Hi , I recently built a 3 cylinder 'PIP' engine from plans purchased at LittleLocos.com. I wrote a build thread on another forum I use so I thought I may transfer it across to here. Bear with me as this forum works a little differently to the one I am used to.

First job is to make a 2mt taper with a 1/2 inch round boss on the end.
This will fit into my rotary table and my lathe nose and will enable me to
swap work pieces quickly while keeping them centred.

 Then machine a 1/2'' hole into my Cylinder blanks to fit the taper and also a 1/4'' grove
to use for holding clamps. I am making four cylinders so I have a spare in case something
goes wrong. The Cylinders are the most complex part apparently.
You can see the taper fitted into the last blank.

The first blank is mounted to the lathe using the taper and face plate.
First job is to open out a bore to .75'' , the combustion chamber is formed by a standard
118 degree 11/16 drill bit then the bore is opened out to .75 ready to fit a steel sleeve
later in the build.
The outside shape of the Cyl is then formed by turning a 30 degree taper leaving
a mounting boss on the end.

Edited By David Kenyon 2 on 17/12/2018 19:09:57

Edited By David Kenyon 2 on 17/12/2018 19:37:44

The rotary table is set up horizontal on the mill table and a milling cutter is used to

mill through the first two fins opposite each of the eight mounting holes.

This provides clearance for the mounting screws to be fitted later.

Had to make a jig to hold the Cyl for the top fins to be cut.

This consists on a large chunk of alloy rod with an expanding mandrel

fitted through at 90 degrees as below

First the top of cylinder is turned to shape

That's ok, I am copying and pasting from another forum so it easy enough now I have sussed the pictures.

The other forum was not an engineering forum so you may find some of the explanations a bit brief / simplistic.

The jig is a copy of the internal bore and combustion chamber shape and is set up on the mill

at a 30 degree angle so the top is level . A taper is drilled dead centre of the flat using a centre drill

and this is then used to centre the jig on my mill as blow.

The table is turned 120 degrees ready for drilling the valve guide seat. This is a bit more involved.

First mill a flat, then drill 7.6mm, ream 8mm, then drill down 9mm but stop about 1/16'' from the bottom.

Then tap M10 fine, again just short of the bottom. A 45 degree taper will be cut on the shoulder at the bottom

were the m8 is left.

The table is turned another 120 degrees and the second valve guide seat is cut.

Remember the set up on the mill was turned 49 degrees , that is because the rocker posts are

fitted at a 49 degree angle from the valves.

So while centred over the valve guide I offset the table 0.344'' and drill / tap a m3 thread, a post is

screwed in with permanent Loctite and then a slot is milled to accept a rocker.

With the cylinders drilled and tapped I need to make the valve seats/guides.

These are made n one piece out of 660 phosphor bronze.

A piece of bronze is turned down and threaded m10 fine to match the Cylinder, then

the first 2mm is turned down to 8mm and the step is turned a 45 degree taper.

I then placed a bit of alloy in the lathe , tapped it m10 and screwed the guide into this

so I can reduce the top halve to form the guide. Two small holes are drilled either side

of the valve guide and a tool is made to insert into these which will allow me to screw the

guides in.