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FLYBOYJ said:I doubt it. Recips are usually started, run for 5 mins and shut down, provided no defects are observed. Break in times could be between 10 - 20 hours. At that time variable RPMs are avoided.
FLYBOYJ said:On smaller GA recips it's usually about 10 hours break-in. I think some lycomings want you to avoid certain RPM ranges. Also during break in mineral oil is used in lieu of the regular motor oil....
wmaxt said:FLYBOYJ said:On smaller GA recips it's usually about 10 hours break-in. I think some lycomings want you to avoid certain RPM ranges. Also during break in mineral oil is used in lieu of the regular motor oil....
Ya, cars and bikes also have rpm restrictions the first 10 hours, some like Suzuki requires running the engine in top gear (for a load) at ~2,000 and wide open to about 2/3ds red line and then blip the throttle (to cool the pistons) as you coast down. You do that about 10 times to force the rings against the bores. Engine oil is normaly just good oil but is changed at 100 to 600mi the first time.
Interestingly one shop I worked at set up a show in another location, to transport the bikes we rode them. As we were trying to stock the second location, across 15 miles of desert and we were young we ran those bikes hard, much harder than we were supposed to. I watched those bikes for several years (until I went back to school) and the bikes we ran the hardest were the best bikes we ever sold. They got measurably better power, economy and required the least maintenance. Valve adjustments in particular required Half the shim changes (overhead cam shim/bucket adjustment) of any other bikes I ever did!
Sorry I strayed from the topic.
wmaxt
FLYBOYJ said:You know, very similar with aircraft engines. i knew a gut who had a Grumman Tiger - Ran it close to red line but maintained it accordingly. The engine has a 2000 hr TBO. His went to 3500 hours, still had good compression and hardly burnt any oil.
Maybe this RR/ Packard mystery is in the "break in?"
wmaxt said:FLYBOYJ said:You know, very similar with aircraft engines. i knew a gut who had a Grumman Tiger - Ran it close to red line but maintained it accordingly. The engine has a 2000 hr TBO. His went to 3500 hours, still had good compression and hardly burnt any oil.
Maybe this RR/ Packard mystery is in the "break in?"
Maybe, or maybe a combination of detailing and break in OR it isn't really there in the first place.
wmaxt
wmaxt said:Recently a DB crank from a Bf-109 was taken to RR. After anyalizing the crank, RR gave it back with the warning: "Take care of it WE can't duplicate it". With an additional 50/60 years advancement in experiance and technical know how it's unlikely they were much better in the '40s, not to mention in a war.
wmaxt
Gemhorse said:Alex Henshaw commented in his book, ''Sigh for a Merlin'';
''The new Merlin engines came from Packards and although they were beautifully finished, they had cut out one of the machining processes on the piston skirt, the result of which was that on many of the machines one would get one or two distinct thuds as if the engines were about to seize up. Mostly, however, they settled down...''
Quite an interesting read on the RR thoroughbreds....
Gemhorse