E-185-1

[Mike Hemsley]

I'm a newbie on the forum and to the Bonanza world, so please go easy on me... Thanks

I have an E-185-1, D-3446 with "727" cylinders.  Can someone help me with determining what exactly that means?  Displacement, HP, etc.. At the time of overhaul an entry was made indicating "727" cylinders were installed. I have been told that they are larger cylinders and the increased displacement bumps the HP from 205-225@2600 RPM and from 185-205@2300 RPM.  I can't find any data on this combination.

[Steve Zeller]

Mike, All the "727" means is that the cylinder head casting is of a more recent design and less prone to cracking than earlier E225 head designs. More recent is a "relative" thing. The last "727" cylinders were probably manufactured at least 30 years ago. Since any jug probably shouldn't be overhauled more than 2-3 times, even the 727's are subject to age and wear.

[Mike Hemsley]

Thanks Steve.. That's very helpful info. 

 

[James Dunn]

Also note that the E185-1 are 470 ci displacement and delivered 165HP continuous and 185 HP for 1 minute in the Bonanza.  The E185-8 and E185-11 were 185HP continuous, 205HP for 1 min.  The E225-8 is also 470 ci displacement delivering 185HP continuous, 225HP for 1 minute.  Late production E185's can be converted to E225's.

Aviation Research has an STC to install IO-470N cylinders on E225-8 engines (not E185).  That might be what you're thinking about.

http://www.aviation-research.com/e2258.html