papatrx
02-02-2005, 06:44 AM
For years I have been thinking about trying a CR250 flat top piston in my bike but have never gotten around to it since they have different wrist pin heights and the space plate customization I would have to do. I know some people have shaved the head on the domed trx piston but the extra heat build up in the center of the piston always concerned me. Now Wiseco makes a flat top piston for the trx250r with the wrist pin 5 mm higher like the 87 -89 models with the 130 mm rod. They have added about 20 grams of weight over the pro-lite to the top of the head to help with heat containment.
My question is have any of you tried this setup and what did you cut the squish angle on the head to? I know some of the CR guys are running 5 to 6 degrees and want to know what is a good number for the trx cylinder and also are you using the small dome head or the large one and how much change did you make to the dome to get compression back up?
And finally have you had any issues with extra heat build up since the flame is now traveling down the center and not being pushed out to the side walls?
My question is have any of you tried this setup and what did you cut the squish angle on the head to? I know some of the CR guys are running 5 to 6 degrees and want to know what is a good number for the trx cylinder and also are you using the small dome head or the large one and how much change did you make to the dome to get compression back up?
And finally have you had any issues with extra heat build up since the flame is now traveling down the center and not being pushed out to the side walls?