2 stroke oil in a 4stroke engine's fuel

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5
Location
Florida
Hi, I'm new here on the forum. I read a lot of interesting topics on this board, like the one I wanted to know about 'Peroxide in the gasoline', being written well before I ever thought of it, and thus know that some of you probably have more experience with my next question, than myself. For a while now, I've been testing 2 stroke oil in my 4 stroke Honda Rebel. This topic mainly will be about using 2 stroke oil in a 4 stroke engine, but aside from my Honda Rebel, I've only used it in my 1 cylinder, 150cc lawnmower engine. So my experiences are towards these. Rather than talking about the Honda Rebel, I'd like to talk more about experiences with 2 stroke oil in a 4 stroke engine. Perhaps some links to some good articles, some people's experiences with it, etc... The first thing I read about 2 stroke oil in gasoline was, that it kept the gasoline stable for longer. Necessary, because my lawnmower can be sitting in the shack for 1 month or more. When I added just a tiny bit of 2 stroke oil, I noted the increase in RPM in my lawnmower. I became curious, and tested it out on my Honda Rebel. I used deductive reasoning when dosing the oil. A 4 stroke engine needs less oil than a 2 stroke, because it needs to lubricate less parts. How much, is the question.... I started out with dosing 100:1, did some tests, and expanded my research from 75:1 to 300:1 doses, tested, and written down the results. At 100:1 the bike runs butter-smooth. Vibrations are way less, and a small mid-range power boost (it accelerates much better to 9k RPM, as where without the oil, the vibrations would shake the machine too much to go much beyond 7k RPM, and I would shift before getting there. I did some research as to why, and it appears on a 4 stroke, that the top end of the cylinder is the least lubricated, and the cause of an engine's greatest friction loss. Every downward motion, engine oil is sprayed on the cylinder walls, and the piston glides over the layer of oil. On the up motion (compression), a gasoline/air mixture is injected, and the cylinder glides over the layer of pure gasoline, which doesn't really work as well as lubricant. After the "explosion stroke", the cylinder goes upward, without compression, exiting the exhaust gasses. At this point the cylinder does not receive any lubrication. Luckily at this point, the lateral forces on the cylinder walls are very low; as less force is being put on the piston at this stroke. So from 2 out of 4 strokes lubricated (the down strokes), and 1 semi-lubricated with regular fuel, Adding 2 stroke oil to the fuel will make that half lubrication a full lubrication; and at an important part of the stroke as well (the compression part, where lateral forces of the piston on the cylinder walls are stronger). So 3 out of 4 strokes will be lubricated! That's the theory behind it all... And my results are showing me vibration reduction, and performance increase are closely connected. The engine with too much, or too little 2 stroke oil, will either have too low performance, or too high vibrations. High vibrations leading to lower performance as well. So, there is a sweet spot! On the Honda Rebel, and that's conveniently at a dose of about 128:1. Convenient for the people using the US imperial system... It means that for every gallon of fuel, they'd need to add 1oz of 2 stroke oil. So the measuring works out easy! That's a good starting point for any 4 stroke engine; but depending on engine to engine you might have better results dosing slightly higher or lower. On a 2 stroke, generally doses of 50:1 are most optimal (sometimes 32:1); so I deducted that on a 4 stroke, a dose of higher than 50:1 is necessary, since the fuel doesn't need to lubricate anything below the pistons. I also noted that plug fouling could happen on 2 strokes, with doses below 32:1; but at 50:1 doses, there was no real plug fouling seen, and the exhaust looked clear. On my Honda Rebel, the following observations where true (it is a carbureted bike): 75:1 : Super smooth engine (vibration wise), lowered performance. 100:1 : Great performance, smooth engine. 125:1 : about the right balance of smooth riding, and good performance. 150:1 : Great performance at the cost of minor added vibrations. 200:1 : Almost normal performance (without additives), but still noticeable less vibrations. 300:1 : The effect of the 2 stroke oil is no longer noticeable in the fuel; both performance nor vibration wise. The performance increased from between 100:1 to 200:1, compared to regular fuel. I don't know if it has to do with better sealing valves or pistons, or just better for my bike because of unique carb setup (and Air/fuel ratio is modified). It may be very engine specific too.. Some may benefit, while others don't... But here's my theory on adding 2 stroke oil to the gas: Adding 2 stroke oil to the gas, does not only rev the engine smoother, meaning less vibrations, which results in less heat generation in the cylinder walls on the compression stroke. Less heat results in a cooler running engine. Better sealing of the valves and cylinders, also results in a cooler exhaust resulting in a cooler running engine Oil in gasoline means heavier gas. Heavier gas means slower burns. Slower burns means more performance at lower RPM, and cooler running bike. All this extra low end torque can be converted to a higher gearing, to get a similar performance as before. The lower RPM of higher gears, combined with the increase in performance due to slow burn, results in similar performance, at a lower RPM/higher gear, and conceives better MPG. So far, it seems to me, that oil always was meant to be in gasoline, as I see how nature balances and gives a more efficient running engine applying this method. After the readout I did some math on the fuel prices. Adding 2 oz in my 2Gal fuelup each time, costs me about 8% more on fuel. This is using a cheap 5 quart 2 stroke oil jar, found on Amazon. If using the small bottles (of 6oz each), prices could rise by upto 16%. Instead I take with me a small, 8oz plastic container, and fill it up with 2 stroke oil from the 5 quart oil jar, and put a shot in the tank just about every time I fuel up. This method is the cheapest, and results in 8% increase in fuel cost. MPG results showed me a consistent increase of 5MPG with same gears (I get between 75 - 80 MPG before, and 80-85MPG after), same riding style, over multiple readouts. The 5MPG gained equates to +8% of total MPG; So my average cost is completely offset by the increase in MPG I get per tank, and a cooler running engine, with less vibrations, which could mean a longer lasting engine. Again, only benefits! Financially I pay the same; but I can do more miles per tank, and I have a better, more efficient running engine. All good in theory, but the only thing so far that's been suffering the heavier gears, faster top speed, and more power, is my clutch. I just have to be cautious with the clutch, that it won't slip, but so far, it's a non-issue. I mentioned my findings in some motorcycle forums, but had only negative comments. On the other hand I challenged each individual to apply the same techniques which they didn't want to (or dare to) apply; to see for themselves the benefits of it all. I also heard some negative remarks concerning plug fouling; and I'm all for doing the research when I can! I asked the very simple question, if they had ever seen a 2 stroke engine using a 50:1 ratio of 2 stroke in the fuel, and if that engine had suffered plug fouling? No one did. The ratio used in a 2 stroke is 2,5x more, so the fouling in a 4 stroke should be 2,5x less than in a 2 stroke. Others mentioned smoke, and pollution. While I can not defend pollution (not enough research material to record the emissions), I can say that smoke is a non issue for a 2 stroke engine running a 32:1 ratio of oil in the gas, or higher. The 2 stroke weed eaters blowing white and blue smoke and suffering plug fouling, often times run at ratios well below the 32:1 ratio (or having more than 1 measure of oil per 32 measures of fuel), oftentimes done by people who don't know what they're doing; or accidentally double oiled the gas... Another benefit is the valves. Not only do they close better (meaning less exhaust leakage, and lower engine temps), they also benefit from lower RPM (when taller gears are installed). Lower RPM means lower wear on the valves. The valves don't suffer from the increase in engine load. Some people mentioned engine lugging. While I firmly believe engine lugging is a non issue on this bike (even with 50% overgearing), some people still hold on that engine lugging could occur. My response was, that engine lugging is more connected to riding style, than gearing. Any sane person will not open the throttle in 5th gear, when going 15MPH. The same is true for any gearing, both stock gearing and modified gearing. Once the Rebel hits 2,5k RPM, that engine does not lug. However, I have noticed with a 50% increase in gearing over the stock gearing (from 9k rpm top speed, to 6k RPM top speed), that the engine does use more fuel going WOT, than with less heavy gears. Increased fuel consumption could be an indication of lugging. So they might be right there. Out of safety, I only go WOT, in 4th gear (second to last gear) on my Rebel, running at 7,5K RPM, where the engine has increased MPG over in 5th gear doing 6k RPM. On the low RPM side, engine lugging happens below 2,5k RPM, and I never go there. It's easy to shift down when necessary. Last benefit is the fuel itself. With 2 stroke added, the gasoline will not only last longer (evaporates slightly slower), but it also will be heavier, meaning octane rating might rise. In the past, gasoline companies used lead to increase octane levels, but 2 stroke oil also helps a bit. You're not going to make your 87 oct gasoline into a successful premium blend, but I do believe that 87oct gas could get upto 88 or 89 oct weight, causing less pinging on high compression vehicles, or vehicles running in high heat weather. I see only benefits in adding 2 stroke oil, with the only con being exhaust emissions. I would like to hear more pro's/cons of using this method. And people's experiences with it..
 
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Messages
12,973
Location
North Carolina
I use a bit of tcw 3 in my outdoor power equipment for winter storage and when i had a motorcycle in that as well. I use stabil and 1 ounce of tcw3 in 5 gallons. I think it helps keep the carbs from gummining up over the winter.
 
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4,825
Location
Taiwan
2 stroke is generally believed to be an effective upper-cylinder lubricant, since that's what it does in a 2-stroke engine. I've wondered whether it might also have some fuel stabilization effect, an issue here because petrol goes "off" quite quickly in the heat, leading to clogged carbs. My understanding is that 2-stroke will generally lower the octane rating, not raise it, but at 1:100 ratios the effect will be negligible. I don't see how it could lead to clutch slippage, partly because it shouldn't get anywhere near the clutch, partly because on most motorcycles the clutch is in an oil bath anyway. I'm surprised you can hear or feel the difference, and frankly I'm not sure I believe it, but I might give it a try. Havn't so far because I'm probably pretty marginal for passing emmissions as it is.
 
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628
Location
DuQuoin, Illinois
4 or 5 years use here. 1 ounce to 5 gallons of TC-W3 ashless ay 1 ounce to 5 gallons of gas. Quicker starting and seems to be smoother running motors. Noticeable reduction in fuel use in mower with Briggs 19.5 HP motor. 87 & 96 Dodge trucks with 318 motors, fuel mileage so close as to be negligible. Has been discussed here several times.
 
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Messages
14,505
Location
Top of Virginia
OP, thanks for posting. I agree with you on using 2-stroke fuel as an additive to straight gasoline for 4-stroke engines, although I have only done it with my small engines. I started doing this after repairing a Honda GCV160 for a co-worker that had a stuck intake valve. He's not a "car guy" or an "engine guy", never uses any fuel stabilizer (despite by constant leaning on him to do so), and gives his equipment less than the bare minimum of maintenance. It finally caught him, and his intake valve stuck open on him. I did some reading about it, and it seems that this kind of thing can happen if you have poor/old fuel running through the engine and you stop the engine with the intake valve depressed open. It sits for a week or two, poor/old fuel vapor deposits and gums on the open valve, and when you spin the engine over a few weeks later, the valve just hangs open, despite the rocker arm not pushing it open. I unstuck the valve and lectured him, again, on using good fuel with stabilizer. But, in my reading, I found a lot of people who recommended using some 2-stroke oil in the straight gas. Not necessarily as a stabilizer only, but as a lubricant to keep things like this from happening to infrequently used engines like mower engines. I started spiking my gas with fuel stabilizer (at the recommended dosing) and also 2-stroke oil at 100:1 fuel:oil ratio. I can't say that I noticed a significant difference, but the engines do run at least as smooth as before, and I don't have any intake valve sticking. To be fair, though, I never had this issue prior, either. In short, I feel that it can't hurt, and can only help. Especially on small and relatively crude engines like these that have few-to-no emission controls to worry about and that sit for weeks on end.
 
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35,631
Location
NY
Thanks for posting, it appears you've spent a lot of time investigating. Typically the dose for TC-W3 in a 4 stroke engine is 1 ounce/5 gallons of fuel. How they arrived at that amount is beyond me. I had the opportunity this past fall to work on a 2 stroke outboard engine with my brother. He bought the engine for parts and upon tear down we decided it was worth a rebuild. The prior owner ran what he called a heavy does of TCW3. 32:1 vs. 50:1 which the engine called for. What we noticed was the rings were really gummed up. We've seen this before in engines that were heavily dosed with TC-W3. I'm wondering if too much in a 4 stroke engine will cause the rings to gum up as well? Have you ever done a tear down and inspection of the rings with an engine using the amount of TC-W3 you're using? Thanks and welcome to Bitog.
 
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35,631
Location
NY
Originally Posted By: HerrStig
Don't know if there is much difference between 2 cycle oil and Lucas "gas treatment".
IIRC it is very difficult to overdose an engine on Lucas gas treatment, but with TC-W3 you can very easily foul plugs if you use too much. IMO they are very different products.
 
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5,047
Location
Pittsburgh,PA U.S.A.
The OP went into great detail about different ratios of 2 stroke oil to gasoline, but forgot to mention the brand or type of 2 stroke oil he is using. What is the brand and or type of 2 stroke oil used in this application?
 
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1,295
Location
Brittany / Canada
I always wanted to try 2troke oil in my cars, but never dared to use it in gasoline engines. I've used some in my diesel with great success, less noise, less smoke, smoother running. Since I'm a bit concerned with long term effects, I am now using special diesel additive with similar benefits, but I still have some 2 stoke oil left, and a Barchetta which will be the perfect lab rat. Still concerned about cat poisonning, injectors fooling, O2 sensor poisonning...
 

MeeLee

Thread starter
Messages
5
Location
Florida
Thank you for the replies. To answer a few questions, I hope I don't accidentally skip one, "My understanding is that 2-stroke will generally lower the octane rating, not raise it," Interesting thought, My current theory on it, is that 2 stroke oil is thicker, and heavier than gasoline. Just like Diesel fuel, it should increase octane in gasoline, not decrease it; but I'll research up on that! The clutch slippage is not an issue of the oil getting there, but of the changed gearing (in my case I increased gearing by 50% over stock, though I felt that stock gearing was 25% under-geared). The combination of a tiny bit more engine torque, and heavier gears making the engine run at it's peak power band at top speed, rather than at the redline (where HP is lower, due to increased frictions like cylinder, bearings, and oil pump frictions), may cause clutch slip; especially when using a wet clutch, and using thinner engine oils (like 5W30 over 10W40), to achieve better economy. Less of an issue on dry clutches, but could still happen. The vibrations on a Rebel are easily noticed, as the engine is a 360 degree PTWIN engine. It vibrates (buzzes) a LOT! With changed gearing and 2 stroke oil, it actually vibrates very little, almost like most other bikes out there. "Typically the dose for TC-W3 in a 4 stroke engine is 1 ounce/5 gallons of fuel. How they arrived at that amount is beyond me. " I'm not sure if TC-3W is the same as two stroke oil for 2 stroke engines. Not every oil works in the same manner. But I've noticed that any dose above 300:1 doesn't make any difference performance wise, nor vibration wise on my engine. It obviously does make a difference, but too little to notice. Perhaps in the long term... 300:1 is so low, that different blends of gasoline may make a bigger impact. The 2 stroke oil I used is Pennzoil 550022757 Premium Plus. Just about the cheapest 2 stroke oil for sale online. It seems to do about the same to performance and vibrations, as some generic oil based 'octane boosters' sold in Autozone; only it is way cheaper. At first I was concerned because the 2 stroke oil has blue colored additives in it, that they would harm the engine, but so far (after 6k+ miles) the plugs look the way they should look (slightly tanned). The oil is also engineered for "clean burn"; so it leaves very little pollution, and carbon deposits. My main reason for using this type of oil is mostly economical, not to have max performance or engine life; as I could find additives ten times the price that could perform better than 2 stroke oil (and may be more environmental conscious as well). But like me, many out here care more about saving the $$$ in their pockets, than saving the $$$ out in someone else's. So far I've not noticed any gumming or carbon deposit in the cylinder. But then again, my engine often runs at 7-8k rpm, so even if it was formed, it won't stay there long. If there was any, or gum, or anything else, it would take as little as 1/8th of a "Seafoam" can in my 2 GAL tank, to clean out the crud. Seafoam doesn't work well as an engine lubricant, and lowers performance of the gasoline it is diluted in; but it helps clean out the crud. Never inject seafoam directly in the carburetor. Dilute it in the fuel, for less aggressive, longer treatment. 32:1 was the old standard for 2 stroke engines. Modern engines have finer tolerances, and should have a 50:1 or even up to 100:1 ratios. Since you're talking about an outboard motor, the gum could be from about anything; From not closing the fuel valve, and have the fuel leak into the cylinders and evaporate; to sucking up some sea or lake water with pollutants that burn and clog the cylinder walls. So far, my research has been limited to engines with carburetors. I don't know the effects yet on the oxygen exhaust sensors of Fuel injection systems. I thought of sharing my data, and was hoping that perhaps some people have had positive effects on their 2008+, fuel injected cars (since I only have one, I don't want to try it out on that one).
 
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35,631
Location
NY
Thanks for the replies, very interesting. It seems you did your homework! Keep us posted on your findings.
 
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4,825
Location
Taiwan
Originally Posted By: MeeLee
Thank you for the replies. To answer a few questions, I hope I don't accidentally skip one, "My understanding is that 2-stroke will generally lower the octane rating, not raise it," Interesting thought, My current theory on it, is that 2 stroke oil is thicker, and heavier than gasoline. Just like Diesel fuel, it should increase octane in gasoline, not decrease it;
Diesel is low octane. Thread on that recently where the OP was wondering if he could extend his range with added diesel if he couldn't get petrol crossing the Sahara. http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3950193/1 I'd rather doubt 2-stroke has much effect on valve sealing either, though I don't know this for a fact.
 

MeeLee

Thread starter
Messages
5
Location
Florida
Originally Posted By: Ducked
Originally Posted By: MeeLee
Thank you for the replies. To answer a few questions, I hope I don't accidentally skip one, "My understanding is that 2-stroke will generally lower the octane rating, not raise it," Interesting thought, My current theory on it, is that 2 stroke oil is thicker, and heavier than gasoline. Just like Diesel fuel, it should increase octane in gasoline, not decrease it;
Diesel is low octane. Thread on that recently where the OP was wondering if he could extend his range with added diesel if he couldn't get petrol crossing the Sahara. http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3950193/1 I'd rather doubt 2-stroke has much effect on valve sealing either, though I don't know this for a fact.
Hi, and thank you for the response. Your questions challenge me to read up on topics I haven't studied closely yet, but so far I've found that in diesel, Octane rating isn't what causes slow burn, but 'cetane'. So in a way we both are correct, although I was wrong to assume it was Octane that was the cause of the slow burning fuel. That's why Diesel can have low octane ratings, yet burn a lot slower than gasoline. All I know is from playing with fire when I was a youngster, that igniting Diesel is a lot harder than igniting regular fuel; and less explosive when it does. Adding oil to the fuel makes the fuel more 'diesel-like'. As far as what the fuel oil mixture does to the valves, according to what I've read, the hottest part in the cylinder are the valves and their seating. When an air/fuel/oil mixture is injected in the cylinder, the hot parts will evaporate the fuel much faster than the oil. One person words it as follows "Oil is attracted by the hotter parts in the cylinder, like the cylinder rings, valve and valve seating, etc..." I would say it's not as much as that the oil is attracted to the hotter parts, it's that the fuel parts evaporate faster than the oil, so the mixture will have more oil remaining on hotter parts. This results in a small layer of oil on the valves, when they close, they don't slam on the engine block (valve seating), but are a bit damped by the layer of oil between the valves, which cause for extra sealing. This sealing is very noticeable by reducing ticking noises.
 
Originally Posted By: MeeLee
Hi, and thank you for the response. Your questions challenge me to read up on topics I haven't studied closely yet, but so far I've found that in diesel, Octane rating isn't what causes slow burn, but 'cetane'. So in a way we both are correct, although I was wrong to assume it was Octane that was the cause of the slow burning fuel. That's why Diesel can have low octane ratings, yet burn a lot slower than gasoline. All I know is from playing with fire when I was a youngster, that igniting Diesel is a lot harder than igniting regular fuel; and less explosive when it does.
Not sure if you are trolling or not here... Cetane if sort of the opposite of octane. A higher Cetane fuel will ignite faster than a lower Cetane fuel. In a gasoline engine the fuel is in the cylinder and mixed with air before it's supposed to ignite. If ignites too soon (before the sparkplug fires) or too easily (before the flame front from the spark can reach it) damage can be done to the engine. This is why a gasoline engine is called a spark ignition engine. In a diesel engine fuel is injected directly into the cylinder at the time it's supposed to ignite. As the spray of fuel enters the cylinder the leading edge of the spray comes in contact with the air in the cylinder and ignites due to the high temperature and pressure present. Any delay in ignition will will cause a loss of power among other issues. This is why a Diesel is called a compression ignition engine. Basically the factors that are used to ignite the fuel in a diesel (high pressure and temperature air) are also present in a gasoline engine. In a diesel engine you want the fuel to ignite because of these factors so the fuel needs to be sensitive to them and ignite easily as soon as it meets them. In a gas engine the fuel has to resist igniting from these factors until the sparkplug fires (and even then, resist igniting all at once and instead burn steadily). Neither liquid diesel fuel or liquid gasoline burn, their vapours burn. Gasoline evaporates much more easily than diesel so it's easier to ignite a puddle of it (or at least the vapors above a puddle of it). In an engine both fuels are atomized so conditions are different.
 
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