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Looking at pros and cons for engine options

rgaynor

Active Member
Hi Everyone,

One of the engine options I am considering for my RV-10 build is a Cold Air Induction system. From your experience can you tell me the pros and cons of going with a cold air induction system? I know if produces more hp, but any ideas on how much that translates into knots and what are the downsides?

Thanks in advance,
 
I think you will find very little detailed before/after testing with this sump, if any. Not sure which brand/model you are considering for your engine, but here is my view based on my IO-360.

The main pros are:
  • reduces intake air temp - no idea how much, but probably some math and physics could calculate this pretty closely - I doubt it's huge
  • looks nice
  • has a lot of ports for measuring oil temp
  • lighter

The cons are, based on my limited experience:

  • costs about $2k (for IO-360 from Superior)
  • intake tubes are different, which is a hassle if you use Ross's excellent intake tube flange upgrade
    (http://www.sdsefi.com/sdsaero.htm)
  • attachment points for things like throttle/mixture brackets might be different from "standard/stock"
There may be other pros/cons based on your exact setup. There is a lot of discussion on this topic on VAF here:

https://www.google.com/search?q=site:vansairforce.com+superior+cold+induction+system+lycoming
 
I ordered my IO-540 from Thunderbolt with standard compression pistons and Cold Air Sump. I was told I’d get ~10 more ponies out of it.

The downside is cost and a more complicated install. The biggest install issue is what to do about the intake filter. After reading the very nice work by Dan Horton it became evident that the simple conical K&N filters was not the way to go.

For my new RV-10 project I’ll be using the revised Sam James RV-10 cowl and plenum. For the filter Jimmy at Sam James has been working on a vastly improved intake filter setup.

On my first RV-10 project I used the original Sam James Cowl and plenum and enjoyed its performance gains.

Carl
 
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Hi Everyone,

One of the engine options I am considering for my RV-10 build is a Cold Air Induction system. From your experience can you tell me the pros and cons of going with a cold air induction system? I know if produces more hp, but any ideas on how much that translates into knots and what are the downsides?

Thanks in advance,

If you’re doing a CAI for the -10, you will want to consider a Showplanes cowl for clearance, and if doing that, their intake plenum with filters works very well.
 
colder air is denser and therefore more O2 per cubic measurement; The only components of air that produce power are O2. Therefore, cooling the intake air will net more available HP for any given ambient temp. However, it is not free HP, like increased Compression Ratio provides. The denser air requires more fuel as well to make that extra HP. Therefore if you care about max power, it is a good thing; However, you only get the extra ponies when WOT and at best power mixture or richer. How much time do you spend there? If you care about more power at the same fuel burn, no help.

Larry
 
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How much HP?

I have a 250 hp O-540 and tend to run it at around 50-55% power for economy. The plane is very impressive in t/o, climb and service ceiling. If it made 300 hp I would still fly it around at 10 gph cruise. I know it is bragging rights to have a monster motor but in practice it would have little value to a minimalist like me. YMMV
 
Motor mount

One downside of the CAI is (was) the need to modify the engine mount to clear the sump - at least with the old style 10 mount and the Barrett CAI.

I have heard, but not verified, that the newer mounts from Van’s may not need the modification. You will want to check on that.

There are other CAI’s available and I don’t know about the fit with those.

As someone else mentioned, the Showplanes cowl will fit a 540 with the Barrett sump and it works with the Custom Aircraft exhaust and Airflow Systems A/C. There is a lot of work on the dual combustion air intakes to work around the a/c compressor. If the new James cowl fits with a/c, I would recommend that option instead.
 
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