A lot of people have pointed out that there is no point in actually holding an engine at high RPM for long periods. But there is one "legitimate" excuse for doing this - and that is durability testing of camshaft and valve gear systems. If you can't afford a Spintron machine it is a simple and...
There certainly was once a view that holding an engine at peak RPM in an unloaded state was potentially dangerous.
The idea being that there was little compressed gas in the combustion chamber to "cushion" the piston at the top of its compression stroke.
Popular legend has that the very long...
PP - BMW's Valvetronic (if that is the system you are referring to) is not just variable fulcrum but an "oscillating cam" system of linked variable duration and variable lift.
Greg - Just what do you mean by "variable intake"? variable lift, duration or length of the intake tracts?
The centrifugal advance mechanism on a diesel injector pump camshaft may give you a few ideas.
I have read that the "Varicam" (or whatever it was called) did operate OK but had little or no measureable effect on the engine output.
I think if you are going to work with conventional...
Greg50H - I am not quite sure what you are doing but it sounds interesting.
You may be also interested to see the following:
http://www.helicalcamshaft.com/
http://en.wikipedia.org/wiki/Helical_camshaft
This is one of the very few (maybe the only?) mechanical varible duration system that...
That is what I was wondering - 12 degrees is not much advance for 4000RPM - 30 or so would be more appropriate.
Maybe when you don't have enough advance it doesn't matter much whether it is 4 or 12 degrees?
Evel - I had a 1965 998cc Cooper (not an "S"). This had the rubber couplings and I think this type of coupling persisted for quite few years after 1965 (in Oz at least). So it just wasn't very early Minis that had the rubber joints. I don't think the "S" types ever had rubber joints.
The Elan...
I am about to encounter the same problem as Dexion with my own little car. I am intending to solidly mount the engine and final drive solidly together with aluminium plates or a small frame and then mount the whole "transaxle" unit flexibly in the car.
PP - I think what Mike Halloran is...
If you are using a motorcycle engine in a boat you can have a chain drive from the engine down to the propellor shaft running under the engine - this also allows a shallower angle on the shaft. I have seen this arrangement a few times on small hydroplanes.
Which reminds me - three-point...
TDI - despite much searching I still have yet to find the Schutting et al paper.
I am afraid I take a somewhat simplistic and less "scholarly" view of the Atkinson Cycle. I regard any engine which has a high CR (too high for "normal" use) combined with any strategy to reduce the combustion...
When you wrote "novel" and "front engine" I thought you were going to describe a boat with its propeller on the bow. These were tried in some speedboats in the 1930s - presumably they were non-planing hulls.
With your boat I don't think you can have the engine weight so far forward and still...
TDI - you originally wrote above: "Atkinson denotes very early intake closing before BDC resulting in a pre-expansion etc."
I don't see how this can be construed as Atkinson by anbody's definition.
TDI - I am afraid I must disagree with your description of the Atkinson Cycle. If you go back to the original idea of an Atkinson Cycle it was with a engine that had a physically longer expansion stroke than compression stroke - thus having a higher TE.
The modern equivalent of this I would...
Warpy - if the lower arms remain unloaded from tractive effort - what does transfer the tractive effort from the wheels to the chassis?
I am inclined to agree about the contact patches not being centered being likely culprits.
One reason that I think the unequal shafts may be the cause...
