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Kahuna 11-01-2013 06:51 AM

Super 8. Documenting an engine overhaul with JB Aircraft
8 years and ~2k hours of flying the Super 8 and its time for an engine overhaul. I have never experienced one of these (sold my RV-6A a few hundred hours before it was ready.)
The engine has been very good to me and its only troubles over the years I have induced. I have become very attached to the reliability and performance of this IO-540. I picked up the motor from a shop in Florida back in the days where 540's were cheap. Certified and yellow tagged with accessories for $17,500. :D Those days are of course over, thank you Vans RV-10.
First few hundred hours were on 1LSE and one mag, then ~300 hours when the mag died, I went dual LSE.
My typically flight is all in to altitude then LOP 2300RPM to my destination so this engine has spent a vast majority of its time LOP. The other times is flying shows with the team ROP and a also a loafing RPM of 2300. CHT's have been kept below 400 generally unless I get on one of my hard altitude climbs to the FL's and I would generally see low 400's to 410 at worst. I have always felt I have treated the engine with respect. Compressions always in the mid 70s with the occasional mid 60 reading that would come back to mid 70's at the next check. Oil consumption was difficult to measure since I spend much of my time upside down with the neg g's tossing a bit even with the inverted oil. Long flights I would see about 1qt over 6 hours and was consistent over its life.
Reaching its 2k hour point, I felt it was time for an overhaul. The engine was not telling me it needed one. I was. The time is right for me during this off season. I can not afford an engine problem March - November.
Back in January I met Jimmy Brod (JB) in Sebring Fl at a show. JB and his dad have run an engine shop, JB Aircraft Services, there for decades. After just a few minutes of talking with JB, I decided that if I ever rebuilt my motor, this is the guy I want working on it. A quiet, humble, down to earth pair of father & son team. You all know how we are about our engines. I dont let anyone touch it that I don't trust my life with. And up until now, no one has touched it but me. I routinely take 'leap of faith' risks flying night ops over inhospitable terrain, hours over open water, IFR ops with no outs below. It has got to be reliable day in and day out.
So off came the motor with the plan to have JB do the overhaul with mostly ECI parts. I have never gone through this process before. I thought I might document that here and report the findings.
Step one. Take lots of pictures so I can get things back to their respective places on reinstall.
Step 2. Pull the motor. Time to pull single handed was 3 hours start to finished on pallet. I didnt break any records. This includes taking the time to tag everything. Here is the engine hanging from my bi-fold door ready to back up the pickup truck. Engine hoist is not tall enough to get this into my pickup truck.

Then truck it down to my local Yellow freight terminal to shipping to JB.

Kahuna 11-01-2013 07:26 AM

Engine Mount
Next was to assess the engine mount. She has been worked pretty hard over the years. A custom built mount by John Marshall(rest in peace my friend) up in Indianapolis. The mount looked fine, but, you can't see under the paint and powder coating. So I pulled the mount for blasting, magnafluxing, and powdercoating.
Here is a shot of the engine mount with the generic nicks, dings and scrapes from years of maintenance.

I found a local shop to to the blasting, maganaflux, and powder coating for $50. i thought that was a pretty good deal. I also inspected it myself after blasting just to make myself feel good. It was in great shape. A new set of mount bolts and the engine mount is back on with a thumbs up checkout.

Kahuna 11-01-2013 07:36 AM

Exhaust Warped
While pulling off the exhaust, I noticed this warpiage located under the heat muff. Hidden for years. My muffs have never been off and I have had no reason to look under them. Hmmm. Whats that?

A quick call to Larry Vetterman... He has seen this before, although rarely. According to Larry, there are 2 cases where this is seen.
1. A wrapped exhaust, or ceramic coated exhaust. I have neither of these.
2. A muff exit blocked where the heat cant get away, either from a scat tube collapse or FW valve that does not dump overboard. Well I have never had either of those. :confused:

Either way, it is what it is. A tap with a punch to check wall thickness in the warpage area and Im satisfied that the warpage does not pose any risk so Im leaving it as is. Amazingly, the rest of the exhaust of completely great. I have never had a crack, support arm break, or anything of that nature in its years of service. Im cleaning it up and putting her back on.

Tom Martin 11-01-2013 08:20 AM

I believe that in the certified world the heat muffs have to be removed at least once a year to check for leaks that could come from an exhaust pipe issue and thus get in the cabin air.
As long as I have flown rockets I remove my heat muff in the spring when it warms up and then put it on again in the fall if I plan on flying in the winter.
Even at altitude there are rare times in the summer when you really need cabin heat, a sweat shirt will usually do the trick. This has the added benefit of using that 2" of cabin heat air for engine cooling. Usually this air is just run through the heat muff and then dumped in the lower cowling; more heat added!
I had an exhaust pipe fail once, just aft of the ball joint and it sure gets your attention. By removing the heat muff in the summer it gives you two times a year to really look at this critical area of the exhaust system.
I have about 800 hours on my 540 and I sure hope that it makes it the full 2000 hours. I love these engines.

Mike S 11-01-2013 10:17 AM

This is gonna be a great thread-----------thanks Mike:D

miyu1975 11-01-2013 11:59 AM


Originally Posted by Mike S (Post 822037)
This is gonna be a great thread-----------thanks Mike:D

Yes it is...any chance JB is going to taking photos of the overhaul?

Kahuna 11-01-2013 12:08 PM

Inside the valve cover

Originally Posted by miyu1975 (Post 822059)
Yes it is...any chance JB is going to taking photos of the overhaul?

Why yes he is. Im getting reports in now. The engine has been disassembled. Case sent off. Crank sent off to ECI.
Below is a picture of inside one of the valve covers. JB has mentioned before that he is not a fan of LOP operations and will be very interested in getting inside my motor given all the LOP hours it has.

Kahuna 11-01-2013 12:54 PM

Those pesky smoke injectors
Some of this will just be me babbling away at different finds as a result of doing an engine overhaul. One of those pesky items us 'smokers' have to deal with is the injectors. They are not the most reliable things. They tend to clog up, require cleaning, and can be a maintenance nuisance. My smoke system is pretty much homebuilt. I have a ~13gal wet wing smoke tank in my left wing under the wing walk area. A smoke pump and filter in the fuse tail area (Anything portable in a super 8 goes in the tail!) and of course the injectors. No valves for flow rate. What I found was my flow rate was about right, given the distance traveled, and the S8 developing a bit more heat. After a few hundred hours of a smoke injector set of tiny orifices being clogged, I just drilled the end of the injector out with an 1/8" bit. With my 2 injectors this seemed to flow about the right amount and never left me being "THAT GUY" with weak smoke on film. Over the years I have watched the SS injectors deteriorate to the point that that are now 1/3 the length they started. I never particularly cared. I pump all the oil in my system would flow and excess unburned oil,..... well only my slot pilot cares. Here are the injectors after being in the exhaust for all these years. I think they have some service life left dont you?:rolleyes:

C-FAH Q 11-01-2013 01:51 PM

Powder coat
Just a thought about your mount. Cracks can hide under the powder coat and not be seen. With your mission, painting it so you can get a proper look at the joints may be in your best interest.

Jerry Fischer 11-04-2013 08:09 AM

Hi Mike
Great thread, I look forward to following your progress. Did Larry V suggest a routine removal of the heat muff at annual cond. insp. to monitor the exhaust? (a pain but...)
Blue skies my friend

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