Another Porting Question

[redfin]

Not my dime but its not for nothing. I'm very intrigued with your work here. Staying tuned. Thank you for sharing.

 

[drf255]

Finished the piston welding. Copper hole would not work. Had to freehand.

The 4047 rod worked great. Flowed good.

Piston was 1.666 in both directions before and after welding. Preheated with a propane torch. Dome filled chamber well as viewed from plug. Had to rework dome and add a spark notch to clear plug. Fits in cylinder well.

Took some metal off under the dome. Using the stock pin and clips, I came in even with the initial weight. Pretty happy with that.

Now for assembly.


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[drf255]

I have ALOT of 4047 if anyone wants to give it a try.


Tig settings
AC squarewave
150Hz
70%EN
.02 pre
5.0 post
125 amps max with pedal
3/32 2% lanthanated
Gas lens with #8 cup

This woulda been a helluva lot prettier if I had a lathe to chuck it in.

 

[drf255]

Final dome with some sanding.




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[mdavlee]

View attachment 388265View attachment 388267

I have ALOT of 4047 if anyone wants to give it a try.


Tig settings
AC squarewave
150Hz
70%EN
.02 pre
5.0 post
125 amps max with pedal
3/32 2% lanthanated
Gas lens with #8 cup

This woulda been a helluva lot prettier if I had a lathe to chuck it in.

I've got a lathe but no aluminum tig set up.

 

[drf255]

I've got a lathe but no aluminum tig set up.

Could do some trading then.

 

[mdavlee]

Could do some trading then.

Yep.

 

[Moparmyway]

I have ALOT of 4047 if anyone wants to give it a try.


Tig settings
AC squarewave
150Hz
70%EN
.02 pre
5.0 post
125 amps max with pedal
3/32 2% lanthanated
Gas lens with #8 cup

I would be interested in some 4047.........

What difference did you see between 65 % and 70 %EN .......... You went with less cleaning action and deeper penetration.
Hard to see the pics on my phone, but did the pinholes and craters get better with the higher silicon content filler ?

 

[drf255]

I would be interested in some 4047.........

What difference did you see between 65 % and 70 %EN .......... You went with less cleaning action and deeper penetration.
Hard to see the pics on my phone, but did the pinholes and craters get better with the higher silicon content filler ?

The area around the dome didn't etch as much with the increased EN.

The 4047 has an orange hue to it when dipping filler into the puddle. It flowed nicer than the 4043. The rod is extremely light for its thickness. Very noticeable when you pick it up.

The pinholes on the other remained, even when I tried to practice on it with 4047. Don't think I can say it was ever the filler or technique.

This was apples and oranges. New piston vs one that likely had embedded contaminants in it.

One other interesting point. I measured the piston when it was hot, immediately after welding. It actually expanded .006 when hot and shrunk back down when cool. I would've never imagined this kind of expansion.

If you'd like some 4047, PM me.

 

[BBP]

Was there any particular compression you were looking for? It looks like it will be a pretty healthy increase.

 

[Chris-PA]

I'm interested to see how it works out. I've wanted to increase the compression on one of my ported Poulan clamshells but have no welder.

I've been toying with the idea of resurfacing the cylinder and grinding out the bearing pockets.

 

[LegDeLimber]

When I was working in an electric motor re-barring shop, We had some sort of stick arc coated rods for welding aluminum.
You could run a bead with the electric welder or you could grab 3~4 of them and a oxy-acetylene with a rose bud tip and work them almost like a brazing rod.
I wish I could still recall the vendor or the alloy.
I would love to have a pack of them to try out on a piston dome

We were welding (braising?) a 4" wide by about 3/8" flat bar onto to the pad of a 10~11 pound slide hammer.
They worked too. The hammer was just a roughly 4 foot long rod with a hunk of round stock
about the size of a large soup can and we gave it hell when we trying to pull those bars out of a stack of laminated sheets.
I still have a funny looking fingernail from that job.

 

[drf255]

When I was working in an electric motor re-barring shop, We had some sort of stick arc coated rods for welding aluminum.
You could run a bead with the electric welder or you could grab 3~4 of them and a oxy-acetylene with a rose bud tip and work them almost like a brazing rod.
I wish I could still recall the vendor or the alloy.
I would love to have a pack of them to try out on a piston dome

We were welding (braising?) a 4" wide by about 3/8" flat bar onto to the pad of a 10~11 pound slide hammer.
They worked too. The hammer was just a roughly 4 foot long rod with a hunk of round stock
about the size of a large soup can and we gave it hell when we trying to pull those bars out of a stack of laminated sheets.
I still have a funny looking fingernail from that job.

You shouldn't try an aluminum stick rod on a piston. I have some. Useless stuff pretty much.

It's for realty thick stuff. And only in a pinch. Super fast and hard to run.

I have a junk piston I can show y'all on if you'd like.

 

[drf255]

Got motor together. Now to grind the flywheel key to advance the timing.

Threw cabers on it. .008 gap.

 

[drf255]

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[XSKIER]

Ooh, a C-E. NICE!

 

[woodeneye]

This is a really interesting thread! Can't wait to see the results. I have a lathe on the way to my home, and was in the process of clearing out room for it. I'm interested in everything and anything porting related. Keep it up!

 

[drf255]

Flywheel keyway ground half way. Advanced flywheel that much as had been pointed out in prior threads.

Compression tested the motor. Hand held the EZ start to it, so I really couldn't get all the cranks I wanted. But oops....




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[AKDoug]

I hope that EZ start holds up to that compression

 

[drf255]

I hope the entire saw holds together with this much compression. Not really designed to handle it.

I hope the factory cooling will suffice.

I was hoping for 200 psi. After the cabers break in, I may be north of 220.

I guess it came in pretty close for just winging it. If I hadn't had to regrind for the plug, I'd likely have been at 250+. It's amazing how much compression a small pop up can create in these tiny chambers.

Gotta Hog out the muffler and port match it next.

When I get it all together I'm gonna do a video of a stock saw and this saw cutting some wood with the same bar and chain.

Does anyone think that .008 ring gap was too little in this saw? I'm a bit worried it may run a bit hot and the rings may bind.