Mastermind Meets The Stihl 090AV

[David Young]

I like the mandrel,
have you used wood much before? normally you see people use steel of aluminum, which would take for ever to cut on my little lathe not to mention cost.

 

[Mastermind]

I like the mandrel,
have you used wood much before? normally you see people use steel of aluminum, which would take for ever to cut on my little lathe not to mention cost.

I've only used wood twice. Both times was on a 090. I'll get a 3" piece of UHMW stock to make a proper mandrel from before I do another.

 

[Nitroman]

Not sure what that is Roger.

Ooops...not thinking clearly with only one cup of joe on board.

Ceramic coating the piston top and sides. Top to protect from meltdowns and sides for lubricity.

http://swaintech.com/race-coatings/

These guys will also anodize the exterior of a jug to black to radiate excess heat.

 

[Nitroman]

I saved this off YouTube from The Chainsaw Guy's site back in Jan of 2011. I had corresponded with him regarding this muff. He told me it was a performance muff back when the 090's were really popular in the Northwest. Thought you guys might like it.
His video is still up!

So who is gonna TIG one of these up? I see a scew boss at the bottom, so probably had a spark arrester screen there.

 

[Stihl working Hard]

Finished jug.

View attachment 21722 View attachment 21723

Nice job Randy great pics and thread there

 

[VinceGU05]

Changed it up.....

View attachment 21727

Now that's a muffler mod lol. That's like running 7" stacks on a pickup truck [emoji13][emoji1360][emoji1360]

 

[bennne]

Hers some info on big stihls for ya

I found this and copy and pasted it
Can I add some info about biggest stihl chainsaws?
Stihl contra (1959-1968) was the first "largest crankcase" stihl, it was 106 cc and 58 mm cylinder/piston bore. It had a power of about 6 PS. Then was produced the biggest stihl contra s (s=super) with a 137 cc. and 66 mm cylinder/piston bore (1964-1968) and 8 PS. To install this biggest cylinder stihl enlarged a little with a boring machine the crankcase in the cylinder basament lodging (from about 64 mm to about 74 mm). Contra S had also a different cylinder cover (the metal one) as the cylinder is a little biggest than the 106 cc, and has also a different fan cover.Contra G (G=gear) has another right crankcase, with a reduction rate (2:1). It was 106 cc (contra G) or 137 cc (contra GS). Other variant was the AV (=anti vibration) handle, mounted on some stihl contra S.
On all contras no decompression valve and the spark plug is not central but is orizzontal on the left side and has long thread. All contras had a zinc cylinder cover, to allow cooling, and on the top a red plastic cover (covering zinc cover and air filter).
In 1968 contras were replaced by 070/090 series: same crankcase of contra s (with big bore basament lodging, so you can mount both 070 = 106 cc. or 090= 137 cc.) and different cylinders, with decompression valve and central spark plug (short thread). Also the external shape of the cylinder is a little different (biggest cooling system of the head) but disposition of all the windows of cylinder (sorry for my english i don't know if the term windows is correct), the exaust and the porting/intake ones are identical to the ones of contra and contra s. Power is little more (070 is about 6,5 PS, 090 about 8,5 PS, maybe becouse of the more performant shape of the piston and air filter. Different is also the 070/090 carburetor (from a Tillotson HL 112, contra, to a Tillotson HL 324, with different position of the carburation screws but identical venturi diameter, so same performance).To allow the more cooled cylinder the cover is now a biggest orange metal one including also air filter. Also contra G was relaced by 090G but, I think it was only 106 cc.
090 had a different fan cover from the 070, the same of contra s. 090 is produced by now for Australia, South Africa and maybe Mexico or Brazil (perhaps for Mexico 070) with a new shape Anti Vibration handle and safety systems. So very little differences from the oldest contra to the recent/actual 070/090. Crank case is, practically, the same of 1959!!!!!

An answer: Has anybody other information about the special 090 with 10 cubic inches (164 cc.)? Cylinder bore? piston stroke? has anybody one of this kit or a picture/drawing?
Thanks
Reply With Quote


Sent from my iPhone using Tapatalk

The 090AV the same as this one mm's working on stopped being sold here about 7 years ago. The 070 became the MS 720 which is still being made, example bellow. Never been ran, only taken out of the box for this now sits on my shelf with a brand new 200t and 660 magnum

October 14' at our wedding shocked a few people when I rocked up to our wedding with a chainsaw... Well some where most where half expecting it

 

[bennne]

And.....after some cleanup work.

View attachment 21717 View attachment 21718

do you use any type of hone on your cylinders?

 

[Mastermind]

do you use any type of hone on your cylinders?

No sir, just emery cloth and Scotchbrite.

 

[ny15]

Ooops...not thinking clearly with only one cup of joe on board.

Ceramic coating the piston top and sides. Top to protect from meltdowns and sides for lubricity.

http://swaintech.com/race-coatings/

These guys will also anodize the exterior of a jug to black to radiate excess heat.

Swaintech is good stuff. I have had some automotive parts done by them, never any saw stuff. Their only 15 minutes away from my house.

 

[sawfun]

I believe hard anodizing works as well. I forget what the coating is on top fuel pistons, I think it was anodizing as they were an olive green. There is a coating used by Nasa and others that when applied to metal, feels oily but is in fact bone dry. I remember a few years back a premium rifle maker put this on his rifle bolts.

 

[jacob j.]

I've had a number of pistons coated by Swaintech and the key to remember is that the pistons will be (slightly) larger in the bore, regardless of the type of coating. So you need enough interference fit for the coating. I've had better luck with coated pistons in steel sleeve or iron liner bores than in chrome or Nikasil bores.

 

[Nitroman]

I believe hard anodizing works as well. I forget what the coating is on top fuel pistons, I think it was anodizing as they were an olive green. There is a coating used by Nasa and others that when applied to metal, feels oily but is in fact bone dry. I remember a few years back a premium rifle maker put this on his rifle bolts.

I had thought of having some snogo pistons coated, then hard anodized. I didn't get them done due to time.

I think hard anodizing might defeat the soft aluminum being able to absorb a piece of debris. On the other hand, then that debris could be ejected out the exhaust port.

 

[Marshy]

I had to make a 66mm mandrel.

View attachment 21720

Your wife must be pissed about your porch.

 

[Scott0154]

I saved this off YouTube from The Chainsaw Guy's site back in Jan of 2011. I had corresponded with him regarding this muff. He told me it was a performance muff back when the 090's were really popular in the Northwest. Thought you guys might like it.
His video is still up!

View attachment 21745

So who is gonna TIG one of these up? I see a scew boss at the bottom, so probably had a spark arrester screen there.

My father in laws 090 has one so I could copy it easy

 

[Scott0154]

My father in laws 090 has one so I could copy it easy

So loud it hurts

 

[ferris]

We will see the ported 090

 

[Mastermind]

It is back on the west coast. Don is doing some tweaks to it. Maybe they will get some video at the GTG.

 

[sawfun]

We will try and have video of it in a hopefully, giant log there.

 

[Deets066]

Here's one while you wait.