Jump to content

B Piston In An E Barrel


blocky
 Share

Recommended Posts

I am in the process of restoring a 241 progress 2 and am currently rebuilding the engine.

I was a little surprised to find that the piston that is fitted is stamped as a B whilst the cylinder is stamped E

Obviously the two should match but can anyone tell me what figures the letters actually refer to ?

Link to comment
Share on other sites

 

They refer to the piston to bore clearance, you should use an A piston with an A barrel and so on You could send the barrel and piston to langcourts and have the barrel replated, to suit the piston. If the barrel has an iron liner fitted it may have been bored and honed to suit this piston ? you need to find out what clearance you have measure the piston with a micrometer 10mm up from the bottom of the skirt (front to back) and note the size then measure the barrel bore with an internal micrometer and minus from the other which will give you the clearance you have check your manual to see if its in tolerance hope this helps and good luck

Link to comment
Share on other sites

 

I am in the process of restoring a 241 progress 2 and am currently rebuilding the engine.

I was a little surprised to find that the piston that is fitted is stamped as a B whilst the cylinder is stamped E

Obviously the two should match but can anyone tell me what figures the letters actually refer to ?

Its probably been replated at some time, and the piston matches the replated size?

Link to comment
Share on other sites

 

Its probably been replated at some time, and the piston matches the replated size?

MUST have been replated. I doubt a B piston in an E cylinder would even runwell when new

Tolerance (diameter) Piston to bore should be 0,035mm when new

0,05mm will rattle a bit

more than 0,07mm soulds like a rebuild.

Size difference per letter is 0,01mm

so could have been 0,065mm assuming both were new when assembled

would sound like a bag of nails or a TY 250! hahahaha

Edited by Lee Harris
Link to comment
Share on other sites

 

Thanks Lee... just what I needed to know.

The cylinder doesn't look as if its been replated but the piston looks too good to be original. I wonder if someone has fitted a replacement piston and mistakenly read the E for a B (easy to do when parts are dirty) when they bought the new piston.

Will have to measure things tomorrow.

Link to comment
Share on other sites

 
 

MUST have been replated. I doubt a B piston in an E cylinder would even runwell when new

Tolerance (diameter) Piston to bore should be 0,035mm when new

0,05mm will rattle a bit

more than 0,07mm soulds like a rebuild.

Size difference per letter is 0,01mm

so could have been 0,065mm assuming both were new when assembled

would sound like a bag of nails or a TY 250! hahahaha

But still much quieter than a 307!

Link to comment
Share on other sites

 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
  • Create New...