F4U-1 engine quiery

[greatgonzo]

The Corsair's R-2800-8 is shown in every book equiped with 'cast-filled' ignition harness. Yet it is possible to find a few pictures of F4U-1 with tubular harness typical for P-47 e.g. My questions are:
- is it accidental situation, or have there been searies of these engines done in such a way.
- do the distributors change with the harness? I'd say yes, but I'm not sure.
- was it possible to find B-searies engined P-47 with 'cast filled' harness leaving one of the factories?

I wonder...

[Cherrybomber13]

I don't know if this helps the conversation but this is our r-2800 on the Sikorsky Memorial FG1-D Built at the end of the war (July 45)

FG1-D Corsair Pratt & Whitney R-2800 by Cherry Bomb Photography, on Flickr

[greatgonzo]

Well, it solves nothing, but... what a plesure to watch!

Thank You very much.

[51fixer]

I don't know if this helps the conversation but this is our r-2800 on the Sikorsky Memorial FG1-D Built at the end of the war (July 45)

FG1-D Corsair Pratt & Whitney R-2800 by Cherry Bomb Photography, on Flickr

That is the cast harness.
Harnesses are particular to the type of Mag used and other considerations, such as altitude used for normal operations.
As you go higher the air thins. This affects how the spark travels in the harness and can cause the spark to be able to jump to a ground at high altitudes that it wouldn't do at lower altitudes.
To compensate for this the harness could be filled with an oily gel substance. I believe this was an early attempt to improve on this situation.
Later they used an air pump rotor built into the distributors to pressurize the harness and parts to increase the air density in the ignition system.
This is all info I remember from long ago so I don't remember specifics but can be the reason why different ignition harnesses are out there that don't correlate to the parts books.
On the FG-1D (under restoration for Paul Allen now) I worked on I remember the distributors having the rotor vanes on them.
This was on the Bendix Mag systems on the B series R-2800. The Mag was in the center top location of the nosecase and looks like a small box.
The 2 distributors are located about 10 and 2 o'clock and are round castings maybe 8" in dia and height.
GE magnetos are different as each unit (1 at each 10 and 2 location) are self contained mag and distributor in 1 larger housing that looks more like a flying saucer. These were on A-26s and were lower altitude units so I don't believe they had an air pump and the harness was tubular.

[agent86]

If I remember correctly(not often these days) there was some kind of issues with the P-47 ignition wires at high altitudes.might be an answer for different wires

[robkamm]

is this what is called "potting the mags and harness"?? i know that is done to stop missfires. if that is what its called

[whistlingdeath77]

I don't know if this helps the conversation but this is our r-2800 on the Sikorsky Memorial FG1-D Built at the end of the war (July 45)

FG1-D Corsair Pratt & Whitney R-2800 by Cherry Bomb Photography, on Flickr

how much corrosion drew?

[greatgonzo]

Thanks for interest.

The harness on the pic is the cast harness with gel and pressurised distributors, as it is typical for F4U-1. The anomaly is what makes me wonder.

Another issue is the harness seems more advanced and prepared to work on higher levels then the simplified, tubular one. But it was used on relatively low operating Corsairs contrary to the tubular one used on high flying P-47. It is interesting what stood behind disign idea.

[mike furline]

This book may answer your questions.
http://www.amazon.com/2800-Pratt-Whitne ... 0768002729

[greatgonzo]

Unfortunately it may not . I rise here the problems I have not found covered in the linked book. Its a fascinating lecture for me anyway.
I appreciate Your help, though. Thanks.

[agent86]

I don't know if this helps the conversation but this is our r-2800 on the Sikorsky Memorial FG1-D Built at the end of the war (July 45)

FG1-D Corsair Pratt & Whitney R-2800 by Cherry Bomb Photography, on Flickr

how much corrosion drew?

How much heat do you think this momo puts out? what a bunch of spinning parts and pistons.they are amazing technology.this is as far as recips progressed.the height of the technology.jets took over and left these behind.I'm a mechanic and still impressed with the complexity of these lumps of aluminuim.

[corsair166b]

If you read the history of early Corsairs they had problems with sparks 'jumping the gap' and shorting out the distributor and had to resort to a pressurized magneto if I recall....far too many bugs in the early Corsairs, amazed they got almost all of the problems worked out DESPITE a project manager that 'did'nt want to hear that the Corsair had any problems!'

Mark

[T-28mike]

G.Gonzo,

You were not specific to where or what era you saw the other harness in place.

Many aircraft in the "civilian" world are highly modified. The original -8 engine was rather problamatic, and maintenance intensive. Many modern examples use a later engine ( such as a CB series ) or an amalgamation of later and early parts to create a more reliable engine.

During the "War" there were many factors that changed what was called out, and what was really implimented. During the course of production there were thousands of engineering changes, parts and material shortages or just outright policy changes ( high altitude mission VS low altitude mission) that would affect equipment requirements, production or availability.

This is only on the "home front".

The operational theater was a completely different story. Mission readiness was No.1 priority at all times. If there was one thing to be recognised from the "ground pounders" contribution to the war effort, it was the un-canny ability to improvise, adapt and overcome. The basic R-2800 would fit many different aircraft. If all I needed to get aircraft X on line was an engine, and another ___ on the line was equipped with a different Dash No. of an engine, I would borrow that one from aircraft Y, and make it work in X.

I have seen this done, and have done it on several in the past (especially R-2800 powered A/C.

The same engine could be equipped with a different magneto (GE Vs. Bendix) This could be denotated as an option on the same dash number (common early on) or as a completely different dash No.

The R-2800-8 (corsair) and the R-2800-10 (hellcat) were essentially the same engine with the exception of one having an up-draft carb, and the other having a down draft carb. To convert one to the other required simply flipping the intermediate blower case 180 degrees (iirc).

Hope that helps.

[greatgonzo]

I am grateful for the response and I admit I could have been not strictly clear.
The whole idea of parts borrowing, making the engines (and frames) operational from scratch and waste is quite clear to me. I am also conscious of the fact the warbirds flying these days use commercial, post war engines very often. But these cannibalising incidents are exceptions, and very hard to pin pricisely when it comes to dates and circumstances.
With a little help of some books I can define basic differances among the R-2800 models specified for particular aircrafts.
What I am trying to find out is: was there some relation of those nonstandard ignition system to time or serial numbers, or even the 'dash' numbers of the Corsair. Four or five pics of different planes forced me to susspect there could have been some method in this insanity.
I am talking about F4U-1 during the war time only.

It is a pleasure to see You guys trying to help. I learned a lot from this forum.