Triumph head flow expert in U.K.?

Fast Eddie

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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)
 
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 .
 
The Pipes are worth 1.000 rpm . & significant horsepower .
And arnt Very Loud .
Below Half Throttle .

A Full Bore Run should be recorded for Posterity .
 
Thanks Matt, I concur with most of your suggestions. But, I’ve done lots of DIY jobs in the past, even doing back to back dyno runs to try and be ‘scientific’ about it.

The best increase I got was nearly 5bhp on a race motor, which I was quite chuffed with, so I don’t think I was getting it all wrong.

But I’m really looking for someone who genuinely deserves the ‘expert’ title. I’m looking for the Comnoz of the Triumph world.

There’s gazillions of hopped up Triumphs out there. Somewhere, someone must be an expert head hopper upper...
 
Nigel,
I have also heard lots of anecdotal misgivings about the cylinder head shop, but also some good reports, not questioning your evidence by the way? He was very helpful in answering my questions when I dropped in when thay were in Wimbledon.

The people I'd talk to (but little personal experience) who seem to make unit triumphs fly (and that requires more than just a dialled in cam and lumpy pistons in my experience), are;

Dave Whitfield and Richard Peckett at P&M in West London - Richard "cleaned up" my T140 head while he was doing the guides and it was a thing of beauty, but no claims of greater flow, though I'm sure they could work some magic and they have a dyno. Richard is a lovely guy, Dave a bit more "difficult", though I'm sure you know of them through your trident contacts anyway?

Not sure if Dave Degens still operating (Dresda), he was experimenting with thinner valve stems 10-15 years ago?

Same goes for Alistair Hillaby, never heard a bad word about his tuning, but not sure if still in business?

Finally there's Hugh Brown of The Bike Shed who can definitely make them fly, dead stock just gas flowed and dynamic balancing (see link below where one of his 650s did 117mph in a 1 mile standing start at Elvington on too-short gearing) but think he only takes on full restorations, not sure?

http://inventivestudios.co.uk/thebikeshed/

Hope some of that might be helpful?? I doubt any of these guys have a flowbench but all know these engines?

Dave
 
Thanks Dave, I did think about P&M but, for some reason, discounted the idea. Now you’ve reminded me, I think I’ll give Richard a ring and at least see what he has to say.
 
Thanks Dave, I did think about P&M but, for some reason, discounted the idea. Now you’ve reminded me, I think I’ll give Richard a ring and at least see what he has to say.
Also forgot to mention SRM who now offer gas flowing, but no view on their track record? They aso have a dyno so no reason why you can't ask them for some dyno results of their work?

Is their a good thread that outlines the tuning progress on your Commando Nigel, don't want to ask same old questions when it's all somewhere on this forum I suspect? I am looking to pep up my newly acquired 850 commando, just limiting it at the moment to a return to twin carbs, but if (limited) funds permit in the future, who knows? Not looking at your kind of impressive build, but I used to have a Fred Barlow (ex BSA comp dept as well as Norton) gas flowed, 4S cammed 850 that flew! Wouldn't mind a bit of that back!! You have too many posts for me to find what I'm after just by trawling!

All the best

Dave
 
Pictures now added at the end of the thread. I couldn’t work out how to re insert them where they belong I’m afraid.

Shudda asked my 9 year old daughter I guess!
 
Good thoughts Andy, thanks.

I know Dave is still going and I know he’s good. Trouble is, I’d get carried away, head welded and squished and etc, I know this cos I’ve been there before!

Don’t know much about George.

Trouble is, I really wanted someone who would flow test CFM and velocity figures before and after like Comnoz did on my Cdo head. But it’s looking like I might have to give up on that idea.
 
Nigel
Please forgive me if I'm giving info you already know.
I would think that George Hopwood - although maybe not as scientific in approach as Comnoz - knows his stuff.
An independent tuner, he was invited to join the Boyers of Bromley team (Stan Shenton et al) back in the day, due to his successes.
If you haven't read it I can recommend Claudio Sintich's book on the Thruxton Bonneville https://www.real-classic.co.uk/2017/05/26/triumph-thruxton-bonneville/ and cheap on ebay. There are many references and a section in the book on George Hopwood.
All the best with the project.
Andy
 
Thanks Andy, I didn’t know that about George, I confess I may have been under rating him!

I’ve always rated Stan Shenton, so if he rated George, that’s a good sign.

I’ll give him a call and have a chat, I’ve nothimg to lose and everything to gain by doing that at least !
 
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