chase@miamiatv.com Posted March 30, 2015 Report Share Posted March 30, 2015 sitting on 66.25 mm cylinders full drag ported stock stroke......... i want to bump my compression up...... the question is do i need 66mm domes ? or can i just run normal domes ? would that be classified big bore ?Roughly putting what domes would put me around the 165 psi range at seal level............ i cant remember what i had in my old bike ....i think 18cc ? i cant remember. someone chime in .... with what they reccomend head wise..... i have no studs in the heads . my builds so close to being a reality. Quote Link to comment Share on other sites More sharing options...
registered user Posted March 30, 2015 Report Share Posted March 30, 2015 whats your reasoning for wanting 165 compression ? you dont want any of the head flat surface hanging into the bore so 64mm domes would be a bad move, if thats what you ment by using normal domes ? if the exh port is hogged out then its likely your compression ratio would be through the roof to get 165psi. if you have a competant shop in the area you might wanna have them take a look before you get headed to far in the wrong direction Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 30, 2015 Report Share Posted March 30, 2015 Any idea on the exhaust durations? Actual Compression ratio will be considerably higher then what cranking compression will indicate if you have something in the 198-202 range. So pick your fuel type and do the tune accordingly. As far as 66.5mm pistons in the domes. I think your definitely in big bore territory but might be better off calling DriveLine or Noss Machine about domes to work with that bore opposed to just tossing 68mm domes on. 1 Quote Link to comment Share on other sites More sharing options...
chase@miamiatv.com Posted March 31, 2015 Author Report Share Posted March 31, 2015 Thanks guys... yes proper domes needed then . thats what i thought. need to be running 110 octane no lower , not much higher... yes im aware of advantages on alky. need my setup for race gas .. easily easily obtainable for me. the ports are not extremly hogged out... Noss maschine deals with direct orders and dome specs ? Thanks guys , enjoy your evening Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 31, 2015 Report Share Posted March 31, 2015 Yes, Noss will fix ya up. He will want your deck height though. Quote Link to comment Share on other sites More sharing options...
registered user Posted March 31, 2015 Report Share Posted March 31, 2015 generally on heads with no locating dowels you machine the chamber diameter just a hair bigger than the cylinder bore to account for any slop when the head is bolted on. that way you dont end up with the mating surface hanging into the bore. be sure you know the bore size other wise youll bring undo grief upon yourself. and dont tell them you want 165psi. best to just let them do all the thinking and you worry about the assembling Quote Link to comment Share on other sites More sharing options...
chase@miamiatv.com Posted March 31, 2015 Author Report Share Posted March 31, 2015 awesome totally awesome........ thanks to you guys for your two cents and helping me.... thanks alot......... Noss it is for the headwork...... thanks Quote Link to comment Share on other sites More sharing options...
Deadbeat Posted March 31, 2015 Report Share Posted March 31, 2015 Driveline Performance will cut you some domes billeh (BANSHEE HP) is snooping around the sb most days http://bansheehq.com/forums/index.php?/user/34717-banshee-hp/ Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted March 31, 2015 Report Share Posted March 31, 2015 Keep in mind at .100 over that skirt is very thin. Any crank wobble or excessive piston to cylinder clearance will cause catastrophic failure . Assembly , squish, tune is detrimental to keeping that motor together Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted March 31, 2015 Report Share Posted March 31, 2015 Most domes are 66 off the shelf so make sure you tell them bore size when ordering domes Quote Link to comment Share on other sites More sharing options...
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