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The kid karts had the best lap times and mph 40.445sec & 78.685mph. I can’t leave them alone for a second! Were going to have to tear them all down.
The top is 2″-6″ depending on how the laser tracked the base. We will be filling in the edges next week. If you go off now its a 2″-6″ drop in some places. The surface is very smooth and the track seems wider.
We will be open for all karts Sunday. The track is a little slick, we have been doing kart rentals all day with no problems with the track surface.
No problem Doug. You just need to be careful when using the term slip fit. If the crank is out of true it will get tight when the cases are pushed on the alignment pins. I was not sure if Rotax had one side that was a press fit like many enignes and you were polishing the crank to get it to slip. I would hope that Rotax could get a crank closer than .004, even .001 is more than twice my tolerance when truing a crank. I try to get them to .0002-.0003 if it is a good crank.
I will put it in here again, some cranks come from Rotax with a slip fit in the case, some do not.
Slip fitting a crank is clearancing the crankshaft to fit the bearings so it can be installed without force. Aligning the crankshaft is truing the crank. Two different animals.
Question is, coming from the factory, does both sides of the crankshaft of a Rotax engine slide into each bearing without force? What is the factory clearance?
Doug,
This is interesting.
I was more than surprised to find out that there are Rotax service centers that think the rules allow them to polish the crankshaft on a Rotax. I do not buy the story that some engines have a loose fit and some don’t. I am sure some cranks do have a loose fit after they have been worked on by some Rotax service centers. The engines are to be run right out of the box with no modifications, right? Isn’t that the premise of the whole Rotax program? When you replace parts you are not allowed to modify them in any way, right? The bearing surface is ground and if they can’t hold a tenth then they should not be grinding crankshafts. If you read the Rotax engine tech rules on page 1 it clearly states that the engine or any of its ancillaries can not be modified in any way. Polishing the crank shaft is a blueprinting operation in my book. It is removing metal any way you look at it. Polishing the crank will make a difference on how the engine runs. What other modifications are they doing to the engines beyond polishing the crank that they think is legal? Is it ok to polish a Leopard, Vortex, Comer, Motori, etc… crank? I don’t think so. It would be interesting to measure a batch of Rotax cranks to see if they vary that much. Rotax builds thousands of engines a year and I do not believe they can not hold tolerance on a grinding operation. If you base a program on everything being equal then why is there a measurable difference on the most expensive part of the engine that is one of the few parts that are precision and the important surfaces are ground? :bs:
Neither the engine nor any of its ancillaries may be modified in any way. ?Modified? is defined as any change in form, content or function that represents a condition of difference from that originally designed. This is to include the addition and/or omission of parts and/or material from the engine package assembly unless specifically allowed within these rules. The adjustment of elements specifically designed for that purpose shall not be classified as modifications, i.e. carburetor and exhaust adjustment screws.
Rotax racing, fair and equal for everyone? I don’t think so now!
