Well I thought it was a carb issue...

[gary55]

View attachment 77047 View attachment 77048 Well, got nothing done except bolt the lathe together
Hopefully finish it off tomorrow with the mill adaption

But a bit of an update for Gary on the piston TDC

Just out of curiosity, what would happen if I remove the bottom gasket with ports etc?

1. Risk a air leak losing pressure in case which could make the engine run poorly if at all. 2. If it somehow managed to seal the lower ports will hinder high RPM but compression and low end torque will increase. Not the route I would take.
One thing I notice is how high above the top of your cyl. the threads end on your studs. This could be a issue not allowing a good seal before reaching torque. pull one of the studs and see if the threads run longer on the other end. If so I would turn them all over and recheck compression prior to milling. What kind of a crush mark was your head gasket showing with the new parts?View media item 60720

 

[Stoneman]

1. Risk a air leak losing pressure in case which could make the engine run poorly if at all. 2. If it somehow managed to seal the lower ports will hinder high RPM but compression and low end torque will increase. Not the route I would take.
One thing I notice is how high above the top of your cyl. the threads end on your studs. This could be a issue not allowing a good seal before reaching torque. pull one of the studs and see if the threads run longer on the other end. If so I would turn them all over and recheck compression prior to milling. What kind of a crush mark was your head gasket showing with the new parts?View media item 60720

Yes I see what your saying, very observant

The head needs 16.6mm there about I have 15mm to the bottom of thread without head gasket on stud
Plus It came with 2 washers on top so there should of been no issue there and no damage to bolts

 

[Stoneman]

I don't think I'll have any problems milling the jug or altering heads

 

[Frankenstein]

I don't think I'll have any problems milling the jug or altering heads

Just don't set it for autofeed and forget about it unless you're about to buy a shorter crankshaft

 

[Stoneman]

Does anyone have any ideas on clamping the jug

Milling is easy but clamping and setting up is a little more involved I'm noticing.

 

[Frankenstein]

Does anyone have any ideas on clamping the jug

Milling is easy but clamping and setting up is a little more involved I'm noticing.

Well I think what you are doing is overkill for decking a cylinder, but if I wanted to put that in a lathe type mill I'd make a 47mm diameter cylinder from wood, drill a good size hole from one end to the other, split it right down the middle, and make a wedging nut to force the 2 halves apart while they are inside the cylinder bore. Or you can cut a cone type shape into the split parts near the bolt hole one one side, put a thin but wider (in diameter) washer on the bolt, and tighten a nut down until the washer starts bending and forcing the 2 halves apart because of the cone or wedge cut into the wood.

That can be chucked into a mill, just make the wood cuts nice and centered.

 

[Stoneman]

That's a great idea thanks for that

What do you mean over kill? What other ways can I go about raising the compression

I didn't get the machine just for decking the the cylinder
I just got excited when I got it

 

[gary55]

Does anyone have any ideas on clamping the jug

Milling is easy but clamping and setting up is a little more involved I'm noticing.

Would a pipe expander work with some pvc pipe to protect the cyl. walls?

 

[Frankenstein]

Would a pipe expander work with some pvc pipe to protect the cyl. walls?

Hey yeah that would work well, even made to get put in a chuck too.

 

[Stoneman]

That is a great idea!
More tools haha

I like the timber one as well, I reckon I could make something up easy enough to get the job done

The pvc idea would make my lathe chuck soft jaw as well...
Would also be cool to make a sleeve protector when cleaning the ports
It should lathe to size easy enough

Thanks for the ideas, perfect actually!