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What were the engines on the majority of PT Boats?

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  • Member since
    October 2003
  • From: Canada
Posted by sharkbait on Monday, August 17, 2020 7:29 AM

You have never been lost until you've been lost at Mach 3!

  • Member since
    September 2012
Posted by GMorrison on Thursday, August 13, 2020 4:58 PM

Also from the world of rail, the fabulous opposed piston "Opie" diesel engine made for submarines by Fairbanks Morse made it into both switcher and road engines. Characterized by very tall hoods. But enough 'jacking.

 Modeling is an excuse to buy books.

 

  • Member since
    November 2005
  • From: Formerly Bryan, now Arlington, Texas
Posted by CapnMac82 on Thursday, August 13, 2020 4:25 PM

And since we are at various ends of necrothreads--I have this memory that the nice people at Packard made a marine diesel to power harbor tugboats, particularly on the west coast.

And, that the design began as the powerplant for a diesel switching locommotive.

  • Member since
    March 2007
  • From: Northeast WA State
Posted by armornut on Thursday, August 13, 2020 4:16 PM

   BOOOM!!Ditto

we're modelers it's what we do

  • Member since
    September 2006
  • From: Bethlehem PA
Posted by the Baron on Thursday, August 13, 2020 3:47 PM

GMorrison

So welcome to the forum, tractor. Jump on a ten year old post and start insulting people.

I happen to know that at least one of the ignorant people in the earlier thread is "no longer with us".

Good information though in  your salvo.

Bill

Yes

The bigger the government, the smaller the citizen.

 

 

  • Member since
    September 2012
Posted by GMorrison on Thursday, August 13, 2020 11:53 AM

So welcome to the forum, tractor. Jump on a ten year old post and start insulting people.

I happen to know that at least one of the ignorant people in the earlier thread is "no longer with us".

Good information though in  your salvo.

 

Bill

 Modeling is an excuse to buy books.

 

  • Member since
    September 2006
  • From: Bethlehem PA
Posted by the Baron on Thursday, August 13, 2020 11:49 AM

Weren't Allison engines used, too?

The bigger the government, the smaller the citizen.

 

 

  • Member since
    February 2003
  • From: Lacombe, LA.
Posted by Big Jake on Thursday, August 13, 2020 11:43 AM

Hi,

In New Orlease we are blessed with the PT-305 as part of the D-Day Museum complex, (boat is at the LAke and you can ride on her)  I have 43 pictures of the boat as well as the engine on my facebook account here.

 

 https://www.facebook.com/search/top/?q=PT%20305&epa=SEARCH_BOX

 

 

 

 

  • Member since
    August 2020
Posted by soaringtractor on Friday, August 7, 2020 11:48 PM
Only 2 planes ever used the Packard built merlins V1650-1 went into 1311 Curtis P40 F & L models of the kittyhawk and the V1650-3 & -7 went into the P51 B/C and the D/K and the V1650-9 or 11 went into the P51 H and only 500 ....and only 20 F82 twin Mustangs got 2 different V1650 merlin and then they switched back to the Allison as the British Contract for the Merlins were cancelled with the end of the war and Packard quit making the merlins
  • Member since
    August 2020
Posted by soaringtractor on Friday, August 7, 2020 11:41 PM
The info that the M2500 was a Merlin is just ignorant people spouting off info they are clueless on. the time line is Packard was delivering M2500 to the US Navy in 1938 and Packard did not run their first merlin until Aug 1941 so it would be a hell of a trick to have an engine 3 years before you made it !!!
  • Member since
    August 2020
Posted by soaringtractor on Friday, August 7, 2020 11:39 PM
The M2500 was NOT a Packard popped Merin. Hell the M2500 was 50% Larger 2500 Cu In displacement to 1650. Packard delivered the M2500 to the US Navy in 1938 and Packard did not run their first Merlin until aug 1941 !!! No way in hell was the M2500 and the merlin the same engine !!!
  • Member since
    August 2020
Posted by soaringtractor on Friday, August 7, 2020 11:36 PM
The Packard M2500 is in NO way related to the Merlin. Only thing similiar is Packard did build 14,000 M2500's and 55,523 Merlins in the same plant in Detroit !!!
  • Member since
    August 2020
Posted by soaringtractor on Friday, August 7, 2020 11:33 PM
The Packard M2500 had NOTHING to do with the Merlin engine. Packard was delivering M2500 to the US Navy in 1938 and Packard did not run its first merlin til Aug 1941 so how could the M2500 be a Merlin? and the M2500 was 50% larger than the merlin !!!
  • Member since
    March 2007
  • From: Carmel, CA
Posted by bondoman on Saturday, December 11, 2010 10:59 AM

I was at a stoplight yesterday down by Moscone Center. There was a beautifully restored "Straight 8" next to me, and a Buick Special too.

  • Member since
    November 2009
  • From: Twin Cities of Minnesota
Posted by Don Stauffer on Saturday, December 11, 2010 8:48 AM

WallyM3

The only reference to a diesel engine for the PT boat (preliminary design work in 1937, with budget submissions for FY 1939) that I've sen s far is to a prototype GM diesel of 1,200 bhp in the blueprint stage. BuEng dropped the idea because the long lead time expected for development would have delayed the whole project. At this time, the proposed hull was 54' and a supercharged Vimalert engine was chosen. All engines considered or adopted thereafter appear to be gasoline.

Interestingly, Packard was the only major US effort to develop a diesel aircraft engine (for range).  They built a prototype, and installed it in a plane ( I think a Curtiss Robin).  But the sparkplug (Oh, bad pun!) behind the effort was killed in a crash of the plane and Packard scrapped the effort. I suspect that also may have killed any thought of Diesels for the high speed marine use.

Don Stauffer in Minnesota

  • Member since
    March 2006
  • From: Bangor, Maine
Posted by alross2 on Saturday, December 11, 2010 8:05 AM

And the moon is made of green cheese...Whistling  Ya gotta love TV. 

The 1937 Packard model 1507 is listed as being fitted with the standard-at-the-time V12 gas motor.  Displacement is listed at 473 cubic inches.  The 4M2500 displaces 2490 cubic inches...

Al Ross

  • Member since
    January 2005
  • From: Tampa, Florida, USA
Posted by steves on Friday, December 10, 2010 11:07 PM

To further confuse the issue in some people's minds, Packard also made automotive V12 engines.  I was watching a TV show a few weeks ago as the two hosts were discussing  a restored pre-war Packard automobile.  When they opened the hood one said "And this is the famous Packard V12, the engine that powered the PT boats in World War Two."

Steve Sobieralski, Tampa Bay Ship Model Society

  • Member since
    December 2005
Posted by PTConsultingNHR on Friday, December 10, 2010 9:31 AM

Various versions of the Packard 4M-2500 Marine engine powered the PT boats in actual service ...

Garth

 

  • Member since
    October 2010
  • From: Arlington, VT
Posted by WallyM3 on Friday, December 10, 2010 9:21 AM

The only reference to a diesel engine for the PT boat (preliminary design work in 1937, with budget submissions for FY 1939) that I've sen s far is to a prototype GM diesel of 1,200 bhp in the blueprint stage. BuEng dropped the idea because the long lead time expected for development would have delayed the whole project. At this time, the proposed hull was 54' and a supercharged Vimalert engine was chosen. All engines considered or adopted thereafter appear to be gasoline.

  • Member since
    November 2009
  • From: Twin Cities of Minnesota
Posted by Don Stauffer on Friday, December 10, 2010 8:59 AM

Rich

For what little it may be worth, I was a teenager during the WW2 years. Like most of my contemporaries I was avidly interested in things military (towards the end was a volunteer aircraft spotter). I have never heard of other than Packards as engines in PT boats. Specifically, the Rolls Royce information is news to me.

Early in the war, before Pearl Harbor, the brits were having a hard time ramping up production to the levels they felt they needed.  They sent a mission to US to get planes and engines built here to their design.  Packard agreed to build the Merlin aircraft engine, a V-12. Thus, the Packard Merlin, designed by Rolls Royce.

There are two versions about the PT boat engines.  Some references say these engines were used in PT boats. Others say that while both were V-12s, the PT boat engine was an existing Packard boat engine design.  And some say it was a Diesel, not a spark-ignition (gasoline) engine.

I would sure like to know for certain the whole story.

 

Don Stauffer in Minnesota

  • Member since
    March 2006
  • From: Bangor, Maine
Posted by alross2 on Thursday, December 9, 2010 7:15 PM

WallyM3

Al, thank you for posting those pics. I see ACF offered on line. Is there a best place to buy copies?

Wherever you can get the cheapest price...Whistling  You could probably find a copy through interlibrary loan for free.

Al Ross

  • Member since
    October 2010
  • From: Arlington, VT
Posted by WallyM3 on Thursday, December 9, 2010 7:07 PM

Al, thank you for posting those pics. I see ACF offered on line. Is there a best place to buy copies?

  • Member since
    March 2006
  • From: Bangor, Maine
Posted by alross2 on Thursday, December 9, 2010 6:44 PM

The only US PT with Merlins (Rolls Royce, not Packard) was PT 9, which was built by the British Power Boat Company  and served as the basis for the 70' ELCO design.  From PT 10 on, US PTs were fitted with gthe 4M2500 Packard V12.

These illustrations are from the 4M2500  Operating Manual:

 

John included a large number of detail drawings of this engine in our ACF V2.

Al Ross

  • Member since
    October 2010
  • From: Arlington, VT
Posted by WallyM3 on Thursday, December 9, 2010 5:11 PM

Bore: 6.375". Stroke: 6.5". Cu. In. Displacement: 2,490. Compression ratio: 6.4 to 1 (100 octane avgas). Red line: 3,000 rpm. HP (max) 1,500. Supercharged/intercooled.

Man, that's gotta be loud!

Well, I think I'm beginning to catch up on my Packards. It seems, at first blush, that the Packard V-1650-1 through -25 (odd numbers) were essentially Merlins, but US Models (?, I assume meaning for installation in US aircraft).

The PT 4M-2500 motors only share the "V" configuration with the Merlin, and nothing else. Packard built a V-12 Aero engine during WWI called the Liberty engine (L-12) with a 1,650 cu. in. displacement, like that of the later RR Merlin engine. The L-12 engine was, in large measure, a product of Packard's design people and sponsored by the US Aircraft Production Board.

Let's start an International incident? Let's suggest that the Merlin was a Packard design!

  • Member since
    August 2008
Posted by tankerbuilder on Thursday, December 9, 2010 4:58 PM

I do believe you should look up any info published by T.GARTH CONNOLLY on P.T. boats.This man knows his stuff , and , if I am correct , based on what I saw in 1959 at SAN FRANCISCO in a warehouse the P.T. there (undergoing repairs and refit to a civilian use) The engines were indeed the second series of PACKARD MARINE HIGH PERFORMANCE engines.They were having a hard time finding parts for them.The things were so massive looking I imagine those puppies generated lots of noise AND heat at high speed. Pity the engineman that had to play with those babies!!  tankerbuilder

  • Member since
    October 2010
  • From: Arlington, VT
Posted by WallyM3 on Thursday, December 9, 2010 2:38 PM

Thank you all for your comments and leads. It's helped to refine my searches and there's plenty of food for thought here.

But, you can see the source of my confusion.

I forgot that I had an unread copy of Norman Friedman's, U.S. Small Combatants, collecting dust in my library (I'm glad I don't have to buy that book today.). I think I need to add some Lambert and Ross material to it.

 

  • Member since
    August 2010
  • From: Heart of the Ozarks, Mansfield, MO (AKA, the 3rd world)
Posted by Rich on Thursday, December 9, 2010 9:56 AM

For what little it may be worth, I was a teenager during the WW2 years. Like most of my contemporaries I was avidly interested in things military (towards the end was a volunteer aircraft spotter). I have never heard of other than Packards as engines in PT boats. Specifically, the Rolls Royce information is news to me.

Rich

Nautical Society of Oregon Model Shipwrights

Portland Model Power Boat Association

  • Member since
    November 2009
  • From: Twin Cities of Minnesota
Posted by Don Stauffer on Thursday, December 9, 2010 8:46 AM

I have read both that the engines were, and were not, Packard Merlins.

It turns out that Packard had long built V-12 marine engines for patrol boats (and racing boats)  (well before they got involved with the license to build Merlins).  So some of what I have read says that the PT boat engines were an upgrade of their existing line of boat engines.

It would be good to read a really authoritative article on this.

Don Stauffer in Minnesota

  • Member since
    March 2006
  • From: Bangor, Maine
Posted by alross2 on Thursday, December 9, 2010 6:24 AM

When I get home tonight, I'll upload the drawings for the 4M2500.

Al Ross

 

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