Porting My MS660

[smokinj]

The only work I did to the actual port was from the red lines outward, as shown by my awesome MS Paint diagram.

-I didn't stick the dremel into the cylinder at all touching the top or bottom. Out from the port on the roof and floor of it I ground enough to clean the carbon off, and sanded it some 200 grit wet/dry sand paper.

-For most of the grinding I'm using the round stones used to sharpening chainsaw chains, these are too course for final polish so I have to pick some more bits. The ones that came with the dremel are about useless.

-I have didn't have a chance to put a bevel back on the side of the port opening

-I haven't taken much material off the piston, I'm just cleaning all the casting marks, then I'll go back through and get it smooth.

-I need to get some solder so I can measure the squish, what is ideal squish for a saw like this?

-Squish, I plan on reducing it. When you make a gasket, do you use Derko or other sealant on it to get a better seal or put it in without sealant?

I dont use any sealant if you fill better just use as little as possiable there should be enough clearance on a 660 (but check to be sure!) just use brown paper sack the heavy kind

 

[Tree Sling'r]

Or.....
I am totally against not using gaskets. Your saw is probably about .028 -.032 stock squish, your gasket is .017. Get it down to .022 -.023 by setting a piece of sand paper on a sheet of glass and running the base of the cylinder back and forth. Bolt on, check squish go from there.

 

[smokinj]

Brown paper shopping bag= usually about .009".

 

[blsnelling]

I am totally against not using gaskets.

I'm curious. You won't run gasketless with just Dirko or Threebond? Is that just because of the mess to clean up the next time you take it off, or what? I find that it works well, but is a pain should you have to take it off. Carb cleaner will dissolve and remove it though.

 

[Tzed250]

Or.....
I am totally against not using gaskets. Your saw is probably about .028 -.032 stock squish, your gasket is .017. Get it down to .022 -.023 by setting a piece of sand paper on a sheet of glass and running the base of the cylinder back and forth. Bolt on, check squish go from there.

Yep...better be careful, squish on a newer 660 is tight. Mine(late '07 production) won't even turn over without the gasket in place.

Stihl quit using paper gaskets on the 660 for a reason...

 

[blsnelling]

Yep...better be careful, squish on a newer 660 is tight. Mine(late '07 production) won't even turn over without the gasket in place.

+1. Same here.

 

[Tree Sling'r]

I'm curious. You won't run gasketless with just Dirko or Threebond? Is that just because of the mess to clean up the next time you take it off, or what? I find that it works well, but is a pain should you have to take it off. Carb cleaner will dissolve and remove it though.

If a customer has an issue, they should not be worrying about what sealant to put on the base of a cylinder. I have not had it happen with my stuff, but I had it happen to me when I was still buying modded, I lost a weeks work with a new saw because the builder machined my P&C kit without comprimising for a gasket, I had no sealant and had to order the right stuff.
Besides when I machine my stuff, it takes 5 extra minutes to do it correctly. I have been there done that with the Dirko, Yamabond and Hondabond - I prefer to do it right since I have the tools to do so.

 

[blsnelling]

If a customer has an issue, they should not be worrying about what sealant to put on the base of a cylinder. I have not had it happen with my stuff, but I had it happen to me when I was still buying modded, I lost a weeks work with a new saw because the builder machined my P&C kit without comprimising for a gasket, I had no sealant and had to order the right stuff.
Besides when I machine my stuff, it takes 5 extra minutes to do it correctly. I have been there done that with the Dirko, Yamabond and Hondabond - I prefer to do it right since I have the tools to do so.

So what you're saying is that I need to buy a lathe? I agree!

 

[troutfisher]

I send my stuff out. Good machinists spend a lifetime learning their trade, I let them do what they do best. I concentrate on trying to make the saws run the way I want them to, and the chains cut the way I want them to. Oh ya, and I do have a lathe.

 

[BloodOnTheIce]

I got the day off and went to Harbor Freight, and picked up some new bits for the Dremel, here's the results.

I've widened the port a little over 3mm overall
The port is now 33.75mm wide and my piston skirt is 34.24mm leaving overlap of .25mm per side. And luckily I didn't change the height of the port either.

Exhuast Side:

I did some more grinding on the piston windows, they look pretty decent.

 

[smokinj]

# and parts look good!

 

[Wild Knight]

Yep, then you can do your own pop-ups

 

[Brownpot Deaton]

looks good. only thing was the right side roof of the exhuast, but nothing serious, just needs a good bevel/chamfer.

welcome to the dark side!

jordan

 

[blsnelling]

That's really starting to look good. Are you going to widen the intake too?

 

[Tree Sling'r]

So what you're saying is that I need to buy a lathe? I agree!

I am hoping for a 9x19 this fall...

 

[Tzed250]

So what you're saying is that I need to buy a lathe? I agree!

Buying the lathe is the easy part...

 

[BloodOnTheIce]

Ambition just bit me in the arse.

After getting the piston and exhaust looking decent, I decided after lunch to tackle the intake. And screwed it all up.

The grinder took more material than expected and lower the port in the botom right corner. Is it possible to save this?

 

[smokinj]

can you put in the #'s

 

[BloodOnTheIce]

Original:

Current:

 

[smokinj]

is the left side also 20.08