Posted May 6, 20213 yr comment_621160 I'm using new 73 style pistons and want to upgrade cam to Comp Cams 280S-110 grind. The head has been surfaced at -.012. My main concern is valve clearance, I do plan to use cam tower shims but I'm unsure how many it might take to make this combination work. Thanks for your help. Specs for stock v. Comp Cams: Comp Cams Advertised Intake Duration: 280 Advertised Exhaust Duration: 280 Intake Valve Lift: 0.460 Exhaust Valve Lift: 0.460 Stock Cam L24 Intake Duration: 248 Exhaust Duration: 248 Intake Valve Lift: 0.413 Exhaust Valve Lift: 0:413 Edited May 6, 20213 yr by rem1313 incorrect information Link to comment https://www.classiczcars.com/forums/topic/65360-73-240z-engine-rebuild-questions/ Share on other sites More sharing options...
May 6, 20213 yr comment_621166 Is your question about clearance between valve and rocker or valve and pistons? Link to comment https://www.classiczcars.com/forums/topic/65360-73-240z-engine-rebuild-questions/#findComment-621166 Share on other sites More sharing options...
May 6, 20213 yr Author comment_621171 The valve and pistons Link to comment https://www.classiczcars.com/forums/topic/65360-73-240z-engine-rebuild-questions/#findComment-621171 Share on other sites More sharing options...
May 6, 20213 yr comment_621175 are '73 style' pistons flat top? If so, it'll be pretty close I think. I'd mock it up with plasticine and check how much clearance there is. Link to comment https://www.classiczcars.com/forums/topic/65360-73-240z-engine-rebuild-questions/#findComment-621175 Share on other sites More sharing options...
May 6, 20213 yr Author comment_621176 Thanks jonbill, The pistons are stock 73 style with the eyebrow cutouts. Link to comment https://www.classiczcars.com/forums/topic/65360-73-240z-engine-rebuild-questions/#findComment-621176 Share on other sites More sharing options...
May 7, 20213 yr comment_621188 rem1313.....If you are using a 73 E88 head and only shaved .012 inches, you shouldn’t have any problems IMO. Those pistons are fly cut. If you use a cam with any more lift than .460, you would need to use a shorter valve seal. Link to comment https://www.classiczcars.com/forums/topic/65360-73-240z-engine-rebuild-questions/#findComment-621188 Share on other sites More sharing options...
May 7, 20213 yr Author comment_621189 Thank you Diseazd, appreciate the feedback Link to comment https://www.classiczcars.com/forums/topic/65360-73-240z-engine-rebuild-questions/#findComment-621189 Share on other sites More sharing options...
Create an account or sign in to comment