ThunderTiger
Hardcore RCTalk User
This is some information i "Collected" a while back. Not sure on the merits of it, but it did come from a long time friend who is an RC Nitro guru and an ex-Racer. The information concerns the air filter and the oil used to retard the entry of particles into the air flow and subsequently the engine and was "Collected" when i first started in nitro. I taped the conversation for future refference and promptly mis-placed it !! i found the tape again today after 4 1/2 years (!!!!) whilst looking for something entirely different in my shed
Ain't that always the way ? Anyway, since i am looking at using this info in practice, I'm looking for some opinions on it.
This is a short transcript of the "Taped" conversation, short due to my machine eating the tape !!!
ME: "So, whats this i heard you going off about with regard to air filter oils and air draw characteristics on a nitro engine then ??"
FRIEND: "OH, That. Well, despite the many tuning abilitys of R/C vehicles, there is one aspect of a nitro engined vehicle that is ALWAYS either completely overlooked, or just glossed over completely as if it did not matter. That aspect, is Air filter oils. Different weight oils equate to different air draw ratings through the filter. Lighter oil will give better air draw characteristics and stop larger particles of dust and dirt entering the air channels and subsequently the carburettor, while heavier oils will give a lower air draw characteristic while blocking smaller particles. Also, oils used in winter months should be lighter than you would expect as the cold makes it "Thicker" due to the colder weather.
This is particularly useful information to some people, especially those that run in dusty areas, or those who plan to run "Lid-less" (or "Top Less" or "Body -Less") on sand or other areas that have particularly "Dirty" and particle contaminated air, caused by running a rig or otherwise. It will also allow a person to fine tune an engine due to taking into consideration the issue of air flow.
What many people fail to realise with a nitro engine is that the oil that they use on their air filters will also play a part in the tuning of the engine, just as much as atmospheric and humidity level changes will.
An example of this is using a thick air filter oil on a hot day. Since warmer air particles are less dense (EDITED Form "Denser" as per Lessen & Pill), having to be drawn through a thicker filter oil will add the need for further carb tuning, moreso than would be needed had the correct oil been used in the first place. The effect of this can be less power availability based on how rich the engine needs to be run to compensate for the air filter oil, humidity level of the day, the variables of fuel nitro content and plug timing (based on the glow plug used) and carb needle settings and it can be a minefield of contradictions."
ME: "So how do I do this then ?"
FRIEND: " Well, the best thing to do when tuning an engine using the "Air Flow" principle, is to run on an "Average" day where it is neither hot or cold. The aim is to adjust (tune) the engines carburettor to suit the weather. This is when you can begin to experiment with different weight oils on several air filters of the same brand. The oil that gives the best overall performance is the one to use in those conditions. In hotter weather a lighter should be used and vice versa in colder weather. It's not a "Science", but you may need to do this on several occasions under prefferably mirrored weather conditions to get the best results.
Generally, try to use good quality silicone shock oils between 10wt and 50wt for tuning the air flow on air filters as these are both the lightest and heaviest weights that should be used. Any lighter or heavier and you cause yourself a lot of aggro that you do not need. Your oils should step-up in increments of 10 for "fun Vehicle" (My note "Bashing") Engines and increments of 5 for performance and racing engines."
Sadly, as mentioned earlier in the post the rest of the conversation was garbled and inaudible thanks to my machine chewing the tape up, the POFS !!
Now, could someone tell me if this is good info please ?
Ain't that always the way ? Anyway, since i am looking at using this info in practice, I'm looking for some opinions on it.This is a short transcript of the "Taped" conversation, short due to my machine eating the tape !!!
ME: "So, whats this i heard you going off about with regard to air filter oils and air draw characteristics on a nitro engine then ??"
FRIEND: "OH, That. Well, despite the many tuning abilitys of R/C vehicles, there is one aspect of a nitro engined vehicle that is ALWAYS either completely overlooked, or just glossed over completely as if it did not matter. That aspect, is Air filter oils. Different weight oils equate to different air draw ratings through the filter. Lighter oil will give better air draw characteristics and stop larger particles of dust and dirt entering the air channels and subsequently the carburettor, while heavier oils will give a lower air draw characteristic while blocking smaller particles. Also, oils used in winter months should be lighter than you would expect as the cold makes it "Thicker" due to the colder weather.
This is particularly useful information to some people, especially those that run in dusty areas, or those who plan to run "Lid-less" (or "Top Less" or "Body -Less") on sand or other areas that have particularly "Dirty" and particle contaminated air, caused by running a rig or otherwise. It will also allow a person to fine tune an engine due to taking into consideration the issue of air flow.
What many people fail to realise with a nitro engine is that the oil that they use on their air filters will also play a part in the tuning of the engine, just as much as atmospheric and humidity level changes will.
An example of this is using a thick air filter oil on a hot day. Since warmer air particles are less dense (EDITED Form "Denser" as per Lessen & Pill), having to be drawn through a thicker filter oil will add the need for further carb tuning, moreso than would be needed had the correct oil been used in the first place. The effect of this can be less power availability based on how rich the engine needs to be run to compensate for the air filter oil, humidity level of the day, the variables of fuel nitro content and plug timing (based on the glow plug used) and carb needle settings and it can be a minefield of contradictions."
ME: "So how do I do this then ?"
FRIEND: " Well, the best thing to do when tuning an engine using the "Air Flow" principle, is to run on an "Average" day where it is neither hot or cold. The aim is to adjust (tune) the engines carburettor to suit the weather. This is when you can begin to experiment with different weight oils on several air filters of the same brand. The oil that gives the best overall performance is the one to use in those conditions. In hotter weather a lighter should be used and vice versa in colder weather. It's not a "Science", but you may need to do this on several occasions under prefferably mirrored weather conditions to get the best results.
Generally, try to use good quality silicone shock oils between 10wt and 50wt for tuning the air flow on air filters as these are both the lightest and heaviest weights that should be used. Any lighter or heavier and you cause yourself a lot of aggro that you do not need. Your oils should step-up in increments of 10 for "fun Vehicle" (My note "Bashing") Engines and increments of 5 for performance and racing engines."
Sadly, as mentioned earlier in the post the rest of the conversation was garbled and inaudible thanks to my machine chewing the tape up, the POFS !!
Now, could someone tell me if this is good info please ?
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