Horizontal induction with cold air sump

[WVM]

Hi,

While preparing to order the remaining parts of my RV-9 I noticed that VANS is unable to supply a finishing/firewall forward kit for a horizontal induction on an IO-320. The second issue appears to be the cold air sump option from Superior.

From what I understand I need to make a custom snorkel, combine the lower cowling from the RV6 with the upper part of the RV9 and order a custom built exhaust system (not available through VANS).

This all was a major surprise to me! My engine supplier tells me that the difference between the vertical and horizontal with cold air sump is that: . The performance and power is better and it would have a higher manifold because the ram air goes straight in. The air will also be colder according to them. As an example they gave me the extra 300: a six cylinder with a horizontal cold induction, according to them with these reasons.

Most builders that I spoke to tell me to not go into the unknown/undocumented area, especially not as a first time builder. I tend to agree on that, but …

Is there anyone that did those modification, maybe has a blog available as a reference for me? Any general advice on this topic is more than welcome!

Thank you!

[RVbySDI]

I do not have a web page but I have posted many times on my forward facing cold air induction installation of my ECI IO-340 on my 9A. Do a search for my name or IO-340 or cold air induction or . . . ??? and you should find many posts, some with pictures of my installation.

Here are results of a quick search I just ran looking for posts on construction comments for my forward facing cold air induction on my IO-340:
http://www.vansairforce.com/communit...rchid=22603901

THE INSTALLATION WAS NOT DIFFICULT!!!!

Just a short recap of my installation to get you thinking about a few things; I used the Van's IO-360 RV7A cowl, Van's snorkel for the IO-360 for an RV7A (IT FIT LIKE A GLOVE! With NO modifications what so ever!). I used a different throttle cable than the supplied cable. I purchased it through Aircraft Spruce. I did have to manufacture a bracket for holding the air filter in the pilot side air intake where the snorkel entrance is.

Send a PM if you want any specific details.

[WVM]

Originally Posted by grubbat

I haven't tackled the snorkel job yet but I have been warned that its quite a job for the benefit it brings. The vertical induction will definitely be the easiest path since you can get all the items from Van's.

The exhaust issue for a horizontal engine can easily be solved by Vetterman's. Clint can help you out there. They are mfg one for my -9 IO360.

Horizontal induction does get you some added free hp but some here will tell you that you don't need that extra HP for a RV-9.

Good luck on your journey and I look froward to hearing about how you mastered this bump in the road.
cj

That is indeed one of the commonly heard things: is the modification worth the benefits... hard to tell from the information I can find.

[WVM]

Originally Posted by RVbySDI

I do not have a web page but I have posted many times on my forward facing cold air induction installation of my ECI IO-340 on my 9A. Do a search for my name or IO-340 or cold air induction or . . . ??? and you should find many posts, some with pictures of my installation.

Here are results of a quick search I just ran looking for posts on construction comments for my forward facing cold air induction on my IO-340:
http://www.vansairforce.com/communit...rchid=22603901

THE INSTALLATION WAS NOT DIFFICULT!!!!

Just a short recap of my installation to get you thinking about a few things; I used the Van's IO-360 RV7A cowl, Van's snorkel for the IO-360 for an RV7A (IT FIT LIKE A GLOVE! With NO modifications what so ever!). I used a different throttle cable than the supplied cable. I purchased it through Aircraft Spruce. I did have to manufacture a bracket for holding the air filter in the pilot side air intake where the snorkel entrance is.

Send a PM if you want any specific details.

Should I consider you to be lucky? Because most comments I hear is that it isn't that easy...

Would you have a picture of the current installation (cowling, snorkel and exhaust) just to get an idea? I found some from your RV from the outside, but nothing related to the process. Or did I miss some things?

[DanH]

Originally Posted by WVM

From what I understand I need to make a custom snorkel, combine the lower cowling from the RV6 with the upper part of the RV9 and order a custom built exhaust system (not available through VANS).

All of which are relatively easy to do.

My engine supplier tells me that the difference between the vertical and horizontal with cold air sump is that: . The performance and power is better and it would have a higher manifold because the ram air goes straight in.

Not entirely true; "straight in" doesn't matter all that much. Converting dynamic pressure to static pressure merely requires slowing the air, and after it is slowed, it flows around reasonable corners just fine.

A snorkel system which takes air from the left cooling inlet has several practical advantages. Air pressure delivered to the fuel servo will be quite good. It is not subject to fatigue and cracking like a vertical induction airbox. It does not complicate cowl installation or removal for service. In the long run, you will appreciate these three points.

If there is a downside, it is that air filter media area is restricted due to limited space on the left cooling ramp.

[WVM]

Originally Posted by DanH

All of which are relatively easy to do.



Not entirely true; "straight in" doesn't matter all that much. Converting dynamic pressure to static pressure merely requires slowing the air, and after it is slowed, it flows around reasonable corners just fine.

A snorkel system which takes air from the left cooling inlet has several practical advantages. Air pressure delivered to the fuel servo will be quite good. It is not subject to fatigue and cracking like a vertical induction airbox. It does not complicate cowl installation or removal for service. In the long run, you will appreciate these three points.

If there is a downside, it is that air filter media area is restricted due to limited space on the left cooling ramp.

So you are actually suggesting to go for a horizontal induction? But to my understanding the cowling on the RV9 with IO320 is easier with a vertical induction that with a horizontal due to the fact that VANS only sells O-320 cowlings for vertical induction.

[RV10inOz]

The anecdotal evidence, based on what Barret's tell me is the 4 cylinder cold air sump makes very little if any difference at all on the dyno, yet the IO540 it does..

For the agro involved, I would stick with the vertical induction and be done with it.

[rzbill]

With all the posts about various FAB issues for the vertical intake, I would do the horizontal and snorkel. It is not that bad of an issue to do the fabrication and install.

Look for yourself. Search FAB and Search snorkel. See what you find.

[RVbySDI]

I do have pictures but work is preventing me from spending time searching and posting now. I have posted several over the years on this forum during the build process and after construction was complete so you should be able to search on my name or any other search terms that come to mind to see anything I have posted in the past on this subject. As I have time to do so I will attempt to research any of my archived pictures for pics of my installation of the snorkel and/or cowl. I have been flying for 4.5 years now with my setup. I am NOT PULLING YOUR LEG when I say it was a simple straight forward installation. I DID ABSOLUTELY NO FIBERGLASS WORK on either the cowl or the snorkel to make it fit! They fit perfectly. And they were both purchased from Van's - not outsourced! You just need to make sure you request from them the exact items you need. In that respect I will say it is not a simple matter of asking them for the stock items in a 320 or even a 360 Firewall Forward Kit. You do need to be specific in what you ask them to send. Vans does have the items needed for the forward facing cold air induction to work. And, I can attest from my build experience and my time flying behind it all now, that it does indeed work, and it works well. I am referring to the installation/construction process as well as the performance of the cold air induction.

Once I have time to get to them I will try to post some construction pics.

[DanH]

Originally Posted by RVbySDI

...I can attest from my build experience and my time flying behind it all now, that it does indeed work, and it works well.

And the smooth cowl looks good on the RV-9.