Warbird Information Exchange

A few weeks ago I decided to pull one of my B-29 APU's out and get it running again. Despite the fact that it hasn't been started in at least 30 years, after a little bit of work, she fired right up!

Here's a video we shot of the first startup. These Andover V-32's are sweet little engines! https://www.youtube.com/watch?v=q7aSEErZUag

This engine is 100% original, right down to the 70 year old sparkplugs, and everything still works!



The complete "putt-putt" installed in a B-29. (These APU's were also used in a number of post-war aircraft as well.)


The next step is to adjust the idle speed and mixture, but first I need to install the cooling fan and such, as these engines get very hot, very fast, without it. I have another complete "farm fresh" B-29 APU that unfortunately is in rather poor condition after sitting outside for who knows how many years, and I'll be using some of the cooling system parts off of it to complete the APU you saw in the video. However, since I like a good challenge, I've decided to try and get the "farm fresh" APU running again as well, so I'll be posting pictures here of my progress. This should be fun!

Despite thousands of these APU's being producing during (and after) WWII, there doesn't seem to be a lot of information about them on the interwebs for some reason (outside of references to the Kee Bird), so I hope that the work I'll be documenting here will be beneficial to those who also own one of these engines. Stay tuned!

Good job, Trevor!! Just make sure you don't hit your head on it.........

Rod Schneider wrote:Good job, Trevor!! Just make sure you don't hit your head on it.........

Thanks buddy! And you know I only hit my head whilst working on the B-17, ha! Surprisingly, I haven't shed any blood on this project yet...obviously I'm doing something wrong!

Cool! Way cool!

However, if you ever find yourself with it, out on the artic ice, double check your fuel lines...

MRK

Worked on one of those in a DC3. It was only running on one pot. Tried everything & then pulled the valve cover to find the rockers & everything else just laying there in "kit form". Put it back together & it fired right up on both

emarkay wrote:However, if you ever find yourself with it, out on the artic ice, double check your fuel lines...

In the near future I'll probably do a post about the fuel pump on these engines and the issues that ultimately led to the Kee Bird fire.

ZRX61 wrote:Worked on one of those in a DC3. It was only running on one pot. Tried everything & then pulled the valve cover to find the rockers & everything else just laying there in "kit form". Put it back together & it fired right up on both

Now that's funny right there!

OK gang, I just made a walkaround video of the "farm fresh" B-29 APU so everyone can get acquainted with the various components, and there's also a couple of nasty surprises discovered along the way as well. Check out the video here: https://www.youtube.com/watch?v=M-QV1vC-4kk

Is there still some life left in this old girl yet, or was there a very good reason why she was put out to pasture and left to rot? Stay tuned--the real work is about to begin!

B29Gunner wrote:

ZRX61 wrote:Worked on one of those in a DC3. It was only running on one pot. Tried everything & then pulled the valve cover to find the rockers & everything else just laying there in "kit form". Put it back together & it fired right up on both

Now that's funny right there!

The rocker arms were mounted on blocks that were bolted to the head, not cast as part of it. The bolts holding the blocks to the head came undone & it all fell apart. Everything stayed inside the valve cover just sitting there. It was one of those "I think I've found the problem" moments.

O.K. I give up........................where is the fuel tank!!!! And I hope you don't use a Jerry can like someone else we know did.

Now that Photobucket is cooperating, let's do some work!

To help us bring this engine back to life, the first thing we're going to need is some good ol' Marvel Mystery Oil. Now, some people will tell you that MMO is nothing but snake oil, while others religiously swear by it for everything from engines to curing baldness and treating broken bones. I personally have found it to be a great product, and I consider MMO an indispensable tool when bringing these old engines back to life and keeping them happy, but your mileage may vary



So the first thing we're going to do is pull the plugs and load the cylinders up with MMO. Right now I cant rotate the crankshaft until I remove the generator and scroll, so I don't know if the engine is froze up or not. But in the meantime, we'll let the MMO do its job and soak down into the piston rings, etc.





As of this post, the cylinders have been soaking for about two weeks now with more MMO added every couple days as needed. Here you can see the MMO doing its job (be very gentle and careful if you're going to probe around inside the cylinder--scratches are not good!)



Next we'll turn our attention to the rocker boxes. Everything looks pretty good on the #1 cylinder (aside from the rusted nuts that backed the studs out with them)...





But if you saw the "walkaround" video I posted earlier, then you already know what we found on the #2 cylinder!









That valve spring is toast! The rocker box covers on these engines have vents built into them (I'll touch on that in a later post), and as you can see, that vent permitted moisture to get in there and that spring is gone. The good news is the valve is closed, so hopefully none of that moisture made it down into the cylinder (it doesn't appear any did).



While the rocker box covers are off, we'll go ahead and drench everything in MMO as well.



At the bottom of this hose is a one-way valve that's connected to the rocker box covers (part of the crankcase ventilation system--have you guessed the purpose of those rocker box cover vents yet? ), so we'll squirt some MMO down there as well.



The next thing we'll do is put the handle of a rubber mallet on the rocker arms and push the valves open to see if any of them are stuck. I'll also squirt some more MMO on the valve stems and let it work down to the valve guides as I open and close the valves.



All of the valves are opening and closing just as they should...except for the exhaust valve on #1 cylinder. As you can see, the exhaust valve (on the left, from this angle) is partially open from when the engine was last shut down. Now, I can open and close the valve to the extent that the push rod will let me, and the valve is not stuck, but considering how long this engine probably sat outside in the weather, this could be a problem! Looking into the cylinder with a flashlight, I can see some scattered areas of light rust on the cylinder walls, and that, my friends, is not good. The rust doesn't look so bad that there's going to be pitting as well, but it's just really hard to tell. Either way, that was all I needed to see---off with the cylinder!!



So to sum up the to-do list, as of right now, I need to pull the #1 cylinder and see how bad that rust is (and it's probably a good idea to pull the #2 cylinder as well), and I need to replace a valve spring on the # 2 cylinder. So much for putting some gas in her and going

Stay tuned!

Obergrafeter wrote:O.K. I give up........................where is the fuel tank!!!! And I hope you don't use a Jerry can like someone else we know did.

You cant really see it in the video, but I used a small, heavy-duty plastic bottle for the fuel tank. What you also cant see in the video is the fire extinguisher and water hose sitting at the ready behind me. I take safety and fires very seriously and don't mess around

Speaking of fuel tanks, I have an original B-29 APU fuel tank that I'll eventually be hooking up to my running APU, but that's a project for another day!

Obergrafeter wrote:O.K. I give up........................where is the fuel tank!!!! And I hope you don't use a Jerry can like someone else we know did.

You know there is old (very old) cars where the fuel tank is just atop the engine and it's designed and certified like that.

That remember me that I have to buy a good fire extinguisher for the car I restore with my father. Just in case... I don't want to reproduce the Kee Bird expericen : sitting and wathing a restoration work burining

To help us bring this engine back to life, the first thing we're going to need is some good ol' Marvel Mystery Oil. Now, some people will tell you that MMO is nothing but snake oil, while others religiously swear by it for everything from engines to curing baldness and treating broken bones. I personally have found it to be a great product

You forgot to mention that it makes a good Martini also!

This is a great thread! Love seeing something considered old junk brought back to life. Thanks for posting your progress. Looking forward to the next installment!