O320 carb to IO340 FI conversion

Hi folks,

Am sizing up the conversion of an O-320 with MA4-SPA carb to an ECI IO-340 with hot sump (Updraft). I would like to use the AFP FM150 FI system. I have a few questions:

1. Will using FM150 servo require modifying the lower cowling. My MA4-SPA carb measures 4.5 inches. I saw a post on VAF that the FM150 servo is 5.5 inches. Currently, there is less than 1 inch clearance between the FAB and the lower cowling. Has anyone made modifications in this area? Is there a work around? Is modifying the lower cowl required?

2. Will the FM 150 servo connect to the Vans FAB box without modification?

3. How about control cables, brackets? Any changes needed there?

Thanks in advance for your help.

Don
RV9a N754RK flying
RV7A - building...

Conversion

This may not apply to your situation- I have Sam James cowl and air filter set-up. I swapped from carb to FM150- Needed to reroute cables, make brackets, required different elbow that connects air filter to throttle servo - am very pleased with the results.

johnso29 said:

Hi folks,

Am sizing up the conversion of an O-320 with MA4-SPA carb to an ECI IO-340 with hot sump (Updraft). I would like to use the AFP FM150 FI system. I have a few questions:

1. Will using FM150 servo require modifying the lower cowling. My MA4-SPA carb measures 4.5 inches. I saw a post on VAF that the FM150 servo is 5.5 inches. Currently, there is less than 1 inch clearance between the FAB and the lower cowling. Has anyone made modifications in this area? Is there a work around? Is modifying the lower cowl required?

2. Will the FM 150 servo connect to the Vans FAB box without modification?

3. How about control cables, brackets? Any changes needed there?

Thanks in advance for your help.

Don
RV9a N754RK flying
RV7A - building...

Click to expand...

I have very little to add but am quite interested in hearing the responses of others who have been down this road as well. I recently did the swap from a O-340 to an ECI O-340, and am considering making it an IO-340. Right now still using a MA-4SPA carb and still not happy with mixture distribution between cylinders.

I did exchange emails briefly with Don at AFP, and he suggested that one alternative would be to put an elbow on the sump and face the fuel control forward to match up with the opening, and use a K&N type cone filter on the fuel control. I'm not exactly in love with this idea, but only because it seems to deviate a little too far from Vans proven designs for my tastes.

Another option I've seen is to cut the scoop off the cowl and glass in a replacement larger scoop from Vans (they sell these separately, apparently). Although that is some pretty major surgery, my airplane is not yet painted so it's a viable option. It might get me some additional exit area to bring down CHTs as well, but at what sort of speed/drag penalty? Also I suspect this would require an entire replacement of the FAB which I don't look forward to.

Finally, I also recall a thread by DanH which planted the seed in my mind that one could make their very own unique air box that might fit inside the confines of the current cowl scoop, even going so far as to use a plate-style K&N filter instead of the round donut. This looks like a bit too much work for me, as I don't have anywhere near Dan's fiberglass skill.
http://www.vansairforce.com/community/showthread.php?t=44856

Has anyone done any of these, or have any other options in mind?

krw5927 said:

I have very little to add but am quite interested in hearing the responses of others who have been down this road as well. I recently did the swap from a O-340 to an ECI O-340, and am considering making it an IO-340. Right now still using a MA-4SPA carb and still not happy with mixture distribution between cylinders.

I did exchange emails briefly with Don at AFP, and he suggested that one alternative would be to put an elbow on the sump and face the fuel control forward to match up with the opening, and use a K&N type cone filter on the fuel control. I'm not exactly in love with this idea, but only because it seems to deviate a little too far from Vans proven designs for my tastes.

Another option I've seen is to cut the scoop off the cowl and glass in a replacement larger scoop from Vans (they sell these separately, apparently). Although that is some pretty major surgery, my airplane is not yet painted so it's a viable option. It might get me some additional exit area to bring down CHTs as well, but at what sort of speed/drag penalty? Also I suspect this would require an entire replacement of the FAB which I don't look forward to.

Finally, I also recall a thread by DanH which planted the seed in my mind that one could make their very own unique air box that might fit inside the confines of the current cowl scoop, even going so far as to use a plate-style K&N filter instead of the round donut. This looks like a bit too much work for me, as I don't have anywhere near Dan's fiberglass skill.
http://www.vansairforce.com/community/showthread.php?t=44856

Has anyone done any of these, or have any other options in mind?

Click to expand...

Kurt,
Have you examined Van's snorkel configuration? It does use the "plate-style K&N filter". I have installed this snorkel setup on my ECI IO-340. It fit with no fiberglass modifications what so ever. I did have to design my own mounting bracket on the aluminum floor of the pilot side baffle but that was really much easier than I thought it would be. If I am understanding what you are saying, everything you are discussing can be accomplished with minimal alterations and can be fairly straight forward.

Here are a couple of pictures of the snorkel setup during my installation of the Van's snorkel with the K&N plate-style filter:

RVbySDI said:

Kurt,
Have you examined Van's snorkel configuration? It does use the "plate-style K&N filter".

Click to expand...

I thought this setup only worked with sumps that have a forward-facing induction. For myself and the OP with carburetors on updraft sumps, is there a snorkel solution that can work here?

Also in search of the answer ...

I recently converted from an O-320 to the ECI O-340.
In order for it all to fit, I had to keep my O-320 carb.

Prior to doing so, I made a visit to Don at AFP and he and he team graciously spent a few hours with me trying to come up with a solution. He even gave me a "homework assignment".

Now that the installation is done, I plan to call him and make a trip with the actual plane. (He is <30 minutes away from me.)

If we can come up with a solution, I will post it here.

My setup is with the "old school" cowl so there is probably far less clearance that the newer ones.

I also purchased a "snout" from Van's ... just in case.

Another point, I too am not happy with my temperatures. Not blaming the engine, it is generating more power and thus more heat. Also the baffling etc. from the prior engine worked fine but this engine is .... well .... different. I also suspect fuel distribution and thus the consideration to go FI.

Kevin tried to convince me to bite the bullet and go FI from the start but I wanted to get it back in the air sooner than that would have allowed.

Finally, those of you who have made the change, what are your impressions?

Mine:
1. SIGNIFICANTLY more climb performance!
2. Sounds very different in the cockpit (Duh!)
3. You can feel that it is "stroked"
4. Haven't been able (yet) to find the sweet spot of performance/temperature/fuel flow in cruise (need more time)
5. Your battery needs to be "up to snuff" to crank it!

James
p.s. I have been writing a report about the conversion but have been waiting until I was finished with various changes before "publishing" it.

jclark said:

Finally, those of you who have made the change, what are your impressions?

Mine:
1. SIGNIFICANTLY more climb performance!
2. Sounds very different in the cockpit (Duh!)
3. You can feel that it is "stroked"
4. Haven't been able (yet) to find the sweet spot of performance/temperature/fuel flow in cruise (need more time)
5. Your battery needs to be "up to snuff" to crank it!

James
p.s. I have been writing a report about the conversion but have been waiting until I was finished with various changes before "publishing" it.

Click to expand...

I agree with all 5 points above. But some of the difference in sound, feel and performance could also be due to the prop swap in my case as well. I went from a wood prop that was not well matched to the airplane (in spite of having it manufactured to my specific airframe/engine combo), to an amazing 3-blade Catto. LOVE the Catto. Climb performance is outstanding, at least until CHTs get to 400 and I start pulling power, which unfortunately isn't long after takeoff.

One thing I almost instantly noted with this engine swap is that CHTs were higher than I was used to, and EGTs lower - on the order of 200 degrees lower in some cases. I've recently re-timed my magnetos (2 slicks) to retard timing by 3 degrees in search of lower CHTs and higher EGTs (now 22 degrees BTDC). I haven't tested that configuration yet, but will report back if there is a major change in CHTs with no other ill effects.

What I'd really like to find is a way to fit an injection system in the O-320 cowl on my 9A. Like you, Kevin suggested an injected engine from the start. But my current cowl wouldn't support it and I had no interest buying all the parts and doing all the work to make it fit at the time.

My O-340 sump has a tapered induction riser, the opening of which would be appropriately-sized for a MA4-5 carb or any number of injection systems. With the MA-4SPA carb as received from Titan, there was a sharp transition between the smaller carb throat diameter and the larger sump opening. This was causing extremely poor mixture distribution. After consulting with Titan, they machined an aluminum tapered insert to fit the sump opening, with an inside diameter equal to the MA-4SPA throat. The insert helped somewhat with mixture distribution, but I still believe the MA-4SPA doesn't flow enough fuel, and it also may be inhibiting air flow as well.

James, if you have an advance copy of your report, I'd sure like to read what you have to say and perhaps discuss similarities/differences in my experience. I'd be especially interested, and I'm sure the OP would be as well, in hearing about your discussions with Don and your "homework"?

krw5927 said:

I thought this setup only worked with sumps that have a forward-facing induction. For myself and the OP with carburetors on updraft sumps, is there a snorkel solution that can work here?

Click to expand...

Yes, true that it is for the forward facing sump. However, it was my understanding the OP was looking at converting the O-340 to an IO-340. If that is not the case then what I am proposing is definitely not applicable for an O-340.

After going back and reading the OP again I see that he was indeed looking for compatibility with the hot sump. Indeed my setup is the cold air induction. So I guess my information is not relevant to the desires of the OP. Having said that, I can attest that if one were to go with the cold air induction, during the build process, changes would not require any fiberglass work or additional fabrication, other than what I mentioned about the baffle. There are changes such as exhaust routing that have to be accounted for but if one makes the decision during the build, the exhaust is an easy bolt on change that Vetterman Exhaust is very familiar with. Sorry to hijack the thread toward cold air induction. However, if anyone is interested in the cold air induction configuration for the IO-340 drop me a note.

RVbySDI said:

Yes, true that it is for the forward facing sump. However, it was my understanding the OP was looking at converting the O-340 to an IO-340. If that is not the case then what I am proposing is definitely not applicable for an O-340.

After going back and reading the OP again I see that he was indeed looking for compatibility with the hot sump. Indeed my setup is the cold air induction. So I guess my information is not relevant to the desires of the OP. Having said that, I can attest that if one were to go with the cold air induction, during the build process, changes would not require any fiberglass work or additional fabrication, other than what I mentioned about the baffle. There are changes such as exhaust routing that have to be accounted for but if one makes the decision during the build, the exhaust is an easy bolt on change that Vetterman Exhaust is very familiar with. Sorry to hijack the thread toward cold air induction. However, if anyone is interested in the cold air induction configuration for the IO-340 drop me a note.

Click to expand...

Steve,

That looks like the RV-7A IO-360 cowl? I was hoping to complete the conversion without replacing the cowl, e.g., use the standard RV-9A cowl. Do you think the IO-340 horizontal induction would fit inside the standard RV-9A cowl? I think that would require the Vetterman 4 exhaust pipe or the "New Trombone" exhaust system to work. But, would it all fit?

Which snout did you order from Vans?

jclark said:

I recently converted from an O-320 to the ECI O-340.
In order for it all to fit, I had to keep my O-320 carb.


I also purchased a "snout" from Van's ... just in case.

A

Click to expand...

Do you know the part number of the snout that you ordered? There are several on the Van's web store but I don't know which one would work.

Thanks for your help...

Don

I installed an AFP FM-150 on my RV-8. I converted an IVO-360 engine, and chose the Superior horizontal cold air sump.
I used a K&N cone filter with an aftermarket automotive filter housing, perhaps like Don had in mind. You can see a few pics and the part numbers on my link below.
If I had selected one of Don's servos with the air inlet that accepts a hose, I could have used an adapter hose. I wouldn't have needed to make the flange mount-to-hose adapter. I think the FM-150 is the only one with a flanged inlet?
If using a vertical sump with adapter elbow, perhaps the cone filter & housing will fit.
I laid up the fiberglass inlet scoop fairing over modeling clay and attached it to the lower cowl with 6 screws. I remove the scoop to ease lower cowl removal, and it gives a little access to the front of the engine. I just experienced the Sky-Tec starter solenoid fail at Vernonia Ore (first trip with wife). I was able to reach in thru the scoop access hole and whack the solenoid enough to get one more start and head for home...