Wanted ASBO Exhaust for Aircooled engine

[Sid]

I've Started collecting parts my IP2 and a Aluminium framed Special now.So ......... has anyone a fancy exhaust/s system/s for my 2x Air cooled motors.Maybe upgrade ignitions, Carburettors ? anything of interest ?THANKSSid in Derbyshire

[Wayne]

I may end up making a race exhaust for my 1988 rc588 race bike if i cant find an origonal exhaust.I am still tring to find some origonal bodywork before i make an exhaust as its a very tight fit.Sid do you know you have to reverse the oil and air flow to put a race extractor exhaust.I would stick with a std ignition. I have a set of 4 fcr carbs i no longer need as usual i have obtaind a set of works fcr carbs. Fcr carbs were used on the 1990 rcw and nrs engines. They were never used on the air cooled engine though. You will need the correct inlets and race ported rotor housings.Regards. Wayne

[Sid]

Hi Wayne,Thanks for the info, I'm learning slowly regards mods that need to be done on the engines,The bespoke Alloy framed special I'm collecting parts for certainly deserves some nice trick parts if available, I'll post some pics soon for advice and opinions.The Interpol 11 that I'm finishing right now has been updated with a few newer parts to bring it up to date, need to keep this with a pillion seat for daily use in summer.Me and my lad also run two 2004 Saetta kart engines for use in open class racing ( he's won all eight races he's participated in this year by a massive margin) they are similar to Aixro's but with dual ignition and nicer castings etc (we've had a few Aixros)Just stripped down one of the Saetta's and low and behold, the rotor is exactly the same as a Norton rotor, I intend to visit Graham at Startrite soon to get scored end plates machined and maybe coated, I know that Molly is popular on here,has anyone nikasil plated or used ceramic tips with success ? Trying to decide what to do with the kart motors at moment.My lads building a big HP RX7FD with R Magic Bridgeported engine now too, all because of how much the karts have impressed us.ThanksSid in Swadlincote DerbyshirePs (I think Tony Hawywood lives nearby as he had a bike shop here for a short time many years ago ?)

[Wayne]

Hi sidI have lent tony parts to get remanufactured he is a top man. He is also building a special from a air cooled engine.I havevno problem helping people out. Currenty i am tring to restore two race bikes. I can tell you origonal race parts are thin on the ground. My moto is dont cut up origonal race parts to fit, make a new part that dose. The probblem with any commander or air cooled engine is the gearbox. Norton blew the std boxes in the race bikes and developed a wide center or offten referd to big gearbox. The other week link was the primary chain, this was repaced at every meeting.A moderately tuned engine should be ok, but a full blown race engine will give the gearbox greafe. I am 1 hour away from tony if you need some help.The yamaha deltabox frame seams popular for specials anda few norton engines have been fitted to this frame.My forum time will be limited as the bikes, trailer and shows will limit my time at the moment.Regards Wayne

[Sid]

Thanks for the info Wayne, I'm not in a position to put all my spare time into these bikes right now as they no doubt deserve, it would be easier for me to pay the guys who can and have built exhaust etc but they seem few and far between,A nice reverse airflow exhaust system is a must for the Alloy framed bike as its been fabricated for one, even if someone's got an exhaust available that's only part fabricated for sale it would help.Does anyone know if Geoff Madden still makes them ? my son's tried to contact him on Facebook at Asbo a few weeks ago but no reply as yet.I've a book here called " Extreme Streetfighter Motorbikes" by Frank Allman & Simon Everett, I've owned the book for years and Geoffs EXUP is framed special is reviewed on 4 colour pages.Although the book does state " Norton race team developed exhaust and cooling system by Pete Gibson " ?Plus it's running twin Amal Concentric 36mm smoothbores ?ThanksSid

[Sid]

Thanks for the info Wayne, I'm not in a position to put all my spare time into these bikes right now as they no doubt deserve, it would be easier for me to pay the guys who can and have built exhaust etc but they seem few and far between.The Alloy chassis I have appears to use twin Mikunis situated under the tank feeding the ports situated right on very top of the engine ( reverese airflow ?) extractor setup, no idea what port mods have been done to disassembled engine as yet, will look at that aspect soon.Does anyone know if Geoff Madden still makes them ? my son's tried to contact him on Facebook at Asbo a few weeks ago but no reply as yet.I've a book here called " Extreme Streetfighter Motorbikes" by Frank Allman & Simon Everett, I've owned the book for years and Geoffs EXUP is framed special is reviewed on 4 colour pages.Although the book does state " Norton race team developed exhaust and cooling system by Pete Gibson " ?Plus it's running twin Amal Concentric 36mm smoothbores ?ThanksSid

[Sid]

Sorry about confusion in my last two posts, using my phone is not a good idea This is correct below:Thanks for the info Wayne, I'm not in a position to put all my spare time into these bikes right now as they no doubt deserve, it would be easier for me to pay the guys who can and have built exhaust etc but they seem few and far between.The Alloy chassis I have appears to use twin Mikuni's situated under the tank feeding the two ports situated right on very top of the engine ( reverse airflow ?) for extractor setup ?, no idea what porting mods have been done to disassembled engine as yet, will look at that aspect asap.Does anyone know if Geoff Madden still makes exhausts ? my son's tried to contact him on Facebook on Asbo link a few weeks ago but no reply as yet.I've a book here called " Extreme Streetfighter Motorbikes" by Frank Allman & Simon Everett, I've owned the book for years and Geoff's EXUP framed special is reviewed on 4 colour pages.Although the book does state " Norton race team developed exhaust and cooling system by Pete Gibson " ?Plus it's running twin Amal Concentric 36mm smoothbores ?ThanksSid

[Wayne]

Hi SidThe last time I spoke to Geoff was when I bought the duckhams race leathers of him, he had hurt his back at the time and was not working. That dose not mean Geoff is not still trading.I own a ex works Gibson ejector from 1989/90, the race system was made from very thin stainless, the bends are a pressing from two halves welded together. The exhausts were made on the bikes due to the different engine positions in frame. Whats not often realised is the ejector outer on the RC air cooled bike was made of aluminium and sometimes melted. for your use I would recommend stainless steel.The above picture is from a 1987 dyno report given to me by Mark SimpsonThe reverse air flow refers to the way the cooling air enters engine. on a air-cooled revers flow engine the air enters on the left and right hand end plates and is extracted via the intermediate plate (the centre plate). This modification alters how the oil is distributed, dose your intermediate plate have oil pipes or provision for oil pipes via open threaded holes for the oil pipes , on the reverse flowed engine these would be blanked off as oil is introduced via the stationary gears which are modified to accommodate this.It may be worth posting a picture of the engine, also you may not know water cooled engines have a triangular exhaust flange and the air cooled engine has a oblong exhaust flange along with steel inserts that press in to the rotor housing. The exhaust flange bolt hole centers are totally different between air and water cooled.You can reverse flow a air cooled engine I don't want to put you off however home work is required, how much depends on how far you want to go.Regards Wayne