a gas flowed BSa ( 750 Trilple ) head here . P 78 picture of intake port .
( also youll see his first exhaust was a woftam , look n figure why , visualise collector flow ) .
Though normally youd ' Vee ' & streamline the guide support , and machine tapered Not shorten the guide .
f 750 NORTON ran 33 mm bore concentrics , so the 32 Id consider a minimum .
the KEEP IT SIMPLE , ' clean up ' - and NO recession on the seats , count for a lot .
You can mess things up tightening the bottom corner , so dont mess it up there .
besides the horribleness , the Recessed ' relieved ' ports IN the CHAMBER are horrible .
Nuther one ruined on the righthand valve - ' relieved ' mass lost flow . VALVE should almost be proud - In Chamber .
Any recession is lost lift . BEST is new hardened seats & no operations on chamber utside the seat whatsoever - -- -
Icrementally off seat , theres unimpeded flowing - not detours .
you can see some wallys ' cleaned up the head ( chamber )
as the valve seats about 1/8 recessed from stock . Oh Dear .
anutha ferkerp .
At Last , you can see the seats still level with the un recessed chamber -
so the flows unobstructed from the get go , lift wise .
Also slight ' flareing ' TULIPING after bend tru to seat - velly good .
tho Guides Unsupported .
Get AHEAD , 1 3/16 ths on a 500 .
nuther one where some ibaciles removed the GUIDE SUPPORT.
ROIT , you can see the ' V ' slitter type ' flowed ' support to the GUIDE . Also this;ll straightn you out , if your wondering . Bouta 1 1/8 port tunnels right on , for a 650 triumph .
Only the pre unit 8 studs unkinked from the head bolts , so flows bettern a 9 stud .
Now , If Hele had worked for B.S.a. . . . .
Look at the foist pitcher ( link ) and laste , moit .