Warbird Information Exchange

Maybe this has been covered before (though I don't recall it in the time I've been here), but what are the strength and weaknesses of the Wright Cyclone vs. the Pratt and Whitney radial engines? Obviously, there are different models among each manufacturer, so take that into consideration. But what engines win in categories such as reliability, serviceability, availability of parts, life span, etc.

Some recent comments on the board have suggested that certain Wright engines are less than desirable...but I would have to assume their extensive use in B-25s and B-17s have proven themselves somewhat over the years.

Obviously, part of any such discussion involves a lot of opinion, plus a good deal of personal experiences. I'm just curious what people's takes are on these two radial engine giants.

We have both Pratts and Wrights.

- 3 R-985s in the Beavers
- 1 R-1340 in the Harvard
- 1 R-182o-86A in the T-28B

I know we never ever have any troubles with the Beavers, we just pull them out of the hanger in the spring and time fire up without much preparation.

The T-28 requires more work when we fire it up for its yearly runup.

Apart than that, not much to say.

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Olivier Lacombe -- Harvard Mk.4 C-GBQB

What I've heard about Wright engines is that they leak more oil than P/Ws. That's all.

Chris

Not really Chris, there's plenty of oil leaking from the harvard, but less so from the Beavers.

Go figure.

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Olivier Lacombe -- Harvard Mk.4 C-GBQB

Ok Ollie, you would know. You know, you just hear things around the airport.

The Harvard used to spray oil all over the place, but it had no gasket between the starter, the generator and the engine!!!

So we put one in and she's a much cleaner lady.

I'll have to ask my old man about the R-1820, he owned a Fennec about 10-12 years ago and flew it quite a lot.

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Olivier Lacombe -- Harvard Mk.4 C-GBQB

Not that I want to confuse things, but Pratt and Whitney Canada built the Wright R-1820-82 Cyclone 9 under licence for the DeHavilland Tracker.

Brian....

Depends on the model. Some, like the P&W R-1340 used in the T-6 have an excellent reputation as "bulletproof" engines. That might be a bit extreme, but it's a reputation that has been built over time. Same goes for the Wright R-3350-26WD...a wonderful engine.

And then there are engines that don't have quite as good a reputation. The Wright 1820-86B as used in the T-28B & C have a higher than normal instance of master rod bearing failures. This problem was uncovered by the Navy and a solution of sorts was discovered by following very rigid guidelines for engine operation (never unloaded, always the engine driving the prop), but the problem was never really solved.

All the R1830's I've been near are pretty incontinent oil wise - not had any experience of Wright motors though so can't really comment.

JC

The R-1820 in my T-28D was built by Lycoming....win a bet on that.

I have worked with both P&W R-1830s,(DC-3, B-24) and Wright R-2600s(B-25) and R-1820s(B-17).

For those that do not know, the number after the R equals the cubic inch displacement of the engine. The next number refers to a configuration of that basic engine.

For example: R-1830-94
R=Radial
1830=1830 cubic inches displacement
94=has front mounted magnetos instead of rear and other minor differences


Here is a basic comparison between the P&W R-1830 and the Wright R-1820 which both produce 1200 HP

P&W R-1830: 2 rows of 7 cylinders for 14 cylinders total.

The engine has more moving parts, but with the smaller individual size of the cylinder and the firing sequence of the cylinders results in a smoother running engine. But, since there are two rows, the rear cylinders do not cool as well especially the top ones if you have front mounted magnetos like the -75 and -94.
In terms of leaking, if you don't keep the oil tank topped of the engine is pretty clean. The DC-3s I flew we keep the oil at 25 gallons instead of 29 gallons. Max Legal oil consumption of the engine is 2 gallons per hour per engine. On a 14 hour trip from Anchorage, AK to Reno, NV I only added 2 gallons to each engine total. If the engine is tight, most of the oil lost is from preoiling the cylinders before the start.
2 row radial engines are a little bit tougher to work on in that replacing a cylinder on the rear row can require more work because of the intake and exhaust tubes that pass by to the front cylinders. It is definetly cramped removing the base bolts that are on the inside of each row. Replacing accessory items such as generators, that depends on the airplane itself and how many items you have. If you have a turbocharging system, that takes up more space.


Wright R-1820: One row of 9 Cylinders.

Due to larger individual cylinders and less cylinders in the firing sequence, the engine has more vibration. But, cooling is better with each having fresh supply of airflow around it and it is easier to replace a cylinder.
The 1820's I have been around tend to leak a little more oil.
Working on the engine is easier, a lot less hardware to remove and not as cramped as a two row. Although, the accessory section can be cramped depending on how many items you have. For instance, each has two magnetos, starter, fuel pump, oil pump and can have a generator, hydralic pump and a vacuum pump. Each engine also has an internal supercharger. Some aircraft have a turbocharger as well for high altitude operations. That requires more ducting and an intercooler to keep the temperatures down to prevent preignition and detonation.


Both engines burn roughly the same amount of fuel. It averages out to about 50 gallons per hour per engine. A long flight will be a little less, while pattern work might be higher. Operated correctly, both engines are fairly reliable, and if you keep a watchful eye, you can usually detect a minor problem before it turns into a big one.

Just like my Wright R-3350 was built by Chevy (OK, General Motors).

SP, if you're on my time zone you should be out sampling the Oz cuisine & Kulcha...

The R-2600 in my TBM is very smooth [mostly]...

Thanks for the replies to my questions.

Mark

We've got a nice group assembled for dinner tonight here in Melbourne. Mr. JDK has got a reservation at Saragossa for 19.30 this evening. List so far...

Mr & Mrs Tweed
SRP
Setter (he's found)
Duvec
OzMatt

Should be good. I'm already enjoying the vino, although many Brits pooh pooh Australian wines.

Looking forward to meeting you in Brisbane, OD.

Steve