Minnie Traction Engine – Cylinder Drilling

[Malcolm FarrantParticipant @malcolmfarrant93389]

Help Please!!

Page 125 of L.C.Mason's boock shows a drawing of the Sectional Plan of the Cylinder. On this are 2 x 5/64 diagonal holes meeting up with the 5/64 Steam Ports.

My understanding is that after the Liner is fitted these 2 holes have to be drilled to meet the extreme ends of the 2 ports and at the BASE of these ports.

My question is:- Is my understanding correct ?

In anticipation many thanks…Malcolm Farrant

Edited By Malcolm Farrant on 27/11/2018 11:44:25

[Malcolm FarrantParticipant @malcolmfarrant93389]

[Richard S2Participant @richards2]

Nearly correct, The 2 separate holes at each end of the cylinder bore enter the respective steam port in the valve chest, but one hole enters the top and one at the bottom of the port i.e parallel holes. It keeps the holes away from the cover studs.

A further drawing on page 127 labelled as 'Rear End' will show the 2 parrallel drilled holes meeting up with the Port(s).

Edit- noticed you stated 5/64" for the steam way holes. Book states 3/32"and the procedure for drilling them is on 133.

Afraid I only have an image of the cylinder bore front end.

 

Edited By Richard S2 on 27/11/2018 14:02:33

[JasonBModerator @jasonb]

You do have a bit of leeway as the goles don't have to meet the extream ends of the ports, start off aiming for there but don't worry if your hole is a little off.

Main thing is to make sure you don't go into the bore, through the port face or drill too deep and hit the exhaust port.

I don't have a photo of the Minnie but this is my Fowler

[Malcolm FarrantParticipant @malcolmfarrant93389]

Richard S2 and JasonB

Thank you both SO much that has been a great help. It looks as if I must just be VERY careful in my drilling !!

Best wishes and repeated thanks

Malclm

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