Cowling differences ?

Hi! I'm new to the site, but have admired Van's designs,(and the people who build them) for many years. I'm finally at the point to begin looking to acquire an RV8.

I've noticed that some aircraft have an air scoop on the bottom of the cowling, while others do not. At first, I thought this was a function of whether the engine was carbureted or injected, that the carbed engine would have the scoop, and injected would not.

But I have seen injected RV8's with the bottom scoop too.

I prefer the sleeker look of the "scoopless" cowl, and had the following questions.

1. What factors determine the necessity of the lower scoop?
2. Can a scooped cowl setup be converted to the non-scooped arrangement?
(Depends on the answers to #1, I would presume)

Thanks !

mustangsqd said:

. SNIP

1. What factors determine the necessity of the lower scoop?
2. Can a scooped cowl setup be converted to the non-scooped arrangement?
(Depends on the answers to #1, I would presume)

Thanks !

Click to expand...

The ?no scoop cowl? uses the horizontal injection Lycoming engine. The cowls with the engine air scoop use a vertical draft carb - or could use a vertical draft injection system. Back before Van?s offered the 180hp horizontal engine many people bought the O-360-A1A engine and backfited something like an AirFlow Performace FMS-200 injection system (that is what I did on my first RV-8A project).

A scooped cowl can be converted - but that depends on your fiberglass skills. But - other than a cobbled together mess this would require either a different engine or modifying the current engine for horizontal injection. Probably not what you want to do unless you are replacing the engine for some other reason.

Carl

IO-360-M1B is the common engine for the smooth bottom cowl. 180hp Fuel-Injected, parallel valve, horizontal induction IO-360.

Here's one I got from from Vince at Rocket:
https://s5.postimg.org/4ccn2x9cn/IMG_0635.jpg
https://postimg.org/image/pyrnjy077/
https://postimg.org/image/sg3er7zj7/
https://postimg.org/image/d7dhdglab/

I have plumbed it with an in-line K&N filter directly to the horizontal cold air induction, so no pressure escape into the lower plenum.

To me, it looks better and less drag (I think).

cowling differences

Thank you guys!

Now I know what to look for, - and if I find not quite what I'm looking for, I know what the tasks are to make the conversion....

I really appreciate the input!

Thanks again!