

Metal Flywheel?????

Man I love it when Yall use those big words like Trailerhouse and Watermelon :hmm3grin2orange: All kidding aside, so if im understanding this correctly it just comon sense that a lighter /well balanced roatating assembly with a poly flywheel should "Spool up Quicker" thus increasing torque in proportion with the rise of the RPM??????? :blob2:

over a saw with a metal flywheel,,,,,, assuming that all things other wise are equal......

So since my WHS buildup 066 with my dual port muffler Mildly Modded that has a metal fly wheel and mortally stomped a hole in my buds newer ms660 (Poly flywheel) as we cut cookies today off the same 24" fresh pine log... I let him cut with it and he was very impressed as he had bucked out the tree earlier in the day with his saw... I wish I had had my video cam to get his eyes buggin out....

Thanks Dean,,,,, :bowdown:

Im Lovin it :biggrinbounce2:

066 Poly vs Metal

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