converting 32:1 to 50:1

Status
Not open for further replies.
Joined
Jan 13, 2016
Messages
4
Location
USA
My leaf blower died just after I filled up my gallon container with new gas and oil.
The old blower used a 32:1 ratio.
My new blower uses a 50:1 ratio. Rather than throwing out the good gas/oil mixture, I would like to figure out how much additional gas I need to add to bring the 32:1 to 50:1?
As a side note, my string trimmer uses 40:1. Would it be OK to use my gallon of 32:1 in the string trimmer instead, or would it cause the string trimmer to smoke too much and possibly cause carbon build up or other unwanted issues?
BD
 
As tom indicated, you would need to add a bit more than 1/2 gallon (0.5625) of gasoline to your existing mix in order to bring it to 50:1.
 
Originally Posted By: tom slick
Multiply the amount of 32:1 by 1.5 and you'll be at 48:1 which is close enough and easy math.


If he adds a half gallon to the mix then he will be at 48:1 like you said. Show your work:

128 ounces plus 64 more makes 192/4 (ounces of oil in current 32:1 mix) = 48:1.

Perfect!
 
I'd stick with 32 to 1. As it provides better wear protection. The leaner oil ratio's, while they provide adequate wear protection under most conditions, engines do experience additional wear as ratio's go leaner than 32 to 1.

As a young man, I worked for a outboard race engine development team. One thing we tested was the affect of oil ratio on engine output. More oil makes more HP, all the way to 8 to 1. We also determined that 32 to 1 was the ratio that provided the highest wear protection, more oil did not help. BUT, Leaner ratio's resulted in more wear, with 100 to 1 showing significant piston skirt and ring wear.

One thing to keep in mind is that the worst wear is often over/above the exhaust port. Both rings and cylinder wear rapidly here with lean ratio's. So the rest of the engine can look perfect and still have low compression due to wear related to localized insufficient lubrication.

We had various engine models, all exhibited the same issues. The only exception was very high HP Kart engines. Those required more oil than 32 to 1 for adequate protection.
 
Last edited:
I agree with Cujet, he knows his 2-stokes. Only exception would be a recreational use outboard can run 50:1 as they are not really stressed even at full throttle .
 
Thanks to all that replied. I appreciate it.
I have a question about what Cujet stated. If I can use a richer ratio of oil (say 32:1 or 40:1) instead of the manufactures stated engine requirements of 50:1, and since my equipment is only for my home use and not for commercial use, do you think this richer ratio could:
1. void the warranty?
2. cause the engine to smoke more?
3. cause any harmful long term carbon or other buildup in the engine?

Thanks again for all the great advice.
BD
 
Originally Posted By: BigDawg1
Thanks to all that replied. I appreciate it.
I have a question about what Cujet stated. If I can use a richer ratio of oil (say 32:1 or 40:1) instead of the manufactures stated engine requirements of 50:1, and since my equipment is only for my home use and not for commercial use, do you think this richer ratio could:
1. void the warranty?
2. cause the engine to smoke more?
3. cause any harmful long term carbon or other buildup in the engine?

Thanks again for all the great advice.
BD


IF you will be using modern two stroke oils then you have nothing to fear about....

API TC....JASO FC/FD and you are GTG
wink.gif
 
1) Void the warranty? Nobody is going to suspect a different, more protective oil ratio. But if you volunteer any information that differs from the manual, any information at all, some manufacturers will void your warranty.

2) There is no question that more oil will result in slightly more odor and more smoke. Most new equipment is equipped with exhaust catalysts. These do a wonderful job eliminating exhaust smoke/odor once warmed up. But upon startup, there will be slightly more. I run my Stihl BG86's at 32 to 1, (oil MX2t) , and I don't see any smoke what so ever. And only a hint of 2 stroke odor upon startup.

3) More oil often results in less carbon. Especially if a quality EGD oil is used. Our testing with 16 to 1 ratios resulted in near zero carbon buildup.
 
Last edited:
Originally Posted By: BigDawg1
Thanks to all that replied. I appreciate it.
I have a question about what Cujet stated. If I can use a richer ratio of oil (say 32:1 or 40:1) instead of the manufactures stated engine requirements of 50:1, and since my equipment is only for my home use and not for commercial use, do you think this richer ratio could:
1. void the warranty?
2. cause the engine to smoke more?
3. cause any harmful long term carbon or other buildup in the engine?

Thanks again for all the great advice.
BD


1. It won't help your case if you were to make a claim.


2. Yes, it would smoke more, remember whatever oil goes in the fuel is meant to
burn in the combustion chamber. If more oil is present then it will smoke
more, leave more carbon and what can't burn will blow out the exhaust into the
muffler.

3. Yes, going from 50:1 to 32:1 or 40:1 will cause the carbon to buildup sooner
(see 2 above) and your engine will not have less wear.
 
i have a 20 year old sthil blower that had hard commercial use. i noticed some power loss a few years ago and switched to 32.1 mix and power is back.
 
Originally Posted By: Mike72


2. Yes, it would smoke more, remember whatever oil goes in the fuel is meant to
burn in the combustion chamber. If more oil is present then it will smoke
more, leave more carbon and what can't burn will blow out the exhaust into the
muffler.

3. Yes, going from 50:1 to 32:1 or 40:1 will cause the carbon to buildup sooner
(see 2 above) and your engine will not have less wear


Carbon buildup has quite a bit to do with oil choice. Most true EG-D oils are very resistant to carbon buildup.

But, more oil does not necessarily mean more carbon. It really depends on the oil. For example, in RC engine testing, the most carbon free engines had a very rich oil ratio of either Pennzoil 2 stroke air cooled oil, Pennzoil syn TCW-III (leaves little carbon but plugs exhausts) or BelRay H1R.

And again, leaner oil ratio's resulted in more piston scuffing.

During outboard race engine development, we found that TCW-III oils at 16 to 1 produced zero carbon in the engine. Same went for our air and water cooled test engines. (kart engines)

Which brings another point to mind. Pennzoil's air cooled 2 stroke oil has consistently performed well in testing. Often far better than much more expensive oils.

http://www.wdarc.org/articles_files/2 stroke Oil Test.pdf

http://www.ultralightnews.com/features/oiltest.htm

http://www.ultralightnews.com/features/oilworks.htm
 
Last edited:
Cujet:
I read with interest your information but wonder if the testing and test results on high performance RC engines outboard racing engines or aircraft engines would translate to 2 stroke lawn and garden variety engines.
Given the difference in their functions and probable stress and heat build up, I wonder if these test would be valid for consumer 2 stroke engine maintenance?
Any clarification is greatly appreciated.
BD
 
I have a 15 year old Echo blower that's been run on Castrol TT-S for it's entire life. 32 to 1. The oil used is an FC oil, quite similar to EG-D oils of today. It's used for cleaning out our aircraft hangar.

I may take it apart to take pics. The ign failed, and it's not worth fixing.

In any case, the compression is superb and a look inside the engine shows no significant carbon.

Yes, OPE exhibits the same carbon buildup and wear related issues as other 2 stroke engines. In fact, the RC engine in the above test, and the blower engine are under much the same loads and RPM.
 
Originally Posted By: super20dan
echo has a lifetime warrenty on ing coil. they will replace it for the cost of labor only


Really? I'll check it out, thanks! It may live again!
 
I would not worry about a couple of gallons of that. 3% is ok, 2% is also totally ok. I would run that fuel as is and switch to a high quality oil (ISO EGD) at 2% after that. You will have good sealing and good lubrication in both cases unless you run some old 10W30 4T oil that cakes the engine in 5 minutes.
 
Status
Not open for further replies.
Back
Top