The Packard V-12 PT Boat Engine

Hi Les, great video! I am a crew on PT658 here in Portland OR. The purpose of the 5M-2500 engine aftercooler was placed on the engine in order to boost the horsepower up to 1850hp. Coupled with the larger diameter of the supercharger wheel and the higher speed of the supercharger give the increase in horsepower. The 4M-2500 has only 1500hp by comparison. One interesting problem that we have discovered with these engines is that we have inadvertently "snapped" 4 of these supercharger drive shafts. They are 1 inch diameter hardened steel splined shafts. What we found out was that when you either slow down or speed up the engine too quickly, the momentum of the supercharger in relation to the crankshaft is too high and the shaft can break very easily. So our new operating method is to slowly accelerate or decelerate when we go fast. We are taking the boat out here on 5-6-7 June 2024 for Portland Rose Festival Fleet Week, so it should be a lot of fun! All of your PT Boat related videos are very well researched and I am a fan. Thanks for these series of excellent videos! Jerry

I worked with a japanese man in the late 70's who's grandfather had been in the japanese navy in ww2, he said they called the american PT boats , the green dragons and most sailors were scared shitless of them. They would seem to appear out of nowhere, you couldn't see them at night except by the wakes, and where so fast you couldn't train you're guns on them fast enough.

My Grandfather worked for Packard Motor Company during WWII building Aircraft Merlin's. I still have his sterling silver lapel pins, a gold 10 year service award and a few of his Micrometers. The man never missed a day of work until he finally retired at 66. He is dearly missed.

In loving memory of McHale's Navy & the brave boys of the PT 73

The contribution of PACKARD to the war effort is incalculable. That the company didn't survive the 1950's is truly a shame. Their place in history needs to be remembered and honored.

In the late '50's my father had a Navy buddy who stayed in after WWII. My dad turned down a commission if he reupped. The buddy, Newton by name was still a Chief Machinists Mate and was stationed at Port Hueneme (pronounced "why-a-nee-mee"), halfway up the coast from L.A. to Santa Barbara. Part of the complex was the Point Magoo Naval Air Station. I was about 12 years old and we would visit the Newton family fairly regularly. On one visit, Chief Newton had a really nice surprise for my one year older brother and me. Port Huaneme had a couple of converted PT boats that they used for "coastal patrols" (a totally useless exercise but since when has the military not engaged in useless exercises to play with their toys). To make a long story short, the Chief had arranged for us to "go for a ride". Two things stick in my mind from that experience. First was just how fucking fast that boat was. Second, we got to go down to the "engine room", an extremely cramped space almost fully taken up with those Packard V-12's. That was the loudest sustained noise I had ever heard in my life. I remember it today like almost a physical presence. No wonder so many WWII vets came home with hearing loss!

My grandfather was Bill North vs pres. Packard motor production. A 52 yr old widower in 42.:sent to London then, met a younger pub manager.brought home a war bride! My English grandmother. Thank god for all of them!!!! A crying shame Packard motor ended as a result of all of this.

My grand father Joe Carville was a engine mechanic on these PT boats . He had plenty of stories about his time in pacific. During his service he became friends with JFK as he was a Boston man.

I once read a story on those PT-boats and their engines. Myth/rumor has it that they were secretly/not-so-secretly tuned/optimized/hot-rodded by some crews because, after a drill at sea, they would sometimes be allowed to race full-throttle back to port, and the fastest boat would get to sea-spray on those in chase. It might just have been a bar story, but I still like the thought of mechanics tinkering to get the very best out of those V12s.

As a PT Boat "Splinter" attending numerous PT reunions with my father, I must thank you for creating this video. I appreciate the effort you put into this.

I worked in a shop that reworked several crankshafts for the Navy they were works of art. Every surface was machined hollow rod and mains stainless steel.

In the late 60's and early 70's these boats would come into our Marina on the Salton Sea from the Naval Target Range and refuel! As a kid, the sound was AMAZING and the size of this boat combined with the speed when they went hammer down as they left impressed me to this day!

In the clips from "They Were Expendable" we see Robert Montgomery, who was an actual PT boat sailor/veteran.

My dad was a WW2 PT Boat machinist in the Pacific. He served in the same squadron as Kennedy. The most hazardous naval duty in the war. He had three boats he served on sunk. On one, he was the only survivor. Needless to say, he suffered with PTSD. PT boaters are all heroes.

50 degree ignition advance indicates slow burning fuel and not a lot of combustion turbulence. Still a glouriosly smooth engine with a great sound.

I had a rare opportunity to help rebuild a Packard Merlin that was for a Lancaster bomber and what a treat it was. When I say “help” I mean I was basically the gopher for the guys that really knew what they were doing but at 23, I was more than happy to help.

I remember hearing those three Packard engines on ELCOs first prototype on her second trip down the Thames River out to theSound for Testing what a beautiful Roar will never forget.😊

Hubert Scott Payne who owned the British Power Boat Company had converted some R.R.Merlin engines for use in his early MTB's. When he learned that all Merlin engines were to be reserved for aircraft production he went to the USA in search of a replacement. He took plans of his boat designs which were the inspiration for the Elco designs. This steered him towards the Packard engines and he secured some for his company. They were so successful that the British Government entered a Lease Lend contract for the Packard engines for Coastal Forces and were used by Vosper when they lost the supply of the Italian Isotta Fraschini engines they had distribution rights for prior to war being declared.

Very thoroughly and nicely produced. Great, serious information and explanatory work. I live about 8 miles down rt 440 in Bayonne and regularly visit the Boat lift built to put PT boats into the water at the end of the Hackensack and Passaic rivers where the empty into Newark Bay . Thanks

I’m USN ‘61-‘63(reserve). I was a SCUBA diver,collector for the Marine Biology Museum @ Pt. Mugu, California. There are 5 Channel Islands offshore and the Navy (Pacific Missile Range) has a presence on several of them. The Navy still had several WWII PT Boats which were used for mail and supply delivery and we(3 divers,collectors)could beg a ride. Occasionally, usually dropped to dive off a couple of inner tubes and picked up on their way back. Very occasionally we would be able to dive off a “Live Boat”(Opening Day of the lobster season 1963. Two lobsters, just the tails, 12# on the bathroom scales)! These had Packard engines(3).