Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Scale Model Gas Engines - Hit & Miss - Throttle Governed - Non-Compression – etc => Topic started by: ShadetreeMotorcycle on October 27, 2020, 08:52:49 pm
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It's HERE!!....I like it....at first glance the M94 was my least favorite..but...taking it out and study it....its really growing on me! Features I admire are the cooling fins in the head really look nice....I guess what I did not like is most of the walking beam and govenor mechanism are hidden behind the Flywheel so it's hard to see just what is going on....the other issue is the walking beam it self is very low on the engine as it pushes on a downward facing exhaust valve...the real issue is the wood box has a recession in it and the walking beam partially is down inside....I think my home built box base I will raise the engine and not let the walking beam be partially hid. Also a little polishing plus my Navy Blue planned paint job should make the walking beam stand out a bit better.
The photo shows some carbon brush soft springs I picked up at Ace Hardware to try this weekend. I have not run it yet because I had a super long day at work...but I will surely fire it up stock before bedtime!
One of the things I am Super curious about is many have gone lighter springs to slow down engine....a couple more adventurous souls have mod piston for less compression, and I will likely try that on at least one of my engines...BUT...it seems like to me the lack of flywheel Weight is a big factor as to why the little engines can not compete with there full size brothers for slow run...I very much want to carve out some brass or copper or cast iron "tires" to slip over the stock flywheels to perhaps Double the weight...I am not sure I can go. That heavy as it will put more load on the bearings...but If I get it slowed down perhaps the lower RPM will help preserve the bearings...anyway...if I get it slowed down some this weekend I have some tire weights to stick on the flywheels...just to test how adding weight might affect the coast phase...I can see where To much weight could be negative as when the engine "Hits" it may not be able to get the heavy flywheels moving...so it seems like it may be a balancing act to find a sweet spot...I welcome input....to be continued.....
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I’ve done the choke and spin method as well. I’ve also used my needle syringe I refill the tank with to clear the line. Simply by feel, I use the needle to find the nipple where the fuel line attached to the tank, advance the needle a bit into the nipple, and push a bit of fuel. It clears the line nicely as well, without resorting to pulling the line off the tank.
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One other hand item to have is some clear tube a couple of feet long that will allow you to cover the fuel tank opening and blow using your mouth your fuel along the fuel line up to the carby and get rid of any bubbles if you get some.
Think from memory it was Bruce or Rog that came up with this hint.
Another way to achieve the same thing without any equipment is to place a finger tip over the opening on the carburettor and rotate the engine perhaps two cycles. This will make the engine vacuum suck the fuel along the fuel line as all the engine suction is operates on the only path available - the fuel tank.
I do this whenever I start and it usually fires first flip. If you draw in too much fuel and flood the engine, it is a simple matter to SLIGHTLY depress the inlet valve and spin the engine a couple of times to clear it out. No need for extra tubes. I stress the word sightly, because if you push it right in, it will come into contact with the piston.
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My china engine tracker said my engine was in IL yesterday!...only one state away....I am super hopeful I Will have it for the weekend.
Your enthusiasm is contagious 😊👍
For the record I use zippo (love the smell) I have the vertical & horizontal engines , I think all the mods have been covered by many on this forum , have fun with your quartet of h&m engines.
Yes....I am Eager to start tuning!
Now my tracker says china Engine at my local post office...not more than 15 min away....I can almost Smell the Zippo fuel burning...Speaking of Zippo fuel....my supply showed up today...just in time....
The small Aluminum plate with the brass pipe plug is a color test....it is dark Navy Blue...the brass pipe plug was to see how well the color goes with brass...my M92 will have lots of brass....it is and M94 that is arriving tomorrow...But the other 2 engines are from same Vendor, So they will not be far behind.
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My china engine tracker said my engine was in IL yesterday!...only one state away....I am super hopeful I Will have it for the weekend.
Your enthusiasm is contagious 😊👍
For the record I use zippo (love the smell) I have the vertical & horizontal engines , I think all the mods have been covered by many on this forum , have fun with your quartet of h&m engines.
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My china engine tracker said my engine was in IL yesterday!...only one state away....I am super hopeful I Will have it for the weekend.
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A dryer vent sounds like a good fix, thanks Scott.
I won the bid on an M90 today!...hopefully I did not snipe it away from a fellow forum member. :o
Now I have All the Horizontal variants(that I know of) coming...that should keep me tinkering most of the winter!
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I have rigged up a 4" duct fan to an outside dryer vent for my shop. It works well for sucking the fumes outside.
I do like to run my motors on the workbench a lot, and this has helped to keep peace in the household!
Scott
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I live in an apartment in a two family house. I don’t have outdoor storage, and don’t like the idea of too much fuel in the house. Definitely not gonna use pump gas. Zippo is relatively less obnoxious, and buying two of the bigger cans at a rip on Amazon it’s not bad, and ships with no issues.
As to ventilation, I’ve initially set up in front of an open window with a fan behind me pushing air out. Then I got an idea to build a vent system I could put in place in the open window like the old style screens we used to have. I bought a 110v powered, 100cfm computer fan, and mounted it to a doubled up cardboard box that just fit the open window opening. It worked pretty good as an exhaust system I could stow when not in use. I’m toying with building what would essentially be like a range hood to pop into the window when needed. I park a small table in front of the window and set up on it. The table is quite heavy, made to hold a potters wheel, so it doesn’t rattle etc when a running engine is on it. It’s not as nice as a dedicated workshop or garage, but necessary compromise when I had to move to the city, when my vision no longer allowed driving. Where there is a will, there is a way.
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Wow!....nearly 5 hrs on that little tank of fuel...that IS impressive.. .the Smiles Per Gallon is got to be off the chart!
Thanks Gil!
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They don't produce much fumes when running the way you want it to run. I had an M90 running on my desk for 4 hrs 56 min on a single full tank. I could not notice any severe deterioration in air quality. Come to think of it, I don't recall any air quality problems. That said, my hvac system circulates the air pretty well.
I see no issue with a short run indoors.
Gil
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Ahh!....found a better price on 12oz cans of Zippo lighter fuel...got it down to $5.08 a can when I purchased 5 cans with free shipping!....I like saving $.... so I can buy more engines ;)
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One other hand item to have is some clear tube a couple of feet long that will allow you to cover the fuel tank opening and blow using your mouth your fuel along the fuel line up to the carby and get rid of any bubbles if you get some.
Think from memory it was Bruce or Rog that came up with this hint.
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That's good enough for me!...I was leaning towards Zippo because I like the can it comes in....was just not sure if Coleman was cleaner as it is a cooking product....I have found 12oz cans of Zippo for as low as $6.99 for as little as these small models burn, that price is fine by me....I just want to run the best performing fuel.
I too like the Zippo cans, I was hoping that the squirter lid would act as sort of syringe to fill the tank as they are bloody finicky but it didn't work as hoped.
I was wondering if anyone has found a clever way to deal with exhaust fumes in the house?...I don't want to run it for hours at a time...but for several min in my spare room workshop....my first thought was to slide a rubber tube over the muffler and drop the other end in a pail of water....in hopes the bubbles rising thru water may purify the fumes some?....probably best to vent out a window?....I think the water method may make some unwanted back pressure....
For short runs with the window open, I reckon you'll be ok (I do it) I hate fumes and I haven't been bothered at all so far with these fun little engines.
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That's good enough for me!...I was leaning towards Zippo because I like the can it comes in....was just not sure if Coleman was cleaner as it is a cooking product....I have found 12oz cans of Zippo for as low as $6.99 for as little as these small models burn, that price is fine by me....I just want to run the best performing fuel.
I was wondering if anyone has found a clever way to deal with exhaust fumes in the house?...I don't want to run it for hours at a time...but for several min in my spare room workshop....my first thought was to slide a rubber tube over the muffler and drop the other end in a pail of water....in hopes the bubbles rising thru water may purify the fumes some?....probably best to vent out a window?....I think the water method may make some unwanted back pressure....
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FYI, though some swear by Coleman, I found a series of pretty scientific shade tree tests of gas alternatives. This guy carbon cleaned engines before and after runs, used infrared thermometers, tach readings under load, even a see through head on a four stroke to compare them. He ran lawnmowers, generators, go carts, and cars.
By far the cleanest, most complete combusting, least problematic in every way was Zippo. It’s pricey but beat Coleman hands down for clean burn and power without knocking.
I've tried a few fuels so far and for me, I like Zippo so far the best. My two H&M engines just run better on it.
For how little they use, it doesn't work out that cost prohibitive. I drain the tank of any left overs back into a fuel holder and buying the Zippo cans in bulk off eBay is a pretty good way for me to purchase and cheaper than a tobacconists.
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FYI, though some swear by Coleman, I found a series of pretty scientific shade tree tests of gas alternatives. This guy carbon cleaned engines before and after runs, used infrared thermometers, tach readings under load, even a see through head on a four stroke to compare them. He ran lawnmowers, generators, go carts, and cars.
By far the cleanest, most complete combusting, least problematic in every way was Zippo. It’s pricey but beat Coleman hands down for clean burn and power without knocking.
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Well...."Some" of my engine supplies rolled in today, I am collecting goodies so I can run my engines when they show up! There is a quart of MM-oil....that "seems" to be one of the favorite oils to mix with the fuel.....there is 2 eye dropper for dosing oil mix...the yellow AA batteries are blanks if I want to drop down to 2 cells vs 3 cells...the syringe is to get fuel into the tiny fuel tank...and the Colegate whiten formula toothpaste is for brass gear teeth polish...they even admit there are micro abrasives in the formula on the box...plus your engine will smell minty fresh!....just need fuel yet I think....got to decide between Zippo lighter fluid and Coleman camp stove fuel....have not determined which is better running or lower smell.....
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Great news! Can’t wait to see what you do with them ;)
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Well,...My M94 cleared import customs on Saturday, I am hopeful that may mean it's only a few days from delivery.
The other good news is I won the bid on an M92 today!!....I wanted both a flying ball model AND one with Flywheel mounted weights....So...now I just need to learn patience for engines to make the long journey....can't wait to break out the wrenches and start tinkering/tuning!
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Thanks for the tip on the M90 Redryder!.... I actually saw your Youtube videos about tuning and lowering compression on Youtube Before I found this forum....it was your videos that inspired me to order a China hit and miss engine!
The link mentioned is very nice...I hope to get even slower idle.
I Did win the bid on an M94 for a decent price...So I got one coming...who knows how long it may take to get here...I am still on the hunt for a nicely priced M92 AND M90 so I will get at least 3 engines....I may try a M91 vertical but they seem to go for more $ and I like the exposed crankshaft look of the Horizontal models....If anyone has tips for finding the best prices it would help as I need so many...lol!
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The M90 may be the easiest to run slowest and coolest.
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I'm pretty new to these engines after recently taking delivery of two, my knowledge of these engines has all come from the members here by reading through all the posts and gleaning bit and pieces of choice info.
There's some really knowledgeable H&M guys on board here.
Look forward to you receiving your engine(s) and the mods that you do, I'd like to make a larger heavier base like you mentioned also.
You might find this thread interesting to read -
https://www.officeofsteamforum.com/general-discussion-scale-model-gas-engines-hit-miss-throttle-governed-non-compression-etc/m-90-modification/
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See...there ARE opinions...thanks guys! I found a good price on M90 but it appears to be old stock as it has the clear spark plug boot...I was hoping to find the upgraded one for a good price.
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I chose m94 because it looks like the simplest. I'm a firm believer in KISS (keep it simple stupid)
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Haha, I’ve only ran the M90 but think the M92 is the best “looker”
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Hmmm....it must be a secret.....
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Ok, I have been bitten by the bug to purchase a China M series and try to tune for lowest possible hits per min.
I am wondering if there is a favorite model? I prefure the horizontal versions...the M90 looks the most simple...the M92 is the best "looker" in my humble opinion with the extra brass and flying ball governor...the M94 has cooling fins on the head but I am unsure of the other differences....so my question is: Is there a model with the most potential to run slow? Anything I should avoid?
I have been inspired by a few videos...I hope to wind some softer springs, probably lower compression...may try to add a brass or cast iron belt pulley to add rotational mass to get longer coast...look for drag in the engine.
I also plan to spruce up the model, likely a paint job and a heavy base to keep the model from walking away...I may try them all if I can find good deals, but was wondering if there was a more desirable model....It seems the newest versions of the M90 come with a better spark plug boot, these are the type of things I am trying to learn about but also wanted to know if there was a model that has more potential to run slow? Thanks for any advise!