Poulan 3400,3700,3800, 4000 stroked crankshaft project. Part 2

[Metals406]

I have some serious shop/tool/skill envy.

Pretty sweet work sir.

 

[lwhaples]

Beautiful work. Will enjoy seeing the end results.

 

[DrewUth]

Blown away by both the scale of the project as well as all the machine work and engineering. Amazing!

 

[dieselfitter]

I have some serious shop/tool/skill envy.

Pretty sweet work sir.

Don't. I don't know what the hell I'm doing. I have no formal training with any of the equipment. I bought the equipment last year and am learning to use it.

 

[Dub11]

Well you a fast learner

 

[Metals406]

Don't. I don't know what the hell I'm doing. I have no formal training with any of the equipment. I bought the equipment last year and am learning to use it.

Likely story! [emoji6]

 

[wcorey]

Don't. I don't know what the hell I'm doing. I have no formal training with any of the equipment. I bought the equipment last year and am learning to use it.

That adds a whole 'nother level of Wow.
Great thread!

 

[X 66 stang347 X]

Great build. Now just Need some port work on that cylinder.

 

[Steve670]

Awesome work bloke.

 

[Nitehawk55]

Very nice !

I think I had one of those chemistry sets when I was a kid back in around 1966 .

 

[pa-aaronq]

Awesome work bloke.

+1

 

[Dub11]

Ok I have been hold back but how did you center the new jug on the chassis? I was think of taking a base gasket from one saw the gasket from the jug make some cross hairs for them over lay them then mark for new holes.

 

[Sty57]

Awesome Build Tim!

I've always liked outta box thinking.

 

[dieselfitter]

Ok I have been hold back but how did you center the new jug on the chassis? I was think of taking a base gasket from one saw the gasket from the jug make some cross hairs for them over lay them then mark for new holes.

I was scratching my head for a while trying to figure out how to do that one. I measured the two different patterns and sketched it out. The two patterns overlapped each other but neither pattern could be moved enough to match the other. I needed to come up with a 3 pattern for the adapter to case that:
1 didn't move too far from the original(the casting gets thin).
2 didn't overlap with the cylinder mounting pattern.
3 didn't interfere with the cylinder skirt protruding down below the cylinder mounting surface.
It got too confusing to sketch out because it was too much work to maintain scale of the drawing to monitor the relationship of everything. I downloaded an autocad program and learned enough of it to get it done. Another difficulty was getting all the numbers to jive in the autocad drawing. Measuring the cylinder mounting holes, they would vary by .003" in location. Not having access to the manufacturer's drawing or dimension, I'm trying to figure out what it is by measuring the part and the measurements are all over the place. I had to manipulate the dimensions(radius, bolt spacing) within autocad drawing until the numbers jived.
Once the numbers jived, I moved the new spacer block mounting screw location to a location that put them equally distant from the cylinder mounting bolts and the cylinder skirt.
Once the numbers were known, it was just a matter of turning dials to get them on the DRO on the mill.
Another thing I did was change hardware. The original cylinder mounting to case bolts were 1/4" course thread. I had considered going to 6mm-1 which is a little smaller(giving me more room in a tight area). I chose #12-24 which is a little smaller yet and more course of thread.

 

[dieselfitter]

If you look at that last pic, you can see how the case ports don't match the spacer block and are restrictive. Adam/Jonseredracket has loaned me his Fordom grinder. Those restrictions will be gone today. I will grind and blend them.

 

[Dub11]

Do you like using course thread over fine ? I holographic press I work on we have better luck with fine thread holding some high temp parts at torque spec and less stripped screw holes

 

[Dub11]

And I hear ya on auto cad I have off center holes all over my press coming from the engineers drawing to the machine shop then back to me for installation. It gets frustrating

 

[dieselfitter]

Do you like using course thread over fine ? I holographic press I work on we have better luck with fine thread holding some high temp parts at torque spec and less stripped screw holes

Depends on material and application. In soft magnesium, I prefer course thread.

 

[Adirondackstihl]

 

[Deets066]

Very cool thread bud.

What piston are you using? 395?