• The Biplane Forum is a large global active community of biplane builders, owners and pilots. From Pitts to Skybolts, to older barnstormers, all types are welcome. In addition to our active community, our content boasts exhaustive technical information which is often sought after for projects and maintenance. This information has accumulated over the 12+ years the forum has been in existence.

    The Biplane Forum is a private community. Subscriptions are only $49.99/year or $6.99/month to gain access to this great community and unmatched source of information not found anywhere else on the web. We are also a great resource for non biplane users, since many GA aircraft are built the same way (fabric and tube construction). Annual membership also comes with two BiplaneForum.com decals.



HO-360 break in CHT issu

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

harleygaz

Well-Known Member
Joined
Aug 31, 2011
Messages
88
Reaction score
6
Hi. I have an overhauled to zero TSMO HO-360 in my Starduster that is giving very different CHT readings on the cylinders. The Lycoming manual gives 65% power and 70% power both at 2700 RPM but I think that's for helicopters so I'm using 2600 and 2700. The engine had an hour on a test stand, maybe 30 minutes ground runs to cecl installation and 3 hours air time. In the climb at full rich and WOT I'm getting over 500 on #3 cylinder and in the cruise at 2700 it won't come below 500. at 2600 it'll come down to maybe 490 and at 2500 470-480. #1 and #4 never exceed about 480 at 2700 and fall to 460 at 2600, #2 never exceeds 400 at all. I've been keeping the RPM down to avoid overheating but I'm afarid that will prevent proper brak in. The 3 flight so far indicate about 1/2 quart of oil per hour and a cold compression checl gave all 4 cyliinders 78 to 79 / 80. Plugs show a very rich mixture. Tomorrow I'll try swapping #1 and #3 CHT propbe (bayonet type) in case it's the probe. Cowling is the standard Starduster nose bowl and baffling and seals look OK. I don't want to ruin my new engine by over heating but I do want to break it in properly so I would appreciate any help in where to look next
 

Latest posts

Back
Top