Author Topic: 1st I.C. build "Tiny"  (Read 42407 times)

Offline 90LX_Notch

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Re: 1st I.C. build "Tiny"
« Reply #390 on: December 06, 2017, 09:48:36 PM »
I know it's getting fuel Bill which would indicate the spring works.  Based on your observation of your spring; which, matches mine of my spring, I'll leave it for now.  It probably won't be until Saturday before I can source an O-ring.  As always, thanks for your support.

-Bob
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Offline gldavison

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Re: 1st I.C. build "Tiny"
« Reply #391 on: December 07, 2017, 12:54:58 AM »
Getting a little closer. 

Switched to pump gas at 50:1.
Ditched the drill as a starter  I have a printer motor hooked up to a pc power supply.  I can now hear what is going on. 

It seamed to have a little life in the form of some weak muffled pops here and there.  Nothing significant, but something.

I'm going to try it tomorrow one more time.  If it doesn't run then, I will add an O-ring.

I know I need a 3/8 od O-ring.  I would guess Viton would be the preferred material.  What is a good cross section diameter?  Can I buy them at an auto parts store?

-Bob

I just used a 1/16 X 3/8 o-ring from my junk box.

Offline 90LX_Notch

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Re: 1st I.C. build "Tiny"
« Reply #392 on: December 07, 2017, 02:25:43 AM »
Thanks gldavison.
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Offline NickG

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Re: 1st I.C. build "Tiny"
« Reply #393 on: January 21, 2018, 07:07:00 PM »
Good to see you are almost at the finish line Bob, it looks great and can’t be far off at all.


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Offline 90LX_Notch

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Re: 1st I.C. build "Tiny"
« Reply #394 on: January 27, 2018, 08:00:03 PM »
Thanks Nick for checking in.

----------------------------------

Partial success! 

I went and purchased fresh fuel this morning and was able to get it to run on straight  93 octane.  It ran well once I got it going.  The other key to getting it to run was a faster starting motor.   I was nervous about running it on straight fuel since I never added the oil hole for the cylinder.  I didn't add it because I made a lapped piston and the intent was to run it with two stroke oil. 

Once I was happy with it on straight fuel I switched over to a 50:1 mix and it continued to run well after the carb was tuned.  Then it happened.  A metal on metal sound started and the engine started to get a tight spot.  Of course I figured it was the piston and pulled the head.  The bore was fine and I evenually found the problem.  The cam follower bolt had backed out and was rubbing against the flywheel.

I put it back together but haven't been able to get it to run again.   I have the batteries charging for the ignition hoping that is the problem. 

-Bob
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Online Admiral_dk

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Re: 1st I.C. build "Tiny"
« Reply #395 on: January 27, 2018, 08:34:16 PM »
Quote
Then it happened.  A metal on metal sound started and the engine started to get a tight spot.

Argh - that sinking feeling - most, if not, all of us has been there - no fun at all  :censored:

Hope that you'll find the solution quickly.

Best wishes

Per

Offline b.lindsey

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Re: 1st I.C. build "Tiny"
« Reply #396 on: January 27, 2018, 09:55:56 PM »
Sounds like success to me Bob...it just down to some tweaking now. Glad you found some shop time to play with it and get it going. Can't wait to see it!!!   :ThumbsUp: :ThumbsUp:

Bill

Offline 90LX_Notch

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Re: 1st I.C. build "Tiny"
« Reply #397 on: January 28, 2018, 12:09:01 AM »
Thanks Per and Bill.

I played with it for the last three hours but failed to get it going again.  I can get it to pop; but I can't get it to run on it's own.  I get it close; but not close enough.  What stinks is that it ran well.  I had it running for 10 continuous minutes this morning.  I had an instance, where the pushrod fellout causing the exhaust gear/cam to slip on the crank and the holder for the magnet to slip.   To make a long story short; I lost all the important settings (cam timing, ignition timing and carb setting).  Sometimes it doesn't pay to be tenacious.  I should have walked away from it for a while.  I wound up doing more harm than good because I stopped thinking and began reacting.

-Bob
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Offline b.lindsey

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Re: 1st I.C. build "Tiny"
« Reply #398 on: January 28, 2018, 12:47:25 AM »
Just sleep on it Bob and get al the settings right again and try again tomorrow. I went through this for more hours/days than I care to count but the upshot is that you get to know the engine inside and out and how it reacts to things. One thing I have found that may help is that the oil in the gas mixture seems to separate and clog that tiny hole in the crossbar of the carb after setting a while, especially overnight. Before trying to run it now I take a syringe and blow back through the threaded end where the adjusting pin is and then choke it until I see fresh new gas coming in through the tube. This has seemed to help. Also I choke it until it pops and then it will usually start (repeat as necessary).
 If it ran this morning it will run again, just hang in there.

Bill

Offline steamer

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Re: 1st I.C. build "Tiny"
« Reply #399 on: January 28, 2018, 01:04:56 AM »
Put her down, have a libation....and attack it tomorrow.....you got this buddy.
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline 90LX_Notch

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Re: 1st I.C. build "Tiny"
« Reply #400 on: January 28, 2018, 01:07:05 AM »
Thanks Bill and Dave.

Bill, I use my handheld vacuum pump to clear the carb and fuel line and I do choke it sometimes.  I won't be able to play with it again for awhile.  The house stinks of gasoline which "is going to go over like a fart in church" when my wife and kids get home.  I can only play with it when they are out for the day.  I need Spring to get here so I can try it outside.

I'm just happy that we recieved a break from the snow this week and I had today off.  My last day off was New Years Day until this Thursday when I had to take off because my youngest had Strep.

-Bob
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Offline Art K

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Re: 1st I.C. build "Tiny"
« Reply #401 on: January 28, 2018, 02:41:09 AM »
Bob,
I've silently been following along, more now that I've got the flue crud that's been going around. The guys have made some good suggestions to remedy what ails you I endorse the relax and have a  :DrinkPint: cold one. Myself I've found I don't think well in the moment, but when I sit back and think about stuff then I can sort it out in my mind. Last spring my goal was to have a running Val at NAMES, and I did have it in one piece but running... :Mad:. I came away with some ideas. I put indicators on the intake and exhaust lifters. Whatever I thought was the right timing was way off. I should have learned from the Upshur vertical, I did the same thing there. Once I had that sorted out it ran great. You've had it running for ten minutes so you're not that far off. You did the ten minute  :pinkelephant:
Art

Offline GailinNM

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Re: 1st I.C. build "Tiny"
« Reply #402 on: January 28, 2018, 07:52:00 PM »
Bob,  Since it ran once  you are close to being there.

I have built 19 "Tiny" engines in various configurations  so may be able to offer some specific help.

The most common problem I encountered on the first ones I built were associated with the intake valve.  The spring originally specified was too stiff making the valve tricky to adjust.   I ended up making the intake valve spring out 0.009 music wile.  18 turns on  0.078 mandrel spaced to spread the turns out to 0.016 spacing using the lathe to wind them.  They were trimmed to provide .09 compression when installed.    For reference, 0.009 wire is very close to the high "E"  string on a guitar.

When an engine  quit  running well it almost always turned out to be a sticking intake valve.  This was caused by the oil gumming up because of the high head temperature.  I tried a lot of different oils, but the only one I found to not give me  a problem was light weight full synthetic oil. I now use Mobil 1  0-20 weight. and have not had any sticking problems.  with valve sticking since.  Be sure the valve moves very freely.  I have about 0.001 clearance between the stem and guide.  The guide is long enough that air leakage is not a problem.

For timing I set the exhaust valve to  be CLOSED about 10 degrees after top dead center.  Where it closes is more important than when when it starts to o open, but it should be starting to open about  30 degrees before bottom dead center.

Ignition timing should be about 5 to 10 degrees before top dead center.   Remember that for most ignition systems the spark is when the points open or the magnet is past the Hall sensor pickup.  If you are in a quiet location you should be able to hear the wasted spark through the exhaust pipe  near the end of the exhaust stroke to know  when the spark is happening.   Just note where the crank is  when this happens.

With the exhaust timing set you can check the operation of the intake valve.  Position the crank to TDC at the end of the exhaust stroke.  Again, in a quiet location , Listen at the air intake of the fuel mixer. Turn the crank briskly through the intake stroke.  You should hear the intake valve flutter at the air is drawn into the cylinder.  Sounds like an old man after eating chili beans. 

Another problem is fuel contamination.  If you have EVER used silicon fuel line, the needle valve the fuel mixer will be contaminated.  Silicon and gasoline don't work with each other..  After a few hours the silicon swells and breaks down and the small bit tend to plug us the fuel passages.   

Other fuel problems occur if you use inexpensive plastic syringes for fueling.  The rubber seal on the pllunger does the same  thing as the silicon fuel line.  Because of the small fuel passages I filter all the gasoline before using it.

If interested, some videos of some to my "Tiny's" and Tiny powered gauge one locomotives are at:
https://www.youtube.com/user/nmsteam/videos

Gail in NM
I would like to be the kind of person my dog thinks I am.

Offline 90LX_Notch

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Re: 1st I.C. build "Tiny"
« Reply #403 on: January 29, 2018, 01:00:06 AM »
Thank you for your support Art.

Gail, thank you very much for taking the time to write your experiences building "Tinys".  It is greatly appreciated.  You have provided me with some great information as well as "some food for thought".  Now I just have to find the time to tinker with my engine.

-Bob
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Offline 90LX_Notch

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Re: 1st I.C. build "Tiny"
« Reply #404 on: February 04, 2018, 12:41:32 AM »
I tried again today.  I was able to get a few consecutive "pops" early on.  It seems as though my spark plug may be the culprit.  It doesn't look fouled; but it is not firing at all.  It looks like I'll have to make a new one.

-Bob
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My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos