What's on your bench today?

[spudulike]

Someones got some fancy new photo software, :lol::lol:

 

Online photo manipulator mate - thought you young uns know it all:thumbup:

[Rich2484]

Online photo manipulator mate - thought you young uns know it all:thumbup:

 

:lol:

 

Don't know me well... I don't do computers. Took me a week to learn how to use an iPad. I don't have an iPhone. I have a phone that calls and texts, the most exiting thing on it is the calculator, it doesn't even have games on it. And no camera either.

 

The last PC I had ended up out the window, and I'm not joking either. The other saw it fly past.

 

Give me an internal combustion engine any day.

[spudulike]

:lol:

 

Don't know me well... I don't do computers. Took me a week to learn how to use an iPad. I don't have an iPhone. I have a phone that calls and texts, the most exiting thing on it is the calculator, it doesn't even have games on it. And no camera either.

 

The last PC I had ended up out the window, and I'm not joking either. The other saw it fly past.

 

Give me an internal combustion engine any day.

 

Ah... Think I am ahead on you as I have put together quite a few PCs and went through a period of severe overclocking and cooling on a rather hot desktop PC I used for gaming - got a bit obsessive....now where have I heard that before:001_rolleyes:

[mikerecike]

Been porting a 371XP tonight, the top image is before, the lower - after.

The exhaust port has been widened as has the inlet though less so. The lower transfers have been modified heavily and the rear transfer has been re-modeled to improve scavanging.

 

Looks impressive even though I'm not quite sure what I'm looking at. Was thinking of having a go on a spare knackd cylinder from a strimmer - just to get a feel for trying some tools and how the metal reacts.With this cylinder the bottom of the exhaust port is a good 3cm up the pot. Is that too far in to work on? Was also wondering if you'd work from the outside for the widening and then only have the chamfering left to do from the inside?

[spudulike]

Looks impressive even though I'm not quite sure what I'm looking at. Was thinking of having a go on a spare knackd cylinder from a strimmer - just to get a feel for trying some tools and how the metal reacts.With this cylinder the bottom of the exhaust port is a good 3cm up the pot. Is that too far in to work on? Was also wondering if you'd work from the outside for the widening and then only have the chamfering left to do from the inside?

 

Personally I work from the outside in, there are limitations on what can be done, there is a known SAFE maximum size a port can be widened - too wide and it can cause excessive wear or a snagged ring.

 

You also have limitations caused by where the rings end and by the type and size of piston skirt. There are again known distances a piston MUST cover a port by and distance a ring end must be away from a cylinder opening including the upper transfers.

 

The only work I do from the inside is re modeling the rear transfer and ensuring a smooth bevel on the inside of all modified ports - failure to do this will snag a ring pretty quick as some have found out:thumbdown:

 

There are many ways of looking at this type of work, I get 80% of the gains with the work I do and don't spend all my life trying to get the further 20% with port timing changes, my porting ethic is to increase flow within the cylinder and to improve blowdown and scavanging plus a hike in compression and generally get between 20 & 25% faster cutting speed with the work I do.

 

A recent MS200 came back to me with 190psi with the owner saying it hurt pulling it over - he had busted his wrist earlier though but still nice to see a modded saw having so much compression with a relaively simple mod. Standard MS200 of that age are generally 150psi and a real good one in standard trim - 170psi!

 

Hope that gives you a little insight - don't think it is easy, don't just attack the ports with nothing but hope, look at how wide your piston skirt is, look at where the rings end on the piston and personally would start by widening the exhaust and inlet followed by a muffler mod and then tune the carb based on what the engine is now doing - VERY generally, this will be turning the H screw IN by between 1/8 and 1/4 turn - this is down to the extra venturi effect on the carb caused by the extra flow you have created.

 

And they said it was easy:lol: Oh - and use diamond burrs forr the nikasil plating and HSS ones on large aluminium excavations - HSS or files are bad news on hardend plating!

 

Good luck:thumbup:

[Peter]

 

A recent MS200 came back to me with 190psi with the owner saying it hurt pulling it over - he had busted his wrist earlier though but still nice to see a modded saw having so much compression with a relaively simple mod. Standard MS200 of that age are generally 150psi and a real good one in standard trim - 170psi!

 

:

 

Fit a decomp valve?

[Eddy_t]

Cylinder fitted and all connected, now I need to advance the timing

 

 

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Ignition advanced, and oh my how easy it is! Take the finned flywheel part off (4 screws) and the magnet flywheel has 3 windows to access the points behind, which is attached by 2 screws, loosen those and slide anti-clockwise, ignition advanced! Runs like a demon!

 

 

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[Rich2484]

Another ms200t has appeared on my bench. They must be breeding. I knew I should have spererated them.

 

This one is up for a bit of mod. No porting just a squish increase and exhaust mod. Don't see much point in porting as they don't leave much anyway and for a saw that is a working saw the squish and exhaust will be plenty. IMO.

 

Might even look at reducing the bottom of the pot a bit to get that extra bit of squish.

[Dan Earp]

If theres no room in the inn GTR then send them to me. Theres always a place for STIHL in my corner lol

[Rich2484]

If theres no room in the inn GTR then send them to me. Theres always a place for STIHL in my corner lol

 

I'm not letting you dirty up my stihls. :lol:

 

Just coz I got more than you. That puny picture on facebook is a disgrace:001_tt2::001_tt2:

 

Call yourself a stihl lover......

 

Better stop now or I will get told of by spud for going on about stihls :lol: