 MassIVe redefined., This should seriously influence future "six Vs four" debates |
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| Brian Mifsud |
 Oct 15 2007, 11:51 AM
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#61
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Mechanical Engineer  Group: Members Posts: 981 Joined: 3-March 03 From: Penngrove, CA Member No.: 384 Region Association: None  |
Overhead cam does not (necessarily) = high rpms (compared to pushrod)
those nuts in NASCAR are spinning all day a 9000-10000 RPM.. and on the other extreme.. my SOHC Ford 4.6 V8 is gasping for breath at 5800 RPM |
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| Jake Raby |
Oct 15 2007, 01:13 PM
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#62
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
It's all in the combo....
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| Mid_Engine_914 |
Oct 15 2007, 02:00 PM
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#63
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Member Group: Members Posts: 195 Joined: 22-September 06 From: Left Coast Member No.: 6,888 |
I've been learning about late model BMW motorcycle boxer "oilhead" engines and they use a compromise design consisting of two cams in the head operating the rocker arms using short push rods.
From Wikipedia: "By this time the benefits of overhead cams were known; higher revs could be obtained before the onset of valve float. However, the basic boxer design did not lend itself to overhead cams. To obtain the benefits of overhead cams without overly increasing the engine width, BMW incorporated a system that was so advanced for its racing bikes that it resurrected it many decades later in the R 1100 RS oilhead. The system was two cams in the head operating rocker arms via short push rods." http://en.wikipedia.org/wiki/BMW_motorcycl...orcycle_History |
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| Mid_Engine_914 |
Oct 16 2007, 02:53 PM
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#64
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Member Group: Members Posts: 195 Joined: 22-September 06 From: Left Coast Member No.: 6,888 |
BMW just introduced a new flat twin motor with proper overhead cam heads. I wonder if they could be adapted to work with the Type IV motor?
(IMG:http://img81.imageshack.us/img81/5537/k1200sr1200shp2sport2ro1.jpg) (IMG:http://img81.imageshack.us/img81/9787/k1200sr1200shp2sport1sx8.jpg) (IMG:http://img81.imageshack.us/img81/8465/k1200sr1200shp2sport3cu7.jpg) (IMG:http://img124.imageshack.us/img124/5188/k1200sr1200shp2sport4tk0.jpg) (IMG:http://img124.imageshack.us/img124/111/k1200sr1200shp2sport5dd9.jpg) |
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