[jakobnev]

Originally Posted by Old Mechanic

Suggesting that the average ecomodder would be capable of "modifying the compression ratio" then adding a means of direct injection of fuel into the combustion chamber, which would require some serious engineering and an additional passageway in the cylinder head, is far beyond anyone outside of a considerably competent machine shop and engineering expertise, that to this point has evaded the ability of many new car manufacturers.

Stop lumping those two together, it's not like it's more difficult to make toast after making a cup of coffee. And yes, if someone went ahead and designed a good enough solution many could do it. (average might be a bit of a stretch tho.) Take the MPGuino as an example, many people are able to build them from plans, but not as many would be able to design them from scratch.

That being said, it may actually come to a point where the existing spark plug hole could be used if a combination direct injector and spark plug mechanism could be designed and produced.

Yes, yes! And someone could make such plugjectors and sell them to people who don't have the skills and/or equipment to make them themselves - just like high-comp pistons are sold today.