I was watching a video of how NHRA dragsters are put together and i found out they put a very tiny amount of graphte in the oil, most likely for better oil characteristics and i was wondering if any f1 (or series for that matter)use graphite
all of that graphite is just going to clog the oil filter. What show were you watching. Its about as bad as that old slik 50 crap it was full of graphite. just clogged the oil filters up.
i've never herd of it in engine oil but i can see why they would use it now that you've said. if you ever think of a set of bushing's in electric motors graphite is used as it has very low friction and wear propertys. But surly this means that the oil could carry a small electrical current with it being an excelent conductor??
Usually you can sometimes find lubricating oil which contains graphite, like WD40 i believe, but as a suspension rather than a solution. Graphite is insoluble in common solvents. This is because of its giant molecular layer structure, with extremely high intermolecular forces between the layers. Dissolving would involve disrupting these forces and replacing them with solvent-solute forces of comparable strength....and you dont want solvent in oil so you have to put up with larger molecules of graphite, hense clogged filters.
Dragsters use metanol so i assume the heat of combustion burns the graphite away. And i (maybe wrong) the particulate filters on dragsters are no where near as fine as a ordinary car due to the huge flow demands
Why would you want to use graphite in oil? The way I understand engine lubrication, it doesn't help at all.
Isn't film lubrication based on, well, films? Why would you want to put pieces of carbon inside the liquid film, which is very thin?
Does it helps with starting the engine, when the film doesn't exist yet and (as I've heard) most of the wear of the engine happens? Is that the basis for using molybdenum bisulfide and graphite oils I've seen around?
And, does sulfur in molybdenum oils helps at all when an engine is made basically of iron? I somehow feel it is wrong to put sulfur inside...
I can understand you using it in things where oil evaporates and leaves behind the graphite, for dry friction improvement, but in a pump driven lubrication system I don't get it, unless it helps when the film hasn't developed by lack of pressure.
I would love to see some figures, in a dynamometer, for those oils claiming they improve lubrication and/or some figures about bush wear during startups with or without these oils.
I would say that car manufacturers must have those figures and, even when they try to show you better numbers for engine life in their promotions, they don't use these oils. What's the reason? I can form my own opinion after reading about the figures, thanks in advance.
to be specific, i think they put it in the rearend (pumpkin, 3rd member, whatever you want to call it) and i don't think they use a filter for that oil, and from that why not transmission oil?
Shrek wrote:to be specific, i think they put it in the rearend (pumpkin, 3rd member, whatever you want to call it) and i don't think they use a filter for that oil, and from that why not transmission oil?
I guess because dragsters only run for a few minutes, they can get away with it. But all the same a small amount of graphite might be able to go through the filter if the particles are small enough.
Shrek wrote:to be specific, i think they put it in the rearend (pumpkin, 3rd member, whatever you want to call it) and i don't think they use a filter for that oil, and from that why not transmission oil?
I guess because dragsters only run for a few minutes, they can get away with it. But all the same a small amount of graphite might be able to go through the filter if the particles are small enough.
Top fuel drag teams tend to do things for reasons they don't fully understand. Adding graphite to the gear oil won't fix the problems top fuel rear end gears have.
Top fuel cars use a hypoid gearset in the rear end. And these hypoid gears are usually much more highly loaded than they really should be. Hypoid gear tooth contacts tend to have very high hertzian pressures, and when combined with the excessive torque loads seen in top fuel cars, the tooth contacts occur mostly under boundary conditions. Thus an EP (extreme pressure) oil additive is necessary to limit scuffing.
Graphite can serve as an EP gear oil additive, but it would need to be very finely dispersed and suspended in the oil, which is difficult to do. Besides, there are many other types of gear oil EP additives that are much more effective than graphite particles.
If the money was available, the proper way to address the problem would be to design a gearset capable of handling the loads. But manufacturing hypoid gearsets is beyond the budgets of most top fuel or funny car drag teams.
riff_raff
"Q: How do you make a small fortune in racing?
A: Start with a large one!"
Ahem...When was the last time you saw a top fueler blow his differential up?
Perhaps you're thinking of the lower classes where the 9 inch Ford is the most common. guys that use limited slip diffs use a modifier that may or may not contain graphite to prevent chatter.
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss
strad wrote:Ahem...When was the last time you saw a top fueler blow his differential up?
Perhaps you're thinking of the lower classes where the 9 inch Ford is the most common. guys that use limited slip diffs use a modifier that may or may not contain graphite to prevent chatter.
4000 hp will blow up every thing from the blower to the rear end.
that's why they have scatter shields on every thing including the rear end.
one"good" run will destroy the engine, the pistons will look like a cutting torch went cruising through both banks but thats what it takes to win.
I repeat..when was the last time you saw a Funny Car or Top Fueler blow up it's differential?
You haven't! You just don't blow up a Chrisman differential.
Second,,THEY USE A SLIPPER CLUTCH!!!! Not all that horsepower is unleashed and doesn't hit the rearend gear with all that horsepower all at once. A good running Pro Stock or even a Competition Class car would strike the rear end harder.
I asked one friend about the graphite and he hadn't heard of them doing that. But there are others I can ask and I will and I'll get baack on that.
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss
I believe the term is staged centrifugal. they must be putting scatter shields on the differential to add weight to the car's rear to get better traction.
in a good run the car engine will come back intact. When a crank or sleeve goes, usually tfhere is a lot of oil and poop all over the track. then the halon system puts out an impressive fire while the car is boucing of the guard rail at 250+ mph
