Carburator position and engine compatibility

[Chris47]

Hello, i’m Christophe and starting an RV8 built.
Just complete the empennage and received my QB wings.
I would like to know if the O360 A4k with an horizontal carburator at the rear of the engine could fit into the engine cover like the M1B?
Does any body did it ?
For a new unexperimented builder is it a good idea?
Thank you very much for your advises

 

[drill_and_buck]

Hello, i’m Christophe and starting an RV8 built.
Just complete the empennage and received my QB wings.
I would like to know if the O360 A4k with an horizontal carburator at the rear of the engine could fit into the engine cover like the M1B?
Does any body did it ?
For a new unexperimented builder is it a good idea?
Thank you very much for your advises

Too many changes to consider. Highly unlikely this will fit. There is very little room between the firewall and the aft portion of the engine. Exhaust pipe routing would also be an issue.

I would suggest exploring what changes you would need to make to the engine to place the carburetor and induction system on the bottom so you could use the traditional firewall forward kit from Vans.

 

[Chris47]

Too many changes to consider. Highly unlikely this will fit. There is very little room between the firewall and the aft portion of the engine. Exhaust pipe routing would also be an issue.

I would suggest exploring what changes you would need to make to the engine to place the carburetor and induction system on the bottom so you could use the traditional firewall forward kit from Vans.

Thank you !

 

[2theskyy]

Hello, i’m Christophe and starting an RV8 built.
Just complete the empennage and received my QB wings.
I would like to know if the O360 A4k with an horizontal carburator at the rear of the engine could fit into the engine cover like the M1B?
Does any body did it ?
For a new unexperimented builder is it a good idea?
Thank you very much for your advises

Or, if you do have the engine already. Get the superior cai and convert it to a horizontal fuel injection. Essentially a M1B.

 

[Chris47]

Or, if you do have the engine already. Get the superior cai and convert it to a horizontal fuel injection. Essentially a M1B.

It could be a good solution !
I Don’t have the engine, but one is for sale to be fully overhauled. And not easy to find a core here in Europe.
Any idea for this conversion kit Price ?
Thank you.

 

[climberrn]

Superior Cold Air Sump. $2700 USD at the first place I looked. Did that to my engine when building to convert from vertical to horizontal induction. Comes with intake tubes. The sump is an easy install for a builder. Beware, the Vans snorkel for horizontal intake will take some extra work.

 

[Chris47]

Superior Cold Air Sump. $2700 USD at the first place I looked. Did that to my engine when building to convert from vertical to horizontal induction. Comes with intake tubes. The sump is an easy install for a builder. Beware, the Vans snorkel for horizontal intake will take some extra work.

Thank you.

 

[IO390]

Agree with the above regarding the sump, you may as well get the Superior cold air sump. Bear in mind that this engine is an A4K so won't be able to accept a constant speed propeller unless you change the crankshaft and modify the case.

 

[Jonnyb]

It could be a good solution !
I Don’t have the engine, but one is for sale to be fully overhauled. And not easy to find a core here in Europe.
Any idea for this conversion kit Price ?
Thank you.

Just price up what you expect an overhaul to cost and compare it to a new engine.
You may find there’s not a lot in it. That’s certainly the case here in the UK.

 

[IO390]

Just price up what you expect an overhaul to cost and compare it to a new engine.
You may find there’s not a lot in it. That’s certainly the case here in the UK.

Agreed, but you can save a lot by stripping down a core yourself and sending items off for inspection/overhaul yourself. It only cost me about £4k to get the case done by Divco, and the crank and rods done by Aircraft Specialties. Everything else on the engine was brand new and total outlay was £17k - I found a D licenced engineer to do the build with me so it could get signed off, but there’s a few engine builders who you can ship a box of new and yellow tagged parts to and it won’t cost absurd money. It only takes a couple of days to bolt a Lycoming together. Engine shop prices over here are way off the charts absurd. And Lycomings are very simple engines, there’s no magic to them, if you can build an RV I’d suggest you can build the engine too.

 

[MidwestMan]

You can easily download the lycoming parts manual yourself and look at part numbers to see all the differences. The A4K has a solid crankshaft so you won't be able to run a hydraulic constant speed prop unless you're rebuilding the whole engine and swapping the crank to an experimental config.

The sump and carb can be swapped for around $2000 with a used sump and a new or remanufactured carb. It's a very easy job, I did it with an O-320 of a different config for the same reason. If I did it again, I would buy a superior cold air sump and convert to SDS EFI, but that would cost more like $10k. You might also need an angled oil filter adapter. You can also resell the old parts and recoup some money.