Guest DonC Posted July 30, 2012 Share Posted July 30, 2012 Has anyone bought a 3300 post ser no 2390? I would be interested to know if mine is the only lemon (again) With the reduced compression I lost 200 rpm ( and several hp ) The revs were regained by buying a finer pitched prop ( at my expense ) but of course cruise speed is down while fuel consomption is still 25.6 lt/hr. Pissed off Link to comment Share on other sites More sharing options...
facthunter Posted July 30, 2012 Share Posted July 30, 2012 The lowered compression will reduce power. As to the fuel consumption, the Lyc 0-235 in the Citabria would use 25 lt/hr with the cruise Hp at about 80 although the engine is rated at 115 hp. This was exactly what the book figures were and that was very consistent, although the engine was manually leaned and the average cruise level was around 5,000 ft. I don't know what your cruise horsepower is, but it may be a bit above 80 so perhaps the burn is not too bad. Nev Link to comment Share on other sites More sharing options...
Tomo Posted July 30, 2012 Share Posted July 30, 2012 Agree, between 24-28ltrs an hour for 120hp (or thereabouts) I'd be pretty happy with for a carby naturally aspirated engine. I'd be concerned about the low compression though, as that won't get any better... and more likely get worse over time. Did the leak down indicate where it was going? Valves, past the rings etc...? Link to comment Share on other sites More sharing options...
RKW Posted July 30, 2012 Share Posted July 30, 2012 Agree, between 24-28ltrs an hour for 120hp (or thereabouts) I'd be pretty happy with for a carby naturally aspirated engine.I'd be concerned about the low compression though, as that won't get any better... and more likely get worse over time. Did the leak down indicate where it was going? Valves, past the rings etc...? Hi Tomo, I think DonC is referring to the reduced compression ratio in the later motors. This was achieved either by a .5mm spacer or a taller cylinder. Also, the spark advance was reduced from 25deg to 20deg which would certainly reduce output. Link to comment Share on other sites More sharing options...
Tomo Posted July 30, 2012 Share Posted July 30, 2012 Ah... I see, that makes better sense! Link to comment Share on other sites More sharing options...
facthunter Posted July 30, 2012 Share Posted July 30, 2012 I reckon the retarding of the ignition to 20 is too far but you guys just keep doing what they say ( as you must). The engine must run hotter with that setting, and lose power and use more fuel. ( But you didn't hear me say it). I'd take it up with someone at some time. I would want to be convinced. Nev 1 Link to comment Share on other sites More sharing options...
Guest DonC Posted July 31, 2012 Share Posted July 31, 2012 I reckon the retarding of the ignition to 20 is too far but you guys just keep doing what they say ( as you must). The engine must run hotter with that setting, and lose power and use more fuel. ( But you didn't hear me say it). I'd take it up with someone at some time. I would want to be convinced. Nev So - Has anyone else bought one, or am I the only idiot? Link to comment Share on other sites More sharing options...
facthunter Posted July 31, 2012 Share Posted July 31, 2012 I don't think you are an idiot. Talk to people who are getting a good run. The six is a smooth motor and climb it faster than minimum speed on a hot day. Don't cook it and it will be OK. NO engine can operate above the recommmended MAX temps without damage. Discussing these things objectively is not easy on a forum. This topic in one way or another is going under about 3 threads at the moment here. Nev Link to comment Share on other sites More sharing options...
Jabiru Phil Posted July 31, 2012 Share Posted July 31, 2012 Don, I would get a LAME to investigate. Leak down test etc. Figures should indicate the problem. Aside to this, I was supplied a full engine analysis print out when I got mine. Check your records it may show up there. Phil Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now