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Todays competition "WTF is that noise"?
Most noticeable between 1200 to 2800 rpm under load - reduces and eases off between 3000 - 6000 rpm and 'off-load' on trailing throttle.
Kinda hoping some of you 'old school' race guys will comment.
Background - 489 cu in BBC. Hot oil pressure 35/40 psi idle/70/80+ psi cruise. Less than 2000 miles after new build. Flat tappet hydraulic cam - fairly aggressive opening and closing ramps on cam - so it is on noisy side (but made worse by phone mounted next to valve cover on firewall. Definately not valve gear related. Sounds a bit like an 'big end' going but appears to be higher within engine. Has always had good oil pressure. Inspected cam, lifters and pushrods - all UK.
Best heard with speakers or headphones!
Most noticeable between 1200 to 2800 rpm under load - reduces and eases off between 3000 - 6000 rpm and 'off-load' on trailing throttle.
Kinda hoping some of you 'old school' race guys will comment.
Background - 489 cu in BBC. Hot oil pressure 35/40 psi idle/70/80+ psi cruise. Less than 2000 miles after new build. Flat tappet hydraulic cam - fairly aggressive opening and closing ramps on cam - so it is on noisy side (but made worse by phone mounted next to valve cover on firewall. Definately not valve gear related. Sounds a bit like an 'big end' going but appears to be higher within engine. Has always had good oil pressure. Inspected cam, lifters and pushrods - all UK.
Best heard with speakers or headphones!