Quote:
Originally Posted by P38 in workshop
A number of posters appear to be assuming that there is a need for 2 stroke engines to run on a fuel/oil mixture,like an old lawnmower engine.With direct injection and forced induction,it doesn't have to be that way.There is no reason why lubrication can't be done by circulating oil in the way it is done at present and in the huge marine engines I referenced in an earlier post it is done this way.As long as we are using forced induction It just needs a valve ,or port, to open for the entrance of air and the fuel can be injected just before ignition.
I don't think i have seen a reference on this forum to the importance of direct injection to the big gains in thermal efficiency of the last few years.Not so many years ago it was verging on impossible to use compression ratios of more than about 13.5:1 because of detonation.Now that fuel is injected directly the rules limit the engines to 18:1 and this is with forced induction.If the engines under discussion don't have to scrape a set of piston rings up and down one extra time in each combustion cycle,won't there be another big step in efficiency gains?The timing of valve/port openings might be some way from what we are used to and may take a little time to optimise but it would be unwise to dismiss the idea of a move to a different form of engine because of what they used to be like.
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To be honest I find this re-visiting old ideas with new technology fascinating. As you say a modern twe-stroke engine should be significantly more efficient than one that takes twice as long to get to another firing stroke. Even if ultimately these engines don't make it into F1 the whole idea has sparked some interest with me.