Aussie Quad Racer Posted December 4, 2007 Report Posted December 4, 2007 static compression is irelivant, the more you increase the exhaust port timing, the lower the static compression will be but the higher the stress when the engine is running under load Quote
J-Madd Posted December 4, 2007 Report Posted December 4, 2007 You cant run stock pistons if you dont have a spacer plate. I have never seen someone cut a dome 4mm and then rechamber it to be the right size. This guy says he doesn't have a spacer plate. The connecting rod between the web is moved outward by 2mm. This changes the top dead center by 2mm as well as the bottom dead center by 2mm giving you 4mm of increased stroke. However far you move the piston at the top position is also done at the bottom position. Therefore no spacer plate is needed unless you increase the rod length as well. Please correct me if I am wrong, but I think I have this correct. This getting very confusing, making me even second guess what I think I know. 1) +4mm crank = Spacer plate OR cut domes. 2) Long rod = 795 series pistons. Either of the above (1 OR 2) can be done without the other, or am I wrong? Quote
blowit Posted December 5, 2007 Report Posted December 5, 2007 (edited) This getting very confusing, making me even second guess what I think I know. 1) +4mm crank = Spacer plate OR cut domes. 2) Long rod = 795 series pistons. Either of the above (1 OR 2) can be done without the other, or am I wrong? 10-4 or blaster pistons but they are actually relocated a little over 5mm and dome is different so not as common any more as the 795s Edited December 5, 2007 by blowit Quote
badassbanshee479 Posted December 5, 2007 Report Posted December 5, 2007 you can only run the blaster pistons when you go to a big bore setup I believe Quote
blowit Posted December 5, 2007 Report Posted December 5, 2007 LOL this is funny I run 200-210 compression and twist mine to 11,500. if your port timing is correct the compression will have little effect on the RPM capability of the motor. you have some tuning issues you need to visit with your engine builder about, he is the one that can tell you or help you with your issues. Thats the kind of compression we like to see. She is not going to sign off with 190 psi static as long as timing curve and air flow are working for you up top. The last one that went out our door pumped up 260psi! Brandon Quote
Bobby Banshee Posted December 5, 2007 Author Report Posted December 5, 2007 what carbs are you running ?? Stock carbs, 30pilot, 2 on the needle clip and 340 mains Quote
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