enginehistory.org

[jjuutinen]

I have often wondered why e.g. Americans did not copy German injection pumps as such? I find the injection system in the R-3350 pretty Heath Robinsonish, mildly speaking.

They did a straight copy of e.g. the German electric torpedo as the domestic one was quite poor a design.

[rhaus]

An interesting idea I had many years ago (and used in a high school project) was the use of direct injection with a swirl combustion chamber:

The fuel was to be injected "upwind" of the spark plug...the idea was to "feed" the fuel into the flame front rather than allowing the flame front to travel across the fuel charge...I figured it would reduce the tendency to knock and allow higher compression ratios with poorer quality fuels.

When I was 18, I built a flow bench model by modifying one of my spare 331 Chrysler Hemi cylinder heads (331 Hemi, I suppose that dates me a bit!)........problem was, I didn't know anyone with a flow bench to test any of my theories on this....but the chopped off chamber still looks interesting on the mantle.

I still suspect the concept is valid in some regards, just look at the compression pressures vs the octane ratings of the fuels burned in a gas turbine and yet no detonation occurs--due in part to a stationary flame front.

Anyway, it's a nice day here in Alaska and I've already seen 2 or 3 Beaver float planes head out to some remote fishing spot...makes me want to go outside to fish and listen to R-985's flying overhead...gotta go!

thanks,
Robert

[szielinski]

I wonder if they really understood/liked them.
TM had an article by an R-R engine tester where he had to muck around with a 'damn silly fool Junkers' for ages just to get it going again.
It seemed there was a whole mechanism missing they didn't notice
(yes, yes, I know the plane crashed).
I'm not sure, but I don't think there were American firms with manufacturing licenses (from Bosch) for injection equipment pre-war.
There were in England as far as I know, and the technology didn't seem to be investigated with much fervour.
-just my opinion, no flames, please.

[jjuutinen]

Perhaps they (Americans) should have tried to convert a diesel injection pump to a petrol injection pump, preferable a pump with separate lubricant circulation as e.g. the Bosch pump did.

And there is allways the option of unlicensed copy:)

The starting problems reported ny the RR guy were indeed odd, as both the Jumo and DB had (as far as I know) a reputation of easy starting engines.