Ronie's 660 kit saw

[Ronie]

This morning I decided to practice some more on the Farmertec cylinder and it's looking good, I cut that raised portion out of the band and it's nice and flat now, .020 squish. I also got the exhaust done, transfers roughed in and some JB weld in the intake. I'm going to see how this one runs and if it does good I'll leave the big bore for another day.

 

[Maintenance Chief]

This morning I decided to practice some more on the Farmertec cylinder and it's looking good, I cut that raised portion out of the band and it's nice and flat now, .020 squish. I also got the exhaust done, transfers roughed in and some JB weld in the intake. I'm going to see how this one runs and if it does good I'll leave the big bore for another day.

View attachment 306441 View attachment 306442 View attachment 306443

Why epoxy in the intake?

 

[Mastermind]

some JB weld in the intake.

I did some testing on the MS660 in relation to intake duration. I ran 82° against 78° with no other changes. The longer duration was faster up to 28" wood. In bigger wood the short duration was better. Neither held enough advantage to be outside the margin of error of my unscientific tests. So, at that point, I decided not to use epoxy in the 660 intake.

 

[Ronie]

Why epoxy in the intake?

I want the intake to be around 80.

 

[Ronie]

I did some testing on the MS660 in relation to intake duration. I ran 82° against 78° with no other changes. The longer duration was faster up to 28" wood. In bigger wood the short duration was better. Neither held enough advantage to be outside the margin of error of my unscientific tests. So, at that point, I decided not to use epoxy in the 660 intake.

I forget what the farmertec intake was, I think it was around 86-87 before I cut the base.

 

[Nutball]

I ran 102, 123, 83 on a MMWS Cross cylinder, it had lots of torque, but still good high end power. I tried an intake of 78 on a farmertec cylinder and definitely noticed a peak in low end torque useful for long bars, though the FT cylinder was over all weaker than the compression modded Cross cylinder. I attribute the low end torque of the cross cylinder to the exhaust height and its high end power to the 83deg intake.

 

[Mastermind]

I forget what the farmertec intake was, I think it was around 86-87 before I cut the base.

Yeah......I'd shorten that up too.

 

[Ronie]

Why epoxy in the intake?

I took a pic of the intake, the floor had to come up quite a bit. I just started on it so it's not finished in the pic.

 

[Maintenance Chief]

I took a pic of the intake, the floor had to come up quite a bit. I just started on it so it's not finished in the pic.

View attachment 306466

So bringing it up increases the saws rpm performance? Or torque?

 

[Ronie]

So bringing it up increases the saws rpm performance? Or torque?

I don't really know how it would react to being low like it was, I'm just going by what the guys with a lot more experience have said works.

 

[Ronie]

I did get the cylinder finished up but it's not on the saw yet.

 

[Maintenance Chief]

Ok , I often defer to experts.

 

[Mastermind]

So bringing it up increases the saws rpm performance? Or torque?

Over the years I've done a lot of testing, and kept notes on every model I do. I've found that you usually you don't want to have the opening point of the intake much past 80.

 

[Maintenance Chief]

I imagine when we start dropping cylinders and trimming pistons or just swapping parts it changes all the numbers .
I should stop flying blind on my builds and put a timing wheel on them, but being lucky has yielded some fun saws!

 

[Ronie]

I straightened up the intake, it was a little off side to side and got the timing numbers with a ring.

EX 99
TR 122
IN 80
Squish .020 without a base gasket.

 

[Ronie]

I put the cylinder on yesterday and finished getting it back together this afternoon. I haven't tuned it yet but it runs and it feels like it has a lot more compression than the other cylinder that has a pop up. I'll get it tuned tomorrow and see how it does.

 

[drf256]

I’ve personally found that the 066/660 like more intake duration. I believe it’s because the darn exhaust port is too narrow and limited by the tiny piston skirt width. They just can’t exhale.

At least for me, and my experience is limited vs the master builders here, they do better and better with exhausts as high as 94*.

Anyone here remember Heath’s 066 at the NY GTG a few years ago, the one that Dunlap built? Pretty sure that saw had a 92* exhaust and it pulled the 36” 404 through that big wood faster than the rest of ours.

 

[Ronie]

I’ve personally found that the 066/660 like more intake duration. I believe it’s because the darn exhaust port is too narrow and limited by the tiny piston skirt width. They just can’t exhale.

At least for me, and my experience is limited vs the master builders here, they do better and better with exhausts as high as 94*.

Anyone here remember Heath’s 066 at the NY GTG a few years ago, the one that Dunlap built? Pretty sure that saw had a 92* exhaust and it pulled the 36” 404 through that big wood faster than the rest of ours.

Thanks for the tips, I need all the help I can get. I was thinking of redoing that Hyway jug that I took off this saw and dropping the cylinder down so I can get the exhaust from 94 to 96/97 and see how it does there and putting the intake around 82.

 

[Ronie]

I got it almost tuned but I think it needs the H richened up a bit, I'm only a half turn out on the H and I think that 74 jet is a little to big for this saw. I'm out of gas so this is as good as I can get it today.

 

[Ronie]

Little richer and a bigger piece of wood, this is where I'm going to leave it for now.