Dome size

fischer550 · Apr 19, 2015

I live at 5,000 ft in Colorado. Going to be installing ada head, factory pipe, and advancing timing on a stock fx1 with a 17/22 skat swirl impeller.

What dome size would be good for running 91 pump gas? 33cc or 31cc? I do not know my compression currently, but it is a healthy stock 701, rides great.

Dartman · Apr 20, 2015

you should be fine on 31cc domes for 5,000 feet

fischer550 · Apr 20, 2015

Ya think? Keep in mind this head uses no head gasket

Dartman · Apr 20, 2015

yes for sure
i have usd ada heads since they started making them
33cc for 2000-3000 ft
35cc for 0-2000
you also can have custom ones made for 1000-1500ft 34cc
keep in mind this is for stock un-ported un-decked 701-718cc cylinders
add a msd inhancer too if running stock cdi

lanmine657 · Apr 21, 2015

I'm in fortcollins(5,000ft), also run ada head, 31's=180-185 33's=165-170, I run 31's on pump gas no issues with 3mil advance, enhancer, drypipe, and ported, I've found that 195 is the mark for race fuel at least for my boat, I'd think your fine with the 31's but every combo can be different, if it pings put the 33's in or blend race fuel with your pump gas but you should be fine, 31's are really the go-to domes around here, just about all my sj buddies with Ada heads run 31's on pump gas

fischer550 · Apr 21, 2015

sweet thanks! Case was telling me about your superjet haha

lanmine657 · Apr 21, 2015

Chase knows his stuff, he helped me build a monster that's forsure, my boat has brought frustration to many, lol

Dartman · Apr 21, 2015

thanks for the backup lanmine657