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Head question

Posted: Fri Mar 02, 2018 5:07 pm
by htroha47
The stamp says +60. I assume it means 60 over, but measures only 40 over stock. Also what is the custom porting for.

Re: Head question

Posted: Fri Mar 02, 2018 6:23 pm
by matt glascock
The +6 marking, as I've learned, has nothing to do with overbore. It is a factory marking that correlates with pistons that have been clearance matched to fit appropriately with that cylinder eg +1 pistons go with +1 cylinders and +2 pistons go with +2 cylinders and so on. I'm speculating that those are some type of DIY finger ports designed to improve transfer of the fuel charge. Racerclam will surely school us on this matter.

Re: Head question

Posted: Sat Mar 03, 2018 3:30 am
by racerclam
Added ports just an outdated method of adding transfer ports . Not much volume , can help with scavenging

Rich

Re: Head question

Posted: Sat Mar 03, 2018 3:38 am
by matt glascock
Hi Rich, I was wondering if those were some kind of boost port for improved scavenging. Aren't they in the wrong position related to the exhaust port? I thought ports set to enhance scavenging were typically on the opposite cylinder wall from the exhaust port.

Re: Head question

Posted: Sat Mar 03, 2018 12:33 pm
by taber hodaka
Something looks a little strange. Are we are looking at a Fuji engine, not used in the hodaka. To me it appears that the new ports are opposite of the exhaust. These ports are the type we oldies added on our own, before we met Rich. ----------Clarence

Re: Head question

Posted: Sat Mar 03, 2018 5:52 pm
by racerclam
sure those ports arnt ultimate but also wont hurt anything

Rich