Author Topic: another Snow engine  (Read 157721 times)

Offline vcutajar

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Re: another Snow engine
« Reply #660 on: March 31, 2019, 08:26:49 PM »
Congratulations.  :praise2: Lovely runner Achim.  :praise2:

Vince

Online Admiral_dk

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Re: another Snow engine
« Reply #661 on: March 31, 2019, 09:31:25 PM »
Wonderful - it looks and sounds the part too  :cheers:

Offline MJM460

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Re: another Snow engine
« Reply #662 on: March 31, 2019, 10:39:24 PM »
Congratulations Achim, a great result for so much beautiful work.

MJM460
The more I learn, the more I find that I still have to learn!

Offline Don1966

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Re: another Snow engine
« Reply #663 on: April 01, 2019, 12:15:44 AM »
Awesome Achim and I bet your aesthetic. She’s a nice runner and sounds great!.....did I say .......I........like........  :Love:



  :drinking-41:
Don

Offline cwelkie

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Re: another Snow engine
« Reply #664 on: April 01, 2019, 12:32:05 AM »
Congratulations Achim!
Another beautiful build from your workshop.
Charlie

Offline fumopuc

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Re: another Snow engine
« Reply #665 on: February 27, 2022, 08:04:30 AM »
Hi everybody,
another 2 and half days of R&D work with this build, after spending 2 and more years at the shelf.
I have had shortly the feeling, it is time no to revisit this build.
Before it was pit into the shelf in April 2018, there have been some issues not sorted out very well.
During the last run one cam lobe came loose and the cooling system has never really worked as it should.
Also the coolant inlet connection into each cylinder was a leaking nightmare at that time.
So it was put on the table in the shop again.


First thing I have detected, the water pump did not turn anymore, it seams to be looked by what ever reason.
A heat gun and some slowly given heat to it has solved this.


The overall timing was checked again after the new adjustment of the one specific cam lobe.
It should be exhaust starts open 40° before BDC, as recommended from Jeff (Rustkolector), thanks again for his support here, but it was mostly 30° only.
Also ignition was checked again, this was fine wit 8° before TDC.


I could start the engine very easy and I have been surprised at the very low revs which could be adjusted down to 450 rev/min.
But unfortunately the cooling did not work.


The very first thing here I recognized, coolant in and coolant out of the engine has been inverted.
No idea what the hell was in my head there, when I have done the plumbing several years ago.
To correct this now, a special bent brass pipe was made to get it done in this small available range.


The connection inlet tubing to the cylinders could be fixed with some suitable wire clips.
But the volume flow was not as expected.
At picture 08 it should be shown, that one cylinder has a good flow, blue coolant visible in the return tubes and at the other cylinder nothing.
May be difficult to recognize at this picture, but at the other cylinder one tube only is blue from the coolant.
So a quick and dirty check set up with a flexible tube and my mouth and lung was done.
This connection was totally blocked.


So no excuses anymore, it must be disassembled, to see what is going on there.


But never the less, here a short video of the engine running now as it was before the disassembling.
The overall run time is nearly 1 and half hour at this stage.
[youtube1]https://youtu.be/jZX8Oy-Wo0Q[/youtube1]
« Last Edit: February 27, 2022, 08:55:17 AM by fumopuc »
Kind Regards
Achim

Offline fumopuc

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Re: another Snow engine
« Reply #666 on: February 27, 2022, 08:33:32 AM »

Next part of the saga.The problem with the blocked inlet was easy to solve.
As supposed already, I have found some cured epoxy glue in the brass tube.
One side complete closed by it, the other side nearly 20% closed.
A 3.9 mm drill bit has get it out easily.
The brass pipes are all fixed with epoxy glue to the cylinder units.
So why I have not check the functionality when it has cured at that time ? No idea.


Before the reassembly it was a good opportunity to do some overall cleaning.


The volume flow seems to be better now, also the critical cylinder does show blue coolant in one return pipe now, but only in one with low revs under 600 rev/min.


The first research was done to increase the ratio of the pump speed by a bigger pulley at the crank shaft.


The coolant in the tank is getting hotter now, so more heat will be transferred there, but still a Delta TEMP from cylinder #1 to #2 of 20° to 25°C, measured by a IR/Laser Thermometer in the middle at the water jacket.
Kind Regards
Achim

Offline Kim

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Re: another Snow engine
« Reply #667 on: February 27, 2022, 04:13:14 PM »
Great detective work there Achim!

I'm impressed that you went back to fix up this project!  Not that it isn't worth it, of course.  It's a beautiful engine!  But I generally can't work up the gumption to go back to a project once I've initially retired it, you know?

Looking forward to seeing it run even better than before!
Kim

Offline RReid

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Re: another Snow engine
« Reply #668 on: February 27, 2022, 04:33:17 PM »
That's a great running engine, Achim. Now I'm going to have to set aside time to go back and read the build thread! Maybe over a glass of our locally made Dunkel Weisse... :cheers:
Regards,
Ron

Offline Rustkolector

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Re: another Snow engine
« Reply #669 on: February 27, 2022, 04:49:33 PM »
Achim,
I did not know you were taking your Snow engine apart. One possible reason for coolant flow difficulty with this engine is the head gaskets. The area of the gasket between the two bolt circles that is directly exposed to liquid coolant will expand into the water jacket space displacing almost 50% of the head water jacket volume. I tried Teflon and different gasket materials. All expanded (bulged) into the water jacket space. I replaced the single piece head gaskets with two piece gaskets removing the center area normally exposed to coolant and covering only the mating areas of the two bolt circles. The only photo I have of the problem is below. I am referring to the center light color area of the gasket. In the photo is is actually a depression.

In the past I have run into design issues of cooling systems and I have switched to positive displacement gear type pumps. They solve many issues, are smaller, and self priming.
Jeff


Offline Roger B

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Re: another Snow engine
« Reply #670 on: February 27, 2022, 08:32:37 PM »
I'm glad your R&D dept. is still open  :) sorting out these problems is a strange sort of fun  :) ::) :headscratch: :thinking: :wine1:
« Last Edit: February 28, 2022, 07:19:19 AM by Roger B »
Best regards

Roger

Offline fumopuc

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Re: another Snow engine
« Reply #671 on: February 28, 2022, 06:56:18 AM »
Great detective work there Achim!

I'm impressed that you went back to fix up this project!  Not that it isn't worth it, of course.  It's a beautiful engine!  But I generally can't work up the gumption to go back to a project once I've initially retired it, you know?

Looking forward to seeing it run even better than before!
Kim


Hi Kim, thanks.
These kind of model engines are really long term projects.
Also to keep them alive is something what could be a kind of own project.
So I do understand people who buy an already build model and are working with in the R&D department only.
At the end, with every run you can discover new issues to improve, as Jeff (Rustkolector) mentioned also in his posting concerning the cooling of this engine.
In my case, the retirement is a clear inducement to attack it.
Some time earlier I did not have the patient and calmness for these kind of jobs.
Kind Regards
Achim

Offline fumopuc

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Re: another Snow engine
« Reply #672 on: February 28, 2022, 07:06:49 AM »
That's a great running engine, Achim. Now I'm going to have to set aside time to go back and read the build thread! Maybe over a glass of our locally made Dunkel Weisse... :cheers:


Hi Ron, thanks.
Hopefully you will have fun to read the old thread about the "making of".
May be we can use this opportunity to add the timing of this special engine into the list of model engines.
Due to its origin, a steam engine, altered into an IC engine, it is something we do not have there, so far.
Also the timing with one cam lobe for inlet and exhaust, it really something special in my understanding.
Kind Regards
Achim

Offline fumopuc

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Re: another Snow engine
« Reply #673 on: February 28, 2022, 07:13:34 AM »
I'm glad your R&D dept. is still open  :) sorting out these problems is a strange sort of fun  :) ::) :headscratch: :thinking: :wine1:


Hi Roger, as mentioned in my response to Kim, R&D department is a special part of model engineering.
But you, as a master of this, does know exactly what it means to find a way there.
You have my full respect and admiration there.
« Last Edit: February 28, 2022, 07:19:43 AM by Roger B »
Kind Regards
Achim

Offline fumopuc

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Re: another Snow engine
« Reply #674 on: February 28, 2022, 07:40:40 AM »
Achim,
I did not know you were taking your Snow engine apart. One possible reason for coolant flow difficulty with this engine is the head gaskets. The area of the gasket between the two bolt circles that is directly exposed to liquid coolant will expand into the water jacket space displacing almost 50% of the head water jacket volume. I tried Teflon and different gasket materials. All expanded (bulged) into the water jacket space. I replaced the single piece head gaskets with two piece gaskets removing the center area normally exposed to coolant and covering only the mating areas of the two bolt circles. The only photo I have of the problem is below. I am referring to the center light color area of the gasket. In the photo is is actually a depression.

In the past I have run into design issues of cooling systems and I have switched to positive displacement gear type pumps. They solve many issues, are smaller, and self priming.
Jeff


Hi Jeff,
thank you very much for your tip with the head gasket here. If never thought about this so far.
I do know exactly know what you mean.
To make it more visible, may be for other Snow engine builder, I made a picture of my set up parts, which has been resting in a box under the bench.
In the moment I do not have any intention for further disassembling, but if this will happen, than these gaskets will be 100% swapped against the split type of your recommendation. That could be an advantage for any general heat transfer also at this special place. The cylinder heads has been the hottest spot, measured at my experiments with the cooling so far.
Next time my plotter will activated, than these gaskets will go at the top of the to do list.


My very first gear pump for cooling is as a CAD model available already, also some gears are purchased.
I have made it motivated by the plans of Art Burns published in MEB in 2007. 
It should be part of the IHC Titan build.
« Last Edit: February 28, 2022, 08:48:46 AM by fumopuc »
Kind Regards
Achim

 

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