Speed the Final Frontier

(Bill Holt) #1

What is the most outrageous thing you have heard about to get more power from your 2 stroke kart engine?
or even the simplest? I’m not after illegal cheats either, within the rules of what ever class your are talking about, please.
I have been storing up little nuggets of wisdom, gleaned from drunk engine builders at karting events which I think should be shared and if a page could be generated of them, well, we budget racers could be pretty competitive.
I am curious because engine building is often seen as a black art that not many people are willing to talk about, and I don’t have the biggest cheque book, or access to dyno equipment to test half the rumors I hear or the weird ideas I have driving back from karting events.
I guess I should also say that trying any of these is at your own risk.

Here are 2 I have heard recently.
When rebuilding an engine, the cylinder barrel should be as close to the crank case as possible, to give low end power. (then have to change head gaskets to get correct squish etc.)
Mini Rok allegedly need a restriction in the fuel line directly before the carburetor, to stop the fuel being forced out of the jet, due to the fuel pump supplying to much fuel to the system.

(Bill Holt) #2

And another I just remembered
On the KA100 - Don’t run the hi-tension spark plug lead up through the spring on the side of the engine.
Reason- There may be voltage leakage through the spring from the lead making less spark.

I saw this one on FB and thought I would ring an engine guy about it. When I asked him he said it would make no difference. A week or so after he put up some photos him doing some testing at his local track, and the hi tension lead wasn’t going through the spring! Make what you will of that!!
And now I haven’t seen a KA with one going through for ages -Zip ties galore though!

(James McMahon) #3

Essentially you are adjusting the port height. Yes lower generally gives more bottom, higher gives more top. Which is going to be faster will depend on the track, gearing and all the other things you can change.

One thing to note of course is that there are often specific port timing regulations for a lot of classes, so be careful to not stray from those. As you mentioned, squish and or cylinder head volume are also regulated and need to be checked.

(31colm) #4

The motor (any, every) should be in line in all planes. Horsepower that the engine uses to drive itself is to be kept at the lowest value. Some older engines come ‘straight’ from the factory and most, but not all, modern engines are already in line. Though check it. Putting effort into a motor that is not already the straightest is a waste of time and money.