Galloway 1/3 scale engine build

[AZDesert]

This is my first post here about my 1/3 scale Galloway Hit and Miss engine build project.  I will post some pictures of my progress so far and maybe a few questions for anyone out there that can comment to help me work out some details..

I started out with the base unit getting the top and bottom flat and parallel.  Then made the mounting feet and made the pockets for them to fit in. I have made pretty good progress thru the small parts.  I am currently working in the carburetor and wondering what is the best way to make the 45 degree needle valve seat.  It is very tight space and I am not sure what kind of tooling would work best to do this without damaging the rest of the bore needed for threads. 

I see another older thread that walks thru the same engine build but is there anyone else that had built one of these recently?  It is casting kit from Ministeam that I am doing.

[redhouseluv]

Good luck with the build, its' a good looking engine and I'll be following along 

[crueby]

The parts so far look great! I've never  built a hit n miss, but love watching them run. Will be following  along...   

[Jasonb]

Off to a good start, probably my thread you mention.

Of the several Lunkenheimer mixers that I have made I have always done the seat with a very small boring bar. Set the topslide over to 45degrees but have the bar set along the lathe axis or slightly angled to clear the threaded opening.

[AZDesert]

Yes Jason,  That is the thread that i have been using as a guide thru this project.  One other question I have for the carb is the hole/thread size for what i assume is the air intake port.  In the attached picture it shows on the right hand side of the carb body a 1/16 -27 NPT fitting.  It appears to be much bigger than that, more like a 3/8.  Is this mislabeled or am i reading something wrong?   The 1/16 size looks like it should be for the fuel line intake.  Thanks.

[rklopp]

The OD of 1/16 pipe is 5/16". The nominal size is 1/16, but that has nothing to do with reality. Likewise, 1/8" pipe is 0.405".

[Jasonb]

Drill it letter C or 0.242". If you compare that to the 1/4" threads on the other side it's right.

[gbritnell]

When Ministeam bought the rights to the Galloway series of engines, the patterns and drawings they hired me to build one of each scale. The original drawings that had been drawn by Richard Shelly were in need of updating so I redrew all of them except the 1/8 scale. Those were done by Bob Nawa. If you have any questions along the way I'd be happy to answer them. The most sensitive part of the carb is getting the fuel valve sealed. Not the needle valve. The fuel valve sits on its seat. The passage from the needle valve is drilled into the seat. When the engine is on the intake stroke the vacuum draws the valve off of the seat and allows the air to flow and draw fuel from the needle valve. The reason for this valve is because the fuel tank is mounted higher than the carb so it prevents the fuel from leaking into the carb when there is no vacuum signal. The stop insert above the valve limits the valve travel.  It doesn't need much travel to operate properly.  The spring on the bottom of the valve only needs to be strong enough to reseat the valve.  Sometimes it takes a little playing with this spring to get it just right. When Bob Nawa built the 1/8 scale engine he made the Lunkenhiemer carb for it. Very small!

[AZDesert]

A question for those who have been thru a build like this.  I am starting on the piston and cylinder for the this engine.  Included with the kit from MiniSteam is a piece of round stock CRS for the cylinder.  I have not worked with this before and as I am trying to turn it on the lathe using a carbide insert I am not getting a smooth surface.  Any advice from the group on how to turn this piece accurately?    It is about 2.4" in diameter and I was using an RPM of about 560.  Thanks for any help.

[Jasonb]

Mine came with a piece of continuously cast iron.

You don't say what inserts you are using bit it is worth trying those intended for Non Ferrous metals, not that familiar with the US code system but the ISO designation has GT instead of MT so a typical insert would be CCGT 060202 as opposed to CCMT 060202

[AZDesert]

I am making some more progress on my Galloway build.  For the previous problem I was having making the cylinder sleeve I replaced the Carbide insert and increased the speed on the lathe an that seemed to take care of the issue.  Nice, smooth surface now.  I am just about ready to press the cylinder into the block and started on bearing blocks for the crankshaft.  I also completed the piston, rod and bearing assembly.  Here are a few pictures along the way.  I am a bit nervous about pressing the sleeve into the block.  I have the recommended .0016 oversize on the mating surface of the sleeve and I made a slight angle on the entry point on the block to help it get started correctly.  I don't have a press so am thinking about talking to a local machine shop to see if they could press it in for me.  Any recommendation or tips to make sure it goes smoothly?

[AZDesert]

Pic 2

[AZDesert]

Pic 3

[AZDesert]

Pic 4

[kuhncw]

Nice work.  My opinion/suggestion:  Make the liner a close slip fit into the cylinder block and seal it in with Loctite 609 or similar.

 I built a 1/4 Galloway this way.

Chuck