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

I forgot to add.......We ground the crank to remove all but a few really deep pits. And then ground the I.d. of the outer races until they were clean. So now with a clean hard crank and clean outer races , we then used these new diameters to create new rollers that gave us the correct bearing clearance. The pockets of the bearing cages also had to be machined to provide clearance for the large rollers......... The bearing clearance is almost .003" . I've got pictures of almost every single square inch of the engine if you have any questions.......DAVE

 

The shots you have of the crank and roller bearings are amazing. I would imagine that this must be a fairly low speed engine as those huge diameter bearings would have a horrific surface speed. Do the rods use Plain bearings, are they pressure oiled or splash oiled? What a fantastic project to be part of. Keep up the good work.

 

Sorry but having worked on quite a few Merlin's and Allison's they ARE an inferior design. Both in operation and to work on. This is WHY the Merlin was the 'engine for the time'. If the Allison was even close in comparison it too would have been the 'choice' of manufacturers.
Try to refrain from using floored US policy to explain away weaknesses in equipment. A poor motor is a poor motor regardless of design ethos.
I didnt blame government failings in selecting the POS F-88 Steyer we were lumbered with to replace the L1A1 (Sweet rifle!), they were just poor weapons.

 

I guess you have seen the merlin Powered Mustang fighter here in Qld? .The owner told me it was a far faster ,better flying plane with the merlin . From the horses mouth I suppose.

 

Yes, funny how EVERY aircraft that utilised both the Allison and the Merlin all performed much better with the Merlin. This is like arguing that a flathead is just as good as an OHC motor. Chalk and cheese.

Is that the one based out of Caboolture? Yes, its only 25min down the road.

 

Thats the one., 45 minutes from me ( Moorooka)

 

They had a civillianised A-26 Invader there for a while too. Last time I spent time there was at the 99 Airshow doing an airborne display there. The Mustang was not finished but I got a good crawl over it on a stop over at the Old Aeroplane Company in Tyabb.
Hehe, ironic really, we have been restoring Judy Pays P-40 N a Merlin powered aircraft and the best performing of the P-40 series!

 

The max RPM was originally 3000. In mid 1944 there was a campaign to adjust the governor to allow 2500 RPM max. This lowered the power to try and save the fragile final drives and transmission.

The mains are 8.440" in diameter..The rollers are .590" in diameter. I've never calculated the surface speed but it would be an interesting bit of trivia...

The rods use a heavy steel copper plated insert. The primary or forked rod holds the insert halves and the secondary rod pivots on the o.d. of this bearing. The I.D. of the secondary con-rod is hard-chromed. The rod journals are pressure oiled with about 120 p.s.i.. The main rollers are splash oiled.

This engine has a 130mm bore and 145 mm stroke. If I remember correctly it weighs 1400 KGS all assembled. The valve covers and pistons are the only aluminum components in the engine..The block, heads, crank mag housing and intake manifold are all cast iron. The crank is a one piece forging..... DAVE

 

A little O/T but check this out........

http://www.ultimatecarpage.com/car/3159/Maybach-Special-Mk-1.html

 

6625 FPM at 3000 RPM crankshaft speed. The rollers are spinning at 42903 RPM, assuming no slippage. I think the math is right. Zoom Zoom Zoom

 

I've never seen a supercharger driven with a u-jointed shaft like this. Extremely KOOL, I like to see a lot of spinning things under the bonnet. As Indian Larry once said: "I like to see all the mechanicalness"

 

Hang on a minute! Its old, German, has torsion bar suspension and a rear engine? You sure this is allowed on the HAMB??

 

Ya, but it's got TWO V12s and a 75mm gun! And I bet it doesn't go tweedle tweedle.

 

Maybachs in the news:
http://www.novinite.com/view_news.php?id=90199

 

So,.....................................
Did Ferdinand have anything to do with it??
I know what I'd rather drive in traffic!

 

Bringing this back up... We just recently finished installing the engine and have started it in the tank for the first time.

http://www.youtube.com/watch?v=eRH2GoIuhmA
This vehicle has 4 separate radiators that require a total of 96 hose clamps to connect them all to the engine and the blowtorch heater.

We've almost finished restoring all the track and hope to test drive the hull within a few weeks. Barring any major problems we hope to have the turret mounted by the end of the year. December 23rd it will be 6 years we've been working on this vehicle... DAVE

 

No wonder they lost - must´ve spent half the war doing up hose clamps!

 

That is just friggin' awesome! Outstanding job there, guys!