Engines in our tractors and octane numbers

[Jparkes43 329]

Hello. 

 

So this got me wondering the other day. 

 

The small air-cooled engines in our tractors have a reasonable amount of compression and running cool etc is a important factor. 

 

Ive always used normal fuel for the engined in my tractor but got me wondering should we use the higher octane number fuesl for the engine. will it be better for it? i also looked at octane additives and additives that turn the fuel into effectively 4 star. is this a good idea for our tractor engines? especially ones with higher compression. I have both in my garage so can do some testing i suppose.

 

Also when using better fuels i assume the ethanol problems are less as well?? also cleaner running, and any other factors that will be occurred with this topic

 

James

Edited May 10, 2016 by Jparkes43

[roadapples 6,981]

I always use high test. I`m told they run cooler...

[Jparkes43 329]

ah ok well i thought it was true anyway especially for air cooled engines. Would be good to see a lot of opinions on this as well, could be a interesting topic.

 

Anything on the lead 4 star substitute? 

 

I might put some in, drain my tank and fill it, with additive, see what happens.

 

Also another question if you use higher octane fuel and put additive in, you will make a even higher grade???

 

James

[Achto 26,554]

I will only run premium, (or recreational gas) in my small engines. Mainly to avoid ethanol.

 As far as octane differences, I believe on a stock engine you would not notice much difference. Not from the drivers seat anyway. With instrumentation connected you might see some change in performance / temps. Low octane fuel will have a noticeable effect a high performance engine, but the effects of high octane fuel on a stock engine are not noticed as much. Adding too high of octane will eventually decrease the performance of a stock engine, there will come a point where you will not have enough compression to burn the fuel efficiently.

My opinion,"Keep small engines and ethanol away from each other" & "The only additive in my gas is Sea Foam"

[Jparkes43 329]

Ah ok thanks. i think over here in the uk its hard to get ethanol free fuels unfortunately. 

 

Sea foam is a good idea to keep everything clean.

 

Ok thanks i didn't think a driving perspective of the octane would be noticeable but meaning its running better may be better for it anyway. But i understand you can have too much as well. 

I may run it in my GX200 clone because that is tuned with higher compression and advanced ignition timing. 

 

Thanks

 

James

Edited May 10, 2016 by Jparkes43

[lynnmor 6,777]

Higher octane fuels usually have the same amount of ethanol as regular.  Ethanol does increase octane so some premium fuels may have even more of this destructive additive. 

[Jparkes43 329]

interesting on the first part!

 

And really???!!! wow thats crazy! 

 

James

[DougC 2,641]

Here in Iowa I still have easy access to regular unleaded gasoline with no alcohol. It is 87 octane  and I get it at my neighborhood gas station. I have never used high octane fuels in my small engines so I am also interested in this topic and reading all the responses. That being said I have never had any carb  or engine problems with my 95 520H I've owned and been using year round since 1997. Perhaps I have just been lucky.   

[Jparkes43 329]

Oh your really lucky! we have quite high ethanol content over here which is a huge pain! so thats really good! I have heard using some aviation fuel or part aviation fuel (which is available nearby) works??? 

Oh ok well this will be interesting i would like to see some results from this. Thats great!! maybe but keep wishing for that good luck. i haven't and don't wish on any as they can be a real pain.

 

James

I can send you a picture of the additives i have tomorrow. 

 

James

[boomers_influence 106]

club

our small engines on average have only a 7 to 1 compression ratio.

back in the day we used PREMIUM fuel for over 10 to 1 compression engines

the high octane fuel by it self is a waste of money for our LOW compression engines.

the higher the octane of the fuel the sooner the candle must be lit.

in other words the timing must be WAY advanced for proper combustion.

because the fuel burns slower.

back in the day i was a tech inspector for 2 different garden tractor pulling clubs.

i could SMELL the AV gas in some of the off lawn STOCK tractor engines,

but i never said anything because their CHEATING was actually hurting their performance.

thank you. boomer ( the used onan engine parts guy, also NOS and new )

[Achto 26,554]

Here in Wisconsin if we want no ethanol gas we have to buy premium or recreational gas. These are usually marked as no ethanol at the pump.

[953 nut 51,680]

, this wont be much help to James @Jparkes43, but here in the states a good way to find non-ethanol fuel is an internet site; buyrealgas.com.

[Jparkes43 329]

Thanks thats really informative i appreciate it!! Its all making sense but its also seems to be a lot of different opinions. i see every side of the arguments however. 

 

Oh wow i wish we had such things but nope! as far as i know they want to up ours from the average of 15% (i think i'm right saying) causing many problems for classic car owners and us alike. There are certain areas and brands that have less ethanol but these are not definitive.

 

no worries 953! 

 

James

[KC9KAS 4,741]

2 hours ago, DougC said:

Here in Iowa I still have easy access to regular unleaded gasoline with no alcohol. It is 87 octane  and I get it at my neighborhood gas station.  That being said I have never had any carb  or engine problems with my 95 520H I've owned and been using year round since 1997.

 That being said I have never had any carb  or engine problems with my 95 520H .

 

Well, with no alcohol that explains the reason for not having problems! 

[WHnoob 21]

My local ethanol-free station sells 87, 89, and 91 octane.  My chainsaw specifies 89, but I just buy 91 for all my outdoor equipment because any 87 left in the hose would reduce the number when filling small cans.  That and I put the first gallon or two in my car to flush out the pump's plumbing