Horizontal induction with cold air sump

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!

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/community/search.php?searchid=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.

grubbat said:

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

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

RVbySDI said:

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/community/search.php?searchid=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.

Click to expand...

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?

WVM said:

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).

Click to expand...

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.

Click to expand...

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.

DanH said:

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.

Click to expand...

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.

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.

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.

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.

RVbySDI said:

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

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

Sorry cold air induction does little...

WVM said:

Hi,
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!

Click to expand...

This came to a huge surprise to me but in the past year I have personally tested over 80 engine configurations on our dyno. For 360 cuin or less the cold air induction does little if anything to improve performance. The stroked 370 and 409 need more air and there is some improvement.

Short pause for clarification....

"Cold air intake" can have several meanings, and it's easy for new builders to get confused.

Without question, we always want to supply outside air to the engine, rather than the very hot air from inside the cowl. The HP difference is significant. In general, there are two Vans-supplied methods to bring in outside air, the vertical induction airbox, and the horizontal induction snorkel. There are also lots of builder and vendor variations, most of which claim the benefit of "ram air". A well sealed outside air source can indeed be configured to convert some dynamic pressure to increased static pressure, i.e. raise manifold pressure at higher speeds.

The Vans horizontal induction snorkel does a pretty good job of dynamic pressure recovery, as it feeds directly from the left cooling air intake. It is also easy to live with long term, as it has proven to be very durable, and doesn't impact cowl removal or installation.

Kevin Horton photo:


The standard Vans vertical induction airbox has shown some maintenance issues, and can complicate cowl installation. However, there are thousands of them out there, and with a little care they work fine.

Romeo Lima photo:


Cold air engine manifolds are a separate subject. The supposed goal is to separate the heat of the oil sump from the intake tract, thus providing cooler air to the cylinder. A lot of us consider significant air heating to be unlikely, and discount that aspect. The real benefit (when and if it is shown to exist on a dyno) is more likely based in slightly increased mass airflow, and with some manifolds, the ability to mount a larger throttle body.

This is a Superior "cold air" intake and sump...


...and a Sky Dynamics "cold air" intake and sump:


The new oil sump may have its own advantages, like better oil pickup or inverted plumbing. That can make the intake manifold replacement worth the trouble even if it doesn't add anything.

We now return you to your regular programming...

Yesterday I again contacted VANS to get a clear view on this. They were not really happy to reopen the subject as I already discussed it in great detail earlier, but anyhow, it made it much more clear.

They state that my engine is not a common engine and basically when I read between the lines, all they are saying is that they can not ensure that it will work. It is up to me.

But then I noticed the dimensions on the IO-320 and the IO-360 from Superior. The IO-360 is only a bit wider than the IO-320. This looks more like an advantage for the IO-320 to me.

A friend is finishing an RV-7 with the IO-360 version of the engine. He used the special RV-7 cowling for the IO-360-M1B and option FAB-HORIZ INDUCTION-1. He also has a sump and horizontal induction. As the fuselage for the RV7 and RV9 are the same, correct me if I wrong, this means that the cowling for the IO-360-M1B should fit as nice on my RV-9, as it does on this RV-7. When it is really true that the engine is only a bit different in width, then the snorkel should fit as well. I followed his installation closely and there was no big difficulty in the installation.

The only difference now is that VANS had an exhaust option "EA EXH 7/7A SUPERIOR", which doesn't seems to exist anymore. For this I need to contact Vetterman Exhaust.

In summary I think that it is really a matter of VANS remaining on the safe side to avoid any discussions later.

I am just waiting on the confirmation from my engine shop to really be 100% sure that the IO-360 and IO-320 are the same. If that is true, then there is no reason to no buy the horizontal induction with sump.

According to the shop I can expect a 5% increase in power over the vertical induction without sump. That this is something really required for an RV-9 is another debate. On the other hand I was always told by my instructor, when you have the power it doesn't mean you always need to use it, but when it is required on a specific situation it can safe your ***.

Please correct me if I may missing something in this.

Note: You may wonder why all the hassle and not use a IO-360 like my friend? This is not allowed in my country. We can only use what is approved by the kit supplier (VANS).

Many thanks all for your comments!

Servo insulator

I am fitting the horizontal induction snorkel on my RV6. I currently have a phenolic spacer installed between the fuel servo and the Superior cold air sump. The spacer with additional gasket moves the servo forward about 1/4 inch. Do I need the spacer as an insulator? If the spacer is a thermal insulator it seems redundant with a cold air sump. I could use the 1/4 inch to gain a better fit for the filter end of the snorkel. What has been your experience?

P.S. I'm the guy tooling up to race the Bonanza F-33.

'Mother'; I'm not using the insulator, the space behind the lower cowl is limited.
'WVM'; If you check the link in my signature, you will see a simple but effective 'straight in' ram air scoop using some common aftermarket auto parts. The scoop fairing is a rough (but very effective) Dan Horton inspired fiberglass molding over a clay plug.
The chin scoop comes off with 6 screws, the air filter canister pulls out, and the lower cowl is free to drop away after the hinge pins are removed.
It's good for at least 3/4" Hg intake manifold pressure increase, observed at full throttle as speed builds up. I did not incorporate a filter bypass or secondary air source.
The Superior cold air sump 'may not' provide a horsepower increase, but it is about 9 pounds lighter than the stock setup, and has a very well thought out sump with threaded & plugged ports for inverted oil, and threaded mount pads for the control cables.
Perhaps you will see something useful for your project; if so use it, improve it and share it with us.
I have been pleased with the Superior Cold Air horizontal intake sump, the Pmag and the Airflow Performance Fuel Injection.

SHIPCHIEF said:

The Superior cold air sump 'may not' provide a horsepower increase, but it is about 9 pounds lighter than the stock setup, and has a very well thought out sump with threaded & plugged ports for inverted oil, and threaded mount pads for the control cables.

Click to expand...

That's why I installed mine - not for any temperature savings, it's really more of a marketing thing than thermodynamics on that point. My install was going to be nose-heavy from the word "GO" so I did a lot of things to minimize weight and shift loads aft to keep the CG where it needed to be. I have a lot of things in the tail or behind the baggage bulkhead that most folks would have in the panel area but it works.