Maintenance, oils and filters

Bob Evans

Grumpy Old Admin
Staff member
Track Side:


• Change the oil after every 20-30 laps whether this is a practice run or race.

• Refill with 12-14 oz. of racing oil. No real HP advantage to running less oil.

• Change your air filter prior to the feature race as well as your plug.

• Clean and oil your air filters each week. An un-oiled air filter is useless! A 4 ? X4 filter is all you will ever need. Larger filters will not help as the smaller ones will flow all the air you ever need.

• For peak performance look for a quick rebuild after 6-8 race weekends.(lapping valves,
and new top ring)

• For long crankshaft life, always turn the motor over without the spark plug prior to starting a couple of times to lube everything prior to firing her up.

• Check all carb and header bolts between races. These things just work loose no matter
what.

Rebuilds

When you rebuild you motor these are the parts you will need to replace. Also check your cylinder to insure it has no worn beyond you target cylinder clearance and has not warped out of round requiring a line bore to the next size!

Parts to replace:

• Piston and rings
• Rod
• lifters and springs and retainers
• carb diaphragm
• worn valves(stem area).
• worn valve guides.


Oils and Additives.(Big can of worms)

This is a very controversial subject, but here are my thoughts on karting oils. Many people will swear by whatever they are running and call all others junk. Must be something we Americans have in our blood(my Chevy is better than your Ford) What I choose to use is based upon years of experimenting and having the results of oil analysis of various oils done by labs to see what’s actually in them. Very interesting results on some of the stuff put out there. I have played with all of the major brands of karting oils(FHS, CoolPower, Power Plus, CRAMAC and others) as well as running real veggie and peanut oil from the grocery. Surprisingly, the veggie oils did well, but have too much fat in them that collects in the motors. Peanut oil (I’m from Ga.) also does quite well, but is a bit expensive. Most any good grade of synthetic auto oil will do well in the lighter weights(10-20W) and all of the major brands of Karting oils are very good.

Most karting oils are synthetic based oils verses a straight mineral(petroleum) based oil.(CRAMAC is the exception as they have both) Synthetics come in two flavors. One is a refined mineral oil and the other comes from some type of vegetable base, generally rapseed oil. Most Synthetics that come from the oil companies are mineral based. They are formed from mineral oil and various other materials such as acids or polymers. The advantage to synthetics is that as a rule they have higher flash points and lower viscosity levels that a straight mineral oil. These are no absolutes here, as additive packages in mineral oils can make them perform as well as any synthetic in our application. All oils come as a base stock and then additive packages are added(mixed) to the oil in various quantities to create the desired results. These additives address several areas needed for an oil to perform well. Metal protection(wear), viscosity, anti foam, gelling agents, rust control, detergents, dispergents and so on. What lab analysis has show me is that many of the karting oils contain no additives at all. Just the straight base stock. This fact and their performance leads me to conclude that we change our oils so often and have so little high pressure friction needs(splash oil system, not forced) that a large amount of additives is not needed.

Many people believe synthetics are needed to “mix” with methanol. Well folks, if we’re getting that much methanol in our sumps mixing with our oils, we’ve got some serious blow-by problems with that motor. Stock motors don’t put enough fuel into the motor to wash the cylinder down, only Tillotson carbed motors such as super stock or limiteds. We have run quite a few Super stocks ands limiteds on CRAMAC(petro based) with no ill affects at all and very good wear results. I do prefer the newer CRAMC Mach II which is a fully synthetic oil.

Many people go for the lightest weight oil they can find in the belief that it will reduce drag and increase HP. Well you’d be surprised how little HP there is between 14 oz. of any good 30W oil and the lightest karting oil around. Very little indeed. I have seen one oil analysis of a new oil being produced(mixed) today that is 50% paint thinner. No joke. It’s very thin and keeps the motor clean as a whistle but...... I don’t think I need paint thinner washing the oil from my cylinder walls.


For me, any of the major brands will do quite well and I personally run CRAMAC in my motors and recommend it to my customers as I helped to develop and test the oil. It does have a very good additive package out of the bottle, so don’t add a thing. Nope, I don’t sell it, just get to tear motors down that run it. The new Synthetic CRAMAC Mach2 is an outstanding oil!! The latest CRAMAC petroleum based oil has a new additive that will ELIMINATE carbon buildup which was a problem for many who used this oil originally.

Oil Additives:

Not a big fan of additives for our motors. Most additives are what is know as extreme pressure additives. These are designed to protect metal surfaces when we have no oil present. In our auto oils most often the additive is Zinc.(Check out what the primary ingredient in STP is). ProLong, Dura Lube and the like, are these types of extreme pressure additives. The cute little bearing test you see some makers use to compare their products is very interesting as straight old chorine bleach will do quite well on this test and will out perform a lot of the products! Slick 50 and others use PTFE(Teflon@) as a solid additive. Both Slick 50 and Motor Up have been sued by the Federal government for false or non-reproducible advertising claims. A recent test by Consumer Reports was unable to re-produce the Prolong no oil test, so take it from there, folks. Sort of like the Split Fire plugs that had to change their advertising claims! Wait till you see the insides of a kart motor that had Slick 50 added to it. What a mess. The stuff doesn’t mix at all with our engines temps. All of this stuff MAY work on big motors but on ours....... Oh well you get the idea. Use a good proven oil, work on your motor seal(valves, rings, cylinder) and get that Kart handling to get to the front! Motor wear is as much a product of changing you oil often and using a clean air filter as any snake oil additive!
 
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