Lift timing

[DuGong]

well. cams have are not in the market yet.

for now. has anyone tested this theory out yet?

i would like to see some evidence to prove that it doesnt work.

hey, i could be wrong.

[qkslvr]

Hey Dylan. Sounds like you know a thing or two about engine dynamics.

The progressive timing and lift adjustment you're talking about is present on modern Ferrari engines. it's the most elegent design in this whole variable valve timing business. it uses a simple 3D cut cam lobe. to adjust valve timing at various speeds in the rev range, it has a mechanism that simply slides the entire cam shaft from side to side.

[Danthuyer]

I hope Craig won't mind me discussing this but I chatted to him a while back about this issue and my POV was that the best solution was to engineer a 'progressive lobe' cam which gradually shifted from a low RPM setting to a high RPM setting, rather then being on 2 seperate lobes. This would produce a smooth transition everytime, as you don't swap cams, and could also be extended to a much higher RPM by continuing the cams size progression (and stiffening the valves and springs, refined pistons and rings, etc, etc)... I think a similar method is used in F1 engines but I could be wrong. The down side is that these need to be precission engineered by hand making them extremely expensive, and the research that needs to go into it, well you may as well design a whole new engine around the cams as well..

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What if Craig does mind????? :P jokes

A progressive cam has been made by a guy in his backyard workshop in AUS (yes you heard right) which is turning head upside down around the industry. It is similar in desgin the the ferarri moving lobe which qkslvr mentioned.

I'll keep you posted ;)

[MR22ZZ]

Hey Dylan. Sounds like you know a thing or two about engine dynamics.

The progressive timing and lift adjustment you're talking about is present on modern Ferrari engines. it's the most elegent design in this whole variable valve timing business. it uses a simple 3D cut cam lobe. to adjust valve timing at various speeds in the rev range, it has a mechanism that simply slides the entire cam shaft from side to side.

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Cheers Kien,

Actually not really I just have wild outlandish ideas that seem to serve good purposes, that's why I work in R&D areas. If I had thought about things more at school maybe I would have done Mechanical Engineering instead of Chemistry, but them's the breaks. Maybe a second degree is in order once I finish my PhD. I'd love to be working in motorsport but don't like my chances unless I can develop a surface structured low drag paint, but even then it would be working for a subsiduary company like PPG rather then being hands on, though the wind tunnel work would be fun :) ...

Craig... I'd love to hear more of this cam if you could keep me posted :D

Later...

Dylan