Engine exceed TBO...

[mhorowit]

I have a lead on a Tcraft with an A-65 engine that has exceeded recommended TBO. It is my understanding the compression is still good.

How should I approach this engine ( i.e. just assume everything over 1800 hours was a freebee and there is no guarantee it's not about to poop out)? - Mike

[John N43951]

Re: Engine exceed TBO...

We had a A-65 with something like 1760hrs, with low compression after 120 STOH, pulled the cyls had them rebuilt (again) decided to pull a rod just to see, no babbit left on #1. Found a low time A-75 to replace it. now if we can solve mag problem hope to have flying soon. I think that after 59 yrs maybe it time for a rebuild.

[paulp]

Re: Engine exceed TBO...

Howdy Mike,

There are a lot of engines out there that are way beyond the "recommended TBO" That does not mean that they are worn out or that they need an overhaul. That being said, I think that one should consider the fact that age just by itself plays an important factor. I would rather have an engine with 1000 hrs on it rather than one that was overhauled and has set for 30 yrs.

The question is, are the compressions good? How is the oil consumption? Also, remember there are the bolt ons to consider. Simply because an engine has been run beyond it's TBO does not in and of itself mean that an overhaul is necessary. On the other hand, it's what keeps you in the air.

Remember, gravity always works and take offs are optional but landings are mandatory.

[crispy critter]

Re: Engine exceed TBO...

Mike,
Another thing to consider is,how much total time is on the engine,how many times has it been apart(overhauled),what has been replaced in the past and how many years ago did they replace it(crank,cam,etc...important stuff),and last but not least,how many hours is it beyond TBO and what year was the last overhaul done?
I have seen these 4 cylinder conts run as high as 3000 hours without even so much as a cylinder replacement(I don't recommend it),I have also seen them blow apart after a few minutes.A lot depends on the type oil used,the type of flying the owner done,the care and up keep of the engine,and how often it was flown AND how it was flown.
Check the engine carefully.Ask the owner/seller to take you for a 30minute to hour long ride before pulling and checking the oil screen....make sure you pull the oil screen and look for steel with a magnant.
Remember,you said it yourself,every hour above TBO is a freebie,it might go for a few hundred more hours or may need an overhaul by the time you get it home.....so try to get it at a price that will help ease the cost of an upcoming overhaul but don't try to deduct a large amount of money from his asking price just because of the same reason,I'm sure the seller has took this into consideration when he priced it....providing he is a loyal and honest seller.

[mhorowit]

Re: Engine exceed TBO...

...,I'm sure the seller has took this into consideration when he priced it....providing he is a loyal and honest seller.

Unless he thinks the a/c has suddenly appreciated in value because of the sports a/c thing. - Mike