hey rick,

I can see deboring being difficult on a two stroke because deboring will throw your port timing off but with the four stroke if the valve clearance and combustion chamber measurement are favorable it could work. I was thinking of turning the f-4 into an automatic but its substantially heavier and bigger than these other engines I want to run and it has its own set of problems associated with it. Running one of these engines allows our car to be shorter, lighter and drop the centre of mass. And I'm getting kind of sick of Seeing F4's and I really want to do something original with this. Finish off my undergrad with a great final project. I have 2 years to make a CVT work and I plan on utilizing it. If the FST engine doesn't work out (if polaris gets me the critical dimensions I need) then i'll be thinking very heavily of a sportsman 600 engine with a TEC3(what we run on all our cars) under boost. I'm also looking at polaris because they sponsor SAE events, I know a couple people there and I want to work there after my undergrad is completed.

By the way, Im pretty sure it was you that helped me with porting my warrior way back in the day (2002ish) you were quite a help [img]i/expressions/face-icon-small-happy.gif[/img]

 

I really think deboring the amount you want is just not an option . If you must use that engine changing the stroke is only way . (Unless you can make a new head)

Where does an F-4 drive it's tranny from ? ( I know I am stuck on The honda , but just exploring options )

 

I don't think a 600 sportsman motor is even close to matching an F-4 .

 

Oh i know what you mean, the sp600 is in no way comperable to the F4 engine, i mean 40hp vs 100hp right? but its not all about horsepower. University of Michigan-Dearborne place 39th with a brigs v-twin making 19hp. Its all about the drivability and smoothness of the operation. the CVT will be able to hold the power and stay on boost longer than the 6speed. Our car last year was an LTZ with a GT12 turbo and there was just too much turbo lag to make it viable in an acceleration event. CVT is the smoothest way of delivering power in the Formula SAE car and with proper clutching it should be able to deliver it quite well. I would be perfectly happy with 50hp and 45ft'lbs of torque if both took place over a 4000rpm spread and allowed steady state throttle through an autocross event...... its still all just schematics in my head right now because the only teams i've seen run CVT in formula SAE havent done well because of improper clutching (which makes sense because understanding of clutching takes some practice)

 

I was wondering why not use the Liberty 600 motor. But that came up later. One of the users here named Lentech had some success with making a turbo for it as well. I think his was a 700, but same difference on the Liberty motor. Is a small bore Vtwin an option? Seems you could find a way to mate up a CVT to a Victory or Kawi Vtwin. Just some thoughts there.