# Farm Boy running



## simonbirt (Jul 7, 2021)

Just thought I would post a link to this short video of my Farm Boy    I have been building it over the last year of and on and ran it for the first time the other day. I should say I have little experience of internal combustion, all my projects so far have been external combustion. 

I would welcome comments and suggestions from all you knowledgable people. It is suggested in the building notes that acetone is a good fuel for this engine. This is what I have used, but it is not great to paint or varnish and as I plan to use both on the engine and base I can see a problem. It also has a tendency to rust steel, the needle valve on the fuel had a surface coating after the first run. 

Starting is a bit tricky, the most reliable method I have found is to flood it, close the needle valve and then open the valve once it starts to fire. Needle valve setting is very sensitive an 1/8th of a turn one way or the other makes a big difference. 

As I say in the video I suspect that it is running a bit slow, although I like slow running it makes it difficult to get going with the governor engaged. 

Finally, I need to make a fuel tank and incorporate a non return valve. Does anybody have a design for one? I am thinking ball and light spring? I have made lots for boilers but they rely on high pressure to keep them closed, I’m assuming that a clack type valve would not work. 

An interesting project so far, makes a pleasant change from steam. Now have to paint the engine, have a go at some name plates, make a base and a fuel tank. Then on to the next project, any thoughts?


----------



## gunna (Jul 7, 2021)

Cant help with your questions Simon, but gee it runs nice as it is.
Ian.


----------



## danallen (Jul 7, 2021)

You don't want a spring on your one way valve. Just a small ball about 1/8" sitting vertical and gravity. Looks good.


----------



## ShopShoe (Jul 7, 2021)

That's very nice. I don't think it's too slow. It's hitting and missing very well.

Thank You for posting.

--ShopShoe


----------



## dnalot (Jul 7, 2021)

I love it. Very nicely done.

Mark T


----------



## Engine maker (Jul 7, 2021)

Nice work,

I built SN# 003and the double size one SN3003-X2. Denatured alcohol or Coleman Lantern fuel (white gas) both work fine, but with alcohol you have to lube after running so it won't get surface rust. As an added point, with Coleman you can run it in the house with almost no odor.

Easy one way valve is a RC fuel filter ( the aluminum ones, they unscrew) with a small ball bearing dropped inside. Just mount it vertically.

Fuel tank height may be a point to look at, may be a bit low. It can pull the fuel up but not too far. Starting both of mine, needle open about 3/4 turn, finger to choke mixer and give a good flip, remove finger. flip and off they go. 

It may be a tad slow. From listening to it your coasting about 10 revolutions between firings. It needs some breaking in and it will get to around 25 - 30.  You can look at this Coolspring engine show video 



 at the 20:15 time and see how long they will coast.  My small one does way above 60.

Jim G


----------



## rklopp (Jul 7, 2021)

Congratulations on very nice surface finish and workmanship. It seems to run great in my opinion. As for a check valve in the fuel line, on my Breisch Hired Man I just have a 1/8" ball bearing sitting on a brass seat under gravity. If I had a drawing for the valve, I'd be hard-pressed to find it now. The internal geometry is a bit like a safety valve for a 16mm narrow gauge steam engine without the spring.


----------



## simonbirt (Jul 8, 2021)

danallen said:


> You don't want a spring on your one way valve. Just a small ball about 1/8" sitting vertical and gravity. Looks good.


Thanks, I was not spotting the obvious (vertical) I had it my head that I would feed fuel from the side of the tank and therefore have a horizontal valve. Gravity is an often overlooked commodity.


Engine maker said:


> Nice work,
> 
> I built SN# 003and the double size one SN3003-X2. Denatured alcohol or Coleman Lantern fuel (white gas) both work fine, but with alcohol you have to lube after running so it won't get surface rust. As an added point, with Coleman you can run it in the house with almost no odor.
> 
> ...



Thanks Jim,

Interesting video, hit and miss engines are something of a rarity here in the UK. For me they are the missing link between steam and the modern internal combustion engine, which makes them interesting to build. 

Simon


----------



## geo (Jul 8, 2021)

Well done


----------



## JohnBDownunder (Jul 8, 2021)

To me (in my minuscule experience), it sounds about right and as has been said by Engine Maker above it will increase in revs after running in.
 I think these are a great little engine. Plan to make one some time in the not too distant future if life stops getting in the way. I thought being retired meant lots of free time - HA, not so as family takes precedence and rightly so.

As a lad,(some 70 yrs ago) the local wood man would sometimes come and saw logs into foot blocks in our back yard. He had a Hit n Miss driving the saw and as designed the miss part got shorter with load. No, he had a horse and cart, not a bullock wagon.

Try adding some load to the off-side fly wheel and listen to the firing sequence change. That's the fun part of these I reckon.   Off side keeps your fingers away from the governors!


----------



## ds engines (Jul 8, 2021)

Hi great engine just finishing one off myself.What ignition system are you using it looks very nice where can i buy the kit to build the ignition  system.


----------



## timo_gross (Jul 8, 2021)

People tend to ask me: "What is it good for?" 
So if you want to impress "the kids", you need to at least be able to charge a smart phone or tablet with it. 

If you want to impress me, already good enough, as is. 
I have no clue how fast it must run, but it looks good to me from an unexperienced spectators point of view.

Greetings Timo


----------



## Brian Rupnow (Jul 8, 2021)

That sir, is a masterpiece. Use Naptha gas as fuel (sometimes called white gas). It is very low odor and runs all of my engines just fine.--and it will not harm your paint.----Brian


----------



## Iampappabear (Jul 8, 2021)

Great looking and running engine Simon, I currently have a Farm Boy in the works which is about 90% complete, only hope it runs as well as yours.... someday.   I guess too much to hope you are in southern Ontario where i might get a chance to see it live.

Colin


----------



## Harglo (Jul 9, 2021)

simonbirt said:


> Just thought I would post a link to this short video of my Farm Boy    I have been building it over the last year of and on and ran it for the first time the other day. I should say I have little experience of internal combustion, all my projects so far have been external combustion.
> 
> I would welcome comments and suggestions from all you knowledgable people. It is suggested in the building notes that acetone is a good fuel for this engine. This is what I have used, but it is not great to paint or varnish and as I plan to use both on the engine and base I can see a problem. It also has a tendency to rust steel, the needle valve on the fuel had a surface coating after the first run.
> 
> ...



These Farm Boys are by far the most smooths {long} miss cycle for there size. Mine ran so well I made a 20% larger on same nice runner. I use propane.
Harvey


----------



## baldavengre (Jul 9, 2021)

Very nice !! 
+1 on the Coleman fuel


----------



## simonbirt (Jul 9, 2021)

ds engines said:


> Hi great engine just finishing one off myself.What ignition system are you using it looks very nice where can i buy the kit to build the ignition  system.


The ignition system is home made, based upon information cleaned on this site. I can send you a board and instructions, not hard to assemble. A few have commented on track widths etc and suggested improvements. I have tested one for many hours on a test rig and it is still fine, in fact it is the one running the engine in the video. Besides I have several boards in stock as there was a minimum order.

If you would like one, let me know where you are and I will send one.


----------



## simonbirt (Jul 9, 2021)

Harglo said:


> These Farm Boys are by far the most smooths {long} miss cycle for there size. Mine ran so well I made a 20% larger on same nice runner. I use propane.
> Harvey


Love the woodwork, very pretty.


----------



## simonbirt (Jul 9, 2021)

Iampappabear said:


> Great looking and running engine Simon, I currently have a Farm Boy in the works which is about 90% complete, only hope it runs as well as yours.... someday.   I guess too much to hope you are in southern Ontario where i might get a chance to see it live.
> 
> Colin


Hello Colin,

Sadly not in Ontario or even Canada, UK. I will make a better video when I have it painted and a base made.


----------



## simonbirt (Jul 9, 2021)

Brian Rupnow said:


> That sir, is a masterpiece. Use Naptha gas as fuel (sometimes called white gas). It is very low odor and runs all of my engines just fine.--and it will not harm your paint.----Brian


Thank you Brian, I really appreciate your kind comment. I think I will get some Colman fuel as another drawback of acetone is that it is kind to O rings.


----------



## ds engines (Jul 9, 2021)

simonbirt said:


> The ignition system is home made, based upon information cleaned on this site. I can send you a board and instructions, not hard to assemble. A few have commented on track widths etc and suggested improvements. I have tested one for many hours on a test rig and it is still fine, in fact it is the one running the engine in the video. Besides I have several boards in stock as there was a minimum order.
> 
> If you would like one, let me know where you are and I will send one.


Thanks I am on holiday from this weekend for 2 weeks I will contact you when I return.


----------



## LorenOtto (Jul 9, 2021)

simonbirt said:


> Just thought I would post a link to this short video of my Farm Boy    I have been building it over the last year of and on and ran it for the first time the other day. I should say I have little experience of internal combustion, all my projects so far have been external combustion.
> 
> I would welcome comments and suggestions from all you knowledgable people. It is suggested in the building notes that acetone is a good fuel for this engine. This is what I have used, but it is not great to paint or varnish and as I plan to use both on the engine and base I can see a problem. It also has a tendency to rust steel, the needle valve on the fuel had a surface coating after the first run.
> 
> ...



Sounds really good.


----------



## JDYKSTRA (Jul 9, 2021)

I am making a Farm Boy as well and have a question. Does a bushing have to be make for the Push Rod Roller?  The roller has a .125" id and the screw that hold it is a 2-56 screw.


----------



## Canyonman (Jul 10, 2021)

Pardon my ignorance but is that a kit or castings?  How might one go about getting the plans and or parts or castings?     Thank You   Ken


----------



## Sprocket (Jul 10, 2021)

Canyonman,
Look here:Farm Boy Hit-&-Miss 4-Cycle Engine Plans


----------



## Canyonman (Jul 10, 2021)

Thanks Sprocket!       Ken


----------



## BaronJ (Jul 11, 2021)

Canyonman said:


> Pardon my ignorance but is that a kit or castings?  How might one go about getting the plans and or parts or castings?     Thank You   Ken



This one is free and is a quite similar engine !



			Free Plans: David Kerzel’s Hit & Miss Engine – MachinistBlog.com


----------



## AndrewW (Jul 11, 2021)

JDYKSTRA said:


> I am making a Farm Boy as well and have a question. Does a bushing have to be make for the Push Rod Roller?  The roller has a .125" id and the screw that hold it is a 2-56 screw.


Hi
You need to make a 2-56 flat head screw to fit. The flat head needs to be thin enough to clear the cam gear. The diameter directly under the screw head needs to match the id of the roller bearing. The remaining length needs a 2-56 thread. I probably don't cover the making of this screw in my YouTube video series. Some content might be of use though. Just search 'Andrew Whale' on YouTube to find my channel and the Farm Boy build series.
Good luck!
Andrew


----------



## simonbirt (Aug 1, 2021)

I have been experimenting with the Farm Boy. It runs fine but is very sensitive to all things mixture and  fuel tank position etc. I made a tank with a non return valve and all was fine Then yesterday it would not run consistently. After some thought I went back to the lash up on the first test run- a small bottle with a siphon tube. Still sensitive to mixture setting but it will hit and miss reliably. 

Second oddity is that Colman fuel which I am now using appears to attack silicon tube, the end that is in the fuel tank expands and becomes soft, this appears not to happen to the part not submerged. Very strange.  

Any thoughts?


----------



## AndrewW (Aug 1, 2021)

Hi Simon
Coleman fuel (Naptha) and silicone do not work well together. There are lots of chemical compatibility charts which confirm that. Viton is extremely compatible with Naptha and I use that for the piston o-ring. However, I couldn't find any Viton fuel tube. I use Nitrile tube instead which isn't fully compatible with Naptha, but I've not experienced any problems.
Hope that helps.
Andrew


----------



## simonbirt (Aug 1, 2021)

AndrewW said:


> Hi Simon
> Coleman fuel (Naptha) and silicone do not work well together. There are lots of chemical compatibility charts which confirm that. Viton is extremely compatible with Naptha and I use that for the piston o-ring. However, I couldn't find any Viton fuel tube. I use Nitrile tube instead which isn't fully compatible with Naptha, but I've not experienced any problems.
> Hope that helps.
> Andrew


Thanks Andrew, it is interesting that whatever fuel used, there is a trade off, especially finding o rings and tubing that will work. 

What do others use for fuel tube and O rings?


----------



## Engine maker (Aug 1, 2021)

As for the cam roller, I've used a small ball bearing from the hobby shop or something that I've junked. The hole will be bigger but that fine, just turn a small bushing that looks like a"top hat". Then counter bore the bushing so that the cap head screw (I use allens) is inside the bearing and the flange on the "top hat" misses the cam gear. If you can't find an exact .312" bearing a little bigger won't hurt, just adjust the placement of the 2/56" mounting so that the end of the bearing is in the same spot.  

Jim G


----------



## geo (Aug 1, 2021)

JDYKSTRA said:


> I am making a Farm Boy as well and have a question. Does a bushing have to be make for the Push Rod Roller?  The roller has a .125" id and the screw that hold it is a 2-56 screw.


I made a bushing to suit the I’d of the bearing


----------



## Harglo (Aug 2, 2021)

Canyonman said:


> Pardon my ignorance but is that a kit or castings?  How might one go about getting the plans and or parts or castings?     Thank You   Ken


JE Howell model engine plans has the Farm Boy plans He was the designer of this engine. Mine ran so smooth that built another on 20% larger an it too is a smooth running engine. They have very long miss cycles for the size of the flywheels. Had brass ones casting in Amish country.
Harvey


----------



## simonbirt (Aug 20, 2021)

A quick update on my Farm Boy.

It has had a few hours running and now misses for about 15 cycles. This seems to have made the fuel tank position and mixture more critical than before. The photo shows the position  of  tank relative to the fuel mixer. I did make a non return valve, but this seemed to make things worse. 






From cold I open the needle valve just less than one turn, then choke for one induction stroke, the engine will fire first time but will stop after 2 or 3 cycles. I find if I help it along by half chocking the intake for 30 seconds or so it gets into its stride and settles down. It is then possible to lean the mixture to about 3/4 of a turn. If it is too lean it may take 2 cycles (i.e. 2 induction strokes before it fires, same thing happens if the tank is lowered. Do others find these fuel systems so sensitive? 

I have now pulled it apart ready for painting. Will post some pictures when it is back together.

Simon


----------



## AndrewW (Aug 20, 2021)

Hi Simon
I'm no expert but your fuel pipe doesn't look right with it looping upwards. On mine I put the fuel tank outlet at the bottom of the tank and level with the fuel mixer intake. The fuel pipe loops down. My fuel mixer is set at 3/4 turn and never needs adjusting. She freewheels 20+ revs between firing.
Hope that helps.
Andrew


----------



## simonbirt (Aug 21, 2021)

AndrewW said:


> Hi Simon
> I'm no expert but your fuel pipe doesn't look right with it looping upwards. On mine I put the fuel tank outlet at the bottom of the tank and level with the fuel mixer intake. The fuel pipe loops down. My fuel mixer is set at 3/4 turn and never needs adjusting. She freewheels 20+ revs between firing.
> Hope that helps.
> Andrew


Thanks Andrew,

I think the commonality is that the tank needs to be quite high, relying on a non return valve does not seem very effective. 

The final version of my set up includes a method of varying the height of the tank. With the tank quite high I found that there is a tendency for fuel to siphon. I think my logic is sound in that it matters not where the pipe goes, the important thing is the relative head of fuel. I am sure somebody on this site will give us the answer.

Simon


----------

