Branch ported Sport heads

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ajay809
Cucciolo - the Lil Pup
Posts: 5
Joined: Wed Aug 25, 2010 4:36 pm
Location: Chicago

Branch ported Sport heads

Post by ajay809 »

hello all...i have, what i was told about 15 years ago when i bought them, a set of Branch ported 750 springer heads that i used for a season when i raced my 750...they came with matched manifolds and 30MM carbs that had been bored out and epoxied a little..they appear to have 36 mm exhaust valves and 44 mm intakes...i still have some arias pistons i ran with the setup.

i guess the question is, does anybody know if Jerry put any identifying marks on them???they do have some #'s stamped on them.

the sport is back to a street bike of sorts and i really have no use for them...sitting in a box on the shelf seems a horrible waste.

thanks in advance for any insight.
Ray O'Donohue
Parallel Twin
Posts: 119
Joined: Tue Oct 13, 2009 8:11 am

Post by Ray O'Donohue »

Those are my old heads! If you look closely at the boss under the exhaust there will be a small # 55 stamped into the casting,apparently indicating their 55th Ducati head work project at Branch Flowmetrics. The heads are essentially what they developed for Cook Neilsson. Those are XR750 valves and springs (106 lbs seat pressure). The problem was,and is, that the valve springs seats lay against only a half-circle of aluminum,which combined with the infamous short guide and even shorter guide bore,all the foregoing being a non-issue in a desmo head,scared me badly in the sprung application.But,It stayed together while I raced it,and apparently for you as well. Jerry B. told me it would probably be OK,and I trusted his judgement a lot more than my own. Those head will NOT work on the street. I tried it a time or two.
ajay809
Cucciolo - the Lil Pup
Posts: 5
Joined: Wed Aug 25, 2010 4:36 pm
Location: Chicago

Post by ajay809 »

WOW...it certainly is a small world...it's been years since we visited your shop and got the heads and i was having a time recalling your name...they are your old heads...the sport was retired from racing and Vee-Two refreshed the motor top to bottom and it sat for several years...just got it up and running again this summer as a race bike turned street bike...the heads have also been just sitting and it's time to let them go onto a better home and just wanted to get as much info about them as possible.

i raced with them for two seasons without incident, except that i don't think i ever had it tuned to it's potential.

if you know anyone who would be interested in them please let me know, and if you have anymore pertinent information i would obviously be interested in that as well.

i can also be reached at [email protected].

thanks a bunch Ray, hope all is well.
Ray O'Donohue
Parallel Twin
Posts: 119
Joined: Tue Oct 13, 2009 8:11 am

Post by Ray O'Donohue »

Well,whoever buys 'em should convert them over to desmo.The guide bores on those things are about 8mm in length,if I remember correctly.I'd run an SS piston with the base gasket surface milled to bring the squish band to about .040 or less (so it can function).This avoids the piston rock/top ring problems connected with many aftermarket pistons.
chas b
Mariana
Posts: 27
Joined: Thu Aug 12, 2010 3:57 pm

Post by chas b »

This is the kind of stuff that I love reading about. Any chance of some photo's of the port shapes etc?

Regards,
Chas.
Ray O'Donohue
Parallel Twin
Posts: 119
Joined: Tue Oct 13, 2009 8:11 am

Post by Ray O'Donohue »

This was pretty much the limit of what could be done with those heads unless you went the Axtell route and got into things like welding up the casting and re-doing the valve angles and position of the port and the configuration of the combustion chamber,etc,etc,....all at that time way beyond my imagination or wallet ! Jerry Branch was both genial and a genius. His set up is closely related to what he and others wound up doing with BMW and XR750 Harleys,which had very similar head/combustion chamber problems.In recent years,I have started thinking that the greatest single part of the performance gains were simply in the larger intake valves.Jerry's seats (a racing aftermarket item) were polished into a dull knife edge,then lapped with the valve. The exhaust ports had a liitle more change done them than the intakes,which were mainly simply enlarged.
Ray O'Donohue
Parallel Twin
Posts: 119
Joined: Tue Oct 13, 2009 8:11 am

Post by Ray O'Donohue »

The Cycle Magazine articles on Cook Neilsson's "California Hot Rod" and a later article by Kevin Cameron on Udo Geitl's BMW racer had excellent photos.
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