dissecting an earthquake chainsaw
- Thread starter o8f150
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well, hell...didn't think of that
Serves you right showoff.... Excellent job, I'd like to do one of mine like that if I could weld that thin metal.
mweba
Addicted to ArboristSite
Good running 38cc! Red Oak?
stinkbait
Addicted to ArboristSite
Yeah, that's redoak. It's been down since last summer. I think that the 3/8 lopro really holds this saw back. I wish that I could find a .325 combo to run on it.
diggers_dad
Sawchologist
Me, too. I can't weld that thin stuff so I have to go with the old heat and bend method. It's slower but it works and doesn't look too bad when I finish. The muffler mod is a MUST on these. The muffler is incredibly restrictive, which may be why we're getting them. Maybe this batch didn't meet emission standards and they had to dump them on the market. Combine those with some customer returns, call them "Sold as is, for parts" and you've got the makings of an internet / CAD love story.
.png "Love :heart:")
I checked compression and squish on mine, which as most of you know has been ported, muff modded and base gasket removed. The compression was around 150 out of the box and now sets at a respectable 162 psi cold. There is much to be gained, however, 'cause squish is .039 with no base gasket.
I'm glad I didn't raise or lower the ports on this one. Now I just have to find a pop up piston or get the cylinder machined...:msp_sneaky:
Me, too. I can't weld that thin stuff so I have to go with the old heat and bend method. It's slower but it works and doesn't look too bad when I finish. The muffler mod is a MUST on these. The muffler is incredibly restrictive, which may be why we're getting them. Maybe this batch didn't meet emission standards and they had to dump them on the market. Combine those with some customer returns, call them "Sold as is, for parts" and you've got the makings of an internet / CAD love story.
I checked compression and squish on mine, which as most of you know has been ported, muff modded and base gasket removed. The compression was around 150 out of the box and now sets at a respectable 162 psi cold. There is much to be gained, however, 'cause squish is .039 with no base gasket.
I'm glad I didn't raise or lower the ports on this one. Now I just have to find a pop up piston or get the cylinder machined...:msp_sneaky:
Forgive my ignoreance, but what is squish and what is a pop up piston?
diggers_dad
Sawchologist
Squish is the distance, in thousands of an inch, between the top of the piston and the cylinder when the the piston is at the top of its stroke. Opinions vary, but .020 to .025 is what I consider ideal. Go above that, say .039, and you aren't getting all of the compression you could. More compression equals more power. Go below that, maybe .010, and you risk a catastrophic failure if there is too much movement and the piston smacks the top of the cylinder or spark plug.
One way to achieve more compression without modifying the cylinder is to create a convex surface on top of the piston, if you could imagine a piece of metal the size of a contact lens on top of the piston. By filling that otherwise empty space with metal, you have effectively increased compression. The piston, once modified, would look like someone popped up the top of it from the inside, hence the term "pop-up".
As I understand it, there are a limited number of ways to effectively gain more power in a chainsaw engine. First, put more fuel through the engine. That could mean opening the muffler, putting in a larger carb, doing a port job, whatever would result in increasing the amount of fuel mixture going through the engine.
Second, increase compression. Machine the head down a few thousands, install a pop-up piston, or find some way to fill that open space. I have seen guys who installed a longer spark plug in there to gain a few psi on the compression, or put a long bolt in the compression release port. You just have to be careful to make sure there's enough room in the combustion chamber that nothing hits.
Third, increase speed, which in effect increases fuel flow. This can be done by specific tuning or just lightening up the moving parts, like the piston. Less weight to move means more speed.
There are other methods but these are the ones most common and cost effective IMHO.
dd
o8f150
Tree Freak
if and i mean a big if the guy follows through monday i will have 2 sold all ready for a very little profit
little profit????? 80.00 profit :msp_biggrin::msp_biggrin::msp_biggrin:
little profit????? 80.00 profit :msp_biggrin::msp_biggrin::msp_biggrin:
o8f150
Tree Freak
Me, too. I can't weld that thin stuff so I have to go with the old heat and bend method. It's slower but it works and doesn't look too bad when I finish. The muffler mod is a MUST on these. The muffler is incredibly restrictive, which may be why we're getting them. Maybe this batch didn't meet emission standards and they had to dump them on the market. Combine those with some customer returns, call them "Sold as is, for parts" and you've got the makings of an internet / CAD love story.
I checked compression and squish on mine, which as most of you know has been ported, muff modded and base gasket removed. The compression was around 150 out of the box and now sets at a respectable 162 psi cold. There is much to be gained, however, 'cause squish is .039 with no base gasket.
I'm glad I didn't raise or lower the ports on this one. Now I just have to find a pop up piston or get the cylinder machined...:msp_sneaky:
personally dd i don't think these little saws are worth putting that much into them unless you just want to see how far you can push it without it coming apart:msp_biggrin::msp_biggrin:
Good training wheels...For me anyway
Hahahaha! Damn it, spell check did not go through this time!
diggers_dad
Sawchologist
They're cheap to play with and if I blow one up, what have I lost? Really? $35? That wouldn't buy a piston for any other saw I run. I love to tinker on these things. I can still sell 'em after I'm done.
Exactly my thinking! I'm no pro but I'm getting better.
That's funny right there. What a word to miss it on. :jester:
squish = a new kind of orange drink for big kids
pop up piston = a new kind of pop corn popper for big kids
:msp_w00t:
If I can win a couple more without getting my shorts sniped on the bay I intend to cut a pop up for one of these things and machine the base of the cylinder, I'm thinking they would run really nice with compression in the 175 range and a larger carb. Has anyone checked the thickness of the piston to see if cutting a popup is possible without adding material? I've cut a few for trimmers and recently one for a cutoff saw and all had plenty of room to chuck up and cut away.
diggers_dad
Sawchologist
I don't know how much you need but the piston is not what I would call "meaty". The cylinder and crankcase are very light, so I'm sure they didn't put any extra material where they didn't have to.
I have a Powerhorse (another clone of these) that has just over 200 psi and I haven't even started to work on it yet. It is rather impressive for a 45 cc saw, especially when you figure it came from China.
Me, too. I can't weld that thin stuff so I have to go with the old heat and bend method. It's slower but it works and doesn't look too bad when I finish. The muffler mod is a MUST on these. The muffler is incredibly restrictive, which may be why we're getting them. Maybe this batch didn't meet emission standards and they had to dump them on the market. Combine those with some customer returns, call them "Sold as is, for parts" and you've got the makings of an internet / CAD love story.
I checked compression and squish on mine, which as most of you know has been ported, muff modded and base gasket removed. The compression was around 150 out of the box and now sets at a respectable 162 psi cold. There is much to be gained, however, 'cause squish is .039 with no base gasket.
I'm glad I didn't raise or lower the ports on this one. Now I just have to find a pop up piston or get the cylinder machined...:msp_sneaky:
It's not that hard to weld sheet metal. You are basically just 'tapping' the trigger (MIG) for a small spot weld. (I would even attempt this with a stick welder) Hit each corner to start then half the distance between those welds then half again, etc until you have a line of spot welds. Trying to do a line of spots in a row usually heats up the metal too fast and burns through, hence the alternating. Then you grind the welds flush. This how body panels are welding in on vehicles. It does take some practice but it's not really that hard. The smaller MIG machines are easier to work with; mines a Hobart Handler 210 set at 2/20. I probably should have backed off the feed speed to 15 but it worked so...
Someone with a lot of TIG welding experience could do these a lot prettier and not need to grind the welds down but IMO it would be a waste of time/expense on this saw.I suck at braising...tend to burn holes with the torch
diggers_dad
Sawchologist
It's not that hard to weld sheet metal. You are basically just 'tapping' the trigger (MIG) for a small spot weld. (I would even attempt this with a stick welder) Hit each corner to start then half the distance between those welds then half again, etc until you have a line of spot welds. Trying to do a line of spots in a row usually heats up the metal too fast and burns through, hence the alternating. Then you grind the welds flush. This how body panels are welding in on vehicles. It does take some practice but it's not really that hard. The smaller MIG machines are easier to work with; mines a Hobart Handler 210 set at 2/20. I probably should have backed off the feed speed to 15 but it worked so...
I suck at braising...tend to burn holes with the torch
I sent you a rep shot for that one, 'cause your explanation makes me want to go try again. I usually just blow huge holes in whatever I work on. I'm thinking about trying my hand at brazing.
naturelover
Tree Freak
Experienced another Quake here this evening.
Box looked like it'd been through one....
Contents.
First one was pretty much pristine, but this one had looked to have been sold, ran, but not to cut wood. Had the Sears tape one it and someone wrote the purchase date and serial number on the manual. Chain wasn't in original packaging like my first one, no file, or oil, but who knows, could have fallen out of the box.
This one has some issues it seems though.....
Box looked like it'd been through one....
Contents.
First one was pretty much pristine, but this one had looked to have been sold, ran, but not to cut wood. Had the Sears tape one it and someone wrote the purchase date and serial number on the manual. Chain wasn't in original packaging like my first one, no file, or oil, but who knows, could have fallen out of the box.
This one has some issues it seems though.....
diggers_dad
Sawchologist
Experienced another Quake here this evening.
Box looked like it'd been through one....
Contents.
First one was pretty much pristine, but this one had looked to have been sold, ran, but not to cut wood. Had the Sears tape one it and someone wrote the purchase date and serial number on the manual. Chain wasn't in original packaging like my first one, no file, or oil, but who knows, could have fallen out of the box.
This one has some issues it seems though.....
Yup, that one looks like total crap. I'll send you $20 for postage and you send it to me so you don't have to deal with all the mess.:hmm3grin2orange:
I'm just trying to be a friend
$25 ??
$27.50 ??
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