Originally posted by downunder
This is a quote taken directly from the Jett Engineering site regarding running in...
"There are more ways than one, but it is important to remember one thing: With an ABC or AAC engine you don’t really have to worry about breaking in the piston and liner as that will take care of itself.The rod and crankshaft journal pin fit is the object of the break in."
I hate to sound rude but just exactly what is your point??
Why do you leave the impression that my post was inaccurate and that engines don't need any breaking in?
If your going to quote Dub Jett, quote THE ENTIRE text not just the part that suits your agenda or your need to attempt to discredit someone you don't even know!!
Dub makes his engines tighter than most because people are willing to pay extra for better machine work. He also expects more power from his engines and makes the bore taper greater and the piston / cylinder clearance tighter than most mass produced engines.
He considers an engine's piston / cylinder to be worn out long before the average Joe does. But he is looking for the most power he can get while the guy with the little TT .46 is happy as long as the engine starts and runs fairly well long after the piston is loose and that "bump' is gone on the compression stroke!!
http://208.56.133.144/tech/breakin.html
That is the link to Dub's page on breaking in his engines.
Here is some of what YOU chose to leave out!!
'Breaking in your Jett: Put your engine on a test stand!!!. You pay a lot of money for your engines and airplanes. You must spend a bit more time and money to get the engine operating well before you fly. "
"Start the engine at full or part throttle, but not at idle. As quickly as possible, move behind the engine (never stand in front of a running engine - see the safety instructions) and advance the throttle to full. "
"The engine should be RICH. Leave the battery on the glow plug for a while and let the engine run. After about one minute you my start to lean in the high speed needle and remove the glow plug battery. "
"For example, if your engine normally should turn a 10x6 APC at 17000, then you will run the engine during break-in at 17000 on a 9x6 propeller --- RICH. "
"The object is to run the engine for at least 30 minutes RICH, and at its proper RPM before it goes into the airplane. This will give you a chance to check out the throttle characteristics and get used to the engine. After the 30-min. test, then switch to your flying propeller and see if it operates properly.
The above was written by Dub Jett himself and is a lengthier version of what I indicated in my post!!
If your gonna post on the net, don't post half truths or miss-information. Some new guy could go out and ruin his new engine by just following the impression your post left!
CK