Webster Build Questions and Progress

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Finished the cylinder, at least I think so. Used 400 grit and 600 grit silicon carbide. Feels and looks very smooth. No mirror shine, but from what I understand, not required for the Webster (please correct me if wrong). Thanks to all that assisted me with my first lapping job. Could be done better; but, I wanted to leave well enough alone. I did finish the bore at .873". Here are some photos.

Now I am moving on to the crankshaft and flywheel. I plan on asking further questions on this part of the build in a separate thread.

Edit: I looked at the magnification of the attached pictures, and they don't look so good. If anyone thinks I should continue lapping, please feel free to say so.
 

Attachments

  • 20241024_143611.jpg
    20241024_143611.jpg
    1.5 MB
  • 20241024_143623.jpg
    20241024_143623.jpg
    1.1 MB
  • 20241024_143844.jpg
    20241024_143844.jpg
    1.3 MB
Last edited:
Finished the cylinder, at least I think so. Used 400 grit and 600 grit silicon carbide. Feels and looks very smooth. No mirror shine, but from what I understand, not required for the Webster (please correct me if wrong).
And it is not necessary for other engines, unless you are working with smaller sizes. No need for this engine, can do it with 2nd engine if you want - maybe...you will learn something ;)
If the measurements are the same then : Great ๐Ÿ‘๐Ÿ‘๐Ÿ‘๐Ÿ‘
Which lapping method did you use ?
 
And it is not necessary for other engines, unless you are working with smaller sizes. No need for this engine, can do it with 2nd engine if you want - maybe...you will learn something ;)
If the measurements are the same then : Great ๐Ÿ‘๐Ÿ‘๐Ÿ‘๐Ÿ‘
Which lapping method did you use ?
Thank you. The measurements are allowing for a slight taper smaller at TDC. As I stated in an earlier post, it is difficult to measure with a telescoping gage. In any event, per my measurements, the taper is gradual from about .873" at BDC to 8727" at TDC. I think this may be a good thing.

I did use the lap similar to Adrian's website link above and that I photographed above shown in post #55. I modified it. In any event for my next ID lapping project, I will probably make a lap similar in design to the one Blondihacks made on her You tube channel.
 
I'd say you're in good shape. As I understand it, when using CI rings you want some cross-hatching in the cylinder walls to retain a tiny bit of oil. With o-rings, maybe an even smoother surface is appropriate - ?? But I would think that as long as the surface is smooth enough not to tear up the o-ring, it will be fine, especially no longer than one typically runs a Webster.

Maybe someone with more expertise will chime in and correct any mistakes I've made above ... :)
 
I'd say you're in good shape. As I understand it, when using CI rings you want some cross-hatching in the cylinder walls to retain a tiny bit of oil. With o-rings, maybe an even smoother surface is appropriate - ?? But I would think that as long as the surface is smooth enough not to tear up the o-ring, it will be fine, especially no longer than one typically runs a Webster.

Maybe someone with more expertise will chime in and correct any mistakes I've made above ... :)
I am, at this point, planning on a cast iron piston with no rings. While on the subject, is the viton o-ring sized such that I could go that route with the current bore of .8727 to .873"?
 
If you want to use O-rings
This is how I used to measure the cylinder bore to see if it was ok with the O-ring OD I was using. It also gave me the groove diameter for the O-ring on the piston
An amateur way ;).

CC.jpg
 
Thanks Minh Thanh. Good to know if I decide to go with o-rings. I doubt I will; but, I like options.
 

Latest posts

Back
Top