Consolidated LB-30/B-24A/MkI/II Liberator engines

[Shessi]

Hi Folks,
Something I have tried to find out about for some time now is, what are the small metal disks behind the props/spinners on the early unturbocharged Twin-Wasp engines?
Please tell me!

Many thanks

Shessi

[AndyG43]

Could they be mechanical superchargers rather than the two-staged superchargers, not released for export at that early date, fitted to the later models? The XB-24 & LB30As used the R-1830-S3C4G/R-1830-33, pretty much the -90 adopted for the Martlet.



May I ask, is this a clue to something forthcoming?

[Shessi]

Well Andy, they could be?

And that's exactly where I'm at, a lot of educated guesses, but no definites...grrr!

I've found Twin-Wasp maintenance manuals, and yes they 'explode' the engine, but does not show that disc/intake etc.

I've emailed the C.A.F several times, about LB30/GRI Diamond Lil, as it originally had the early engines with those discs. DL doesn't have those discs on the engines now, so either they've down rated the engines by removing the superchargers (if that's what the discs are part of), or changed the engines for another type, but I've had no reply from them.

And yes for possibly something in the future....

Cheers

Shessi

ps Please keep looking and suggesting folks! ta.

[Mike71]

superchargers are all mechanical superchargers - either single or clutched two stage. Single stage - no shift levers but higher than 29.92 inches of manifold pressure at sea level standard day.

2 stage, can shift to hi blower as the 1st stage loses compression ability at altitude.

Turbochargers are powered by engine exhaust waste gates, no levers, handles etc normally, just governed by throttle position

[Shessi]

Thanks Mike,

Yes, I'm aware of the differences between super and turbo chargers, so yes we can only be talking about superchargers...if those discs are anything to do with them??

I've been posting on other sites, and a couple of interesting things, one, is this pic, which would suggest it's either a cover or, two, possibly a device to help speed up airflow to the cylinders and heads,..again???

Cheers

Shessi

[Mike71]

Thanks Mike,

Yes, I'm aware of the differences between super and turbo chargers, so yes we can only be talking about superchargers...if those discs are anything to do with them??

I've been posting on other sites, and a couple of interesting things, one, is this pic, which would suggest it's either a cover or, two, possibly a device to help speed up airflow to the cylinders and heads,..again???

Cheers

Shessi

They look like a simple cover for the propellor /engine gearbox. Maybe better airflow around the engine?

Yhe supercharer assembly in normally mounted to the rear casing of a recip.

[Dev One]

Well Andy, they could be?

And that's exactly where I'm at, a lot of educated guesses, but no definites...grrr!

I've found Twin-Wasp maintenance manuals, and yes they 'explode' the engine, but does not show that disc/intake etc.

I've emailed the C.A.F several times, about LB30/GRI Diamond Lil, as it originally had the early engines with those discs. DL doesn't have those discs on the engines now, so either they've down rated the engines by removing the superchargers (if that's what the discs are part of), or changed the engines for another type, but I've had no reply from them.

And yes for possibly something in the future....

Cheers

Shessi

ps Please keep looking and suggesting folks! ta.

Now my alternate suggestion would be that they have removed the spinner, but left the backplate.
Keith

[Hurricane91]

It might be a baffle to direct airflow to the outer cylinder ends and heads, and increase airflow velocity through the cowling in certain cowl flap positions.

[Desert Rat]

The only devices like this I've heard of is an oil reservoir for the prop/spinner?

[Shessi]

M and Dev, it was just suggesting a form of intake for the supercharger, not the assembly itself, but I think we can put the thought of intake/supercharger gubbins etc to bed now.

Dev, I see what you're saying, but this P&W was not fitted with any large spinner, the Hamilton prop boss you see is the one you always get, and never had a spinner cover fitted.

M and H, well I've been asking elsewhere and someone has also suggested the same as you two. That is was a device to deflect/speed up airflow to increase cooling, which sounds good to me......

Another initial thought I had was, if it had some weight to it, could it be an engine/prop vibration damper?

Also someone else suggested a prop de-icer liquid storage tank?

Jamie, just saw your reply, thanks. Yes, possibly could be. Hamilton prop's used engine oil pressure rather than an independant system, and the prop boss was in fact an oil storage tank, so would they need two?


Keep 'em coming...and we need HARD evidence folks!....thanks.

Cheers

Shessi

[normb]

Could possibly be for alcohol prop deice. Small tubing visible on front face and (I think) small tube on prop grip. Slinger system.

normb

[Shessi]

Yep Norm,
Here and on a couple of other places I've asked, we've come closer to the idea that these discs are localised de-icer fluid supply tanks, for the prop slinger de-icing system, that includes the block and small tube you mentioned at the base of the prop.

Two things, one is, that if these discs are localised feeder tanks to the slinger rings, as these are not big enough to supply the system for very long, then why have an extra tank in the system when the main supply would be in the wing? The second is, we need hard evidence folks!

Cheers

Shessi

[normb]

I agree. Manuals for B-24 talk about one or two tanks for alcohol. (One for inners and one for outers.) But if I had a dime for every engineering decision I didn't understand until I got deeper into it or finally found the guy who did it I could have retired much earlier than I did. That's why I consider this only a "maybe".

[Shessi]

Here's what we have....

1) Discs only fitted to early P&W 1830 engined LB-30/A/B/B.II/C-87.
2) Discs fitted to engines fitted with both Hamilton and Curtis props.
3) Discs appear to be fixed to crankcase hub boss, and do not spin.
4) Discs appear to be connected by tubes/wires to the slinger ring/prop hub.

I'd certainly give you a dime (maybe even a quarter!) if you found out what these damn discs are for!!

Cheers

Shessi

p.s Sorry if this subject is boring people, and seems quite petty, but I have my reasons.

[AndyG43]

Took myself out to the local bookshop on Sunday, which is not an aviation specialist but is the largest second-hand bookshop in England, to see if I could find anything to plug the holes on my bookshelf (which isn't too shabby anyway). I picked up a Polish title on the Liberator, a rather nice book by Edward Shacklady and the later version of the Detail & Scale book. And, after scouring them all (including Warbird Tech and a few others) the only reference I could find for this was in the D & S book



and a couple of pictures of an early LB-30 in camo, but I'm not even sure if it has these "plates".



There was also a model show at the Royal Engineers Museum, the Medway Model Club, so I swung by there as well (been meaning to go there for some time but the MH problems make things like that a bit of a hill). Should have realised that a model club based near to the R.E. Museum & Chatham Dockyard might be a touch light on bomber fanatics.

So the end result is ....... nada. You want info, plans and cutaways on structure, internals, armament ..... no problem, the early engines not a hope. I don't have the Warpaint Liberator book, they can often be more revealing, and I gather there is a book on the Lib in the Haynes series. But I'm out of options. Sorry gents, I did try.

[normb]

Nice find on the top picture! At least they are mentioned. Need to find an early parts manual for the aircraft. I wonder if they are in fact only "plates" to perhaps close up the inlet area and /or keep moisture/crap off accessories. Maybe to alter inlet air pressure/ volume to support engine cooling. Maybe work with the engine baffles and such. I've seen lots of strange engine baffle shapes to guide and alter cooling flow and pressures. Maybe..maybe....maybe.........

[Shessi]

Nice colour pics Andy...
I have almost everything there is on early Lib's, including books by Crowood, Warpaint, Profile, Osprey, that Bojove Polish book, and even the very expensive JaPo Czech book on the B-24 in RAF CC service (which is superb). And nothing about these discs in any of them. The problem is that, it's finding the right topic, and therefore the correct forum, book or site they fit under, is it aircraft, engine or props?

You never know, the discs may have several functions. They may be a localised supply tank for the prop de-icing system, but also designed to aid engine cooling??

We'll see.......

Cheers

Shessi

[Dev One]

Went to Brooklands Museum Wednesday a treat from my son who drove me there & back. Interesting to note that the exhibition Wellington has fixed radial slotted domes but no spinners, whereas the Viking, Valetta & Varsity have spinners. Vikings were usually flown without spinners, or discs IIRC, so maybe spinners &/or discs were removed for better cooling? So the Liberator discs were for modifying the airflow or keeping the ancillary's clean ?
K

[Shessi]

That's a nice day out Keith.....not been but would like to.

Nice spot! Yes, the early engined Welly's did have those slotted domes on the engine front, interesting, they may have been for the same reason ie to help air flow to the cylinder heads.

As said it could have had a dual purpose ie de-icing tank and airflow.

Thoughts and info are petering out at the various forums I've posted this on. These discs are so petty and of no real consequence, but I just really want to know...ha ha!

Cheers

Shessi

[Miggers]

Why not ask Pratt & Whitney themselves?

https://www.prattwhitney.com/

They don't make those big'ole round growlers anymore,but I bet they've got and archive dept. and all those original blueprints to 'em.

[srgalahad]

I checked.
Service manual for R-1830 -75 & -98, Maintenance Manual R-1830-S1C3G. No mention of a tank, pump, or other appurtenance on the front around the gear case.
(If anyone wants either manual, let me know - they are rather large to post (38Mbeach as a .pdf).
I suspect the object in question ( and I lean toward a tank of some sort) was a 'bright idea' tested on one, or very few B-24s that never saw widespread use.

Edit: you can start your own search at the links below:
http://powerplants.warbirdsresourceg...Twin_Wasp.html
http://enginehistory.org/Piston/P&W/R-1830/r-1830.shtml

and if you want the manuals you should be able to download from here:
https://ww2aircraft.net/forum/thread...-manual.38038/

[Shessi]

Thanks M and SG, for suggestions and info.

I think I'll give P&W a try, you never know!

Many thanks for the links.

Cheers

Shessi

[Miggers]

Thanks M and SG, for suggestions and info.

I think I'll give P&W a try, you never know!

Many thanks for the links.

Cheers

Shessi

How did you go on Shessi?
Did P&W come up with the goods?

[Shessi]

Hi M,
I emailed them when I said, got an automated reply about them receiving the email and then.............................................

I got the same with the CAF and Diamond Lil, sent three emails to them...nothing!


I really am very surprised that no one seems to know what they are, and that's on three big aviation related sites??!

Cheers

Shessi

[Motormouse]

I really am very surprised that no one seems to know what they are, and that's on three big aviation related sites??!

Cheers

Shessi

You could try Kermit Weeks place in Florida, they have a knowledge bank

Ttfn

Pete