RV-6 engine replacement

[newt]

My RV-6 is on about 1830 hours. I'll have an annual condition inspection in October, then I think there'll be engine work in 2021.

Current engine is a carburetted O-320-D2A with a Sensenich fixed-pitch cruise prop.

I didn't build the aircraft.

The current fuel system has plumbing feeding an Andair valve supplying the suction side of a Facet fuel pump on the inside wall of the fuselage between the pilot seat and the rudder pedals, with the pump discharge feeding a gascolator on the engine side of the firewall, which in turn runs to the engine-driven fuel pump.

It's still more than a year and a half away, but planning is good, and the direction I'm tending towards now is to take the O-320-D2A off and replace it with some variant of an IO-360, probably also with a fixed-pitch prop.

The change from carburettor to fuel injection is going to involve fuel system modifications: I'm anticipating that the Facet pump will end up in the trash, with a new high pressure fuel pump and new plumbing.

I'm sure someone has gone down the path of carb to fuel injection before, and if anyone has advice I'd love to hear about it.

Are folks generally keeping high-pressure fuel out of the cockpit, so where's the right spot for the electric pump? Is the gascolator necessary? Considerations for routing fuel lines to avoid vapor lock? How are fuel systems handled in modern certified aircraft? Anything else I'm not thinking of?

Thanks,

- mark

[Sam Buchanan]

If it has good compression, doesn't use oil, and isn't making metal......fly it!

....unless you just want a new engine......

[N941WR]

Originally Posted by newt

My RV-6 is on about 1830 hours. I'll have an annual condition inspection in October, then I think there'll be engine work in 2021.

Current engine is a carburetted O-320-D2A with a Sensenich fixed-pitch cruise prop.

I didn't build the aircraft.

The current fuel system has plumbing feeding an Andair valve supplying the suction side of a Facet fuel pump on the inside wall of the fuselage between the pilot seat and the rudder pedals, with the pump discharge feeding a gascolator on the engine side of the firewall, which in turn runs to the engine-driven fuel pump.

That is the "standard" fuel system for a carburetor, with the exception of the Andair valve, the builder opted to replace the standard valve with the Andair same location, same function.

Originally Posted by newt

...

The change from carburettor to fuel injection is going to involve fuel system modifications: I'm anticipating that the Facet pump will end up in the trash, with a new high pressure fuel pump and new plumbing.

I'm sure someone has gone down the path of carb to fuel injection before, and if anyone has advice I'd love to hear about it.

Are folks generally keeping high-pressure fuel out of the cockpit, so where's the right spot for the electric pump? Is the gascolator necessary? Considerations for routing fuel lines to avoid vapor lock? How are fuel systems handled in modern certified aircraft? Anything else I'm not thinking of?

Thanks,

- mark

The "standard" FI setup is to put the high pressure backup pump just forward of the Andair fuel valve.

The gascolator comes out and can be replaced with a bulkhead fitting to fill the hole.

Somewhere in that mess, you might want to think about installing a fuel flow meter (the type depends on your engine monitoring system).

Contact Van's and ask them for the drawings for the fuel injected setup, they are pretty generic.

What I don't know is if you will need a shorter engine mount when you switch to the IO-360 parallel valve engine from your O-320.

Good luck!

[newt]

Originally Posted by Sam Buchanan

If it has good compression, doesn't use oil, and isn't making metal......fly it!

That's certainly a consideration. But it butts up against the extremely annoying way that I get left behind on the outside of echelon turns with RV-7s An IO-360 is less than 7 kg heavier than an O-320. Hardly any weight for quite a bit of extra power margin.

Besides: It's 2020, and we worked out how to eliminate carb ice risk half a century ago. It's borderline embarrassing to still have to deal with it.

- mark

[newt]

Originally Posted by N941WR

What I don't know is if you will need a shorter engine mount when you switch to the IO-360 parallel valve engine from your O-320.

That is a fascinating consideration, and I'm glad I asked here.

Thank you!

- mark

[az_gila]

Originally Posted by newt

That is a fascinating consideration, and I'm glad I asked here.

Thank you!

- mark

I switched from an O-320 to an O-360 during my build on a RV-6A and used the same motor mount.

[DeeCee 57]

re carb icing, never had any icing with my O-360 despite extensive use in conditions prone to produce. But never say never...

On the other hand the main advantage of switching to a fuel injection would be fuel economy since a more effective LOP can be done. Inlet icing is still very possible and probable in given conditions, so an alternate air is a must.

[Sam Buchanan]

Originally Posted by newt

Besides: It's 2020, and we worked out how to eliminate carb ice risk half a century ago. It's borderline embarrassing to still have to deal with it.

- mark

Just as a datapoint.....I've been flying my RV-6 (O-320, carb) since 1999 and have had two minor carb ice incidents, both during mile-long taxi with a cold engine after the first start of the day. Even though we see very humid conditions in Alabama I have never experienced in-flight carb ice with the O-320.

Now the O-200 in the biplane is another matter...that thing can make ice in a heartbeat!

[Mark33]

Originally Posted by az_gila

I switched from an O-320 to an O-360 during my build on a RV-6A and used the same motor mount.

Gil, can you tell me ?approximately? how much further the 320 mount pushes the engine out as compared to the 360 mount? I?m thinking about using the 320 mount on my Catto prop equipped PV 360 -7 build to help with W&B.

[Northernliving]

I’m in the middle of converting from an O-360 to a newly built IO-360 in an RV 8. This is the pump that I plan on using.

https://airflowperformance.com/index...pump-assembly/