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Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Quieting ramps / Andrews Mk 2
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<blockquote data-quote="oexing" data-source="post: 178748" data-attributes="member: 1493"><p>For hardness testing the olde toolroom checks will do, get a file with an edge or a scriber for scratching the part. The Andrews came with gears pressed on and the bores were quite hard, suitable for all those needles. Basically down to 58 HRC no reduction of calculated loads is necessary, the lower you go with hardnesses you have to factor in less loads. But you could run needles on alu spindles with clean oil and low forces. Like with Laverda 750 twins, they got high tensile conrods, but not like 60 HRC or hardened liners in the big end. But they did extra wide bigends plus two each alu caged roller bearings side by side, exactly same bearings like in the 600 cc Earles BMW R 69 S, running on a 36mm crankpin. </p><p> These crowded needle bearings in my camshafts are a factor higher load carrying than the rest of the valve train, don´t confuse that type with common needle bearing assemblies with cage and inner race. The inner race will have quite thin spindles then and the space for the cage offers only half of numbers of needles and shorter too, so maybe only one third or less of loads a crowded type would take. </p><p> Would you share a photo of your roller followers - or are they secret tech that no competitor may find out ? I see the limit of all loads in the valve train in the bearing of the roller follower: You can have a bush or just hardened faces of spindle and roller in there, for racing it will do a while. But for road use it will not last very long, you really want crowded needles in there, nothing else will do high mileage. Certainly all bearing components will want 58 plus HRC for needles. </p><p> High spring forces actually matter only while at low revs and tickover. At very high engine speeds there is near to no spring force on followers, no matter how aggressive the cam lobes may be. You will be happy to have any small load at all on the followers at that speed as the valve train is wanting to leave contact on the cams from acceleration stage before. All extreme forces on cams and all are based on masses of all components that get shifted in valve lift. So low weights are what matters most in high revving engines, not the spring forces which just care for keeping contact on cams and prevent valve float. </p><p> Again, an argument for alu pushrods, 29 gram , 40 gr the steel originals, heat growth the other matter. </p><p> Not keeping valve clearances in limits will show well with air head BMWs, they will get quite noisy once too much play is set as in consequence the quieting ramps will become uneffective and acceleration of valve gear gets harsh and damaging on components. That is why I´d like to draw attention to valve clearance matters. Other flaws in timing gear are certainly a thing to watch and work on. </p><p> Greg, did you ever check for valve clearance on a hot engine right after killing it at home ? Certainly provided you set it for nil at cold first . The 460 cc Regina with all alu engine and alu tubes would like a bit more heat growth of pushrods when hot but I cannot think of any idea how to achieve this - and I will not go for some hydraulic gadget in there.</p><p> Below my modded roller followers from prewar Horexes, the 1935 Guzzi got same treatment with needles more than 30 years ago, did 30 000 km since. </p><p></p><p> Vic</p><p></p><p>[ATTACH=full]61916[/ATTACH]</p><p></p><p>[ATTACH=full]61917[/ATTACH]</p><p></p><p>[ATTACH=full]61918[/ATTACH]</p><p></p><p>[ATTACH=full]61919[/ATTACH]</p></blockquote><p></p>
[QUOTE="oexing, post: 178748, member: 1493"] For hardness testing the olde toolroom checks will do, get a file with an edge or a scriber for scratching the part. The Andrews came with gears pressed on and the bores were quite hard, suitable for all those needles. Basically down to 58 HRC no reduction of calculated loads is necessary, the lower you go with hardnesses you have to factor in less loads. But you could run needles on alu spindles with clean oil and low forces. Like with Laverda 750 twins, they got high tensile conrods, but not like 60 HRC or hardened liners in the big end. But they did extra wide bigends plus two each alu caged roller bearings side by side, exactly same bearings like in the 600 cc Earles BMW R 69 S, running on a 36mm crankpin. These crowded needle bearings in my camshafts are a factor higher load carrying than the rest of the valve train, don´t confuse that type with common needle bearing assemblies with cage and inner race. The inner race will have quite thin spindles then and the space for the cage offers only half of numbers of needles and shorter too, so maybe only one third or less of loads a crowded type would take. Would you share a photo of your roller followers - or are they secret tech that no competitor may find out ? I see the limit of all loads in the valve train in the bearing of the roller follower: You can have a bush or just hardened faces of spindle and roller in there, for racing it will do a while. But for road use it will not last very long, you really want crowded needles in there, nothing else will do high mileage. Certainly all bearing components will want 58 plus HRC for needles. High spring forces actually matter only while at low revs and tickover. At very high engine speeds there is near to no spring force on followers, no matter how aggressive the cam lobes may be. You will be happy to have any small load at all on the followers at that speed as the valve train is wanting to leave contact on the cams from acceleration stage before. All extreme forces on cams and all are based on masses of all components that get shifted in valve lift. So low weights are what matters most in high revving engines, not the spring forces which just care for keeping contact on cams and prevent valve float. Again, an argument for alu pushrods, 29 gram , 40 gr the steel originals, heat growth the other matter. Not keeping valve clearances in limits will show well with air head BMWs, they will get quite noisy once too much play is set as in consequence the quieting ramps will become uneffective and acceleration of valve gear gets harsh and damaging on components. That is why I´d like to draw attention to valve clearance matters. Other flaws in timing gear are certainly a thing to watch and work on. Greg, did you ever check for valve clearance on a hot engine right after killing it at home ? Certainly provided you set it for nil at cold first . The 460 cc Regina with all alu engine and alu tubes would like a bit more heat growth of pushrods when hot but I cannot think of any idea how to achieve this - and I will not go for some hydraulic gadget in there. Below my modded roller followers from prewar Horexes, the 1935 Guzzi got same treatment with needles more than 30 years ago, did 30 000 km since. Vic [ATTACH type="full"]61916[/ATTACH] [ATTACH type="full"]61917[/ATTACH] [ATTACH type="full"]61918[/ATTACH] [ATTACH type="full"]61919[/ATTACH] [/QUOTE]
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Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Quieting ramps / Andrews Mk 2
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