Panther Publishing Ltd
10 Lime Avenue
High Wycombe, Bucks
HP11 1DP, UK
+44 1494 534778
info@panther-publishing.com

Bunn Breather Kits

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Revolution in Classic Motorcycle Engines

The New Bunn Breather Kit... A New Engine Breathing System for Older, Classic Motorcycles

Panther Publishing Ltd announce a revolutionary new engine breathing system for classic motorcycles – a new kit developed and designed by Carlel P/L Classic Restorations. The patented new system is the first significant advance in classic motorcycle breathing, since the invention of the flapper valve and the timed breather, many generations ago. It suits nearly all four-stroke, overhead valve engines, whether singles, twins or multi-cylinder engines.

There are two versions, The BlowBye Breather, a simple kit for helping engine breathing problems and The BUNN Breather Kit, the complete solution to engine breathing described below.

The Bunn Breather Kit (BBK)… Cuts Oil Leaks AND Reduces Engine Wear, as it Flushes Toxic Blowby from your Crankcase & Rockerbox. It is warranted in use for two years with unlimited mileage.



The new Kit cuts oil leaks by restoring original crankcase air pressure, back to the levels classic designers planned. Over the decades, the OEM breathers malfunction and air pressure increases. Oil leaks are often the first sign. The Kit suits all the usual four-stroke makes, whether singles, twins or multi-cylinder engines, i.e. AJS, Ariel, BSA, Harley Davidson, Indian, Matchless, Norton, Sunbeam,Triumph, Velocette,Vincent. The BBK Kit also cuts engine wear by flushing filtered, fresh air through your crankcase. This controlled airflow forces out corrosive blowby gases that otherwise cause this damage to your engine, each time we start up:- * Contaminates and dilutes oil * Washes oil film off engine internals * Rusts ferrous components and bearings * Sludge forms * Pressurised crankcase causes oil leaks * Rubber deteriorates * Crankcase becomes a fire hazard

The BBK Kit includes- valves, air filter, tubing, cable ties/clip, spare seal, balloons to test operation, and comprehensive instructions. It's a simple, easy-to-install solution for classic engine oil leaks, crankcase pressure problems and blowby wear and corrosion. It can be fitted to nearly any four-stroke engine, to improve engine operation. It involves no permanent or unsightly changes to your engine. Flowing fresh, filtered air through the hot, closed-off rockerboxes and crankcase helps oil return and the engine to run cooler. It also helps prevent any dirt being sucked into the engine via existing oil leaks. Engine power may be enhanced on some bikes, as crankcase air pressure,downforce work-loads and drag reduce. Research shows oil leaks are signs of more serious problems. Noted Classic engineer and Norton racer Peter Williams says, in his June 2005 Classic Bike review of engine breathing..."...leaked blow-by gas is nasty, obnoxious, and corrosive stuff and it is best to have as little as possible in the crankcase..." Blowby occurs every time we ride. It forms a corrosive, flammable mixture, that eats away at our engines, if left inside. Blowby is ~70% fuel, water, sulphur dioxide, nitrogen oxides, soot and ash. It's like a concentrated acid rain. The BBK Kit is an effective conservation aid, designed to keep classic motorcycles on the road into their second century.For a full Instruction Sheet, click here For Royal Enfield Instructions click here

First Dyno trial- A Vincent series B Classic racer.
“… my engine is a Vincent 1949 late series B unit…I had the two small one way valves [BBK Exhaust valves] on the engine breathers fitted to the tappet covers and there was next to no oil emitted. The second run I took off the [BBK] breather valves and had short straight pipes, and oil sprayed out (it appeared to be entrained by the bi-directional airflow)…. the only conclusion I can make is that having the crankcase ventilated in one direction [ by the BBK], offers some benefits….” David W, Vincent owner, September 2006.

Second Dyno Trial- A Skyline Drift Racer
“…What I have done [on the Drift racer]…is isolate the crankcase from the cylinder head…, so now the crankcase has its own breathing system….With this arrangement the dyno showed an increase of 3.6 HP [with the BBK installed] and a decrease in acceleration time [up to approx. 3000RPM]. I think this is due to the reduction in pressure under the pistons [created by the BBK]….on a single cylinder or Harley-Davidson V twin with its uneven firing configuration, I believe your [BBK] kit would work wonders….” David P, Drift Racer and Harley-Davidson Mechanic, October 2006.

Original Reports are held on file at Carlel Pty Ltd. Material is provided with the owners kind permission.

The Kit is being marketed and sold in the UK and Europe through Panther Publishing Ltd. who is stocking the kit. All enquiries welcome.

Price is just £29.50 including postage for most classics but there is also a kit specifically for modern Royal Enfields including the Electra priced at £34.50 including postage.

NB: For the many riders using my first "Flapper" and 'BlowBye' engine breather Kits, the new BBK Kit is compatible with them. Another novel aid for Classic motorcyclists, from Carlel Classic Restorations in Sydney, Australia. Classic Bike Breathing specialists. Copyright, 2006.

Bunn Breather Kit
Price: £29.50

including postage to the UK and Europe.

Bunn Breather Kit - Royal Enfield (Bullett, Electra)
Price: £34.50

including postage to the UK and Europe.

BlowBye Breather Kit
Price: £11.00

including postage to the UK and Europe.