661 Oil Test 32:1 vs 40:1 vs 50:1 ?
- Thread starter redbull660
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Moparmyway
Its just a saw
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Mastermind
Work Saw Specialist
Think whatever you want. The saws I build always get an increase in compression. More oil keeps the bottom ends from failing. I've seen the results of 50:1 in a performance engine. Melted rod bearings are common at that ratio. If any saw I build is used at 50:1, I will not be responsible for it's failure.
Oh, since I've only built about 800 saw engines in the last five years......am I screwing with saws too much?
I'm sure those guys were using stock saws. 50:1 should be fine.
WOAH!
Back up a little man I wasn't trying to offend anyone. I've seen saws you've built in action and have all the respect for you and other builders. I was just telling it how it is from someone who uses saws in a different way then the recreational guys. Work saws see much much more abuse then any firewood saw will ever see and recieve minimal maintainence at best. And these saws continue to cut all day everyday for years.
I'm not saying your way is wrong at all. The saws you build are in a whole different category. I'm just trying to point out that keeping things simple is just as good as using all these crazy oils and fuels and all that. I'm sure in a built saw those things are needed.
Exactly I'm talking stock work saws that are used in the tree removal industry.
KenJax Tree
Terraphobic
WOW!! Brad and Randy AGREEING on something?? I'm gonna buy some lotto tickets.
HuskStihl
Chairin'em for the sound
Wait a minute, are you telling me that guys who run saws for a living treat them like tools of the trade? I can't believe these guys don't drive 50 miles for ethanol free gas and run oil designed for engines with triple the output of their saw? I'm calling bs on that
KenJax Tree
Terraphobic
Yes mine have never been violated, brought in the house, they stay alone on the truck in the yard during the weekend, and they've never been polished[emoji33]
HuskStihl
Chairin'em for the sound
Ken, that's just plain nuts! You must not understand what kind of difference the right oil could make in u'r life!
You mean you don't wash, blow dry with purified air, wax, and then clean all the crevices with a Q-tip and sing it a comforting little song while you're attending to it's needs every time you fuel? I'll bet you even let your saws get rained on and covered in dust. Barbarian.
Back on topic. Oil? Meh, somewhere around 40:1...depending on how much I slop down the side of the fuel jug and how much time I want to spend trying to get the last micro-ounce of oil out of the container. Bailey's synthetic seems to do just fine.
I remember my grandfather's stihl 028 that he abused for nearly two decades on his farm, he would add a good dollop of 30 wieght engine oil into a can of leaded fuel and away he'd go. He was mechanically illiterate and believed any problem could be fixed with more oil. Cleaning an air filter was somthing to do if your saw did not start. Problem with any engine could soon be fixed with more oil. He never killed that saw. l remember riding his farm AG bikes which were 2strokes and there was always a trail of blue smoke following you everywhere no matter how long it was running. He fixed almost everything with wire, bail twine and oil.
32:1 is about perfect for a saw unless milling our in huge wood constantly. I might look at 20:1 in those situations and tune the car accordingly with the caveat that a quality oil that doesn't inhibit combustion is used..
And detonation occurs after the plug firing....
Mastermind
Work Saw Specialist
Yes it does......
And predetonation doesn't exist...
I would expect a temp gun reading of the cylinder head or wall to read higher as the amount of oil increases. The film of oil between the piston and cylinder acts as a heat transfer medium and thus it would stand to reason the cylinder would run hotter. It also stand to reason that the most important piece in regards to heat, the piston would be running cooler.
I would also see these tests have so many uncontrolled variable that they are a goat rodeo at best..
I would also see these tests have so many uncontrolled variable that they are a goat rodeo at best..
Please define "after." Is BDC the dividing point, like 12am is the start of a new day? When is "after" one ignition event different than "before" the next ignition event?
After the exhaust port has closed on the up stroke and before the plug fires=pre ignition. After the spark plug fires but before the exhaust port is opened on the down stroke=detonation..
