Dogging in vs self feeding - Tooth length too! The truth of it.

[Vintage Engine Repairs]

@Vintage Engine Repairs can you get your hands on another to run it against? I think maybe it’s sick.

Thanks David! Hmm sounds strong, 165 psi too. We’re just dealing with very dry & hard timbers out here.

 

[Wonkydonkey]

It would be good to get some timing # up first

I,m guessing the exhaust is @95 int@75 trans@120
Oh and the squish is probably massive @30thou

So As @ferris & @davidwyby said timing adv, mm, bgd for the squish to be 20 thou. and while your there figure out those timing #..

 

[Squareground3691]

Thanks David! Hmm sounds strong, 165 psi too. We’re just dealing with very dry & hard timbers out here.

Lol

 

[ferris]

Thanks mate, yes it’s stock. How much would you advance the timing?

About half the key

 

[Vintage Engine Repairs]

About half the key

Thank you I’ll try without modifying the key and just leaving it out and going a few degrees. If I don’t like it I can always just put it back.

 

[bogieboy]

Thanks David! Hmm sounds strong, 165 psi too. We’re just dealing with very dry & hard timbers out here.

165 is ok... granted this is a mildly ported 661 with .0205" squish...

measure that squish, and see if you have room for a base gasket delete.... it really woke up my 044... all grunt too, as it lowered the exhaust by almost .020

 

[davidwyby]

Thanks David! Hmm sounds strong, 165 psi too. We’re just dealing with very dry & hard timbers out here.

I cut the same stuff mate....90cc I have never run a bar that short, and saws have never had trouble pulling them. Then again mine are all ported, but still...25", that's short for 70cc for me.

 

[Vintage Engine Repairs]

I cut the same stuff mate....90cc I have never run a bar that short, and saws have never had trouble pulling them. Then again mine are all ported, but still...25", that's short for 70cc for me.

Yeah 25” out here is standard on 660’s and even then you’ll bog them down if you lean on them good. There are so many species of gum some very soft, some incredibly hard. This lot I’m cutting is crazy hard. This timber makes bluegum and jarrah feel soft.

Edit: The chain just bounces off this wood unless you dog in and lean on it and when you do you can literally see it rips the fibres on the outside of the log even with a freshly sharpened chain.

I let the saw mill owner use it and he said it runs great. He’s had 660’s all his life, so I’m not convinced it’s down on power.

 

[Vintage Engine Repairs]

165 is ok... granted this is a mildly ported 661 with .0205" squish...
View attachment 410580
measure that squish, and see if you have room for a base gasket delete.... it really woke up my 044... all grunt too, as it lowered the exhaust by almost .020

Thanks mate, I’ll get round to mapping the numbers and report back.

 

[Vintage Engine Repairs]

This is a freshly sharpened chain (first cut since sharpening and refilling) 25” bar. Edit: if you zoom in to my previous cut that is still part of this round, you can see the rough ripped wood. You can even hear the chain rattling and that’s with a H/O oiler.

 

[Squareground3691]

This is a freshly sharpened chain (first cut since sharpening and refilling) 25” bar. Edit: if you zoom in to my previous cut that is still part of this round, you can see the rough ripped wood. You can even hear the chain rattling and that’s with a H/O oiler.

What kinda chain do you use and grind ,

 

[Vintage Engine Repairs]

What kinda chain do you use and grind ,

This is Stihl chain, full comp 3/8 semi chisel hand file. I’ll see if I can find a pic.

Edit: I don’t have one in my album, I’ll snap one in the morning, but I take a lot of care to keep the teeth all the same length to have even set across the whole length, all the depth gauges are set with a progressive guide and I make a conscious effort to keep all angles the same.

 

[davidwyby]

Looks about right for stock.

 

[Maintenance Chief]

This is Stihl chain, full comp 3/8 semi chisel hand file. I’ll see if I can find a pic.

Edit: I don’t have one in my album, I’ll snap one in the morning, but I take a lot of care to keep the teeth all the same length to have even set across the whole length, all the depth gauges are set with a progressive guide and I make a conscious effort to keep all angles the same.

What are you normally cutting with instead of the 660?

 

[Vintage Engine Repairs]

What are you normally cutting with instead of the 660?

I have an 034 Super and an ms 260

 

[Vintage Engine Repairs]

Looks about right for stock.

Thanks mate, yeah I’d love to get a bit more out of it

 

[davidwyby]

Thanks mate, yeah I’d love to get a bit more out of it

Try a BGD and if you want more send the cyl to @huskihl

 

[Maintenance Chief]

I kind of agree with everyone else in the fact that getting the squish down to 20s and a muffler mod are going to net good results. Timing advance might? Seems to work magic for some and not so much on others.
I have 2 660s I've built from scrap yards and they both like more fuel then rationally what I think would be great? ,could be I pretty much run 32-34" bars on them ? They love fuel though, and lean out in the cut just the same.

 

[bogieboy]

This is a freshly sharpened chain (first cut since sharpening and refilling) 25” bar. Edit: if you zoom in to my previous cut that is still part of this round, you can see the rough ripped wood. You can even hear the chain rattling and that’s with a H/O oiler.

As others said, looks about right for stock 660... its always fun to do mods and get more out of it... this is my 661 with mild porting, .0205 squish, modded muffler and no timing advance in rock maple with a hard nosr bar, so loosing some efficiency there...

 

[Squish9]

Back to you were saying about equal cutter lengths. I see that having that different lengths work for guys on the internet but in dry hardwood it doesn't seem to work.

If you have 1 short cutter, the next in line behind it gets the corner knocked off it quickly. The chain still cuts fine so you keep going. When it's time to sharpen now you have a cutter with a lot of damage and the following one has taken a beating as well, so you file them back.

Now you have 2 that are very short and a 3rd that's in between. You go cut again and the cycle repeats, the short ones look ok but the mid length one is hammered and so is the next one behind it. This keep happening and you get a short life from the chain.

It's due to the side plate tapering inwards. You can compensate for the height difference between the cutters with the depth gauge but can't compensate for the reduced width. This doesn't appear to be an issue when cutting green or softer woods.

When I cut for a living I use to break out the damaged cutters and replace them. I would throw the damaged sections in a bucket and keep them for matching up to other damaged chains later on. It was more cost effective than wearing out a chain sooner than expected.

After watching a bunch of sharpening videos on YouTube I'm being to wonder if people get away with doing this because they remove so much every time they sharpen. Guys seem to love going to town with the file and taking out a heap of the tooth every time. If they only get 7 or 8 sharpenings out of a chain they probably never have an issue with this.

I try to sharpen small amounts often. A few swipes after a tank of fuel works better for me than going until it won't cut them hacking off a heap of metal.