New Norrie Kerr pipe?

[smallframe66]

Heard at Marl that someone has copied the old Norrie Kerr race pipe off his smallframe racers and that the person who has done it has modified it to make even more power. Can any of you confirm and let me know any specs there might be on it please. I am interested in buying one also as I have an original NK pipe minus the spigot off LC2.

[Brosi]

the original topic

[amazombi]

hi marc,

resonnance length and downpipe details have been changed to make more power at lower rpm (without sacrificing max power, which was the tricky bit). peak torque was also improved by some 10 %.

i don't think the modifications will make the exhaust suitable for your engine tuning goal. for peak power at 10 grand plus you will have to make your own pipe, I'm quite sure the only thing to get even close to your target rpm is the mr2000, but any engine with this chamber will be a real dog for circuit racing.

[smallframe66]

hi marc,

resonnance length and downpipe details have been changed to make more power at lower rpm (without sacrificing max power, which was the tricky bit). peak torque was also improved by some 10 %.

i don't think the modifications will make the exhaust suitable for your engine tuning goal. for peak power at 10 grand plus you will have to make your own pipe, I'm quite sure the only thing to get even close to your target rpm is the mr2000, but any engine with this chamber will be a real dog for circuit racing.

<{POST_SNAPBACK}>

I don't need 10,000 plus if the power is there at lower rpm then great. I would rather have lower rpm, I just need 20-25 bhp. minimum! I may go the way of Chris and use a motocross pipe modified to fit. This is simply the biggest headache for me deciding which way to go regards exhaust.

One other question is does anyone know how I could use a barrel off a Runner 180 or Malossi 172 on a smallframe and get good horsepower as they are disc valve induction? I ask as in the British racing rules the barrel has to be a scooter barrel for that model - this means a Piaggio barrel is legal so I could go full water-cooled, any ideas? This would be a special and at present there is no lower ccm class (group 5 - 160 cmm max.) I will have to run against 260ccm Lambretta specials.

Mark

[amazombi]

I don't need 10,000 plus if the power is there at lower rpm then great. I would rather have lower rpm, I just need 20-25 bhp. minimum! I may go the way of Chris and use a motocross pipe modified to fit. This is simply the biggest headache for me deciding which way to go regards exhaust.

One other question is does anyone know how I could use a barrel off a Runner 180 or Malossi 172 on a smallframe and get good horsepower as they are disc valve induction? I ask as in the British racing rules the barrel has to be a scooter barrel for that model - this means a Piaggio barrel is legal so I could go full water-cooled, any ideas? This would be a special and at present there is no lower ccm class (group 5 - 160 cmm max.) I will have to run against 260ccm Lambretta specials.

Mark

<{POST_SNAPBACK}>

sure the runner is disc valve induction? i always thought i'd spotted a reed somewhere down near the crankcase. the last time i checked your racing rules i thought i had read just what you state above. barrel should be one intended for the model. runner may be the same make (and even that is a point which may be argued, i seem to remember that though the engine is supplied by piaggio the maker is gilera) as your smallframe, but it certainly is not the same model.

for 20 hbp get yourself a polini barrel (or keep your malossi) and sort out the parts you have. 20 brake is quite possible even with a rotary valve engine. for the other end of the interval you name check this forum here, there are at least two smallframe engines around (one of which is still roadgoing) which get close or even past the mark you name. i have a feeling that tuning an engine tends to get excessively complicated the further you leave proven tracks behind. excessively complicated, btw. translates into: time consuming and expensive. the conversions you consider certainly are eligible for the category complicated, whether they are eligible for racing i'm not all that sure.

Bearbeitet 13. Juni 2005 von amazombi

[Luccio]

runner's crankcase :

http://www.mbdevelopments.co.uk/other/gt1.html

no disc valve induction....

Bearbeitet 13. Juni 2005 von Luccio

[smallframe66]

sure the runner is disc valve induction? i always thought i'd spotted a reed somewhere down near the crankcase. the last time i checked your racing rules i thought i had read just what you state above. barrel should be one intended for the model. runner may be the same make (and even that is a point which may be argued, i seem to remember that though the engine is supplied by piaggio the maker is gilera) as your smallframe, but it certainly is not the same model.

for 20 hbp get yourself a polini barrel (or keep your malossi) and sort out the parts you have. 20 brake is quite possible even with a rotary valve engine. for the other end of the interval you name check this forum here, there are at least two smallframe engines around (one of which is still roadgoing) which get close or even past the mark you name. i have a feeling that tuning an engine tends to get excessively complicated the further you leave proven tracks behind. excessively complicated, btw. translates into: time consuming and expensive. the conversions you consider certainly are eligible for the category complicated, whether they are eligible for racing i'm not all that sure.

<{POST_SNAPBACK}>

Hi

I meant that the Runner was crankcase induction so my apologies there. Also you are correct that the barrel must be from the original type of scooter so I couldn't use a auto barrel. I'm going Reed valve induction on the Malossi as I want more than 20 bhp. Looking at Chris Voicu's figures Harry and I are sure that 23-25 PS will be reliable, plus Harry has assured he can do this. If we can't then I will buy a Billet barrel off him that he has built which he says will make 30 PS completely air cooled.

We plan to be at the August race in the Eifel mountains and I will be running at least one of the engines there.

Lastly are you selling these pipes you've made if so how much as I may be interested, if Harry and I can't get one of his to work. Oh and we're going with 2.86 primary now as 2.55 and 2.34 will be just not work with Harry SF 4th.

Best as always from your UK friend.