Hey,
I've recently pulled down a gt250 engine, it has X7 heads which have been heavily ported and the crank, I think, has been modified to a 4 bearing crank, it doesn't look standard as the centre bearings have been pushed next to each other and to the left and the centre seal is off to the right side. The cranks cases have been machined to suit the modified crankcase too.
Does anyone have or know of any race engine modifications to gt250's that may help explain this?
Also does anyone have a suggestion for minor modifications to a standard engine to get a little more out of it for road use? Im going replace the engine with a standard engine with .5 mm oversize pistons and a possibly higgs expansion chambers.
Hey mate. I have a gt250k race bike which hoots along quite quick. It has 1mm over pistons , port work , and the heads machined to a 1mm squish gap. The port work alone took nearly 4 seconds off my lap time at Morgan park.
how much port work can you do before it is annoying to ride in traffic?
I want to do minor work so it is quick but still reliable and easy to ride in traffic.
Hi Steve, My bike has mild porting and would be ok on the road. There are a lot of casting marks that cleaning them away makes a good start. Fit an electronic ignition system as well and you have great spark all the time and no more crappy points and condensers. Also I was wondering if you still have that race motor. Cheers Don.
Hey Don,
The cases and crank are no good. The cylinders look ok but the exhaust threads are cross threaded and wont hold anything on them. Im going to hold onto the cylinders to see if i can get them repaired.
you dont have the port timing degrees fo a standard engine at all do you?
