Tangler's Air Cooled Farm Boy

[RReid]

Very nice work Rod, looking good. You may be able to have a combined first Pop and second Jab party. 

[Jasonb]

Not long now Rod, will you test run before painting?

[tangler]

Yes 

[youtube1]https://youtu.be/btT6ixnrIq4[/youtube1]

Well, that was quite a surprise    That's the easiest first run I've ever had,  pretty much first pull on the flywheels.  I was actually feeling quite good about it - after grinding in the valves the compression felt good and bouncy but there did not seem to be any movement of the inlet valve.  I made a new and much weaker spring and got a good "parp" as I pulled the flywheels round.  The Hall sensor is positioned to give a spark on or slightly after TDC.  The cylinder is hand hot after 5 minutes so I think I'll do the fan thing as Jason suggested.

Thanks for looking in, I'll post some more pictures when it's painted and, perhaps, sitting on a trolley.

Rod

[RReid]

Sweet! Gotta love the sound of a smooth running Hit-n-Miss in the morning. Congratulations!

[Jasonb]

Looking good and running well Rod, look forward to seeing it with the fan and a lick of paint and I'm sure you will do a nice job on a wooden sled or cart judging by your other woodworking exploits.

[Kim]

Congratulation! Your engine is running first time, and very well!  You should be excited about that! 

Here's my non-IC guy question:  I hear this engine hitting 4-5 times in a row, then missing 4-5 times, then hitting again.   Is there a way you can vary the hysteresis in the governor?   I've heard some hit & miss engines that hit 1 or 2 times, then miss a bunch, then hit again 1 or 2 times.  What changes the number of hits vs misses?  (I mean, beyond the obvious speed of the flywheel.)

Thanks,
Kim

[Brian Rupnow]

Kim---you can change the ratio of hits to misses by changing the weight of the counterweights or the strength of the springs that hold the counterweights in place.

[Jasonb]

The flywheels also have quite an effect with larger heavier ones storing more momentum so the engine can run longer between hits and combined with that the strength of the hit as a weak firing engine won't put as much energy into the flywheels as one that hits with a big bang. New engines can also be a bit tight in both the ring/piston fit as well as the bearings so you often find an engine will run longer between hits as it beds in.

The model engines seem to suffer the "double hit" more often than the full size sometimes it can be fuel draining back or the different air volume through the carb as the first hit is when the engine is running slow and the second when faster so it draws the air faster and opens the valve better

[Admiral_dk]

Congratulation is in order here - very impressive first run and on your first IC too 

Now time for a happy dance   

Per

[Art K]

Rod,
Glad to tune in and see your farm boy running so well!
Art

[Kim]

Thanks Brian and Jason.  Appreciate your responses.

Great work on the engine Rod!  It's fun to watch a hit & miss that both hits and misses!

Kim

[crueby]

Thats first run? Amazing! 

[Don1966]

Awesome….. 


 
Don

[Pete49]

Excellent work Rod or as we say down here...beauty cobber....well some of us ....a few of us.... ok just me.

[Roger B]

Excellent     

We will have to work out how to calibrate a 'parp' for successful suction inlet valve  That seems to be the cause of many peoples problems