Saville

Saville

Well Known Member
Hi all,

So I'm looking at an RV-8 that is 16 years old with about 900 hours TT. I'm told it never spent one day outside of a hangar. I've been given a list of squawks and they are mostly electronic/instrument. I'm told the engine is sound and has good compression and isn't leaky.

What I'm curious about is the life span of various accessories such as:

fuel senders/pumps
oil pumps
prop governors
C/S props
engine sensors
voltage regulators
alternators

Assuming the airplane was well cared for, and also assuming all the parts are original, what is the typical life span of these things?

A 16 year old car - I'd be expecting to be replacing lots of things.

16 year old house? Everything should be working with lots of life left.

I rent planes that are older than 16 years, but they may have had parts replaced.

I'm trying to get a handle on whether, at the age of 16, with 900 TT, I'm looking at an airplane where system after system is going to start to fail.

Not looking for absolutes or guarantees..just people's ideas/opinions.

thanks
 
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Comparing my 1966 Cherokee 140 on some items. I recently replaced the original alternator and regulator, along with some original associated wiring.

I believe the fuel pump is original but it gets disassembled and inspected every annual. It has no CHT or EGT sensors but I've heard that EGT sensors need replaced every few hundred hours, depending on their heat exposure.

Oil cooler was replaced due to a crack but they should generally be sent out for flush every time the engine is overhauled, if not sooner.

The typical engine is overhauled every 2000 hrs and accessories should also be done at that time, if they were not done previously.

I know of a relatively new RV-8 that is for sale at 3J1 for a very fair price. Hasn't yet even been painted and is in the hangar in which it was built. The owner/A&P has a new project so it has to go.

PM if you'd like details.
 
Raymo said:
Comparing my 1966 Cherokee 140 on some items. I recently replaced the original alternator and regulator, along with some original associated wiring.

I believe the fuel pump is original but it gets disassembled and inspected every annual. It has no CHT or EGT sensors but I've heard that EGT sensors need replaced every few hundred hours, depending on their heat exposure.

Oil cooler was replaced due to a crack but they should generally be sent out for flush every time the engine is overhauled, if not sooner.

The typical engine is overhauled every 2000 hrs and accessories should also be done at that time, if they were not done previously.

I know of a relatively new RV-8 that is for sale at 3J1 for a very fair price. Hasn't yet even been painted and is in the hangar in which it was built. The owner/A&P has a new project so it has to go.

PM if you'd like details.
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Hi Ray,

Very useful info thanks.

PM sent
 
The only thing on your list that I'd be concerned about is the prop. Has it ever been inspected since new? Hartzel and McCauley usually recommend having a prop shop open them up and look for internal corrosion every 5 - 6 years. While they're at it they can grind the blades and paint so it's as good as new. Plan on $2K or so. OTOH if this prop has been re-ground several times, the blades may be approaching minimum thickness, so they cannot be overhauled anymore. Just something to take into account when setting a price.
 
What part of the country is the plane stored? I see you are in the north-east. The #1 cause of pre-mature engine failure is corrosion on the cams. This can not be inspected without major work. Unless the hanger was heated/conditioned year round, the North East is not friendly for idle planes. Did he use CamGuard? of the 900 hours, are they evenly spread-out with normal use, or has the plane been sitting a lot ?
Don't worry about the components, they will be fine. It is the cams that you need to give consideration to.
If the plane has been flown at least monthly and he used CamGuard, you are probably OK.
 
Many of those items likely have recommended TBOs that should be followed. some of them are 500 hours so you could check in the logs around the 500 hour mark to see if some things were checked.

In your list the alternator, governor and prop likely all have recommended TBOs. The alternator in my Cherokee is 500 hours, not sure about C/S prop-related stuff ...

Other things to think about not on your list that have lifespans to worry about:

- Vacuum pump (if any)
- Magnetos (500 hours overhaul recommended)
- Spark plugs
 
somebody once told me that when you buy an old airplane, expect to put $3k-$5k into it to get it to the way you want it with all the squawks cleared. Of course if you need a major then that doesn't apply. But all the little stuff adds up quickly. When I look back on my experience that seems about right. So if you bank on that sort of amount barring disaster you should be ok. As for senders and such, there is no way to know - you just run 'em till they quit. Fuel pumps and mags obviously need to be approached a lot more carefully.
 
sblack said:
somebody once told me that when you buy an old airplane, expect to put $3k-$5k into it to get it to the way you want it with all the squawks cleared. Of course if you need a major then that doesn't apply. But all the little stuff adds up quickly. When I look back on my experience that seems about right. So if you bank on that sort of amount barring disaster you should be ok. As for senders and such, there is no way to know - you just run 'em till they quit. Fuel pumps and mags obviously need to be approached a lot more carefully.
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That's about right for non-complex types. I spent about 3k on my Cherokee and I did most of the work. The next annual will be 500 or less.
 
pa38112 said:
What part of the country is the plane stored? I see you are in the north-east. The #1 cause of pre-mature engine failure is corrosion on the cams. This can not be inspected without major work. Unless the hanger was heated/conditioned year round, the North East is not friendly for idle planes. Did he use CamGuard? of the 900 hours, are they evenly spread-out with normal use, or has the plane been sitting a lot ?
Don't worry about the components, they will be fine. It is the cams that you need to give consideration to.
If the plane has been flown at least monthly and he used CamGuard, you are probably OK.
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The plane is located in Texas.
 
do the logs always tell the story?

You should be able to see some history, and thus age of accessories in the logs, as others have noted.
the question; did the guy buy an alternator at a swap meet, install it at 500 hrs, and call it 'new'? There is a lot of latitude in the experimental world with times, origins, etc. that may not be clear.

I think there is strong empirical evidence that some components are life limited; for example, some guys that were flying a Beaver around the arctic circle studied this, and found that the jugs on a P&W radial either failed in the first 50 hours, or not until 400, so they cached a new cylinder halfway along their route.
yep, they actually used it!

but nearly impossible to predict with any certainty the life cycle of things that have been flown daily, or only a few times a year. Ditto to what folks have said about corrosion being more a concern than wear.

I'd be as concerned with belts, hoses, control cables etc. as much as the components that will give more indication of impending demise.

(FWIW, not an expert, mechanic, or Mensa member)
 
BillL said:
Texas - - there are some mighty good pre-buy inspectors available there. You might just get an inspection.

BTW -Did you buy Robbie Ottawa's RV6?
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If there are good Texas Pre-Buy inspectors I'd very much appreciate some contact info. I know of no one in that area.

No not interested in an RV-6. Just and 8.
 
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