Originally Posted by Davoakes@att.net
I was told that a 360 could be increased to 200-210 HP I do not know the truth. I know about 200 hp 360's but what would a 10HP decrease do to the performance.
Angle valve 360's average around 195HP stock, despite the 200 horse label. Monty Barrett developed the 390 in an attempt to deliver 210+HP without loss of TBO, which was was indeed down to 1000 hours or so among performance-oriented customers. Classic formula; add cubic inches, and not so much CR.
BTW, just for fun, do a little math.
390 / 360 = 1.08
195 HP x 1.08 = 210 HP
The originals were built on modified 360 cases. The buzz was good enough to interest Lycoming, who undertook design of a new 390 case and put together a kit for assembly by independent shops. The deal gave Barrett an exclusive for several years, followed by expansion to (IIRC) five other vendors. Things rocked along nicely until Lycoming suddenly ended the kit engine program. Today 390's are sourced from Lycoming only.
Originally Posted by Jared_Solomon
The price of the IO-390 and Angle Valve IO-360 are about the same. The angle valve will run hotter (possibly less longevity) and not climb as well for very little savings in money.
There is no notable cooling difference between the 360 angle valve and the 390 angle valve. Same basic cylinder, slight bore difference, 5.125 vs 5.319. FWIW, any
angle valve Lycoming will indicate lower CHT as compared to a parallel