026 build running a bit lackluster

[NateSaw]

I'm dull. Yes, just like cutting the skirt to advance the intake timing. With you fellas I'd be cornering myself with dyslexia lol.

Can I also dm you @drf256 ?

 

[Mastermind]

Randy, can I dm you?

Absolutely.

Or call. 931-310-3363

 

[82f100swb]

If your cylinder is just glazed, and the coating doesn't show any damage, I will put good money on it still being in spec, and would be fine with a new piston.
I'd offer you a known good top end, but I'm sure some of these guys on your side of the border can get you straightened away at less shipping cost.

 

[NateSaw]

If your cylinder is just glazed, and the coating doesn't show any damage, I will put good money on it still being in spec, and would be fine with a new piston.
I'd offer you a known good top end, but I'm sure some of these guys on your side of the border can get you straightened away at less shipping cost.

Thank you so much brother!

 

[drf256]

Can I also dm you @drf256 ?

Of course

 

[NateSaw]

How do guys like to chamfer the bore before cutting the base? Should I persist with diamond burrs? I'd rather not repeat the chipping of the nikasil... Or, is it your experience that with the lathe, this doesn't occur?

 

[Mastermind]

How do guys like to chamfer the bore before cutting the base? Should I persist with diamond burrs? I'd rather not repeat the chipping of the nikasil... Or, is it your experience that with the lathe, this doesn't occur?

I cut the plating on the lathe before I cut the base. From the inside...it doesn't chip that way.

 

[NateSaw]

I cut the plating on the lathe before I cut the base. From the inside...it doesn't chip that way.

Makes sense. It is in top of the aluminum. And harder. Badass. So do you chamfer? Or just roll each pass from the inside out? In my limited lathe/mill experience I'm used to taking no more than 10k per pass... Should this be done in 5k or less per?

 

[Mastermind]

Makes sense. It is in top of the aluminum. And harder. Badass. So do you chamfer? Or just roll each pass from the inside out? In my limited lathe/mill experience I'm used to taking no more than 10k per pass... Should this be done in 5k or less per?

I set it up to cut the squish, then before I take the just out of the lathe, I cut just the plating at the base. I know how much I'll be cutting off the base, so I use my boring bar to go that deep, about .020 into the bore.

 

[NateSaw]

My janky setup. I'll be lucky if I get it to indicate well at all. I should've made the plates bigger, used thicker all thread outside the cylinder, and drilled and tapped the base plate so I could've bolted the jug to that.

 

[NateSaw]

 

[Mastermind]

Looks like it will work.

 

[NateSaw]

Looks like it will work.

If, in theory, I can even get it to indicate in, I assure you the finish will be fodder. I'm using an hhs boring bar. There WILL be chatter. Also that 5mm all thread has flex. So also in theory, I'll be taking small nips of likely no more than 3 thou. Cause it's gonna be moving. I'm leaning on the fact that up until now, it ran on a mortar and pestil ground squish. I'll likely do that again, after. So far it looks as though I'll be incredibly lucky to get it in center and parallel within .010"
My limited 3 years experience machining, was enough to teach me that I should be scared of this setup. The only good news is that I scrapped this cylinder already by destroying the lowers.

 

[Mastermind]

If, in theory, I can even get it to indicate in, I assure you the finish will be fodder. I'm using an hhs boring bar. There WILL be chatter. Also that 5mm all thread has flex. So also in theory, I'll be taking small nips of likely no more than 3 thou. Cause it's gonna be moving. I'm leaning on the fact that up until now, it ran on a mortar and pestil ground squish. I'll likely do that again, after. So far it looks as though I'll be incredibly lucky to get it in center and parallel within .010"
My limited 3 years experience machining, was enough to teach me that I should be scared of this setup. The only good news is that I scrapped this cylinder already by destroying the lowers.

I just use a plate at the top. On a lot of jugs I mill a flat spot on top first. That helps.

 

[Rich Fife]

When possible, I enlarge the bolt passages through the fins so that I can utilize modified bolts/studs... should resolve most if not all chatter issues. Your set-up has excessive weight away from the chuck, then add the rotation/axial forces (wanting to twist and catch)... due to the lack of rigidity.
Hopefully you don't ming me dropping pics and a video or two to show what I do. I feel it could help tremendously to reduce/remove chatter. There's many ways to skin a cat.. this is just how I do it.

 

[Rich Fife]

 

[Rich Fife]

***Warning*** my videos suck. Lol

 

[NateSaw]

When possible, I enlarge the bolt passages through the fins so that I can utilize modified bolts/studs... should resolve most if not all chatter issues. Your set-up has excessive weight away from the chuck, then add the rotation/axial forces (wanting to twist and catch)... due to the lack of rigidity.
Hopefully you don't ming me dropping pics and a video or two to show what I do. I feel it could help tremendously to reduce/remove chatter. There's many ways to skin a cat.. this is just how I do it.

Of course I don't mind man. This is a forum. Lol. I joined to learn. For right now, I've learned I need to try some of this stuff on another project, first, I need 3 saws that will work for me so I can make money. Then, I'll dig back in to this porting stuff... Or not lol. If I were still at the machine shop, the first thing I would do is make a solid fixture. My buddy and I were looking at those fin holes. But chatter was the least of my worries. It was simply impossible to achieve reasonable parallelism, or eliminate runout. It's back together, and it runs, but it's a carved up wobbly paperweight. I wouldn't expect this thing to make it past a couple tanks of gas. And even though I haven't put it in wood yet, I can tell it's roached.

 

[NateSaw]

I just use a plate at the top. On a lot of jugs I mill a flat spot on top first. That helps.

Welp, I roooned it lol. But then again, that was established with the hogged lowers. Sheeesh.
It runs... But feels flaccid. Like my pride right now lol.

 

[Rich Fife]

It would be much easier to dial-in the cylinder if you remove the outer piece of aluminum and added nuts on both sides of the cylinder flange...