# Bruce-MacBeth Gas Engine Electric Plant



## Rustkolector

This project was posted back in September in the Photos section, but wasnt quite complete. And I know the video wasnt great either. I am still no better at videography, but results are a little better this time. 

This is a 1/10th scale 1915 vintage Bruce-MacBeth stationary 100 hp gas engine electric plant. This engine project was a collaboration between Doug Kelley, and myself using an engine from the collection of the Coolspring Power Museum and another owned by a fellow engine collector Dave Johnson. Both were quite accommodating in the project. The only castings are the flywheels. All other parts and assemblies were fabricated from brass, and steel. The model uses a 1 bore x 1.2 stroke, and has a wet oil sump with splash lubrication. A top mounted camshaft is driven through a pair of miter gears sets from the center of the crankshaft. This drive arrangement was unique to Bruce-MacBeth engines. The rocker arms are roller type on both ends, as original. The real Bruce-MacBeth engines operated at 500 RPM, or less. The model will run at 500 RPM, but oil splash is marginal. It does very well at 575-600 RPM as shown in the video. 

The propane fuel system used is ideal for this type engine, and for anyone wanting to run their engine for long periods. It took me a while to understand it, but now I prefer it whenever it can be used. It is almost odorless, wont flood, wont ruin paint jobs, and burns extremely clean. 

The alternator was added after the engine was completed. My engine looked lonesome by itself so the alternator became a secondary project. It is a similar vintage Westinghouse design. The alternator stator started out as an old induction rotor ceiling fan. The rest was fabricated including the permanent magnet rotor. The output is nominally 115vac at 700 RPM. Being a 2 phase motor the output phases are separated. One phase is used for demonstration load. The other phase is used for powering the cooling fan. The engine/alternator has demonstrated 90 watts resistive output at 115v at 700 RPM. It struggles, but surprisingly still has more throttle left. 

The cooling system is comprised of a deaeration/expansion tank, computer radiator, 5 speed fan, circulating pump, and temperature gauge. It works great and keeps the engine at 150-160F with light load even at the lowest fan speed. 

It was a lengthy, but fun project. If anyone is interested in plans for the engine, Dougs excellent build series should be in Home Shop Machinist sometime later this year. 

Jeff 


[ame]http://www.youtube.com/watch?v=a5yUtb7baOk[/ame]


----------



## lazylathe

WOW!!! woohoo1 th_wav

That is amazing!!!
Runs like a dream too!

Andrew


----------



## flyingtractors1

WOW!!!  th_confused0052. Incredible.  th_wav. Absolutely unbelieveable. Great job Guys, and the video is also superb. Ralph


----------



## Don1966

Wow! That is a very unique setup, being an Electrician and Electronic Tech I can appreciate all your efforts. You have a one of a kind unit. Very good work. I would like to build one but would like to make it smaller. I am currently working on a marine engine to power a PM Reasearch Dynamo I Machined from casting. Very small setup. I love the Fan Motor conversion you done also. I will be looking forward to Doug's post. th_wav th_wav th_wav

Regards Don


----------



## kuhncw

Hi Jeff,

I believe your Bruce McBeth is one of the nicest running low rpm engines I've seen. I'm looking forward to the HSM article to see how you and Doug built these engines.

Regards,

Chuck Kuhn


----------



## Rustkolector

I appreciate the comments guys. I tend to favor slow running engine designs because they can sound soooooo nice. Glad there are some others out there that like them also.  

Jeff


----------



## b.lindsey

Beautiful and beautifully running engine Jeff. I have seen Doug's as well though not running. Both the pictures and video are great by the way!!! Thanks for posting this wonderful engine in its finished state.

Bill


----------



## steamer

OUtstanding Jeff!

You two should be very proud!

I can attest, it's even better looking in person!

 :bow:

Looking forward to the build article.....this just might make "the list"....

Dave


----------



## John Rudd

Marvellous...I'd love to build something like that but just dont have the time at the moment..maybe when I retire and have completed all the other jobs thus far....

Congrats to a creation well made...


----------



## mh121

Absolutely stunning job, runs really well. Could I ask how you done the lettering on the crankcase covers if you did not use castings?


Cheers,
MartinH


----------



## vcutajar

Unbelievable. th_confused0052

I never cease to be amazed here.

Vince


----------



## Rustkolector

Martin,
Thanks. The raised letter making process is called photo, chemical, or acid etching. The background was dissolved away leaving the raised lettering and door border. Identical to the way printed circuit boards are made. There are numerous sites on the internet that explain it. 

Jeff


----------



## steamer

That's great Jeff!
Did you do that in your shop?

Pictures?
 ;D

Dave


----------



## Rustkolector

Dave,
Yes, I did. Everything except the flywheels (done on a friends 12" lathe) was done on my old Logan 9" and SX-3 mill/drill, but I just got a new 11" lathe so hopefully all future stuff will be done in-house. 

My basement shop is small, comfortable, but messy. Sorry, no photographs!

Jeff


----------



## jonesie

jeff you and your partner did an excellent build on both parts engine and gen. also very nice runner. jonesie


----------



## Debian

Marvellous work. That's art!
I guess that, togheter with the Holt Engine, these are the most impressive model engine to look!


----------



## steamer

Rustkolector  said:
			
		

> Dave,
> Yes, I did. Everything except the flywheels (done on a friends 12" lathe) was done on my old Logan 9" and SX-3 mill/drill, but I just got a new 11" lathe so hopefully all future stuff will be done in-house.
> 
> My basement shop is small, comfortable, but messy. Sorry, no photographs!
> 
> Jeff



Hi Jeff,

OH I know you machined the parts! ;D I didn't make myself clear. I was interested in the photoetch process......

On a model of this scale those raised cast letters are a very important and prominant feature that needs to be done well or it can really detract from the rest of the model.  I must say you did that very well! :bow:

Dave


----------



## Rustkolector

Dave,
The process isn't that difficult. Getting a good result, however, can be until you learn the how it works. I wrote an article on the process for the Gas Engine Magazine a long time ago. I looked and it is still our there at:

http://gasengine.farmcollector.com/Equipment/DIY-Brass-Nameplates.aspx

This slow etching process works fine for low relief nameplates when you use 360 brass stock, but 220 brass works better. If you want higher relief detail, you will have to set up a more elaborate warmed, and pumped etchant system for faster etching. Too much mess for occassional projects. So, I have decided that doing the artwork and giving it to a commercial etcher is the best way to go. You can get either the cast look or the sharper detail look. The cost is reasonable if you do the artwork. 

If you want lettering only, Doug Kelley used a different approach on his Bruce-MacBeth engine. He purchased cast metal letters which he glued to his inspection doors. He milled the relief for the border. They look great. He says they are very expensive, and require a very steady hand to lay out properly, but the results in the photo below look very nice. One small problem with the cast letters is the very limited font sizes available. Don't ask where he got them. 

Jeff


----------



## b.lindsey

IIRC, Doug told me he used letters supplied for making foundry patterns....see the attached link for example

http://www.freemansupply.com/choose/patternletters.htm

Hope this helps some.

Bill


----------



## Rustkolector

Bill,
Yes....that is the company. Thanks!

Jeff


----------



## Nickademusss

Thats great looking and sounding, I even love the vintage looking lights your powering!

Great job!


----------



## BronxFigs

Question:
If a two-cylinder version of this engine was to be built from the published drawings, what would be the best crank configuration?   Just asking.


Frank


----------



## TorontoBuilder

BronxFigs said:


> Who can argue with that?  Thanks for the suggestions...I think.
> 
> The question still stands.
> 
> 
> Frank



Haha that's funny. 

But just so we all know, that post is not suggestions for you but rather ineffectual spam for construction contracting services in Haiphong Vietnam. A moderator should delete that post.


----------



## Charles Lamont

That is a lovely job, and it makes such a refreshing change to see, and hear, a model ic engine working under a proper load instead of just ticking over or being revved.


----------



## johanvanzanten

Hi Jeff,

Well done, runs very good with a lovely sound. What do you think about a period switchboard and some tiles on the floor?
Do you start it by hand or with the use of a power drill?
Anyway a very successful project. Heat off !

Kind regards,
Johan.


----------



## Rustkolector

Hi Johan,
A switchboard and tile floor will be part of the my current project. It is progressing now. The Bruce-MacBeth usually starts easily with a few turns by hand. It runs on propane, which helps. 

Jeff


----------



## BronxFigs

Re: Posting # 22:
Hoping some forum members will speculate, or offer opinions regarding the crankshaft configuration for a modified, two-cylinder, version.  One piston up, the other down... both up....??

Thanks,
Frank


----------



## gbritnell

Hi Frank,
Just some random thoughts. With a 180 degree crank you would stand a better chance of balancing due to mass up, mass down. Some Triumph motorcycle engines were 360 degree cranks, both up at the same time and operated fine. It's just that more counterweight is needed. Personally if I were to build one I think I would go with the 180 crank. You will also get a different firing cadence with the two configurations. 
gbritnell


----------



## BronxFigs

G. Britnell-

I appreciate the input, and for the explanations regarding both crankshaft options.


Frank


----------



## DickInOhio

Beautiful engine. did u build the radiator or modify and existing product?


----------



## Rustkolector

The radiator is a standard 120 mm radiator used by the overclocking computer gamers. There is quite a selection now of these radiators. Mine uses a 4 speed cooling fan powered by the the engine driven alternator. 
Jeff


----------



## mfrick

The Engine is outstanding.  I would like to see a set of plans for the Alternator put into print I would like to build one but I don't have any idea where to start.

Mike


----------



## Rustkolector

[FONT=&quot]Mfrick,[/FONT]
  [FONT=&quot]While I am quite pleased with the B-M alternator it is not ideally suited to a model engine in the 500-700 RPM range for which it was designed. It is better suited to much slower RPM engines due to its rather high output voltage at 500-700 RPM. I suppose I could use a transformer to reduce the voltage, but the model then starts getting bulky and heavy. 
[/FONT]
  [FONT=&quot]On an IC engine project I am finishing up, I built another slow speed generator to address the weight and voltage issues I have with the B-M alternator. It was designed for a slow speed 2 cylinder 1 bore engine so the output was reduced to 3A @ 12vdc and 500 RPM. I am still chasing some finishing details on it, but I hope to share some photos and maybe a video soon. 
[/FONT]
  [FONT=&quot]If you have any specific questions, PM me.[/FONT]
[FONT=&quot]Jeff[/FONT]


----------



## mfrick

Hello Jeff
I in the process of building the Macbeth out of the Home Shop Machinist mag and i have a question regarding the drilling of the intake and exhaust and coolant ports.  I drill them as shown on the print and they seem to be backwards so I'm looking for some clarifications. On the print they show the bottom of the head and it just doesn't work or I not understanding the print.  

Mike


----------



## Rustkolector

Mike,
The print is correct. Note that on the upper left portion of page 38 the cylinder head assembly drawing item #19 shows four views. The center right hand view is labeled the bottom view of the head. The center left hand view is actually the top view of the head. Keep in mind you have to rotate the top view right to left to see the bottom view and things get reversed. The top most view shown is the exhaust manifold mating side of the head and the bottom most view is the intake manifold mating side of the head. I hope this clears it up for you.

Jeff


----------



## mfrick

Hello Jeff

The problem that I have is the location of the center of the holes lands right at the bottom of the water jacket so when you drill the holes for either intake and or exhaust halve the hole ends up into the water jacket.  

Mike:wall::wall:


----------



## Rustkolector

Mike,
I sent you a PM.
Jeff


----------



## mfrick

So I'm building the Bruce MacBeth Engine What a great looking engine.
 So I would like to have some basic dimensions for the distributor. I'm building it from scratch . So what I basically need is the overall diameter and the length of the cap and body rest is pc of cake. So any help would be greatly appreciated, rest of engine is coming along nicely.  :thumbup:


Mike


----------



## Rustkolector

Mike,
I used the distributor sold by Roy Sholl at S/S. The cap is 1" OD. The length of the current cap and base available from Roy is slightly longer so I cannot give you an OAL dimension. The real B-M engines did not use a distributor ignition system. They used two small magnetos, one on each end of the camshaft. Like air craft engines, they were redundant feeding two spark plugs per cylinder. Use boots on the spark plug cable ends with the smaller Viper spark plugs. If I were doing this engine over again I think I would eliminate the distributor and use two wasted spark type ignition systems. They would add a little more cost, but should be more dependable.
Jeff


----------



## mfrick

Hi Jeff

Thanks for the reply and the information.  I will look into your suggestion and look at building two magnetos to fit.  My brother is an expert on magnetos he restores old engines so he's a good resource plus he will have something that I can use as a modeled to scale down.  :thumbup:

Mike


----------

