Engine TBOs

[KraziKanuK]

Anyone have data on the TBOs of WW2 a/c engines?

I would think this would be year dependant. ie. when first introduced, or in late war Germany.

 

[FLYBOYJ]

Anyone have data on the TBOs of WW2 a/c engines?

I would think this would be year dependant. ie. when first introduced, or in late war Germany.

As far I know there was no established TBO set on many US engines, overhaul was dependant on oil consumption and compression, espeically on Radials. I read some where that Packard Merlins rarely got 100 hours on them before an engine change.

 

[Glider]

Wartime factory Merlins normally had a TBO of 500 hours whereas modern refurbished ones normally have a TBO of 800 hours. In wartime this is obviously dependent on type and use.

A sobering thought is that engine changes in Bomber units were uncommon, as the planes didn't last that long. This observation was made on a film shot on a bomber base during the war.

 

[quayhog]

My (1942) Pratt-Whitney R28000-8/-10 operators manual states:
"General reccommendations on the number of flight hours between overhauls,
to serve as a starting point for maintenance procedure, are acceptable only to operators who are begining to operate new equipment with which they have no experience. From then on, the time between overhauls is governed by the individuals operator's experience. The safe procedure with new equipment is to start with a conservative time limit, such as 350 to 400 hours, then gradually approach longer periods (preferably in incraments of 15%) based on the satisfactory condition of the engine at overhaul and the service record of dependability."

My Pratt Whitney R-985 book has the same paragraph without the 350 hours, it reccommends 400 hours. My Ranger 770-C1 book provides no guidance.

My father flew Lockheed Venturas (R-2800) in 1944 and logged almost 500 hours on a combat tour. He told me they only changed engines when performance deteriorated enough to inhibit safe operation or battle damage.
The performance deterioration was mostly due to propellor damage from coral dust and salt air corrosion.

These airplanes flew daily patrols between Tarawa and Roi-Namur, a distance of approximately 600 miles for eight months.

The November 1960 issue of the Naval Aviation News has an article about a VW-3 P2V-5 that has over 1500 hours on its original engines.

 

[FLYBOYJ]

My (1942) Pratt-Whitney R28000-8/-10 operators manual states:
"General reccommendations on the number of flight hours between overhauls,
to serve as a starting point for maintenance procedure, are acceptable only to operators who are begining to operate new equipment with which they have no experience. From then on, the time between overhauls is governed by the individuals operator's experience. The safe procedure with new equipment is to start with a conservative time limit, such as 350 to 400 hours, then gradually approach longer periods (preferably in incraments of 15%) based on the satisfactory condition of the engine at overhaul and the service record of dependability."

My Pratt Whitney R-985 book has the same paragraph without the 350 hours, it reccommends 400 hours. My Ranger 770-C1 book provides no guidance.

My father flew Lockheed Venturas (R-2800) in 1944 and logged almost 500 hours on a combat tour. He told me they only changed engines when performance deteriorated enough to inhibit safe operation or battle damage.
The performance deterioration was mostly due to propellor damage from coral dust and salt air corrosion.

These airplanes flew daily patrols between Tarawa and Roi-Namur, a distance of approximately 600 miles for eight months.

The November 1960 issue of the Naval Aviation News has an article about a VW-3 P2V-5 that has over 1500 hours on its original engines.

Interesting information! I'd like to compare the data you have from the R2800 and compare it with the maintenance manual....

Today most GA recips have between 1800 to 2000 hours as a TBO. Some engines go as high as 2400...

 

[quayhog]

I found an interesting forum thread with pictures at the practical machinist website. The text deals with wartime aircraft TBO's plus it has some real nice Centaurus sleeve engine pictures. Have a look.

http://www.practicalmachinist.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=11;t=001242;p=0

 

[KraziKanuK]

I found an interesting forum thread with pictures at the practical machinist website. The text deals with wartime aircraft TBO's plus it has some real nice Centaurus sleeve engine pictures. Have a look.

Nice site.

Nice story as well. Thanks.

 

[chris mcmillin]

Interesting about the @350 hour comment Quayhog,
My father had a Beech UC-43/GB-2 (it had been in both services) other wise known as a Staggerwing. The original logbook for the engine indicated it had been on a JRF for 350 hours from new, and then removed and overhauled. It was installed on Dad's Beech and flown on it through surplus, and when we were flying it in the seventies it had about 500 hours on that forties overhaul. It ran smooth, and would clean up after a few hours of continuous operation. The oil control rings seemed to be happiest when the engine was operated on a semi-recent basis. If it sat for a long time I would push it way out and start it with the tail pointed away from where anyone would walk as it would need to deposit some oil for a while. After a quick wipe down it would be happy and clean again.

Dad flew the Ventura as an executive transport, he said they ran a lot of power and had the airline version CB-17 engines fail the reduction nosecase's in about 200 hours. They cruised it at 350mph true airspeed, so it must have taken 65% power or so even with all of the Howard aerodynamic clean-ups to get that kind of speed.

Chris...

 

[FLYBOYJ]

Very cool chris! Where do you fly your Pitts out of?

 

[the lancaster kicks ass]

does this look like a good siggy to anyone else? i think it's a bit big though ...........

 

[Gnomey]

Reduce it down more and you have an avatar, which it would look better as in my opinion.

 

[evangilder]

That is one good looking staggerwing, Chris!

 

[chris mcmillin]

Thanks guys.
Lancaster; Nice thought, I'll try to edit my pic and profile.

Gnomey; As an avatar, good idea.

FLYBOY J; Chino. My hangar is on the west side, across from Aero Trader.

evanglider; Nice pics yourself. Thanks, Dad sold the Beech when I started college. My brother-in-law has an early B-17R Beech at Chino, though so I get to them still.

Thanks all for a warm welcome.
Chris...

 

[Gnomey]

Thanks Chris, here it is as an avatar for you...

 

[chris mcmillin]

Gnomey and Lancaster,
Thanks for the avatar idea, I wouldn't have thought of it.
Chris...
evanglider,
Do you do air to air's too?

 

[Gnomey]

No problem Chris.

 

[DaveB.inVa]

If I remember correctly some of the early carbureted R-3350's would make around 200 ~ 250 hrs, near the end of the war after numerous improvments and the addition of direct fuel injection they could make around 500 or more hours.

 

[chris mcmillin]

The really amazing thing about the Wright 3350 is how the WWII version bears next to no resemblance to the later Skyraider or P2V versions. The exhaust ports were forward facing on the B-29 and the cooling was very bad through some multitude of restrictions that were discovered and corrected. After the war the engine was completely redesigned and became the reliable powerplant used on the later designs, including airliners.

The much later Turbo-Compound version was very reliable, and the slow nose case used on the very last Constellation L-1649 made it a 3400hp engine with cruise hp in the 1000 hp range a 1000 hr tbo engine at TWA.

This EA-2 civilian nosecase is highly sought after in air racing circles.

Chris...