Chainsaw Repair
Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Modified Ported Work or Race saws => Topic started by: man of stihl on May 20, 2011, 06:34:59 pm
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This thread makes me lol everytime I read it. If you've got enough fuel, non of the above lean situations happen. Runons, glow plugging, auto ignition is all lean situations, period!
No side gapping, 180psi on pipe, big ports, 20% nitro in over 10 second long cuts with WG carb.
https://youtu.be/sXCyOETVQaE
https://youtu.be/YNFo1aBSqvQ
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Back around 1989 I was mechanic in a large Stihl shop and had my own fleet of competition saws for each class. In my archives I had some old data on running Kart motors on Nitro mix,it said 25% nitro was the hottest percentage you could use. So I made a 25% nitro/75% methanol mix,I used synthetic Amsoil mix oil because I know mineral oils will not mix with methanol,so that was my fuel/oil mix.
For information I went to the master mechanic at a local Speed shop,This guy had experience in building drag cars on alcohol or Nitro. He told me that to rum alcohol you needed twice the fuel flow and nitro needs almost 3 times the amount of fuel flow. I was using my 084 hotsaw as a test mule,and I knew I would have to modify the carb and circuits to flow a helluva lot more fuel than for gasoline.So I would pull the carb off,enlarge the fuel circuits,then test run the saw but still too lean.I had to repeat this process about 8 times until finally the carb would actually flow enough fuel and I could richen or lean the HS screw and make the saw rev to whatever top rpm I wanted-success!
However I discovered that 2-strokes aren't really a good design for running nitro on,because during it's normal cycle you have fresh mix entering the cylinder while burning exhaust is going out,and with nitro fuel this results in the incoming nitro fuel being ignited,causing"Auto-igntion"-the nitro fuel is ignited before the spark plug even fires. So what happens is about 10 seconds after you start the saw the motor will start racing like crazy,10,000 plus rpms while your finger is off the trigger! So when this first happened I was freakin' out and immediately hit the stop switch but the motor kept screamin',so in a panic I yanked the spark plug wire off and got a helluva shock but the motor kept revving and was obviously running without spark,then luckily I tried closing the choke and the motor stopped. So in tests after that to shut off the saw I merely snapped the choke shut and opened the throttle at the same time it it would quit nicely. So unlike my other race saws I had to leave the choke assembly in the carb.
It was just a week before the annual local Loggers Sports competition,then I found out the rules clearly stated gasoline fuel only allowed,so all my hard work was in vain. I did have a can of Klotz Nitro Power Additive and I added it to my 090 hotsaw at ratio recommended on the can(which is a very low percentage),but when I ran it in my 090 at the event there was a very strong chemical smell in the exhaust,and quite a few other competitors immediately asked me what I was burning in the fuel,I suggested maybe it was from some anti-friction additive that I had in the fuel,but I don't think anyone believed me,but the fact is nitro isn't legal in the fuel and even a tiny percentage the smell is a giveaway...
I guess it's possible to build another nitro-burner like my 084 to do some interesting demonstration runs at an event... That would be cool.
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first thing , hold throttle wide open with switch turned off will kill most run ons , next ALWAYS have your squirt bottle you prime the saw with to start it with you , just squirt your mixed gas into carb on saw that's running on , it will quit . Are you guys cutting the ends on your spark plug , if you that's your trouble , the end of your plug will glow when running nitro/alcohol and will not shut down until its flooded , you can turn your switch off but it will not matter . Next if your running a pipe with wide skirt piston and ports to match you donot need or want big compression
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Had a run on on the 4ci at the Murray KY show after the cold start and 3 cuts :o. Was fun trying to get her shut down.
Makey one poop-po their pants alittle. :D
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They can run away. I had to hold the decomp in and pull the trigger to let it die once. Switch off and it still was running away.
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Held the switch in or just flipped switch off 99% of the time worked. If had a run on flood it with mix squirt bottle or plug the carb hole.
You can see folks in the videos running with squirt cans to a run on saw of a racer.
Know of 30% in stock appearing saws. My 4ci cube liked that best. But I was one to try and just run the same 12% or so in all the same saws. Had like 8 ingredients in my sprint mix from Va. Called Nitrodine.
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Well I ran 25% nitro and alky in my 084,it took a lot of work to get the fuel flow needed,I got it to run excellent and then found it was illegal here.
First of all if you ran nitro how did you get the motor to stop?
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Finally have started playing with this nitro stuff. Had to add a little pump gas to get it to run and not run away. This was 15% nitro rc fuel and 91 e free 50/50.
https://youtu.be/dYim7Cy77pE
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I forgot to mention,very important,after every running,I drained the nitro mix out of the saw and ran a normal gas/oil mix thru the saw as soon as possible,and left some in. Nitro and alcohol will eat rubber and other things quickly.
Yep always had a flush fuel for after racing. Would run it till saw bogged down then drain.
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I remember having a runner run on at KY. Nothing was killing it. Freaked me out but somehow got it killed. Cant remember how.
At Webster I noticed all the top guys running over with their prime bottles to flood out the saws that were running on.
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I forgot to mention,very important,after every running,I drained the nitro mix out of the saw and ran a normal gas/oil mix thru the saw as soon as possible,and left some in. Nitro and alcohol will eat rubber and other things quickly.
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If you have an effective de-compression button, that will kill the motor too
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I experimented with Nitro in my 084 Hotsaw back around 1988.I was running 25% nitro with Methanol,and Amsoil mixed with it fine at 32-1. I found I really had to upgrade the fuel system for far higher flow,and had to make large increases in the fuel circuits in the carb.I also installed an NGK B9HV spark plug. Finally after increasing the fuel flow and carb circuits I got the saw so the carb adjustment screws were funtional and I could set the carb ok. Results were suprising,The saw ran great,and very cool,but always after about 60 seconds running the saw would auto-ignite and be running without the ignition(Not abnormal),so it would race and not idle down,but when you opened the throttle it carbereted fine,so I didn't worry about the racing,it pulled very hard thru the wood. Then came the trick to stopping the motor.Turning it off did nothing,first time in a panic I yanked the plug wire off to no avail,the saw stayed racing,finally I learned to turn the motor off by closing the choke and opening the throttle,worked every time.
Well after all the hard work I found that nitro was illegal in my hotsaw so all my work was in vain for that class of racing...
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If I was closer I'd take that leftover stuff. I'm going to call a couple motorcycle shops today and see if they have anything.
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Havent heard back but looking at the VP fuel I am thinking this was it. I am only guessing, not sure.
VP Q16
Q16 will work well in any drag racing application -- naturally aspirated, nitrous or blowers. Q16 is highly oxygenated, requiring a 4-6% increase in fuel flow, which will make 3-5% more power than competitive 116 octane fuels. Q16's oxygenation will significantly expand the range of air/fuel ratio acceptability, so performance will be more consistent and won't vary as dramatically with altitude or density changes. For bracket racers, variations in ET from run to run will be substantially reduced. This added fuel flow also effectively increases its octane by 6-8 numbers above its standard ASTM octane rating.
TYPICAL VALUES
• Color: Yellow
• Motor Octane 116
• Research Octane: 120+
• Specific Gravity: .716 at 60° F
http://www.vpracingfuels.com/vp-drag-racing
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I text woodheater and he has 4gal of that yellow VP left he would give me. I dont want it. He said when he gets back home he would text me what it was.
Wish he would come on here and tell you about it. I was impressed with it for the short time I seen it running in his gas saws and gains.
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Check out "Spuds nitro notes" lots of good info especially in regards to jetting for different %'s of nitro. Not what you might expect as the specific gravity of nitro vs methanol. Creates an interesting jetting dynamic below 30%
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Thanks Kevin. I'll look into that stuff Shaun. This other than woods port stuff is a lot more interesting.
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Going to merge threads Mike.
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I know there was some yellow colored fuel a guy aka woodheater username from Sandusky, tested here at the house from VP that had to be flushed. It had great gains in a gas saw that could flow it.
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Nitrodine I used to run in hotsaws and was for karts. Had like 8 ingredients and 12% to 15% nitro.
I'm out of this stuff since 2010.
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You should try VP M5. We use it in our gx200 kart engines. They say 5-7% more horsepower but if you have the compression to utilize the nitroparaffins you'll get more like 20%. Plus it's premixed and stable unlike normal nitromethane. They'll sell it in a 5 gallon drum and it will stay fresh in the drum for a long time.
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I'm going to link this thread here from 3 different thread I found. http://chainsawrepair.createaforum.com/ported-saws/nitromethane/msg45493/#new
Racesaws was loaded with good info on subjects like this. :'(
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The air fuel ratio is drastically different and a gas carb needs to be drilled out to supply enough fuel.
Nitro can be very corrosive and needs to be flushed out of the chainsaw after running with the nitro. It forms nitric acid. The saw will rust all inside if not flushed.
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I have merged 3 different threads on methanol alcohol alky, nitromethane, nitro nitropane etc.
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I was just trying to learn more about running nitro in a saw that's not piped. Any and all help welcome.
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;D---which is why I don't fool with the stuff ----.
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Nitro Methane forms nitric acid during combustion. Your engine will rust inside after running on nitro and setting around in the shop.
Some people run the saw on some none nitro fuel as a after run clean out.
Methanol itself is hygroscopic and will attract moisture and cause rust on the crank, rod, and bearings.
Regular two stroke oil will not mix with Nitro Methane or methanol. You will need to run Klotz Benoil as a lubricant.
Even though, you stihl need to use a lot of WD40 in the crankcase as a after run oil to keep the rust away. It takes a thin oil to flush the castor oil away.
Nitro methane and ultra violet light do not get along. Exposure to extended sunlight or fluorescent light will ruin the nitro and cause it to form other compounds that cause very unstable running. The end result is that you will never be able to set the mixture correctly on your chainsaw. The engine will sound rough and rich up to the point where it is too lean and shuts off on you. After learning this, you try to set the engine up a little rich to allow for a margin of error so the engine doesn't quit on you but in a multiple cut, heat will build up in the engine and the mixture will go lean and the engine will quit on you anyway.
Methanol by itself or even with nitro does not have a good sound to an experienced alky hall runner. It takes about 2% acetone or amyl nitrate (wad blaster) to stabilize the running so it sounds smooth. Being as Methanol is hygroscopic and mixes readily with water, you want to make sure of the purity of your fuel components.
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There is a certain smell of methanol ,nitro and castor oil .Unmistakable once you've been around it .
Now I don't know what the applcation might be but this stuff is strictly for a racing situation .In a stock application it might make it run faster but the engine life could be measured in seconds.
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You might try a race site for more info on this kind of stuff. You must be a member to see all the boards and ask stuff.
Competition Saws http://competitionsaws.createaforum.com/index.php
Racesaws http://www.racesaws.com/
;)
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Back in the day I bought alcohol carbs for my hotsaws from Russell Karting out Kansas City. Even had cans of fuel sent across the line here in Canada, sure can't do that today :D
Russell sold WB alcohol carbs and also real nice Mikuni 34mm diaphragm type carbs similar to the Tilly HR-HD design.
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The main thing is the jets in the carb will need to be doubled in size if you are going to use nitro and methanol
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I was wanting to run a saw on nitro for a while now. I would like to know if anyone knew what type of compresion was needed or what has to be done to ignition timimg so the saw does not turn into a hand granade.
Thanks
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Got a good surprise today. Fuel at the house when I got home. Big thank you to the one that came thru.
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Can't source fuel, the 357 has to go. No good to me sitting on the shelf.
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i get mine from the Torco guy who sells oil to the shop i work .
check if is any torco oil available near you,then ask them to order methanol,they have nitro too
klotz sells nitro,but very expensive.
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Nitro is getting harder to find. >:(
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+1
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We can get VP from the Mansfield NAPA ;)
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This was the place where all the drag race, circle track, and model airplane fuels ultimately came from in my world. It is just South East of San Antonio but they have dealers all over. If you want 500 or 1000 gal they will send a truck up and drop it in your tank.
http://www.vpracingfuels.com/master-fuels-table
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Found this place in bowling green KY that sales nitromethane methanol etc
http://www.hiperfuels.com/
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Methyl Hydrate and Methanol are the same thing but watch your water content
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Is Methanol the same as Methyl hydrate? One search they came up the same. I have gallons of methyl hydrate around.
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One of my NAPA's carried VP so they pretty much could get anything.
Speed shops too
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No race tracks close. Will check Napa.
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Around here race tracks, race shops, even NAPA parts stores.
Hope you can find it up your way because Hazmat is about the same cost of 5gal of Meth from KY. http://www.motorsportsracingfuels.net/index.php?categoryID=48
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Where do you buy methanol? Want to make some race fuel.
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I did misunderstand, I thought 40 percent nitromethane actually a 40 % total fuel mixture.
Mighty max with 80 percent nitro, i thought you were running it whole not as a mixture.
I can see clearly now.
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Kevin, just out of curiosity, with the octane rating of nitro about 45 and you used 40 percent even in 120 fuel you would have an octane rating of about 80 and in 80 percent about 70.
How do you get a saw to run on such low octane?
You must have missed read something somewhere Jeff. Where did I say I ran 40% nitro gas? Heck I only seen some guys run 30% in the alky 3ci and 4ci.
Think about this, you buy 40% nitro and mix sevearl ounces with a gallon of gas. That would be a pretty low percentage of actual nitro. ::) ::)
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Kevin, just out of curiosity, with the octane rating of nitro about 45 and you used 40 percent even in 120 fuel you would have an octane rating of about 80 and in 80 percent about 70.
How do you get a saw to run on such low octane?
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That looks good too. I just wish they sold it in smaller quantities. So i could try it first.
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This stuff is better then the klotz nitropane. But epa had made it really pricey and only place I could find it was in Texas. For gas saws.
Power Fuel Max race is 40% Nitromethane and is what I used in the 5000 gas at races in 07 early 08.
If I had to do again I would go with the Mighty Max 80% nitro.
company link.
http://www.shop.pricechemical.com/
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Well i may try that nitropropane before i jump into the good stuff. We'll see. ;)
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I really dont know. A friend of mine that has been building saws for a long time says it will keep for a great long while ;) Wish i could help you more :(
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I get my nitro from a racing shop about 30 miles from me. 20 bucks a gallon!!!!!!!!!!!!!
Can you tell me what the shelf life of nitro is?
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Its 6 bucks a gallon i think :-\
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Has anyone tried this? (http://www.klotzlube.com/proddetail.asp?prod=KL-600_Pint&cat=8)
The Klotz Nitropropane (is what I used to buy) I used to run in the gas saws when allowed. I seen a good tenth knocked off in 1 cut in 8x8. jred up by you has tested it too and might still have some.
At the end of the gas saw racing I quite running it because of being lazy and anything I gained was killed by my poor operating.
The old PP 375 on 93 octane Klotz 32:1 ran in the PINE wood at Chardon 3 seconds for 3 cuts and a 4.58 cold start on that run. Never timed just 1 cut on that run. But it is in the 2010 chardon perlim video.
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I get my nitro from a racing shop about 30 miles from me. 20 bucks a gallon!!!!!!!!!!!!!
Watcha getting methanol for a gallon ;D ;)?
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I get my nitro from a racing shop about 30 miles from me. 20 bucks a gallon!!!!!!!!!!!!!
That's a little better than $120 a gallon from Klotz.
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I get my nitro from a racing shop about 30 miles from me. 20 bucks a gallon!!!!!!!!!!!!!
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Has anyone tried this? (http://www.klotzlube.com/proddetail.asp?prod=KL-600_Pint&cat=8)
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Thats cheap for hazmat.
They say that guy in VA has the best nitro. He also is the guy that makes the Nitrodine.
Talk to Brent Combs. ;)
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Holy expensive shipping! :o http://www.klotzwarehouse.com/index.php?productID=8640 Where do you guys buy yours?