Brian Riley
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- Joined
- Apr 19, 2020
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I’m looking for some help / info on norton 500 domi exhaust tunning, I’ve got 1” 5/8 OD pipes at 38” long and 1”3/8 OD at 40” long with 14” long skinny megga that opens up to 60mm in to a silencer no reverse cone the silencer has a 50mm outlet and 8” long to keep to the UK 105DB rule
The engine revs to 7200rpm with 12.5” inlet total lengh from the valve seat. With 1”5/32 twin carbs
The engine has the full JS kit ie conrods 10.5-1 hi comp pistons with a 0.020” head gasket, js 2 cam timed to spec same as the PW3 profile but smoother, JS valves and springs, head has been ported both on the exhaust and inlet side one piece crank basically the best of everything including a TTI 5 speed gearbox and I can’t get it above 40BHP at the back wheel, I’ve tried different inlet lengths with this being the best in the midrange, but tried a couple of exhausts and made no difference, where am I going wrong? Any help would be appreciated.
Current exhaust set up and curved inlet manifold to get around the oil tank pics, all to club rules to the pre 1955 class of race bike
The engine revs to 7200rpm with 12.5” inlet total lengh from the valve seat. With 1”5/32 twin carbs
The engine has the full JS kit ie conrods 10.5-1 hi comp pistons with a 0.020” head gasket, js 2 cam timed to spec same as the PW3 profile but smoother, JS valves and springs, head has been ported both on the exhaust and inlet side one piece crank basically the best of everything including a TTI 5 speed gearbox and I can’t get it above 40BHP at the back wheel, I’ve tried different inlet lengths with this being the best in the midrange, but tried a couple of exhausts and made no difference, where am I going wrong? Any help would be appreciated.
Current exhaust set up and curved inlet manifold to get around the oil tank pics, all to club rules to the pre 1955 class of race bike
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