Maryak 10

[NickG]

Bob,

No problem, everybody found it very enjoyable and probably learned valuable lessons.

Can't wait to see the hit & miss!

Nick

 

[Philjoe5]

Fantastic journey Bob. Thanks for taking the time to show us how it's done. The video was pure class.

:bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow:

Cheers,
Phil

 

[zeeprogrammer]

That was GREAT! Thank you so much for sharing.

 

[Maryak]

Phil and Zee,

Thanks Guys :bow: :bow:

Best Regards
Bob

 

[ozzie34231]

Hello Bob,
Wandering through the files here at HMEM, and found this magnificent work. I mean your work in both the build and your descriptions, and I need to add, the pictures.
I downloaded all of your PDF's and read all 30 pages of this set of posts.
I have a couple questions about lapping, and if it has already been covered I apologize in advance.
I know you said you start with a medium grit, can you estimate what number grit that might be?
How much material do you leave for lapping?
What is the size of the lap compared to the bored size of the cylinder?
Is that the same for the piston?
And finally, when are you finished lapping; as soon as the piston will go in?
Any idea what the clearance is?

Many, many thanks for this gift you've given all of us,
Ozzie

 

[Maryak]

Ozzie,

Below is my attempt to try and answer your questions.

I know you said you start with a medium grit, can you estimate what number grit that might be?
Coarse around 80, Medium around 120, Fine around 220.

How much material do you leave for lapping?
Between 0.001" and 0.002"

What is the size of the lap compared to the bored size of the cylinder?
The lap starts out around 0.005" undersize for the cylinder.

Is that the same for the piston?
The piston laps are a reverse of the cylinder laps. i.e. cylinder lap 3 x cylinder length and -0.005" cylinder dia, piston lap 1/3 piston length and +0.005" piston dia.

And finally, when are you finished lapping; as soon as the piston will go in, any idea what the clearance is?
If all has gone well I would estimate the clearance to be between 0.0001" and 0.0002"

I hope this helps.

Best Regards
Bob

 

[ozzie34231]

Cool Bob, Thanks,
Ozzie