Author Topic: another Snow engine  (Read 157755 times)

Offline Hugh Currin

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Re: another Snow engine
« Reply #600 on: July 24, 2017, 04:21:08 PM »
On my Corliss Twin build I used a taper-lock hub, using the design that Chuck Fellows had posted.....

I used a taper lock on my Webster build. Here, starting with post #67 documents my adventure with taper lock and QD type flywheels. Post #73 points to Chuck Fellows' thread. Post #74 gives the difference between "taper lock" and "QD" types.

In the Webster the timing gear is attached to the flywheel. If the flywheel slips it throws off the engine timing. I had problems with this. Further in the thread, starting with post #171 documents my efforts to solve this. I finally went to a shaft key.

Hope this is of interest. Thanks.

Hugh
Hugh

Offline fumopuc

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Re: another Snow engine
« Reply #601 on: July 30, 2017, 07:28:19 PM »
Getting a Snow engine alive, next episode.


First of all thank you very much for all your thoughts and comments.


Next to say, the fidget spinner has left the room.


After getting the 4 mm keybroach last week from arceurotrade I have done the decision not to use it for this problem. So I have marked the gear train and took the crankshaft with flywheel off.
A gauge was made for a proper positioning of the taper on the shaft.
The taper was fixed with Loctite 648.
Next attempt for a fire up, but still heat in cylinder 3 and 4 only, cylinder 1 and 2 cold.
Getting a sneaking suspicion, that the compression is lost.
Loss of compression confirmed by measuring with the pressure gage.
In my opinion, there could be only one reason for this, the piston is not fixed to piston rod any more.
Next decision, to open cylinder #1 at the end of the engine. A view into it confirmed my suspicion.
Taking the piston rod from #1&#2 off carefully, a good opportunity to make the forgotten chamfer at it first.
The set screws were fixed with Loctite 222 now.
Now I had to get it in again without any further disassembly if possible. So a sleeve had to be made, inner diameter same as cylinder, outer diameter a little bit smaller than the inner diameter of the combustion chamber. One side with a big smooth chamfer to help the piston ring gliding into the sleeve.
The next attempt to fire up was not so bad, I could measure the same heat in all four cylinders now, but running without the help of the power screwdriver last only for 2 to 3 seconds an than the engine dies.
I think I cannot find the right carburettor adjustment.
Using an ENYA 09-IV (09430) carburettor, I have seen the recommendation here in forum, should be the right way, but to be safe I will try the little OS carburettor from the Hoglet next, to get any feeling about this things.
I do understand now why some people prefer to build single cylinder engines only.
« Last Edit: July 30, 2017, 08:41:31 PM by fumopuc »
Kind Regards
Achim

Offline Roger B

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Re: another Snow engine
« Reply #602 on: July 30, 2017, 08:38:58 PM »
More progress  :ThumbsUp:  :ThumbsUp:  A fairly simple carburettor should allow to run at some fixed speed, the problem may be somewhere else. Have you rechecked the ignition timing? Possibly a little more advance may help. Have you rechecked the valve timing? If some other components have come loose maybe so has  part of the valve system. What does the compression feel like, is it 'bouncy'? If you flick the flywheel round by hand does it bounce back from the compression.
Best regards

Roger

Offline Rustkolector

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Re: another Snow engine
« Reply #603 on: July 31, 2017, 04:14:13 AM »
Achim,
The Enya 09 carburetor should work. Doug Kelley had good success with this carb, and I did also. I have tried a number of other carbs and found that the smaller they are the better they work on the Snow. I currently use a 3 mm throttle carb now with good results. When attempting to start your Snow make sure the carb throttle setting is near closed. Enough so that the intake air makes a slight hissing sound when cranking. Start with the carb needle valve near closed and slowly open a click at a time while cranking and you should quickly find the setting you need to start.

Jeff

Offline fumopuc

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Re: another Snow engine
« Reply #604 on: August 01, 2017, 12:26:40 PM »
More progress  :ThumbsUp:  :ThumbsUp:  A fairly simple carburettor should allow to run at some fixed speed, the problem may be somewhere else. Have you rechecked the ignition timing? Possibly a little more advance may help. Have you rechecked the valve timing? If some other components have come loose maybe so has  part of the valve system. What does the compression feel like, is it 'bouncy'? If you flick the flywheel round by hand does it bounce back from the compression.
Hi Roger, thanks for your thoughts and comments.
Ignition timing rechecked, 8° in advance as recommended. 18° in advance was tested also.
Valve timimg rechecked, starting to open exhaust valve 25° BBDC as recommended.
I will recheck the compression again at each cylinder, I do have this bouncy feeling and all 4 combustion chambers do have the same heating after some driven use of the engine.
May by all 4 are bad ?
Kind Regards
Achim

Offline fumopuc

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Re: another Snow engine
« Reply #605 on: August 01, 2017, 12:39:22 PM »
Achim,
The Enya 09 carburetor should work. Doug Kelley had good success with this carb, and I did also. I have tried a number of other carbs and found that the smaller they are the better they work on the Snow. I currently use a 3 mm throttle carb now with good results. When attempting to start your Snow make sure the carb throttle setting is near closed. Enough so that the intake air makes a slight hissing sound when cranking. Start with the carb needle valve near closed and slowly open a click at a time while cranking and you should quickly find the setting you need to start.

Jeff
Jeff thank you so much for your suggestions. Very good to know that the same basic hardware configuration is working at other places.
This will lead me to another direction I have been until now.
Currently my needle is open by a 3/4 to 1 turn and it fires only if the throttle is nearly full open.
I will try this more sensitive click by click method.
Kind Regards
Achim

Offline Roger B

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Re: another Snow engine
« Reply #606 on: August 01, 2017, 01:27:20 PM »
"Valve timimg rechecked, starting to open exhaust valve 25° BBDC as recommended"

Hi Achim,

Have you checked the complete cycle for inlet and exhaust? The exhaust should close slightly after TDC. The inlet should open slightly before TDC and close a little after BDC. The overlap period at TDC is probably more important than positions around BDC.
Best regards

Roger

Offline fumopuc

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Re: another Snow engine
« Reply #607 on: August 02, 2017, 07:45:08 AM »
Hi Roger, I will check the complete circle as you have mentioned.
To be honest I never put Dougs recommendation into question, because it should be a proven system.
Two rockers, one for exhaust the other for inlet, both running on the same CAM, does not give a lot of range.
Kind Regards
Achim

Offline fumopuc

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Re: another Snow engine
« Reply #608 on: August 02, 2017, 07:48:11 AM »
Achim,
The Enya 09 carburetor should work. Doug Kelley had good success with this carb, and I did also. I have tried a number of other carbs and found that the smaller they are the better they work on the Snow. I currently use a 3 mm throttle carb now with good results. When attempting to start your Snow make sure the carb throttle setting is near closed. Enough so that the intake air makes a slight hissing sound when cranking. Start with the carb needle valve near closed and slowly open a click at a time while cranking and you should quickly find the setting you need to start.

Jeff
Jeff thank you so much for your suggestions. Very good to know that the same basic hardware configuration is working at other places.
This will lead me to another direction I have been until now.
Currently my needle is open by a 3/4 to 1 turn and it fires only if the throttle is nearly full open.
I will try this more sensitive click by click method.

Hi Jeff, another question about the ENYA carburator set up, is there any known prefered adjustment for the idle speed needle available ?
Kind Regards
Achim

Offline fumopuc

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Re: another Snow engine
« Reply #609 on: August 20, 2017, 07:51:19 AM »
Hi Jeff, many thanks for your advice.
After checking the timing again, was something of 40° instead of 25° BBDC, I am getting some more pops.
I have tried a more precise method for the measurement of the valve movement this time.
<a href="https://www.youtube.com/watch?v=cZaQvjBE3VI" target="_blank">http://www.youtube.com/watch?v=cZaQvjBE3VI</a>
But I am still fighting to get it to a real run.
Kind Regards
Achim

Offline vcutajar

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Re: another Snow engine
« Reply #610 on: August 20, 2017, 12:16:18 PM »
Thanks for the update Achim.

I feel your pain.

Vince

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Re: another Snow engine
« Reply #611 on: August 20, 2017, 12:26:27 PM »
Seems so close to running properly - could you relieve the compression somehow and run it in on the drill to bed everything in?

Simon.
Ars longa, vita brevis.

Offline fumopuc

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Re: another Snow engine
« Reply #612 on: August 20, 2017, 01:15:01 PM »
Vince, thanks.


Simon, I believe there is still an issue with the mixture control.
In the mean time I have made a 3 mm air restrictor for the carburettor.
I have earned 5 to 8 seconds more runtime.
Another one with a 2 mm hole is also made now, but unfortunately the battery of the screw driller is still at the charger. 
Kind Regards
Achim

Online Kim

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Re: another Snow engine
« Reply #613 on: August 20, 2017, 03:21:31 PM »
Achim, I have no meaningful advice to offer, but it sure looks close to me!  You can hear it trying really hard to keep going...  I know you'll get there soon!

One question - what's beaker for there? Is there oil coming out of the exhaust?

The engine looks beautiful!
Kim

Offline fumopuc

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Re: another Snow engine
« Reply #614 on: August 20, 2017, 03:47:24 PM »
Hi Kim, yes it is oil. I have started with Coleman fuel and MMO 50:1, so the exhaust pipe spews some oil and creates a little mess.
Thanks for watching.
Kind Regards
Achim

 

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