Originally Posted by Werks

Hey Tyler,

In a nutshell USP45 is correct in his answer. Were talking about oils again so without going too into depth our fuel is composed of both synthetic and castor oil. Modern day synthetics have great lubrication properties however there is one thing that castor oil is unbeatable in and that is providing what I would call protection in lean conditions. Traditional oils (including synthetics) thin out as temperatures increase (in essence reducing the level of protection that they offer), castor oil actually does the reverse, it thickens or basically it's viscosity increases. A basic way of explaining this (and the numbers on not correct so this is only an attempt to explain it) is for you to think of caster oil being like 15 wt automobile oil under normal use. Temperatures start to increase and it becomes 20 wt, gets hotter and now it's 30 wt. So it's protection is increasing. Caster can also have a much higher flash point (temperature that it starts to combust) than synthetics.

Where this starts to come into play with RC engines is that as an engine starts to run lean, friction starts to build causing temperatures to increase, this increase in temperature then causes the synthetic oils to thin even more which again increases the amount of friction which again increased the amount of heat repeating it's self and on and on, it's basically a vicious circle until eventually the oil is no longer able to maintain film strength (it's ability to provide a protective layer between the piston and sleeve). At this point a hot spot will form from direct metal to metal contact which is often seen is as scoring on the piston and sleeve and most commonly happens on the exhaust port side of the sleeve. Run like this long enough and the engine will eventually lock up completely. Castor comes into play in this type of situation. I've already mentioned that castor thickens the hotter it gets, well what happens is as these hot spots start to form the viscosity of the castor oil will increase in that specific area providing additional protection for a period of time there by possibly saving your engine.

The quantity of castor oil to use in an fuel is a trade off. It has a higher film stength but also results in more parasitic drag inside of the motor (in basic terms). So you actually loose a bit of performance but you gain significantly in protection. What the right percentage that should be used is frankly up to the specific fuel manufacturer to determine through testing, not all caster oils are equal. We are taking a very basic approach to discussing fuels and lubricants (basically we're just scratching the surface) so please note that it can also be highly dependent on the additive package (VI improvers, pour point depresants, detergents etc. etc.) there is a whole slew of possible additives that a company can add to improve and/or alter the performance of their lubricants if they choose to do so and are willing to assume the cost of doing so. Of course when you start doing this you are really moving from the realm of just a traditional fuel blender to a lubricant manufacturing/formulation also.

To surmise though, in my personal opinion it is not advisable to make a strictly synthetic fuel for use in car engines. Airplanes quite often run very high castor percentages in their fuel because their engines are not realy performance oriented meaning, how quickly they spool up and providing the maximum amount of possible hp is not that critical like it is in cars but as USP45 said, you will hardly ever see their engines fail. Taking things a step farther though I will say that in my opinion fuels used for on-road have a different lubricant package requirement than fuels used for off-road purposes for optimum performance. What most of us do now making a single type of fuel for both uses is a compromise, something that if you go through my post you will hear me mention often.

Regards,

Ron Hopkins
Werks Racing

Originally Posted by Gearhead racer

What do you think of guys mixing their own oil packages for their fuel? One of my buddy's wants to do some experimenting with different oils in his traxxas fuel.
Tyler

Originally Posted by pete 26

Very cool thread.Thanks Ron and Steve.Nice to see two different fuel guys talkin' shop without any egos involved.Really appreciate all the info.

Originally Posted by Werks

Pete26 & Gearhead racer, looking back through the thread I noticed that unfortunately the contributions are starting to look a little one sided lol! To date it looks like the only other manufacturers involvement has been limited to Steve's defense of the inclusion of dye in his fuel and that's basically it.

I've given this some thought over the last day or two and I think that at this point I'm going to step out of this thread for a bit. If other manufacturers would like to start actively participating and contributing some of the knowledge that they may or may not have I have no problem popping in periodically with some of my thoughts. The development of a performance fuel is a time consuming endeavor and most most manufacturers are quite hesitant to share their input about this. Part of the reasoning behind this I think is that there is truthfully a general lack of understanding about the products that they are attempting to produce and the 4-5 people in the industry here in the US that I know of that actually do understand it, will not talk about it. I've been watching some of the stuff happening on the other fuel related threads on here and frankly I think it might be in the best interest of my self and my company to distance my self from those involved.

So at this point as mentioned I'm taking a little break from this thread and I'm going to pull down most of my posts on it. I will say that it has been fun talking to you guys and hopefully those that have read this thread over the last couple of days have benefited in some way from the knowledge that I have gleaned through my involvement over the last 8+ years with the Italians in engine development and manufacturing, 2+ years of lubricant & fuel testing in rc model car engines and 5+ plus years of race fuel manufacturing. I'm happy to say that our products have been proven successful at the highest levels of competition as indicated by a small selection of the race results from some of the major events that our engines and fuel have participated in over the last 2 years alone under my signature. Again thank you guys it's been fun, I'll see you at the track!

Best Regards,

Ron Hopkins
Werks Racing
2008 World Champion, FSR-V 3.5cc Boat
2008 Pre-World's Champion, Buggy
2008 RC Pro Series National Champion, Buggy
2008 RC Pro Series National Champion, Truggy
2008 Austrian National Champion, Buggy
2008 Finnish National Champion
2008 Swedish National Champion
2008 Canadian National Champion Truggy
2008 Canadian National Champion Buggy
2008 Taiwan National Champion Buggy
2008 Portuguese National Championship
2008 Nordic X-Ray Challenge TQ & 1st Buggy
2008 Nordic X-Ray Challenge TQ, 1st & 2nd Truggy
2008 Neo Buggy Race UK pole position & 3rd
2008 Novarossi Memorial Race, 2nd
2007 ROAR US National Champion 1/8th On-Road
2007 ROAR US National Champion Truggy
2007 Canadian National Champion Buggy
2007 Finnish National Champion
2007 Portuguese National Champion,
2007 Nordic Champion
2007 Korean National Vice-Champion