Brian Builds the Kerzel Hit and Miss I.C.

[NickG]

Brian, good experimentation there. It's what we all thought - friction, so now that's proved it some of the other methods you've discussed would help even further. Gail has had some interesting results with his graphite piston so that could well be worth a try for the little time / effort it would take.

Nick

 

[Brian Rupnow]

The engine is running out in the big garage as I type this. I can hear it from my office. Its been running for 21 minutes straight now, which is the longest its ever ran without stopping. Its funny, but with the engine running "at a distance" you can really here it bark when it fires. Right now it fires 3 times, then coasts, then repeats the cycle. I don't know why, but the exhaust note is distinctly different with only one ring on the engine. I only have one governor spring on it now, but it is not adjustable at all. I am going to set down tonight or tomorrow morning and design an adjustable tension single spring and bracket to fit between the two bob-weights on center. I am SOOOOO CLOSE to having that thing fire once, coast for three or four cycles, then fire again a single time and repeat that I can almost taste it!!!

 

[jpeter]

That's pretty sweet. Your on the right track.
You know, if a little is good, more is better. You outta loosen the ring some more.

 

[Brian Rupnow]

The engine ran good for 31 minutes straight. after 31 minutes, it quit missing and ran in plain 4 cycle mode. It ran that way for another 4 minutes, then quit. When I tried turning the flywheel, everything was still very free turning. Then I checked the gas tank, and seen it was out of gas. I added a tank of gas, but it doesn't want to run right now, so it may have sucked up a bit of dirt when it ran out of gas. It actually ran long enough that there was steam coming off the water in the cooling reservoir, just like you see in the full size hit and miss engines. Of course its colder than a witches tit out in the main garage, so the steam was much more visible. This is very encouraging!!! I will have to bring it back into the office after it cools down, or it will suffer the fate of so many full size engines with water cooling reservoirs----it will freeze and burst the block.
EDIT---I found the problem---My pushrod had unscrewed itself out of adjustment. I'll make a locknut for that tomorrow.

 

[jpeter]

That's a pretty long run. You got enough battery for that?

 

[Brian Rupnow]

That's a pretty long run. You got enough battery for that?

Its a 12 volt heavy duty wet cell boat battery.

 

[jpeter]

That outta work.

 

[Brian Rupnow]

I made up a locknut this morning for my engines pushrod, and adjusted the Kerzel lever to set just a tad closer to the pushrod notch that it locks into. I started it once again out in the big garage, and it has now been running for 110 minutes non stop on the original tankfull of gasoline. It is getting a lot more hit and miss action now, and seems to be running much much cooler and using much less fuel. I made a video again this morning, just to show the diferences as this tuning progresses. I am going to try and find a source for a lighter tension spring for the counterweights this afternoon.

 

[gbritnell]

Brian,
At some point when you get everything adjusted as close as you can you're going to find that the last issue is the centrifugal weight of the flywheel. You will only be able to get it to 'miss' so many strokes and then the flywheel inertia won't be strong enough to kick it back over the compression stroke. That is the issue of trying to get any small engine to run slowly, either you make a flywheel that is out of proportion to the engine or just live with the higher rpm.
George

 

[Brian Rupnow]

Three hours and 20 minutes and still running on the original tank of fuel. I am going to call a bearing company this afternoon and check out the price of needle roller bearings for the crankshaft main bearings. You can see the nearside flywheel move a little every time the engine fires----Thats the slop that has developed on the brass main bearings it is currently running. I am absolutely boggled by how long this thing is running on a single tank of fuel. That tank is 0.9" inside diameter x 3.2" long inside.

 

[Brian Rupnow]

The engine just ran out of gas. Holy cow---What a marathon. It ran for 3 hours and 38 minutes on what I calculate to be 1.2 ounces of fuel. (Thats Imperial gallon measure) Somebody check that for me please---the tank is 0.9" inside dia. x 3.2" long inside. The engine stayed amazingly cool throughout the entire run, and stayed in "hit and miss" mode thru the entire run.---Brian

 

[NickG]

Wow ;D :bow:

That's good going. It seems to be running really freely now, what George said makes a lot of sense though - it's a small engine so it's always going to lose speed quickly once not firing so needs to fire a couple of times to get back up to speed. It would be interesting to try a flywheel with much higher inertia if you had one you could swap but it looks nicely in proportion and runs well as it is.

Nick

 

[Brian Rupnow]

I have some news and some information. I went to Canadian Bearings this afternoon, and they have needle roller bearings made by Koyo that are 3/8" i.d. x 9/16" o.d. x .375" long part #B66 and they cost $22 for two of them. Since my current crankshaft was made from 3/8" dia. cold rolled stock with 7/16" dia. sleeves loctited over them in the bearing area, I am going to pull the crank out, heat up the sleeves and remove them, and modify my existing engine to take these roller bearings. I think part of the problems I have had with my main bearings quickly wearing out is that the sleeves I made and loctited onto the crank were not bored concentrically (This was proven to me 2 weeks ago when I did the concentricity check on my tailstock). The needle rollers bearings should also cut down on some more friction.

 

[Maryak]

Brian its around 0.37 floz or 10 cc(ml), say 2 teaspoons of fuel.

Best Regards
Bob

 

[Brian Rupnow]

Check your math Bob--Two teaspoons aren't going to fill a tank almost 1" dia. x 3.2" long. I'd borrow the wifes measuring cup and check it, but she'd scalp me.

 

[Brian Rupnow]

I just snuck upstairs and "borrowed" the wifes measuring cup and a bottle of Canola oil. The tank holds more than 1 ounce and less than 2 ounces. Now I have to take the engine outside and dump the tank and sneak the wifes kit back upstairs. What in Hell is a Canola???

 

[Maryak]

Brian,

If only I could remember to use PI :-[

How does 33 cc 0r 6.5 teaspoons or even 1.2 floz sound ???

Best Regards
Bob

 

[Metal Butcher]

Quoting Brian: What in Hell is a Canola???

Canola oil from the rape seed, referred to as the Canadian oil because Canada is
mainly responsible for it being marketed in the USA. The Canadian government and
industry paid our Federal Food and Drug Administration (FDA) $50 million dollars
to have canola oil placed on the (GRAS) List "Generally Recognized As Safe" .
Thus a new industry was created. Laws were enacted affecting international
trade, commerce, and traditional diets. Studies with lab animals were
disastrous. Rats developed fatty degeneration of heart, kidney, adrenals, and
thyroid gland. When canola oil was withdrawn from their diets, the deposits
dissolved but scar tissue remained on all vital organs. No studies on humans
were made before money was spent to promote Canola oil in the USA.
a cooking oil.

http://www.ithyroid.com/canola_oil.htm

-MB

 

[kjk]

Canola was formerly known as rapeseed oil and still is in some locales.

 

[metalmad]

I think im just gunna go check the kitchen