XP-IO-360 not developing full power

I'm having a problem with my XP-IO-360 not developing full power.
XP has horizontal induction with Van's FAB.
I'm using a 3-blade Catto Prop 66x78.
No MP guage.

Superior & Catto have been very helpful in troubleshooting.

Prop may be overpitched by about 2" when compared to similiar flying 7's.
I suspect an overpitch but am troubled by the range from static and wot is only about 225 rpm

Here's my specs and understanding of what I should be seeing.
Static RPM= 2130-2150 (a bit low, should be around 2200)
Climb out = 2200 rpm (should be static + 100)
Level Flight WOT 2350-2380 rpm (expect static + 500)

I've adjusted my throttle bracket/mix to insure full range to stops.
No obstructions using fab. I opened the fab emergency door to insure additional air. No change.

I've not used a meter or the strobe to verify rpm but believe my rpm reading is about right when comparing airspeeds.
My IAS is reading 150mph/4000' with no paint or wheel pants.

My next test is to remove the fab and test static rpm directly from intake removing the fab from the equation.

Any additional thoughts would be appreciated.

Thanks.

A few possible causes, in no particular order:

1. Ignition timing problem.

2. Bad tach.

3. Mixture way too rich or lean.

4. Internal cam timing problem.

5. Induction leaks.

6. Restriction in fuel flow.

Dan:

I am going to preface everything I am about to post by saying that I am no engine expert.

Having gotten that off my chest, I will give you my experiences. I too was not real happy with my static RPM. I have a midtime 0320-E2D with a Catto three blade that was originally set at 66 X 68 at Craig's suggestion. I was getting 2080 static, with WOT at around 2300.

Sent my prop back to Craig and he took 2" of pitch out, as I indicated to him that Mark Phillips has a similar setup to mine and had a 66X66 three blade and was getting the proper numbers.

Put the prop back on and still was getting only around 2080 static. Had my mags timed and all was well there. Then we did a quick and dirty check of how good the mags were by seeing how much of an arc was produced when holding a plug close to the cylinder. Only was getting about a half inch of spark. Decided to get new mags/wiring harness and plugs. Engine now runs like it really wants to. Static is now about what you are getting, which is within the expected range.

With the addition of my gearleg fairings and wheelpants, WOT is now 2750.

Not sure if any of this will help, but may be of good reference. Believe me, I feel your pain.

painless said:

Dan:

Put the prop back on and still was getting only around 2080 static. Had my mags timed and all was well there. Then we did a quick and dirty check of how good the mags were by seeing how much of an arc was produced when holding a plug close to the cylinder. Only was getting about a half inch of spark. Decided to get new mags/wiring harness and plugs. Engine now runs like it really wants to. Static is now about what you are getting, which is within the expected range.

With the addition of my gearleg fairings and wheelpants, WOT is now 2750.

Not sure if any of this will help, but may be of good reference. Believe me, I feel your pain.

Click to expand...

Thanks Jeff.
My plugs, mags & wiring should be ok as rhey are all new.
I have the data from Superior when it was run on the test stand. The were getting full rpm with there standard test prop.
Someone else told me their rpm increased substantially once they had attached the fairings. I just couldn't believe it would increase the rpm that much.
I'll be running the engine tomorrow with cowling off to insure I have no induction problems. If there's no change, I'll have Craig repitch to 66x76 removing 2". I just hate to have to ship it cross country and have to wait.
I guess that would be a good time to get the fairings completed.

I'll let you know what happens.

Are there any other RV builders in your area who could loan you a prop? It would only take an hour or so to exchange props and for each of you to do a static run-up with each other's "loaner" prop. Then you could compare your engine's static rpm with his engine's static rpm and see if it is an engine or a prop difference.

I'd certainly do that before I'd have the prop modified.

Catto Prop and 0-320 - no full power?

Hello Dan ...
It's August of 2006 ... a year and a half after your original post regarding your new Superior engine and Catto prop not running full power.

I am experiencing the same propblem with my new 9a.
I have a new Aerosportpower 0-320, a new slick mag, a new PMag. fab and carb.

My statric rpms are 2250, and I can never get the WOT rpms over 2590 to 2610.
Craig Catto says that I should be getting a 500 rpm spread ...
This is with all fairings installed, throttle cable adjusted, with best TAS of 165-168.

Were you able to solve the problem?
Did removing the FAB help indicate that there was an induction problem?

I'm really interested in hearing about the result.
Thanks,
Tom

Tom Sampson said:

Hello Dan ...
It's August of 2006 ... a year and a half after your original post regarding your new Superior engine and Catto prop not running full power.

I am experiencing the same propblem with my new 9a.
I have a new Aerosportpower 0-320, a new slick mag, a new PMag. fab and carb.

My statric rpms are 2250, and I can never get the WOT rpms over 2590 to 2610.
Craig Catto says that I should be getting a 500 rpm spread ...
This is with all fairings installed, throttle cable adjusted, with best TAS of 165-168.

Were you able to solve the problem?
Did removing the FAB help indicate that there was an induction problem?

I'm really interested in hearing about the result.
Thanks,
Tom

Click to expand...

Hi Tom,
My original post was on 7/31/06.
The FAB had no effect.

The concensus was to break in the engine, add the farings to reduce drag.
At 12 hours TT, my rpm was picking up from 2350 to 2450-2500 @ 3000msl. I'll have the fairings complete by next weekend 8/26.
We'll see if I get the rpm with the reduced drag component.

Dan,

I have an RV9a with the ECI 0360, a James cowl/plenum/induction, and a Catto 3 blade prop (66x76). I had a similar situation as do you with regard to power production when I started flying my bird. My max rpm on the first flight (no fairings) was 2420 and static was only 2130. After much testing and experimenting with potential solutions I now have a static of 2180-2200 and a wot of 2660-2680 at 8500 d alt. Here is what caused the increase:

1. The engine gradually produced more power as it gained time--it now has 55 hrs on it.
2. I made my own carb box out of fiberglass based on the simple elbow system used by the Rocket guys. The original box that came with the cowl was too restrictive (they have since redesigned it). To check the effieciency of your induction you can check mp prior to start up and then right at lift off. An efficient system should loose less than 1" mp. My original box lost 1.8"--my new one looses .6".
3. The addition of the fairings cleaned up the airframe so much that the engine was able to spin up an additional 125 rpm (speaking based on memory here) and therefore produce more power.

Don't be in a hurry to repitch your prop---wait untill you have some time on the engine and all fairings on before you do this--you may find that the pitch is just right on a clean airframe.

Hope this helps.

You are gonna love your bird!!!!

Cheers,

db

db1yg said:

Dan,


Don't be in a hurry to repitch your prop---wait untill you have some time on the engine and all fairings on before you do this--you may find that the pitch is just right on a clean airframe.

Hope this helps.

You are gonna love your bird!!!!

Cheers,

db

Click to expand...

Thanks db.
Your numbers are comparable to mine. I feel more at ease knowing all will be well on the performance side. The FAB wasn't an issue for me as I removed the airbox and their was no change on the static. Craig Catto told me there might have been an issue with the Sam James cowl using his 3 blade. Something about creating a bit of turbulance at intake.

Dan