Good Day,

Some continental questions...

O-470-U engines. Some are 1500TBO and some are 2000TBO. What makes the engine a 2000TBO in some of these models?

0-470-R25B.....anyone have any comments on this model of engine....good or bad?


Cheers


Macdon221

Sorry.....Forgot the "T" in Continental!!

I've heard of an O-470R but what's up with the 25B?

macdon221 wrote:Good Day,

Some continental questions...

O-470-U engines. Some are 1500TBO and some are 2000TBO. What makes the engine a 2000TBO in some of these models?

0-470-R25B.....anyone have any comments on this model of engine....good or bad?


Cheers


Macdon221

The 0-470-U model was a departure from the other 470's in that it incorporated high-compression steel pistons instead of aluminum. These engines make 230 horsepower at 2400rpm instead of 2600. Some applications make 250hp at the 2600rpm. The requirements for the 2000-hr TBO are spelled out in TCM SB #M89-13 which clarifies steel barrels must be used in the cylinders, not chrome. A desirable 0-470 to have on your 182/180.

The R model is very common as well as the -L, -S. All of the 0-470's have perhaps the best bottom-end in the business, cylinders are another story. The parallel valve J-model is the only one that is usually frowned upon.

I know several guys who've had good luck running their J model engines to TBO & beyond. Usually some valve/guide work involved along the way, but that's SOP for Continentals in my experience, at least for the 4 bangers & the C145.
I've always heard "if it's an A, stay away" (heard that about J's too), but I've talked to a couple guys who still had the A engine in their 53 or 54 model & they were OK with them.

-25B = 7.88 inch oil cooler, Cont (Bendix) S6RN1225 mags (large case), 3/4 inch mag lead connections.

all from looking up O470R25B on Airpower web site.

Tim