Round eng in shermans

[uh1h430]

was wondering about these sherman tanks that had radials I think the 975 in them and how they handle hyd lock on start up. I know the stearman guys use some of the parts off those engines from the tanks

[rwdfresno]

Well in regards to radial tank engines being used in airworthy aircraft I know that the Continental W-670-9A engine is an engine that does have some airworthy parts, That engine was built for landing craft, LVT, and M3 Stuart tanks can have some parts interchanged with an airworthy engine. Here is an article pertaining to this.

http://www.radialengines.com/docs/FAA_S ... _446_1.pdf

This may also be the case with the R985s used in Sherman tanks. I believe that hydraulic lock was avoided by cranking the engine over 2 revolutions with the starter before energising the ignition.

Ryan

[uh1h430]

yea but what I'm asking about is how the tank crews took care of the hyd lock problems

[retroaviation]

I think because the way the engines sat in the tanks (at steep angles or maybe even horizontally), they weren't as prone to locking up. But I'm no tank guy. I think that the helicopter guys did okay about not having hydraulic lock too bad, but surely it still happened on occasion.

Gary

[Second Air Force]

As some of you know, my dad worked on the Sherman, Grant, etc. in North Africa and Italy. The radial in the Sherman mounts just like it would in an aircraft. He mentioned "bumping" the starter to clear any liquid locks before going for a start, and if the tank had been dormant a long time you'd use the hand crank to clear the lock.

There is an excellent shot of a crew doing an engine change here: http://www.strijdbewijs.nl/tanks/sherman/eng.htm Page about halfway down for the snowy scene.

Scott

[Arty163]

I posted this question on a tank site and this was the answer I recieved.

"You're supposed to hand crank them x-number of times before starting if it's been sitting any length of time. It's the same thing as hand-turning the props on radial engined aircraft. Unfortunately, I can't remember the recommended duration nor number of cranks (CRS)... "

Arty

[retroaviation]

Well I'll be a monkey's uncle. I learned something new today. Good info y'all.

Gary

[Hal B]

Years ago, I worked with an old boy that had been a crewman on Shermans in Italy. He talked about hand-cranking when starting after sitting for awhile and mentioned that sometimes, in the heat of the moment, that went by the wayside. And he said that there were instances of the lower jug being blown off the engine, and they just kept running...

[Second Air Force]

Arty,

You're absolutely right about the hand cranking. Dad told me that most often the combat crews never had the engines shut down for long enough to get a "good" lock. Even if they did, they usually just bumped the starter through the lock, threw the switch, and fired it up.

Dad was in a forward maintenance battalion, and if a tank had a blown jug the entire engine was usually pulled and replaced with a spare. They generally didn't have time to mess with cylinder changes and just plugged in a "take-out" from another knocked-out unit (if they had one). I don't remember him saying they did more or less engine changes on the radial powered tanks versus the other types, but he did cuss the Cadillac powered M-5. I forget exactly why, another reason we should all record the stories of our veterans.

Hal, was the vet you know in 1st Armored? He might have crewed a tank my father wrenched on.......

Scott

[Holedigger]

Having read a book about Brit Stuarts in N Africa (Brazen Chariots IIRC). Starting problems were scary. You didn't want to keep the engines running too much because fuel supply for those engines was always an issue, but you also didn't want to be stuck sitting still cranking your engine with panzers charging at you either. The Stuart was FAST as long as it had fuel! If you can't fight em, RUN!

[Cindy]

Hand cranking - 75 times and trust me....you get TIRED! Definitely a 2-person job.

I will say, our engine runs much better once we switched to automotive fuel + lead additive. We used to run avgas which is more expensive and we kept fouling plugs.

Cindy Novak
Planes of Fame Motor Vehicle Corps (aka Motor Pool) fundraising coordinator

[Clifford Bossie]

And this is the beast,



That powered these:

[N3Njeff]

http://www.youtube.com/watch?v=UXLL5hxk ... re=related

It does what it does!!

[Hal B]

Hal, was the vet you know in 1st Armored? He might have crewed a tank my father wrenched on.......

Scott

Sorry Scott, can't help you. I never heard (or maybe I've just forgotten) which outfit he was with. I last worked with him in the mid to late Seventies; he retired shortly thereafter and passed away about 15 years ago. Another one I wish I'd have paid more attention to when I was younger...

[rwdfresno]

yea but what I'm asking about is how the tank crews took care of the hyd lock problems

I believe that hydraulic lock was avoided by cranking the engine over 2 revolutions with the starter before energising the ignition.