Engine Options & downsides ?

[Niels3n]

I'm at the point where I need to find or order an engine for my RV10 and appreciate that the ideal is the IO-540-D4A5.

For those have have opted to use other variants of the IO-540 has it caused much additional work ? Has anyone purchased an engine that they regret buying ?

Is an IO-540-C4B5 a good option (removed from an Aztec) ?

Has anyone used an IO-540-C4D5D which has a dual mag, I'm assuming that this wouldn't be ideal but have a friend who may have one available shortly.

Any experiences that other builders can share would be appreciated - I'm really trying to keep the aircraft build as close to plans as possible.

Thanks Niels

 

[lr172]

Is an IO-540-C4B5 a good option (removed from an Aztec) ?

I got a C1B5 from an aztec and converted to C4B5 during overhaul. It is pretty much the same as the D4A5 buit with an RPM restriction you don't need to respect. Very happy with it. Be cautious though, as many Aztecs had C1B5'S and shouldn't run those with the hartzel compact hubs; Needs different counter weights and pins.

 

[Kyle Boatright]

A 540 removed from a Comanche is identical internally to the D4A5 Van's sells (except it'll be 60 years older and probably have a narrow case). The RPM restriction difference is arbitrary on the engine. The accessory may be different (Starter, fuel injection type, etc).

That said, all new from Van's is eye wateringly expensive, but so are all the other options. I'd take a hard look at factory new.

 

[Clangenf]

I went with an IO-540-C4B5. It was a 0 SMOH engine, but that overhaul took place a very long time ago. I am having it freshly overhauled by Aerosport Power. They come highly recommended.
The C4B5 is identical in terms of parts when compared to a D4A5, it is just rated at 2575 RPM versus 2700 RPM. As mentioned above, the RPM limitation to 2575 is widely considered arbitrary.
Mine is a narrow deck engine. If opportunity presents itself, I hear that a wide deck is preferred -- but not mandatory.
Call Darren at Aerosport Power. He has been great to deal with thus far.
I had originally thought about an angle-valve IO-540 for my RV-10... but after researching how much extra work that would entail, I stuck with a parallel valve engine.
Frankly, I am not done yet, so take all of this with a grain of salt!

 

[lr172]

.
Mine is a narrow deck engine. If opportunity presents itself, I hear that a wide deck is preferred -- but not mandatory.

that is debatable when talking with those that work with them every day. Inexperienced folks just assume the newer design must be better than an old design and wider must be better than narrow. Both of my engines are ND and have given me great service.

 

[Jesse23]

The only time I reach 2700 (2680) is on take off.

 

[jacoby]

In addition to what everyone has posted the C4A5 may also have different mounting ears than the D4A5. My C4A5 core has the incompatible ones. They are not hard to change but run $200-250 each used or $800+ each new.

Iirc the dual mag accessory case is different than the two mag one. Research would be needed for fitment. Switching to the two mag version would be quite expensive.

 

[lr172]

In addition to what everyone has posted the C4A5 may also have different mounting ears than the D4A5. My C4A5 core has the incompatible ones. They are not hard to change but run $200-250 each used or $800+ each new.

Iirc the dual mag accessory case is different than the two mag one. Research would be needed for fitment. Switching to the two mag version would be quite expensive.

I think many of the older C series engines have the wrong mount ears for our application. Mine certainly did.

 

[Niels3n]

Thanks for the information so far, it’s really helpful.

The C4D5D is from a friend and I know the full history and have know that it’s been running faultlessly - but I know nothing of the Dual Mag and this is putting me off.

Assuming that the engine and dual mag fits within the standard RV10 cowling - is a dual mag an option ? (I spoke to engineer builder who advised that changing it to standard mags
Isn’t cost effective).

I see that there are a handful of Rv10’s on the FAA register that have the D (dual mag) designation- does anyone have any experience with them ?

Thanks

 

[jacoby]

I think many of the older C series engines have the wrong mount ears for our application. Mine certainly did.

It seems to be the norm with to have the wrong mounts on twin engine applications? I’ve never been able to find any reasoning behind the two styles. My core came out of a F model Aztec.

The parts manual says the C4A5 could have either.

 

[lr172]

Thanks for the information so far, it’s really helpful.

The C4D5D is from a friend and I know the full history and have know that it’s been running faultlessly - but I know nothing of the Dual Mag and this is putting me off.

Assuming that the engine and dual mag fits within the standard RV10 cowling - is a dual mag an option ? (I spoke to engineer builder who advised that changing it to standard mags
Isn’t cost effective).

I see that there are a handful of Rv10’s on the FAA register that have the D (dual mag) designation- does anyone have any experience with them ?

Thanks

While not well read on the subject, I would likely steer clear of the dual mag thing. You can try to find an accy case from the many outlets that sell these used parts. I think the cases are stand fit across most of the Lyc line. Better yet, stick one mag on the case and get one of the many elec ign products for the 2nd. Can also do dual EI, but will require a some planning in power storage and distribution. A lot of us are now using two EIs with no mags; I do.m I don't know their vulnerabilities, so can't speculate on the risk of putting one mag there.

 

[lr172]

It seems to be the norm with to have the wrong mounts on twin engine applications? I’ve never been able to find any reasoning behind the two styles. My core came out of a F model Aztec.

The parts manual says the C4A5 could have either.

Not really wrong, just a different style than what vans chose to use. Lyc offered options here and the airframe mfr decided which style of mount/isolator they wanted to use.

 

[airguy]

that is debatable when talking with those that work with them every day. Inexperienced folks just assume the newer design must be better than an old design and wider must be better than narrow. Both of my engines are ND and have given me great service.

My IO360 on my 9A is a narrow deck, and so is the 540 I took off an Aztec for the 10. I am going to send my 540 over to Rhonda Barrett and have her work her magic on it before installation.

With 1980 hours on my 9A, I ran across a guy a while back (here on Vans) that was parting out a narrow deck 360 with a cracked case and bought his cylinders. I had them overhauled to P10 (all 4) and have them sitting in 5-gallon buckets of oil right now just waiting for top overhaul.

 

[Kyle Boatright]

Iirc the dual mag accessory case is different than the two mag one. Research would be needed for fitment. Switching to the two mag version would be quite expensive.

I think it is worse than just the accessory case. The bosses for mag gears and such on the engine case halves are different. If you buy a dual mag engine, I think it is impractical to convert it to two conventional mags (or sureflys or pMags). You're better off going with an electronic ignition timed via the flywheel, like one of the SDS offerings.

 

[lr172]

I think it is worse than just the accessory case. The bosses for mag gears and such on the engine case halves are different.

good point here. If you are considering the new accesory case route, give divco a call and ask about it. There is a good chance they can modify the case to accomodate the accy case with two mags. I have been pretty surprised with the level of modifications they are able to make. They blob on a bunch of metal via TIG and machine back to different configs. I had to have my accy case modified to support a 1 piece cam. They also converted my conical mounts to dtnafocal.

 

[Niels3n]

I think it is worse than just the accessory case. The bosses for mag gears and such on the engine case halves are different. If you buy a dual mag engine, I think it is impractical to convert it to two conventional mags (or sureflys or pMags). You're better off going with an electronic ignition timed via the flywheel, like one of the SDS offerings.

This sounds like a better option - do you know of anyone that has done this and how well it has worked and if it was straighforward or needed other engine modifications done ?

 

[Kyle Boatright]

This sounds like a better option - do you know of anyone that has done this and how well it has worked and if it was straighforward or needed other engine modifications done ?

If you went with an SDS system, you'd simply remove the mag and mag drive, seal the mag holes, and install an SDS dual ignition. That would mean mounting 4-5 magnets in your flywheel, adding sensors for those magnets, planning on some sort of battery backup for the ignition system, and installing the SDS. For what it is worth, SDS installation is simple, but the instructions are not as easy to follow as they should be.

 

[andoman]

I have a dual SDS CPI2 and it works very well. I found The SDS instructions straight forward enough. I agree that it is a relatively simple installation.
The system has a backup battery feature designed in so there is no need to make changes to the overall architecture of your electrical system.
If I were to do it again I would have gone the full SDS EFI route. If your fuel and electrical systems aren’t designed and installed yet it’s worth considering regardless of which engine you decide on.