200T Video & Seal Thread

[Mattyo]

https://en.m.wikipedia.org/wiki/Bakelite

 

[Lone Wolf]

Bakelite is not flexible

No it aint. You are still saying they are not all Bakelite then?

 

[Mattyo]

Correct. ..at least 2 different materials

 

[Mattyo]

They still rely on some type of rubber seal

 

[Lone Wolf]

Correct. ..at least 2 different materials

How are you coming up with that?

 

[Mattyo]

Because the part that does the sealing is flexible

 

[Mattyo]

The opening in the oem seal is around 8mm....it has to flex and pucker to get around a 12mm shaft

 

[Mattyo]

Were u thinking it was all one piece? All one material?

 

[Lone Wolf]

Well you can keep thinking that they are half rubber and half Bakelite! You didn't even know what they were till I said! What is the working thermal range of Bakelite and the black rubber seals?

 

[Mattyo]

Huh?

 

[Mattyo]

It looks to me like some type of rubber mated to a bakelite /plastic frame...
If you know otherwise please educate me

 

[Mattyo]

I'm trying to get on the same page here.... some type of rubber does the sealing...in both types of seals.....yes or no?

 

[Mattyo]

Ok....it is my contention that in both types of seal...some type of rubber makes the seal. Oem seals are flexible at the part adjacent to the shaft. This material cannot be bakelite. ...therefore bakelite does not do the sealing. Bakelite does resist heat well...so as a frame to a seal I suppose that makes it an acceptable material....but then you have to compare that frame material to the metal frame of the am seals....and it's thermally resistI've properties. Then you can compare oem rubber properties to am rubber properties. ...that's a fair comparison

 

[Mastermind]

I've never used anything but oem seals in a 200T.

I think they are designed to be very low in fiction so they don't hold back the engine at all.

As to what they are made from?

Who cares???

 

[Al Smith]

I think the whole idea of the roller bearings instead of ball bearings plus the seal design is to lessen parasitic losses .You have to remember these little "Jack Russel terriers" were made to run like scalded dogs .Problem is the bearings are shorter lived before they develope side slop which takes the seals .

Before they came out with after market cylinders and piston there were dozens of crankcases on flea bay because the same P and S in OEM was half the price of a new saw .About 50 bucks would buy one and probably every one needed seals and bearings .I know I bought two to repair a couple of case leakers and of course had to replace seals and bearings on both .
On that which were done a couple of years ago I didn't press the seals in or use some special seal driver .It must have worked because mine is still doing okay and the two I did for a trimmer bud are still on the job .---more than one way to skin a cat ya know---

 

[Mattyo]

MM, Lone Wolf was saying, and I don't want to misquote, that the bakelite seals are one single material and that bakelite has higher thermal resistance than nitrile rubber...

"Well you can keep thinking that they are half rubber and half Bakelite! You didn't even know what they were till I said! What is the working thermal range of Bakelite and the black rubber seals?"

Of course nitrile rubber has less resistance thermally than does bakelite, but thats not a proper comparison. You have to compare frame materials against frame materials, and seals against seals. bakelite vs metal (whatever type of metal it is)
and some type of rubber (oem) vs nitrile rubber. All I'm asking for is a fair comparison here. The other aspect to the question, and where the sticky wicket remains ( I think ) is that Lone Wolf believes that the bakelite seals are all bakelite...which to me isn't possible because bakelite isn't flexible, and there definitely is a flexy part to the oem seal. Bakelite does not touch the crankshaft.


Al, you bring up ANOTHER interesting point. Why the roller bearings? there is more surface area contact with rollers than with ball bearings. ....on the crankshaft of all things.... seems like this would ADD friction instead of lessen it. I'll say one thing for sure, it makes installation easier w/ the rollers instead of the usual 6202 bearings!

 

[Mattyo]

btw, been thinking all night long of how to actually TEST the amount of friction an oem seal produces vs an am.... have no idea why this topic is so interesting

 

[Definitive Dave]

I am trying to get some time to box up some MS200Ts to send to Lone Wolf I will include both oem and my favorite AM seals and gaskets for comparison.
Dave

 

[Mattyo]

nice! like I said earlier... I have an expensive pile of poo showing up from ebay and will try the am seals then

 

[Lone Wolf]

I think the whole idea of the roller bearings instead of ball bearings plus the seal design is to lessen parasitic losses .You have to remember these little "Jack Russel terriers" were made to run like scalded dogs .Problem is the bearings are shorter lived before they develope side slop which takes the seals .

Before they came out with after market cylinders and piston there were dozens of crankcases on flea bay because the same P and S in OEM was half the price of a new saw .About 50 bucks would buy one and probably every one needed seals and bearings .I know I bought two to repair a couple of case leakers and of course had to replace seals and bearings on both .
On that which were done a couple of years ago I didn't press the seals in or use some special seal driver .It must have worked because mine is still doing okay and the two I did for a trimmer bud are still on the job .---more than one way to skin a cat ya know---

Well since they use roller bearings and also us Bakelite seals it stands to reason that you are on to something there about the reduced friction. Makes perfect sense to me . I was thinking you would chime in. I got to agree with you.