1srt run to .8 hrs on hobbs

[Bugsmasher]

Started 45 half today found a couple slow oil leaks. Took care of those and continued running to get some time on it. After 35 -40 minutes the last full power pull on it yielded 3160 rpms- 1225 egts- 315 chts- approx. 55 lds O.P. running Frank's 56 x 24 prop. Sounds very ready to pull something from cockpit! Want to put another 4 or 5 hrs on it before flight though. I am putting on a set of cooling tins to get cht down... happy so far.

[Poorman2]

That is awsome Bugsmasher. What did you do for your exhaust system?

[Bugsmasher]

I made up some short stacks of 1.437' SS tubes around 10" total length from flange to tip. Has smooth points near 1050 rpms and 2150. Hope there is another smooth point just above full power now- hoping for more power - for climb-out. It did pick up around 120 rpms from first full power run.

[Poorman2]

Joe Spencer's 45 hp didn't loosen up until he had about 50 hours on it, If I remember correctly. They are like a fine wine. They get better with age!!!

[Poorman2]

Nice job on the exhaust, by the way.

[Flyguyeddy]

Make sure to route some cooling air down the exhaust port area too

[Bugsmasher]

Well I thought things were going too well considering everything else. Engine now has 4.6 hours of run time. Couldn't get 3 of four valves to remain in adjustment and they kept getting loose as it would seem. Always take notes of everything you do to spot trends. I had started checking valve clearances every time the engine was run. Having an issue checking the third time find yet even greater clearances again it was time to investigate. After close inspection of everything we found that the pushrod cup of the rocker arms was just wearing away. We also found the swivel feet ball sockets beginning to seat the ball deeper in the pocket with wear there too. There is no lack of oil to the top end and no heat indication { galling } on any of the affected parts or lack of lubrication to the pushrod ends and rocker assemblies. These were aftermarket parts not from Hummel. So we conclude this is a heat treatment issue. So much for claims of being better made performance parts.  Not seen so many new parts failures in the last 10 of my 30+years racing and fab work. The machine shop reports that this is not uncommon now. Obtain the best parts ....... from Scott. Now installing new parts. Now I am having a hard time getting the correct rocker geometry with stock rockers without going to extremes.  Stay tuned for the next adventure.....it will either be flying {hopefully} or sold. My patients and pocketbook are nearing their limits. 99% there....175% to go

Yes I have made a set of cooling tins and the helped out a lot on carrying heat out. On the engine from 1 hour of initial run time.