What is hit and miss?

[paulnb57]

Hi form a newbie!
Ive seen "hit and miss" engines mentioned in posts on the forum and have no idea what it means...............
thanks in anticipation and what an inspirational site!
The creations on this site are absolutely stunning!
Paul

 

[Tin Falcon]

Paul:
A hit and miss engine is an early Internal combustion engine . Typically portable engine used on farms. The design included a governor to keep a constant RPM. When under load the engine would fire more often than when idling . When idling the engine may only fire once every several revolutions on the crank shaft The sound is something like boom -chug - chug - chug chug -Boom Chug - chug-chug- boom- etc IIRC they are sometimes referred to as farm engines. they usually have a bit of a squarish boxy look do to the sqarish water jacket around the cylinder. They were usually water cooled but no radiator.
Hope this helps.
Tin

 

[paulnb57]

Thank you!
Paul

 

[rake60]

Hi Paul

Here's an example of one.
It's my 1934 Maytag washing machine engine.

[ame]http://www.youtube.com/watch?v=LkoII8hsg8w[/ame]

Rick

 

[Brian Rupnow]

To enlarge a bit on what TinFalcon said---The hit and miss engines had a mechanical governor on them (generally a set of "Bob-weights" that were operated by centrigugal force.). There was no throttle on the carburetor, and it was designed so that without some kind of "interferance" the engine would run "wide open" (To the point of blowing apart from high rev's). The governor would be adjusted for a specific engine RPM, and when the engine reached that speed (generally quite low) the bob-weight governor would operate a mechanism which prevented the exhaust valve from closing. This meant that the engine could not make any compression, so it would not fire.---It just coasted (thus the miss part of a hit and miss engine). It would coast untill it slowed down enough that the governor would allow the exhaust valve to close, the engine would build compression on the next stroke, and then the engine would "fire"--Thus the "Hit" part of a hit and miss engine. These engines ran at comparitively low speeds, and had massive flywheels to keep them from "stalling" between "Hits". When one of them fired under a heavy load, if you were standing close to them you just might be in for a change of underwear.---they really "barked".

 

[Brian Rupnow]

Rake---I never knew that there were hit and miss washing machine engines. All the ones I remember from the late fourties/early fifties were conventional 4 cycle engines with a throttle on them. They had a rather fishy governor that was a flapper plate that had a link going to the throttle and were operated by the air which was blown off the cooling fins on the flywheel.

 

[Andrewinpopayan]

We had a similar setup on fishing boats, they used Hundested 2 stroke diesel engines, but in this case instead of opening the exhaust valve, the governor would not inject fuel, These motors were 80HP single cylinder 2 stroke diesels, a 350 psi compressed air starter and "fireworks" for the heater plugs. They idled at about 80 rpm and redlined at 800 rpm. the flywheel was roughly an 8 foot diameter, 2 foot thick cast iron disc. Lubrication was forced from a pump and an extenal oil tank, believe they has roller bearing bottom ends.

 

[CrewCab]

It all sounded quite manageable till you came to the flywheel

the flywheel was roughly an 8 foot diameter, 2 foot thick cast iron disc

That's a piece of kit that demands respect :bow:

CC

 

[Kludge]

We had a similar setup on fishing boats, they used Hundested 2 stroke diesel engines, but in this case instead of opening the exhaust valve, the governor would not inject fuel, These motors were 80HP single cylinder 2 stroke diesels, a 350 psi compressed air starter and "fireworks" for the heater plugs.

This sounds like some of the older commercial boats here. I've never been aboard any but I heard them a lot when I still lived a lot closer to the piers where they tied up. Thank you for telling about them

BEst regards,

Kludge

 

[gt2ride]

Here is an old gas eng. of mine. It is 1 1/2 HP Its weight is 450 lb. It is has a water jacket . A hit and miss engine will have a valve held open till it slows down and then it will fire.

 

[Stan]

I have worked on a few Maytags that were Hit & Miss but cannot guarantee that all Maytags were. They made many models in the early part of the twentieth century. As far as I know, all Maytags were 2 cycle (mixed oil with gas).

 

[LuvToFish]

I'm a newbie to this forum but wanted to share a photo of a model "hit and miss" engine I built several years ago in High School shop class. The designer and copyright holder is Harold Depenbush (Columbus, KS). He still sales the plans if anyone has an interest in building this awesome engine.

-luvtofish

 

[RollaJohn]

Luvtofish, I do like that little engine. Have a John Deere hit'n'miss that runs and just got an Interrnational Harvester that is well rusted and is the next reclaiming project. This model sure catches my eye and I've sent an order for the plans to Harold, on his website. The model is just too cute and will be a nice addition to the display.

Thanks for mentioning it.

 

[Stuart B]

Hi I am a Newbie here, and this is my first post. I couldn't resist reponding to this post after lurking for some time.

Another marine engine based on the hit and miss principle was the Bolinder from Sweden.
Back in the early 1980's I helped out on restoration of a Narrowboat fitted with one of these beasts. The engine was made in the early 1920's and had a number of interesting features, including a hit and miss governor. The basic spec was a 15HP single cylinder 2 stroke semi diesel. Bore and stroke were about 7 inches each, with a capacity of about 7.5 Litres.

An interesting innovation was that it had no gearbox, it was a direct reversing engine. A control lever controlled motion work which disengaged the forward fuel pump and engaged a second pump, which gave the engine a early squirt, before it reached TDC. The objective being to stop the engine dead and send it into reverse. Quite a strain on components and from memory, not that reliable.
Being a Semi Diesel, it had a hot bulb which needed to be heated to glowing red, before kick starting the beast, via a spring loaded pin in the flywheel. Another control varied the spray angle of the diesel injector. When idling or under light load, the injector was set to spray a wide cone, which kept the bulb hot enough to keep the engine running. Under full load the injector was adjusted to fire a narrower jet, for increased power.

The following link is to a video of the boat I worked on and the soundtrack is a great example of the hit and miss governor in action.

http://sickle.freehostia.com/videoTug1.html

More info on Bolinder engines here
http://www.oldengine.org/members/diesel/Marine/bolinder.htm

Stuart.

P.S. Not yet started my first engine, but working on it !

 

[Twinsquirrel]

Great first post Stuart!! Love the "bark" of that engine!!

David

 

[Stuart B]

Hi David,
Thanks for the welcome. Finding that video brought back some great memories for me.
I never was brave enough to try kick starting the Bolinder myself..
On the model engine front, I managed to pursuade SWMBO to buy me a set of Stuart 10V castings. Now I just have to clear out the garage and build the workshop to make it
Also need to bring back the skills I learned during my engineering apprenticeship 25 years ago.

 

[Twinsquirrel]

Also need to bring back the skills I learned during my engineering apprenticeship 25 years ago.

There are a few of us here in the same boat, it seems that once you have a little experience as a youngster this machining bug incubates and niggles away at you until you just HAVE to make some chips again.

Looking forward to seeing your workshop come to life!

David

 

[LuvToFish]

TS...you said a mouth full there! I've came back full circle to where I began some 27 years ago. Even though my career has taken me away from my passion, I somehow never let go nor forgot all the great things I learned as first a student and later an apprentice Tool & Die Maker. I've spent the last 5 years building a workshop that houses the very machines that started it all for me some 30 years ago...

Once you have the bug, it will never let go!

-LuvToFish

 

[CrewCab]

TS...you said a mouth full there!

But an accurate one

CC