~60cc shootout 962 Efco vs 361 Stihl vs 036 Stihl

[terry2tmd]

Look's like Harbor Freight has the dial indicator kit that would be perfect for finding TDC.

 

[parrisw]

Look's like Harbor Freight has the dial indicator kit that would be perfect for finding TDC.

Don't do it that way. You'll never get it perfect.

 

[terry2tmd]

Don't do it that way. You'll never get it perfect.

You use the solid stop thing? Maybe It would help if I told you what I am doing. The 394 cylinder I am running is ported and runs like crazy I want to see what changes were made to the cylinder to get this kind of power.

 

[parrisw]

You use the solid stop thing? Maybe It would help if I told you what I am doing. The 394 cylinder I am running is ported and runs like crazy I want to see what changes were made to the cylinder to get this kind of power.

Yes positive piston stop is the only way. TZ250 did an excellent thread on it.

 

[tdi-rick]

Yes positive piston stop is the only way. TZ250 did an excellent thread on it.

Ditto.

It's fast and dead accurate.

Remember there's always a small amount of piston dwell at TDC, using a positive stop and rotating the crank forwards and back and splitting the difference gets TDC absolutely dead on.

We used to use a dial indicator for ignition timing a two stroke, but then it's only really useful with a centralised spark plug hole.

 

[terry2tmd]

Thanks guys I will give it a shot. Ever feel like a kid at xmas waiting for TW to post again been checking this every day he's got us cliff hung.

 

[terry2tmd]

Just got thinking about this, every engine has TDC Dwell, the trick is how long it is, and how it affects the combustion cycle, that's why you map. You also have a certain amount of BDC Dwell, I can see how the solid stop would be faster and cheaper, as well as accurate, but I was taught to do it on V-8's with a dial indicator, it is pretty much the same thing I like your way because it uses the K.I.S.S. principal.

 

[parrisw]

Just got thinking about this, every engine has TDC Dwell, the trick is how long it is, and how it affects the combustion cycle, that's why you map. You also have a certain amount of BDC Dwell, I can see how the solid stop would be faster and cheaper, as well as accurate, but I was taught to do it on V-8's with a dial indicator, it is pretty much the same thing I like your way because it uses the K.I.S.S. principal.

Even on car engines I use a piston stop.

 

[JJay03]

Love the look of that 036 and sounds good too.

 

[8433jeff]

Subscribed.

 

[timberwolf]

Here is the 962, but waiting for a new piston... More on that later.

 

[timberwolf]

More 962 pics.

I wish I could say a new piston was needed due to the casting flaw in the pin boss, but it was caused by a flat washer that I must have dropped in the when messing with a PITA spring clamp on the intake. :mad2: :bang:

Fortunatly it locked up at idle and cylinder was ok.

 

[timberwolf]

962 very narrow stock esp when considdering how wide the skirt is.

 

[timberwolf]

More ports

Muffler mod was quite simple given there was a deflector shield on the front of the muffler making for an easy hole and screen behind it. I'll get a pic of that later.

 

[timberwolf]

Here is the 361

 

[timberwolf]

More 361

 

[timberwolf]

361 cont...

 

[timberwolf]

361 muffler

 

[mtngun]

Great pics and impressive work as always, TW.

I presume the stock 962 piston is on the left. What's the piston on the right ?

This pic is the stock 361 transfers, though it was mixed in with the 962 pics.

And your modded 361 transfers. What is your scheme on this kind of mod to the lower transfers -- it's increasing the base volume, but also shortening the duct length. Are you OK with the increased base volume on this saw ?

The edge of the skirt lines up with the transfer duct on the bottom of the pic, but not the top. Does it matter if the edge of the skirt lines up with the transfer duct ?

Any difference in the base compression between the 3 saws ?

 

[timberwolf]

Actually the port does line up with the skirt down where the window is, it is just hidden in the undercut area.

036 is a few cc tighter on the base and the 962 a little bigger.