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Prop strike engines

jibby212

Well Known Member
I have been searching for an o360 for my rv7 and have found many which have had a prop strike. There is a o360 a1a WITH 346 SMOH for 12950 on Barnstormers but it has had a prop strike, flange dials good but I have a feeling that don't mean a lot. I'm thinking I should stay away from these engines but any professional opinions would be appreciated.
 
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I have been searching for an o360 for my rv7 and have found many which have had a prop strike. There is a o360 a1a WITH 346 SMOH for 1295 on Barnstormers but it has had a prop strike, flange dials good but I have a feeling that don't mean a lot. I'm thinking I should stay away from these engines but any professional opinions would be appreciated.

Lycoming says ANY prop strike, no matter how minor, requires a tear down and complete inspection. One of the most common fail points is the crankshaft/camshaft gear bolt.
 
I assume you left off a zero on that number (1295). The engine might be worth half that with the prop strike, IMO.

I am in the process of a prop strike inspection (slow boat) on an O-235. I tried selling it as is with the strike noted in the log book and amazingly had a few people ask to buy the engine but without the log book entry. I declined.

See SB 533B for everything required. The dial-indicator check for a bend flange, as Mel said, is still required but only part of the overall inspection. Lots of parts have to sent off for NDI.
 
I bought one this summer that was a prop strike 13xx since major. I thought it worth the risk. It said the crank dialed .0015". I found it to be accurate after it got here. I planned to rebuild the engine anyway so the only risk for me was the crank itself, I thought. So after tearing it down, I sent off everything in the cases for inspection/repair. It all came back after necessary work with papers for just over $3k. I'm happy.

Ditto what Mel said. One area on the crank that takes abuse, I found out, is where the cam drive gear mounts to the front of the crank. Some cranks can be repaired there. This one didn't need it.
 
I am in the process of a prop strike inspection (slow boat) on an O-235. I tried selling it as is with the strike noted in the log book and amazingly had a few people ask to buy the engine but without the log book entry. I declined.

Why? (Both why not sell, and why would they want it without the log book)

Tim
 
I had a sudden stoppage back in the day with an 0-470-K.

Back then the sentiment was check the crank flange and if good...carry on.

My flange checked out good. Against the advice of all my aviation friends, I tore down the engine anyway. I can't say the damage was directly related to the sudden stoppage but I found a cracked crankshaft and two cracked rods.

It can get expensive :eek:
 
Why? (Both why not sell, and why would they want it without the log book)

Tim

They want it without the entry mentioning the prop strike. Then they can list it for sale without a prop strike, because there is no record of a strike in the logs. A fraudulent practice that could get someone killed.
 
They want it without the entry mentioning the prop strike. Then they can list it for sale without a prop strike, because there is no record of a strike in the logs. A fraudulent practice that could get someone killed.

Oh ****. I did not think of that. It never even occurred to me.

Tim
 
Why? (Both why not sell, and why would they want it without the log book)

Tim

The buyer would have likely put the engine on a certified plane and went flying or sold it to an unknowing buyer.

As an A&P mechanic (mostly Blackhawk experience but drinking from the hose of knowledge every day), I could not have that on my conscience.
 
The buyer would have likely put the engine on a certified plane and went flying or sold it to an unknowing buyer.

As an A&P mechanic (mostly Blackhawk experience but drinking from the hose of knowledge every day), I could not have that on my conscience.

Raymo,

Agree. Just never even occurred to me. I am probably a little naive in the bending/breaking rule aspect.

Tim
 
If you are looking to buy an engine that has had a Prop strike and hasn't been tore down, then you have to consider that engine as core value only. I know some here will disagree but if you want to be safe then consider making an offer to the seller for core value only.
 
An unmentioned issue is what is the proper way to check the crank.

A friend of mine is a long time auto engineer. He was on several initial design team for new OEM engines in Detroit.

The generally unknown factor that leads to a wide variance in damage is the timing of the strike. If the prop contacts almost anything just as a cylinder firing pulse lights off, the loads go to Valhalla.

A 3000 amp Magnaflux machine may check to about a depth of .375", but it was easy with prop strikes to develop fracture planes deeper than that.

He would not use a "prop strike" crank unless it had been examined with an industrial X-ray machine.

YMMV
 
I have been searching for an o360 for my rv7 and have found many which have had a prop strike. There is a o360 a1a WITH 346 SMOH for 12950 on Barnstormers but it has had a prop strike, flange dials good but I have a feeling that don't mean a lot. I'm thinking I should stay away from these engines but any professional opinions would be appreciated.

From my 3yrs search for a 360 motor, $12950 is in the range of acceptable prices for a used motor with good books, good oil analysis and recent run history and serviceable/useable accessories. With a prop strike its the suckers price. If you want to know the real price its worth, ask a rebuilder (who wont BS you) what hed pay for it. But yeah, drop the zero maybe add 1k to it and youre in the ballpark from what I've heard and seen.
 
Thanks for the opinions, I will stay away from these engines for sure. I have a little time yet so I will just keep looking.
 
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