Amanco hired man

[fourstroke]

Hi.
My name is Dougie and I live in Scotland.
I thought I would share with you guys my progress on the Breisch castings I bought recently
The pics will explain a lot I hope but first some comments about the kit
The castings are very good in general but I have found one or two problems.
First big problem was the base casting, the drawings call for a base to crank centre height of 3 3/8", as supplied my base was shorter than this and after machining left me with a centre height of 3". I will have to reduce the diameter of the flywheels to suit.
The hopper top had a fair bit of pattern shift, you might notice the JB weld filler in some of the pics, nothing insurmountable so here we go.

I set the base casting as true as I could get it and machined the base flat.

After milling a base jig as true as I could I mounted the base casting and set the angles for milling the bearing seats.

Once the bearing caps were finished and attatched to the base the jig was set up against an angle plate and the main bearings were drilled and reamed. The mount for the cylinder was machined to size at the same setting to ensurethe cylinder mount and the crank were at right angles.

I mounted the cylinder casting in the 3 jaw chuck in my lathe and got the bore running as true as I could, it was bored and honed before mounting it on a mandrel to finish the cylinder head mount to size and ensure it was square to the bore.
The cylinder was bolted to the mill table and the mounting flange machined to a close fit in the base casting. I clamped everything together to mill the top of the cylinder casting and the top and sides of the mounting flange to give a register to mark out and drill the holes for the cylinder studs.

The main bearings are made from two pieces of brass soldered together, I rough turned and drilled the bore to 12mm before parting off and reaming to finished size, I then mounted them on a mandrel to finish the outside diameter to size.

The last two pics are the results so far, fitted together to check the fits.

I tried to get the pics seperated by there descriptions but I dont know how to do that on this site, anyway, I hope you enjoy the work so far.
Regards
Dougie

 

[Jasonb]

Looking good so far Dougie, I think I would be inclined to keep the flywheels as large as possible, they should clear once the engine is on a sled or cart.

J

 

[Herbiev]

Looking great Dougie. Thanks for sharing.

 

[gbritnell]

Jason is right. The flywheels will clear a sled or base under the engine so I would also leave them as large as possible. These engines can really use all of the centrifugal weight they can get.
gbritnell

 

[Dr Jo]

The flywheels stick under the bottom of the base on the original.

Jo

 

[Jasonb]

I think that the camera angle may be making it look that way, here is one on a flat surface

I suppose if you don't want it on a sled or cart you could JB Weld a plate to the bottom of the casting and shape to suit which would just give the required lift.

 

[Dr Jo]

Maybe they fitted different flywheels to these engines. You can see the bottom of the base through the flywheel in this view of the same engine.

 

[Rivergypsy]

Still, a nice oak or teak base never goes amiss ;D

 

[JLeatherman]

My full-size Associated 2 1/2 hp engine (later version of the 2 1/4 hp) had flywheels that would have touched the floor if it wasn't on skids. I wonder if the flywheels got bigger when they increased the rating to 2 1/2?

 

[fourstroke]

Thanks for all the comments, they are much appreciated
I ave started on the cylinder head but have hit a problem, I'm hoping someone out there might hav come across this before and can help with some advice
The problem is the exhaust support cast into the head, no matter which way I turn it it wont fit in my four jaw chuck to let me cut the valve ports, the exhaust support always gets in the way
I made a support ring to mount it on but that didn't cure the problem totally, I am seriously considering cutting or breaking off the support to let me complete the machining
Before I do this has anyone any solutions?
I should say my chuck is 10" diameter so its not small, is it safe to increase the diameter of the center hole in the chuck? That was another thought
Regards
Dougie

 

[Jasonb]

Dougie, the usual way is to make a fixture to hold the head by holes that are used to mount it to the cylinder. Some people cut clearance into a solid block, I prefer a tooling plate and standoffs.

Have a look at how I did it on my 1/2 scale domestic
http://www.homemodelenginemachinist...-stovepipe-build-17470/index3.html#post182016

J

 

[fourstroke]

Thanks Jason
I had thought of something similar but your idea of a flat plate might be better than my idea
The only worry I had about this is I can only use 5BA or at a push 4BA threads, I was worried they might not be strong enough to hold the head securely, what do you think?
Regards
Dougie

 

[Jasonb]

If you take light cuts you should be OK and any screws you use make then allen headed ones which should be a bit stronger.

Your head is also a lot smaller than the Domestic , that flange is about 4.5" dia

J

 

[fourstroke]

Here is an update and some pictures of the latest progress
Thanks to some good advice and some pictures from Jason B, I managed to get all the machining on the cylinder head carried out
Who would have thunk of reversing the jaws in the 4 jaw chuck....DUH.
The first pics are the set up in my lathe to cut the valve ports and machine the 45* valve faces
The later pics are of the set up to drill the inlet and exhaust passages and the completed head with its valves fitted
One of the pictures is of a VERY long reach spark plug I made, the head is 3/4" thick at the plug boss, I was going to counterbore the head but that would get very close to the exhaust passage so I decided against it. The plug works fine but I might refine it a bit
Finally a big thanks to Jason for the advice
Enjoy and comment
Regards
Dougie

 

[rklopp]

FYI, I use a standard reach commercial spark plug in my Breisch Hired Man. It runs fine, even though the spark electrodes are recessed quite a distance from the head face.

 

[Brian Rupnow]

Dougie--Nice work and good pictures. It looks like you are doing a fine job.---Brian

 

[fourstroke]

Hello everyone
I thought I would post some pictures and details of the progress I have made so far.
The first pic is of the setup I used to drill and tap the exhaust rocker support.
The eagle eyed amongst you might notice the little bit of braze at the base of the support and the brighter looking inlet valve guide.
This was as a result of dropping the head on the floor and snapping it off, no problem I thought, I can braze it back on. My son also pointed out that one of our full size amancos has the exact same repair, so it makes it a bit more authentic.
The new valve guide is as a result of not watching where the oxy acetylene flame was playing on the head. DUH. I managed to melt part of it!!
It wasn't possible to repair so I machined it off and made up a new top half of the guide and fitted it along with a brass bush for the valve stem.
The next pic is the way I held the crank gear to bore it to 1/2" dia and the ones that follow are pictures of the various governor parts and the exhaust rocker showing the setups I used to silver solder the parts together
Anyway, I hope you enjoy
Dougie

 

[Brian Rupnow]

Very elegant. Thanks for the pictures.--Brian Rupnow

 

[idahoan]

Hi Dougie

I have been enjoying the progress on your engine build; too bad about the rocker arm mount. It looks like you were able to recover with out too much trouble.
Your fabrications are great! it is always fun to see how others tackle these challenges.

Thanks for taking the time to document your build.

Dave

 

[fourstroke]

I made some more progress on my engine so I wanted to share some of the pics with you

I also have a question regarding the cylinder head and running the engine on LPG
The last pic in the series is a scan of the head drawing to illustrate what I want to know.

The first pics are of the setup I used to machine the flywheels and cut the keyway, sorry about the shaky pic of the keyway cutter, this was home made a few years ago. The faceplate I bought recently just for this kind of job.
The flywheels were finished on the rotary table to true up the inner faces then a session with the dremel rounded the corners.
I couldn't resist fitting all the parts together to see what shape things were taking and there are a few pics of the work so far.

The last pic relates to my question to anybody out there who might have some experience or advice.

The 4-40 threaded hole I have highlighted is I presume to hold the carb in place, I have altered the design slightly and do not need this to secure the carb.
I would like to try running this engine on propane so my question is this.
If I drill and tap this space, would I be able to feed propane in here and use the carb just as an air supply to mix with the gas?
Has anybody tried this before?
If you have, please let me know what your results were
Any other comments will be greatly appreciated
Enjoy
Dougie