O/T More old big Engines, Maybach V-12

Great project. The technology in these 65+ year old engines is amazing.

 

Hows yours coming along LB?

 

too cool!!

 

Slow, I've been pretty busy lately and have not had a whole lot of time to dedicate to finishing it up. I keep gathering up the odds and ends that I needed to finish it. I just need to get back on it and get it done.

 

Bringing this back up....We started the engine yesterday.. After years of work It's ALIVE!!!!!!

http://www.youtube.com/watch?v=4VZQVLQAk94

 

WOW! Fired right off, and sounds great! Always nice to hear one come back to life, I imagine this one is extra special given it's history. Which one of the four guys are you? Congratulations!

I just looked at the site where the disassembly pictures are. Does that crankshaft ride on roller bearings? Some of the stains on it look like it might.

 

I saw that show - way too cool!

 

It fired right off in this video because I didn't show you the previous attempt (s) Our first try was about a month ago and we had a few issues.

I'm the one with the safety glasses kneeling to the right of the engine that then dances in front of the engine like a drunk chicken..

The crankshaft does ride on roller bearings. I have some more pictures here.. http://www.kodakgallery.com/davemarian/main/panther_engine_pictures

We removed about .010" from the crank main journals to clean them up. There are still a few really deep pits, but for the most part the crank looks brand new. You can't remove too much material or you grind through the heat treat. The outer bearing races were pitted very similar to the crank in the pictures. We had a shop in Chicago grind the I.D of these races and then create new rollers that create the correct bearing clearance. The bearing clearance is almost .003"

Once I get the water hooked up I'll post up some more video while tuning the carbs and timing and such. DAVE

 

Saw that show on the Canadian Discovery Channel.
LOTS of work.Very cool.

 

Wow, I have never seen connecting rods made like those ones before. Is that a common thing in big engines like that or something that is special about this engine? Thanks for posting all the pictures and the videos. Looking forward to the test/tune video.

 

I've never had a Harley apart, but I guess they are similar..In this case one of the reasons for this rod set-up is to keep the engine as short as possible. The cylinder heads are not offset like a typical V-8. This 1400 inch v-12 is about the same external size as the U.S. built 1100 inch Ford v-8 that was used in Sherman's.

I'm not sure if there are other engines that use this crank style. but it's one of the coolest parts of this engine....the books call it a disk style crank, it's a forging that has the rod journals way out on the edge of the discs.

This next week ought to be pretty good at work, I'm hoping to get some more running time with the engine while tuning the carbs and mag timing.


DAVE

 

Sweet, can not wait!

 

Lets see an overhead cam v12 hemi. wow

 

Very sweet engine. You guys should be proud.

Some of the engine technology just blows me away. For having been designed in the 30s, that thing has some neat features. The block looks like a work of art. It's pretty intricate. The Germans sure could build some neat stuff. The fact that it's physically smaller than a Sherman engine on the outside, but displaces 300 more cubes on the inside, says something of their engineering capabilities.

Of course, it probably has at least twice as many parts as a Sherman engine!

Nick

 

really unusual and typical of a situation where cost was no object..they are often refered to as Fork and blade conrods.

 

The Ford V-8 tank engine actually started off as a V-12 aircraft engine.That didn't work out so they chopped off a few cylinders for the tank engine.I believe the Ford is a 60 degree v-8 instead of the common 90 degree?
Maybeck also build large,over 2000 cubic inch V-12's used in Zeppelins in the 1920-30's.

 

The block is one of the most intricate castings I've ever seen...There's a collector in England that has looked into re-creating the blocks but I can't even imagine how expensive that would be??

I've also read that the Ford V-12 and V-8 shares the same bore spacing and bore size as the RR merlin. I don't know how true it is but it makes sense... DAVE

 

I can not see your picture. Can anyone else see it.

 

Very cool. Please keep the updates coming. I wish there was a tank motor in my garage!

 

I have to ask...How do you get the needle bearings into the mains when you're assembling the engine?

As a machinist, I see some nice work! Keep up the good work, and a longer video of it running would be cool, too!!

Nick

 

I have pictures of the con-rod set up in this folder..

http://www.kodakgallery.com/davemarian/main/panther_engine_pictures


There's a few shots of the rods in the crank case and the rods by themselves...... DAVE

 

I have pictures of the crank and bearings here:

http://www.kodakgallery.com/davemarian/main/panther_crankshaft_and_bearings?

This crank has seven large roller bearings, 6 of the outer races are installed in the block first. These bearings are retained by long flat wires that are installed through holes in the block near the oil pan flange. We installed these 6 outer races first.

With the block resting on the bell housing flange we drop the crank into the middle of the crank housing and outer bearing shells. At this point there are no rollers or roller cages.

We now lower the crank into the crankcase. We drop it in lower than it's installed position.

Each of these first 6 bearings has an aluminum cage that separates each roller in the installed position. These six separators are fed from the top down into position and held in place while we load each bearing with the rollers. The rollers are installed dry to avoid making a greasy mess. We originally thought we would use grease to hold the rollers in place, but with the block vertical and level the rollers were actually fairly easy to load and keep in place.

Once all the rollers are installed we used thin metal strips to hold the rollers out against the outer races.

Once all the rollers are installed and held in place with the strips we pull the crank back up into the correct position. The edge of each main is chamfered to help get the crank started into the rollers. The bearing clearance is about .003" so it's not super tight.

With the crank installed in these 6 rollers the rear most large roller bearing can be installed. This rear roller bearing has a riveted brass cage. This last bearing is the one that controls the thrust. With out this bearing the crank is free to slide in and out of the block..

I 'm hoping with the pictures in the above album it will make sense? We ran the engine more today and I'll post more videos in a bit.... DAVE

 

Dave,
As an Engineer, I am not easily impressed by antique mechanical devices...

But that impresses me. The design work and engineering that went into that engine is at least 40 years ahead of it's time. If I did not know what I was looking at, I would have SWORE it was mid 60's cutting edge design.

It's perfectly obvious the block was designed by tallent recruted from the jewlery and watch-making trades of the time.

What impresses me even more is your ability to take a big ball of rust, fuzz, and lint,,, and actually restore it back to the work of art it originally was. I would imagine your benefactor has some pretty deep pockets to make this dream a reality.... My hat is off to both of you.

I only wish my Grandfather was still around to see this. He was an engineer also, and was responsible for "back engineering" a lot of the captured technology after WW2, and he spoke often of his admiration of German war machines.

 

Daimler benz ,Maybach and Mann built some amazing stuff prior to hostilities breaking out ,especially aircraft engines. jewel like the workman ship may be but it was entirely automotive in it's conception and execution. And don't forget that Daimler had been manufacturing autos to a high standard for 50 years before that engine was built .

The English and the Americans built variuos engines to such a standard too,it'as just that with passing of time a lot of those achievements have been forgotten by the general public .

 

People seem to forget just how advanced and ground breaking the Merlin/Griffin engine series was. Look at its contemporaries, it was only the Germans that came close the Allison is VERY second rate in comparison.
Big motors copied them for decades.

 

The Allison was not an inferior design,it's supercharging was never properly devoloped because of US gov't mandated turbo chargers that took a long time to sort out.Merlins were not without problems and they were solved by a massive British engineering program.Allison Engineering despite being owned by GM was always a small company with limited resources.The Allison used about 10 percent less fuel than the Merlin for the same power.The Allison also didn't have the rocker wear issues like the Merlin cause it used roller rockers.Many say the Allison has a superior bottom end design also.
But...the Merlin was the engine for the times.

 

caddydave, amazing work! really love seeing things brought back! I was kinda wondering about that crank though. no way you could have gotten it hard chromed and ground back down to size instead of putting it back together with pits on the races?? that's how we repair the seals in aircraft engines at work.

 

Thanks, the pics explain it now.

What sets the thrust on the crank? It doesn't look like the crank "races" have any lip on the edges? Is there some kind of thrust plate for the crank snout or something, like on a small block Ford cam?

Nick

 

You got to hand it to those Germans regarding their machanical knowledge. They had some pretty good ideas regarding how to go fast and keep it light.

Now their WWII politics were another matter....

 

I've been told that hard chrome won't hold up to the force of the rollers. Hard chrome would brinnel or flake off and cause all sorts of problems. We only removed about .010" from the diameter which wasn't enough to remove the hard surface. We tested the hardness after grinding and it was in the 60-62 range on the "C" Rockwell scale. I've been told by the bearing manufacturer that it needs to be 58 or better to last.

The thrust is set by the rear most bearing and bearing main. Picture " ste 0848 " in this album http://www.kodakgallery.com/davemarian/main/panther_crankshaft_and_bearings?shows the step in the main. The rear most bearing outer race is pressed into a large housing that is then bolted to the back of the block. This housing is then shimmed in and out to center the crank in the block. The clutch assembly is mounted inside the transmission so there probably isn't much force on this bearing. Hopefully my explanation isn't too confusing? DAVE