JoeB
ArboristSite Lurker
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This 066 Grenaded........What The Hell Happened???????
- Thread starter Mastermind
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sefh3
Addicted to ArboristSite
That has to be one of the first that I have seen to not score the piston but to break a rod bearing due to not enough oil.
Thank you for sharing this information, Randy. I've been running 40:1 with Stihl Ultra. I think it's time for me to switch.
Thank you for sharing this information, Randy. I've been running 40:1 with Stihl Ultra. I think it's time for me to switch.
hardpan
Addicted to ArboristSite
That was a fun game and a powerful message sent. Thanks Randy.
Oh, I've been running Belray H1R 32:1 since you told me about it a few months ago. Funny how engine failure threads turn into oil threads. I like oil threads.
Oh, I've been running Belray H1R 32:1 since you told me about it a few months ago. Funny how engine failure threads turn into oil threads. I like oil threads.
Back when I was old enough to be around chain saws all we used was 24:1 or 32:1. I think 50:1 is just plain nuts.
Any of the saws benefit from 32-40:1. Huskies seem to be more prone to this than stihls.
Unreal. Thanks for sharing Randy. I dont even like 50:1 and tell the firewood cutters 32:1 and no more then 40:1 on stock saws. Fck the epa and their 50:1 ****. Why folks think all them big end bearings and crankcase bearing go bad. Lack of fing oil.............
I was wondering why you had added 32:1 to your sig line
I was wondering why you had added 32:1 to your sig line
cowroy
Addicted to ArboristSite
Randy, you gettin kick backs from bel ray?
Mastermind
Work Saw Specialist
I was able to get a Platt crankshaft for testing. It is in TRX250R180's 066 milling saw. The saw is ported just like the saw in this thread. So far the crank had been fine. I also have another 066 out there running an aftermarket crank that we rebuilt and ported. So far, so good. The problem is that when I order one of these cranks, I can't be sure I'm gonna get a Platt crank, or a "white box" crank of unknown origin. Because of that, I'm staying away for these parts.
Here's the thread on Brian's 066 build.
http://www.arboristsite.com/community/threads/testing-a-raisman-platt-crankshaft-in-an-ms660.237350/
I like oil threads too. They can make my job less stressful.
I think most engines are gonna be fine at 40:1.......and I'm not sure all oils will work well at 32:1. In the engines I build, I would like to see Belray H1R @ 32:1 used. After using it myself for the last couple of years, I'm convinced that the engine will live a long and healthy life by simply dumping 4oz of this oil in each gallon of gas. I buy it in liter bottles on ebay........it's not expensive, or hard to find.
http://www.ebay.com/itm/BEL-RAY-H1-...Parts_Accessories&hash=item53fe3b2d7a&vxp=mtr
It's not piston scuffing that I worry about with 50: or even the 80:1 oils that I see being used. The piston will be fine most times. The bearings need plenty of oil when power output is jacked way up......that's way I'm so adamant about having more oil in the mix.
The 390XP has been know to have bearing failures, as has the 372XT. I know of several of these saws that are running 200psi and more in production use for over a year with zero issues.......they are not being run on 50:1
HuskStihl
Chairin'em for the sound
Allegedly, particularly my beloved 385. I run straight diesel in it just to be safe
Mastermind
Work Saw Specialist
Randy, you gettin kick backs from bel ray?
I need to see if they would be interested in sponsoring Ol' Mastermind huh?
Looking at your pics on page one, in the third pic down, take a close look at the exhaust port roof. Also, notice the scuff on the exhaust side piston skirt, which started in the ring lands of the second pic. Agree it is a lubrication based failure, but I think as things began to tighten up the ring fracture and rpm energy had no where to go popping the bearing race. You would see heat discoloration on the bearing and connecting rod if there were skate problems prior to the failure.
Mastermind
Work Saw Specialist
Good point, and well researched.....
I had an unmodded 066 crank bearing let go. I have heard of others. Maybe a weak design point?
Mastermind
Work Saw Specialist
After thinking about this post I looked again and took more pics. The big end of the rod is starting to change color.....in these pics you can see it plainly.
The bearing, crank, and case area are also very dry.
Maybe, but at what oil ratio were they running?
GrassGuerilla
Olympic Piss-reving wanna be.
The thing that's funny about this is I know quite a few grass guys use Sabre at 80:1 and even 100:1 in string trimmers and blowers in the heat of summer. Some have for a decade. I realize the stresses of a trimmer and a chainsaw are very different. But blowers come a bit closer with the constant load and prolonged WOT.
Is the power produced by this ported saw simply consuming the available lube? Was it tuned way lean too? I'm not sure I understand. As dry as the bottom end of that looks, it makes me wonder how other machines can run that mix seemingly without issue?
Is the power produced by this ported saw simply consuming the available lube? Was it tuned way lean too? I'm not sure I understand. As dry as the bottom end of that looks, it makes me wonder how other machines can run that mix seemingly without issue?
Mastermind
Work Saw Specialist
Remember that we add compression......that raises both static, and dynamic cylinder pressures. That, in turn, adds a heavier load to the connecting rod and bearings. The oil is a protective film that acts as a layer of protection between the moving parts. I think that the layer is too thin with 50 - 100:1 mixes and is hammered out, allowing the parts to make contact, and create fictional heat.
Notice I said I think.......I don't have all the answers. That's why I enjoy these threads......it gives us a chance to compare notes, and do some brainstorming.
Notice I said I think.......I don't have all the answers. That's why I enjoy these threads......it gives us a chance to compare notes, and do some brainstorming.
zogger
Tree Freak
Three things I learned on this site fast after toasting an expensive to me new saw, running it bone stock,..do not trust these "as shipped" carb settings on modern saws, they are to be suspected of being way too lean on the H screw, the mufflers may be quieter than olden days mufflers but are usually way too choked up to let the saw run well or stay cool, and 50:1 gas/oil is most likely some sort of emissions deal and not honest engineering.
Well...4 things. The 4th is, don't keep all your saws in the same place, and take security seriously before bad things happen...
Trx250r180
Saw polisher
My 2 cents on the oil ,i have torn down stock saws run on stihl mix 50 to 1 ,the bearings were getting lube ,but turning black carbon color ,i have torn down my saws 32 to 1 and there is a generous coat of clean oil on everything and bearings look clean ,another finding 32 to 1 is leaner ,thicker oil through the same jet size allows you to pour in more fuel ,more fuel = more power ,ask husk how his saw ran at 50 to 1 and 32 to 1 ,he can vouch for this i think ,i see a better performance gain running the 32 to 1 ,a cooler engine will make more power ,better ring seal with thicker oil means better compresion which = more power ,last thing the math is super simple for dummies like me ,4 oz oil 1 gallon gas ,easy peasy
zogger
Tree Freak
Pulling wood chips in varied diameter and hardness logs, with different sharpness and configged chains, is a lot different than pushing a string or impeller at a relatively constant torque and rpm load. IMO, can't prove it, but seems reasonable. I mean, example, how do you "dig in the dogs and lean" on a blower?
Freaking two stroke oil is so dang cheap......why penny pinch on it?
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