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KIMURA
03-15-2007, 05:15 AM
Hi

I'm actually build up a R-2800 with Solid Edge CAD-Programm, just for own pleasancea d later on I'll animate it. Now I need some info about the crankshaft housing situtation, especially the housing bearing poits for the crankshaft. Info of any kind on that would be nice.

edit: Here the update model so far.
http://mypage.bluewin.ch/a-z/kimura-hei/R2800.jpg

XyZspineZyX
03-15-2007, 09:59 AM
I recommend contacting a firm that really builds these engines.

Your model could be beneficial to them, and they would have drawings you could refer to

Box-weasel
03-15-2007, 11:53 AM
Hi Kimura, I found these:
CrankHX (http://www.enginehistory.org/NoShortDays/CrankHX.pdf)
P&W R-2800 Crankshaft (http://www.warmkessel.com/jr/flying/td/jd/78.jsp)
R-2800 pic (http://books.google.com/books?id=8SBbA_jW3SkC&pg=PA63&lpg=PA63&dq=%22r+2800%22+crankshaft+housing&source=web&ots=mGQzHrQ7PO&sig=z1ORvUVA1Xe1tyGPCi90vyOQNGM#PPA63,M1)
Dbl-Wasp install (http://cgi.ebay.com/F4U-1-Corsair-Engine-Blueprint-Plan-P-W-R-2800-B-8_W0QQitemZ270082532405QQihZ017QQcategoryZ4717QQcm dZViewItem#ebayphotohosting)
http://www.pimaair.org/Acftdatapics/PW%20R-2800%20034.jpg
http://airpower.callihan.cc/images/Engines/04-POF-PrattWhitneyR2800.jpg
http://www.midwaysaircraft.org/images/pw_r2800%20(5).JPG
This may be the most useful:
Inside the Radials (http://www.nomeking.com/animations/radials/engi.html)

Antoninus
03-15-2007, 12:31 PM
Do you know this article about the development of the R-2800 Crankshaft?

http://www.enginehistory.org/NoShortDays/Development%20...800%20Crankshaft.pdf (http://www.enginehistory.org/NoShortDays/Development%20of%20the%20R-2800%20Crankshaft.pdf)

KIMURA
03-15-2007, 04:20 PM
here the work of that evening. Some things may be change, like the cogwheel that drives the cam shaft drive or the shape of cam shaft housing etc.,
http://mypage.bluewin.ch/a-z/kimura-hei/R2800-1.jpg

http://mypage.bluewin.ch/a-z/kimura-hei/R2800-2.jpg

http://mypage.bluewin.ch/a-z/kimura-hei/R2800-3.jpg

http://mypage.bluewin.ch/a-z/kimura-hei/R2800-4.jpg

Box-weasel
03-15-2007, 10:36 PM
Wow. Coming along wonderfully. Does that pgm use Lightworks?

BadA1m
03-16-2007, 02:30 PM
Way cool.

Falcon500RC
03-16-2007, 07:27 PM
WOW! i tried to make the PW-R4360 for my exam (high school teacher said 10 parts and gave the example of an engine) I ended up crashing his computer, I compressed it and put it on a CD, when I decopmressed it all the parts were a mess (but i still got credit)

yeah I dont know anything about engines really, learned as I went along, I was going to put plugs on top but that 56 more pieces.

[URL=http://img83.imageshack.us/my.php?image=gcs0010yw9.jpg]http://img83.imageshack.us/img83/9017/gcs0010yw9.th.jpg [/URL

KIMURA
03-16-2007, 08:10 PM
I reworked the cam shaft housing now. It seems that -8, -10 or other R-2800 variied the parts that were fit to the engine. There are slight diff. on camshaft housing covers, magnetors etc. Tomorrow or the day after tomorrow I'll add new pics.

Falcon, 10 parts to build up a complete engine seem way too few to me.

bentbluewings
03-19-2007, 09:51 PM
Kimura, I have an observation for you. The gears on the end of the black tubes are wrong. I was a mechanic on Convair 240/340/440 (R-2800), and DC-3s (R-1830) at an air cargo company. Those black tubes are the valve pushtube housings. The pushtubes (inside the black tubular housings) actually ride between a disk type cam and the intake/exhaust valve rocker arms with an up/down motion causing the lever action of the rocker arms which opens/closes the valves.

In the top cutaway picture you posted you can see the silver disks that the push tubes ride on, one in front of the front crankshaft Journal, and the other behind the rear crankshaft Journal. As for the push tubes, both ends are ball shaped and milled onto the shaft. The push tube is hollow and there is a hole in the ball to allow oil to pass through the tube from the crank case to lubricate the rocker arms.

Other than that, your model looks very good. Great job and it is apperent you did a lot of research. I look forward to seeing your model with the ignition harness installed.

you might try www.bentwings.com (http://www.bentwings.com) which is the webpage of a friend of mine which shows great in-depth detail of the restoration of an FG-1D Corsair. You might find some photos of the engine there also.

|ZUTI|
03-20-2007, 01:50 AM
bentbluewings: mate, thanks for the link of that corsair restoration. Oh man, wish i could participate or just see it with my own eyes.

KIMURA
03-20-2007, 05:58 AM
Originally posted by bentbluewings:
Kimura, I have an observation for you. The gears on the end of the black tubes are wrong. I was a mechanic on Convair 240/340/440 (R-2800), and DC-3s (R-1830) at an air cargo company. Those black tubes are the valve pushtube housings. The pushtubes (inside the black tubular housings) actually ride between a disk type cam and the intake/exhaust valve rocker arms with an up/down motion causing the lever action of the rocker arms which opens/closes the valves.

In the top cutaway picture you posted you can see the silver disks that the push tubes ride on, one in front of the front crankshaft Journal, and the other behind the rear crankshaft Journal. As for the push tubes, both ends are ball shaped and milled onto the shaft. The push tube is hollow and there is a hole in the ball to allow oil to pass through the tube from the crank case to lubricate the rocker arms.

Other than that, your model looks very good. Great job and it is apperent you did a lot of research. I look forward to seeing your model with the ignition harness installed.

you might try www.bentwings.com (http://www.bentwings.com) which is the webpage of a friend of mine which shows great in-depth detail of the restoration of an FG-1D Corsair. You might find some photos of the engine there also.

Bentbluewings thanks for pointing out the things that are not right but those gears are not existing anymore. I first thought the R-2800 would use 4 valves per cylinder and would drive OHC on the housing atop the cylinder.
The gears there I used as a kind of place holders. As I found out there is at least 1 inside teethed cam ring to drive the black push rod that leads in to the rocker housing. Do you know if the inlet valve and outlet valve used separate cam rings?

Here an update of my work. The crankshaft so far. The arrows are for things that may receive further changing. The bearings are now the same. The inner one fits well – a common barrel roller bearing. But at the ends I would expect things like a couple of radial bearing and axial bearing on each side. Can you confirm such thing?
http://mypage.bluewin.ch/a-z/kimura-hei/001.jpg


Here the master rod I made after template from and engine book. Inside an bronze bearing with face flute that holds a steel cage into position for fixing the other 8 rod bolts. Arrows for better showing here.
http://mypage.bluewin.ch/a-z/kimura-hei/002.jpg


Arrows show the rod bolts fixed by the steel cage. Pistons the 3 piston sealing rings and 1 oil wiper ring
http://mypage.bluewin.ch/a-z/kimura-hei/003.jpg

Pistons aligned with cylinder – arrow. 2nd arrow shows the hold for push rod that may change in location if there a 2 cam rings.
http://mypage.bluewin.ch/a-z/kimura-hei/004.jpg


1st row of cylinders are hidden for better showing. 1st arrow shows the rocker housing that will be reworked soon. That housing is a damn tricky part. As I found out there are different kind of those housing depending of R-2800 subtype. The 2nd arrow show the locaction of the exhaust tube, I ˜ll check that.
http://mypage.bluewin.ch/a-z/kimura-hei/005.jpg

bentbluewings
03-20-2007, 09:51 AM
Zuti, I know what you mean there! I wanted to help with that project myself. It is complete though, and I'm not sure of the status of the aircraft now.

Hey Kimura, more great work there!

Like I said, my memory is a bit fuzzy, it's been 12 years since I've seen the inside of an R-2800, and there were certain areas of the engine that we were not allwed to even open up due to the tolerances and results if those tolerances were out of limits even slightly. But I'll try to remember what I can. We had the CB varient on our Convairs which are a downdraft carbourator like in your pics, while the Corsair had an updraft carbourator. You might try to email my friend through his site with the restoration documentation. He's been all through the P&W manuals, as well as the Chance Vought manuals. He may still have access and be able to give you more detailed help than I could. Tell him "Doc 8X" sent you.

The valve cam: I believe it was one disk machined differently to make a forward plane and an aft plane which were offset so one would drive the intake valves, and one would drive the exhaust valves.

I'm really not sure about the bearings themselves as they were major overhaul items which had to be addressed by an FAA liscenced repair shop. There were two which we delt with, but I don't remember their names. I do remember one was in Texas, and the other in Florida. I will say your crank assembly looks right though so far.

The Master Rod: Looks good, except for the brass sleeve. The reason the brass is there is because it is a soft metal and designed to take the damage from normal usage. That said, I'm not sure whether it was locked by teeth, or just a "press fit". I am sure that the brass only was exposed to the crankshaft. The teeth as depicted in the model of the Master Rod to lock the brass would have damaged the crankshaft as the brass sleeve wore down. Also they would have been a weakness in the design do to torque effects of the different mated surfaces. I'd suggest if they are toothed like that (I don't remember) that the teeth didn't extend all the way to the surface that rides on the crankshaft, but rather only were machined half way into the thickness of the brass sleeve.

Rod Bolts: Sorry, I don't remember the details there at all, I saw the rod assembly once outside of an engine. I don't remember how the rod bolts were actually retained in the assembly

Piston rings: You have that spot on with the details and placement of the 3 sealing rings and the wiper ring. Don't forget to stagger the slot in each ring so they don't line up and create an oil passage straight down the piston.

Valve Pushtube Assembly hole: Thinking back, one pushrod per cylander was slightly longer than the other, I don't recall which one (intake or exhaust) was the longer one. They were easy to get mixed up, and when one was that pushtube if it was the longer one on the short side would get bent and be unservicable the first time the engine was turned through. My memory very strongly says that the holes were slightly offset to ride the different levels of the same ring. The difference in levels was only hundreths of an inch with just enough cam motion to open each valve appropriatly to intake or expell the gasses.

Rocker Boxes: What you have there is a very good representation of a CB engine right down to the 6 cover bolts. The only thing I see missing is the hole that the rocker pivot rod was inserted through. This rod was held in place by a cap-nut on each side which was safety wired to prevent it from backing off.

Keep up the good work!!

Taylortony
03-20-2007, 07:29 PM
Stunning work

This will give you most of what you need

http://www.nomeking.com/radials.htm

http://www.enginehistory.org/r-2800.htm