dropdatsun Posted October 23, 2011 Report Share Posted October 23, 2011 Ok so i have a l20b that im building i bore it and stroke it. i has a z22 crank with ka pistons, and a u67 head with a isky stage 2 cam. now i just pick up my head from the machine shop last night and notice that the intake valve opens quiet a bit. now i wasent sure if it was going to hit my piston or not so i put some claydow on top of the piston to check my clearince. i im verry close to close for confort im thinking of adding a shim to it so that way i wont have a problem in the future. has any one else had problem with this or is it just me. Quote Link to comment
datzenmike Posted October 23, 2011 Report Share Posted October 23, 2011 Contact http://community.ratsun.net/user/2344-sealik/ I think he has the KA pistons with L head and bigger cam. Quote Link to comment
albyneau Posted October 23, 2011 Report Share Posted October 23, 2011 Ok so i have a l20b that im building i bore it and stroke it. i has a z22 crank with ka pistons, and a u67 head with a isky stage 2 cam. now i just pick up my head from the machine shop last night and notice that the intake valve opens quiet a bit. now i wasent sure if it was going to hit my piston or not so i put some claydow on top of the piston to check my clearince. i im verry close to close for confort im thinking of adding a shim to it so that way i wont have a problem in the future. has any one else had problem with this or is it just me. Did you measure the clay's thickness? A good rule of thumb is in the neighborhood of .080". That's for higher revvin motors, and .060" is a good safe street number. I use .080 to pad myself a bit~ cuz if a rod bearing ever lets go.... Quote Link to comment
dropdatsun Posted October 23, 2011 Author Report Share Posted October 23, 2011 well i did not mesure the thickness on it, but when u can see the light throw the clay i know is to close, and i havent even torque it down yet. Quote Link to comment
Guest kamakazi620 Posted October 24, 2011 Report Share Posted October 24, 2011 well i did not mesure the thickness on it, but when u can see the light throw the clay i know is to close, and i havent even torque it down yet. Was the Headgasket on when you did this???? if it was get a thicker gasket and try again,was the head shaved at all??? Quote Link to comment
datzenmike Posted October 24, 2011 Report Share Posted October 24, 2011 Just add 1.2mm for a crushed gasket thickness. You can also notch the piston top. Quote Link to comment
Sealik Posted October 25, 2011 Report Share Posted October 25, 2011 Contact http://community.ratsun.net/user/2344-sealik/ I think he has the KA pistons with L head and bigger cam. Bigger cam...but Z24 pistons. Quote Link to comment
HRH Posted October 25, 2011 Report Share Posted October 25, 2011 I don't see why you'd have any issues. I have flat tops in my 20B, which come right even with the deck, and with a rally cam, don't have any issues of hitting and that's with a U60 (same as U67) head. Your KA pistons have 2.5 cc of dish roughly if you're using the truck pistons, considering the Z20E pistons I have have no dish and slight valve reliefs that only fit the Z head anyway, I wouldn't think you're all that close. Quote Link to comment
dropdatsun Posted October 25, 2011 Author Report Share Posted October 25, 2011 ok i think i have found out im having a problem the pistons thati got are from a early ka, the ka24de has a deaper dish than the ka24e. and i have the ka24e my friend came over yesturday and he said that with a shim i should be just fine he has acouple races cars that he runs, he knows what hes doing. i dont think that theres been any work done to it before every thing look good wen i pulled it apart Quote Link to comment
HRH Posted October 25, 2011 Report Share Posted October 25, 2011 If you got the actual 9.2:1 domed pistons then yes, that will be a problem with clearance. Quote Link to comment
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