Chaps,
As most of us know, cylinder head flow is crucial to good performance. I had a striking reminder of this when my Comnoz flowed head yielded an additional 9bhp on my Cdo!
At some point I’ll be looking to refresh the top end on my ‘68 T120. I have 6mm stemmed Kibblehwite valves, a Morgo barrel, and lightweight billet MAP pistons on the shelf to make a nice crisp 750.
But I’m loath to do all this with a stock head. I’ve flowed plenty of Triumph heads in the past but my Comnoz experience has made me realise I was really shooting in the dark!
Doing it by gut feel just ain’t good enough these days! I’d like to entrust the head flowing to a known expert in the field.
So... Any recommendations?
(Anyone saying the “Cylinder Head Shop” will be soundly ignored)
More Triumph Heads haVE BEEN WRECKED BY ' hEAD eXPERTS ' THAN YOUD BELIEVE !
oops.
Main Considerations are Seats / Location .
Oversize Valves usually get you out on the seat edge, where the valves sit proud INTO the Chambers .
This gets you higher comp & unshrouded flow .
Recessed seats , or cleaned up seats , so the valve face is homogonous ?? with chamber ( Same Curve or further back )
are neve gunna flow as well.
The Dreaded 1 3/16 Carbs & Maybe 1 5/32 Throats , unimpedeing a trile about the guide boss,
tapered ends to Alumn Bronze Guides , gentle tuliping to the opened seat radius/ I D ,
And the new fangled RADIUS version of the tree angle seat ,
First used on this planet in 78 By Hooker on my 8 stud 650 head , gave 9.75 : 1 C R on the 9.5 pistons .
NOT the high crown horribles .
Came Alive with 1 3/4 P U pipes when cut to the recomended ( Boyer ? ) length , 32 " to valve face .
Think this is 27 1/2 O A .
With the Wassel Megas ( long perforated baffle things from 16 G steel - ya can still gettem )
on part throttle , came on a 93 mph . In Third . Run to 110 on the stop . Change to 4th required undivided attn .
24 T so you can figure the RPMs / speeds in top - about the same as Malcolms. Un Streamlined .
coulda pulled another tooth . 25 were available .
This pipe length on a 2 litre ohc Ford , a beer jug exactly matches the VOLUME for equal pipe capacity .
and gives 8.000 on a dead stock injun. IF you loctite the big end nuts ! with a V 6 carb .
The Bonnie ran a ' Thruxton ' / or the Light Pear Flanked 68 ?? crank .
( Sold to me as a 72 , probly didnt like the crankyness )
ideal for tarmac , needs your eye in on the dirt roads . But smooths out past the Ton there .
Ran the Lighter 61 Rods, too. So with the lighter carank, rods & pistons , would piss on most things .
Match a Z1 W F O . better off the line , more stable .
If the Valves arnt proud in the chambers, your loosing power .
And it didnt let go using more R P Ms than the girlie boys say .
Cutting a Few In of the 56 pipes at the Head End ( 2 1/2 ?? )
Gets them tucked in better . Armours ?? produced the pipes for Triumph. And still do them .
The Single row primary robs less power than the Twin Row. as with Dual Ball races on the Crank .
a Push In CORK segmented plate ( There hollow ( and LIGHTER ) for the corks . You Boil Em and
squeeze em in with a Spoon Handle . Then throw in lathe . Of course maybe Cork isnt what it used to be .
Can be scorched if your a turkey , but will let in / take up with better grip than any other ,
as in not fully out untill in the powerband with the wheel a foot or two up , alll the way .
If your really in a rush , youll have to paus till the count of three for it to drop , on the shift to third .
Stock P U Cams . T 100 R cams have more duration & lift . The Tree Piece Crank T100R has a 8.000 rpm
redline and runs to 8 100 ok . they had the W&S Predecessor to NORVIL Springs .
The Norvil / W & S your gunna have ta watch ya dinnay go much past 8 500 I would think .
Hop to it . Clean it Up , Dont Butcher It .