O or IO

Which would be best the IO 320 or the O 320?
What have most installed
Likes and dislikes

What plane would this be going into?

Never mind, I just saw this in the RV-9 forum. Ignore me

This is almost like the primer debate. A quick search for carb vs injection will bring up tons of reading; here's one http://www.vansairforce.com/community/showthread.php?t=119830&highlight=carb+injection Or check out the Carb vs FI article here http://www.vansairforce.net/engines.htm

My summary - nobody I've heard of wants to ditch FI for a carb, but there are plenty of folks with carbs who have no desire to switch, either. Carb'ed 320's can be difficult to get LOP, however. Mine will be a carb because thats the engine I found a good deal on. New, there's not much reason not to go FI, the way I see it...

Chris

Soarandtow said:

Which would be best the IO 320 or the O 320?
What have most installed
Likes and dislikes

Click to expand...

I have an O-320 on my RV-6 because that is what I got a great price on.

It depends on price difference of O or IO. Years ago, there was several thousand dollar difference and many went with the less expensive carb. If you shop at all the engine suppliers that advertise on VAF, you will find that on a NEW engine from them, the IO is almost a thousand dollars more. When you consider that the IO will require a slightly more expensive fuel pump, the IO is still about $1,200 to $1,400 dollars more than a carb. Since the IO has much better fuel distribution, one can typically save the cost difference in fuel savings over the life of the engine.

There is only one down side of the injected engine. When it is HOT and the engine is HOT, it can be more difficult to start till you LEARN one of the techniques that will allow you to hot start it.

As you can tell, if I were buying new, I would go with the IO. It is only slightly more money up front but the better fuel distribution and possible fuel savings will save me money in the long run.

If you are buying an experimental engine from Vans, the difference in price is only $50.00. However, you will spend more on the fuel pump and filter combination. When I built mine it was about $500. Current price from Vans is $670 vs $45 for the pump used with the Carb Engine. With the IO, you also will not need a priming system. As they say, it depends on the availability and price of the engine you are looking at.

Both of my engines in my -9 had carbs. Would I like FI, yes and no.

Carbs are simple and easy to start while FI is simple and also easy to start once you learn how.

With dual P-mags, I can run LoP and my CHT's are fairly close together. Not as close as if I had a balanced FI system though. I'm also running an O-360 in my -9 and they say it has better fuel distribution than an O-320, so that may the reason. My O-290-D2 couldn't run LoP with the same ignition.

If budget is an issue, put a carb on it, save your money and install FI later, if you feel you still need it.

Cost difference aside, I would always recommend an IO. You can tune the injectors and run more efficiently lean of peak. Carb's are easier to start, especially hot, but that's the main advantage.