A different Lycoming

[patterson]

Hello to the engine gurus who frequent this site.
I have a question about doing a one-off cylinder (4 actually)for an O320. I like the angle valve on the 360 motors, or the GL 480. Realizing that the barrel of a 320 is shorter, is it feasible to use two cores (a 320 and a 480), mate the angle valve head of the 480 to a barrel of the 320 and have a little O-320 angle valve motor???

Am I dreaming?

I wonder if it could possibly breath better, be more efficient, get maybe 10 more Hp without increasing the standard compression ratio?

Of course, I think the camshaft might need a special grind, the piston size would need to be calculated for a correct compression ratio, the exhaust would need to be a custom one-off as well as the intakes. What else am I missing or not considering that is a real concern?
Ron
N8ZD
RV-4 - 480 hours

[Mike S]

Mahlon Russell on this forum should be able to tell you, or the good folks from Barrett Performance, who are also members here.

Or, call LyCon in Fresno CA.

Sounds like an interesting experiment

[jrs14855]

This used to be fairly popular. However the 480 cylinders will only mate to a narrow deck 0 320 case. I don't know what else is involved. Six 320 cylinders equals 480 cubic inches. You see these engines occasionally on ebay or barnstormers. Also good 480 cylinders might be hard to find. Should be good for almost 20 horsepower.

[RV6_flyer]

I remember reading about using the 480 angle valve cylinders on the smaller engines. Do not remember if it was the 290 G or the 320. The old T-18 newletters that were published back in the 1960's time frame talked about doing stuff like this. I also think there may have been an Ez that used parts from different engines to get his speed up for racing. Doing a Google search, there are AirBoat guys doing what you are talking about.
http://www.southernairboat.com/phpBB...ic.php?t=31111

A lot of Lycoming parts are interchangeable. The valves in the parallel valve 320 / 360 are the same part numbers. Look at the parts numbers in the different parts catalog and you will find that a lot of parts are the same part numbers. I remember reading in the old T-18 newsletters about how Lycoming engines evolved into what we have today.

If you want to read about the History of Lycoming, it is on their web site. Unfortunately, it does not go into how they developed one engine from another.

[Andy_RR]

Angle valve cylinders are HEAVY. There is about 1.3kg (2.8lb) difference between an angle valve and a parallel valve barrel.

[patterson]

I have a fresh wide deck case all ready to go. Are you certain this only works with a narrow deck? seems to me the bore is the same, no?
Ron