P38 Lightning powered speed boat

[Wreck]

Attachment 31618Hello,
I was wondering if anyone has ever heard of someone who has put a p38 Lightning engine in a boat.

I know of such a project and was curious if another has been attempted,i think he could use any info on the best prop choice.

Its a v drive ,hand crafted 32 ft,i saw it a year ago with the turbocharged motor in.
Peeking inside the hull its all stained wood with copper tubes running all over and aluminum,the motor sits in front of the driver and there was a belt that goes down to some kind of gear box he created in his machine shop that gives him a 3 to 1 gear reduction or some such thing,you will have to excuse me i am not very technical but the thing is really amazing ,a work of art.

I visited the other day,he's going to machine some intakes for me and he offered a tour of the boat again and even agreed to let me snap some pics

Motors out and its in the paint booth these pictures really dont show how wicked this boat truly is,i hope to get some better pictures in the future.

[tom28571]

As many as three of these Allison engines were used in PT boats in WW2 as well as many Gold Cup unlimited racing boats. Many were built by Packard. Hope someone has access to a fuel outlet.

[Jimbo1490]

Packard built the Roll-Royce Merlin under license, the Allisons were a GM product. Rolls bought out Allison in 1993. You'd be better off with a turbine than to try to keep one of these cantankerous old, high-strung, high performance piston engines running. That's why they disappeared from aircraft use. With 12 cylinders, 4 valve heads, overhead cams with their associated drive shafts and gearing, dry sump lubrication with multiple oil pumps, it costs a fortune to rebuild one of these. But they are valuable to the vintage aircraft market, so if I owned one, I would sell it there and use the proceeds to get my hands on a (unairworthy, of course) P&W PT-6, Walter, or an Rolls/Allison 250 turboshaft. Steer clear of the Lycoming T-53 and it's civilian variants; they are NBT (nothing but trouble). The Turbomecas are awesome, too, though I doubt you can find one for a song as with the others I mentioned. Many of these turboshafts can be rebuilt on a bench by an experienced mechanic. Don't even think about trying that with a 4 valve headed V-12.

I've heard of people using the bigger Garrett APU/GPU turboshafts with success also, though the biggest there is 'only' going to be about 500 SHP.

Jimbo

[tom28571]

Thanks for the correction Jimbo. I knew Packard was involved but got the wrong engine. I remember crawling through some PT boats in the discard pile in Pearl about 1950. That is where I saw so many with three of those monsters inside while some only had two. The PT boats that I have seen used as private yachts all had the 12's removed and diesels installed. All they could do was putter along at hull speed of 11 knots or so.

[Ol-Paint]

Not quite. Packard did build the Merlin under license, but the PT boats used the Packard 4M2500, which is a much larger engine than either the Allison V-1710 or Rolls-Royce V-1650 Merlin and was a Packard development. The 4M2500 was around 2,490-2,500cid, while the Allison V-1710 was--rather obviously--~1,710cid and the Merlin was ~1,650cid. I haven't come across a good source of information on the Packard marine engines, although the Aircraft Engine Historical Society has done some articles on the Packard aviation engines that share development history (and apparently components & castings).

The Allison & Merlins were both used in hydroplane racers, post-war, and there was one Allison powered racer on the circuit as recently as a couple of years ago, although I am not sure it is still running as a piston powered boat. I caught some races in Detroit on TV a few years ago and the Allison boat was competitive with the turbine boats if the driver could get the inside line on the track. It had better acceleration and could hold a tighter course, but much lower top speed. Interesting.

Packard 1A-2500 information: http://en.wikipedia.org/wiki/Packard_1A-2500
Wiki PT boat article:http://en.wikipedia.org/wiki/PT_boat It has some engine information, but the engine designations shown there don't agree with other sources.

Douglas

They have thunderboats in Detroit?
There is a sound, a feel, to these things. To put turbines in hydros would 'bout kill the sport - akin to a computer program competing with Olin Stephen's eye. I'll take that ol' Allison off his hands - even haul it away!

[Wreck]

Gentleman thank you for those informative posts.

I am reluctant to tell him to sell the engine and find somthing else,i have a small project stuffing a different motor in a hull also and have had people tell me "that wont work" it sucks,i did however print the info out and will give it to him.

There might be some real difficulties for him,Tom mentions a fuel outlet does that mean av fuel will not work?.
But as for working on the thing,first of all he has two of em and this fellar builds transmisions and gearboxes from scratch.

He is an older guy and does not use the computer,thats why i decided to post the project mabye i can help him a bit ,i know there are some very smart people out there on the subject,thanks

Mark if an engine is available i will let you know .

I will try to post more on the project, i have to get a pic of the inside of the hull it is a real work of art.

I tried putting up a pic of his second motor but it aint letting me

[jim lee]

I'd agree with jimbo here. Sell the motors to the warbird crowd. It also solves the worry of getting lynched if they find out he's putting one in a boat.

Does he have the P38 that they came from? Last I checked, they were going for $2,000,000 in about any condition on the open market.

-jim lee

[Jeff]

I would definitely love to see more pictures of this project!

[Wreck]

I dont think the plane is around anymore,to clarify i have only visited this place twice,the first time i think my friend said hey do you want to see the nicest boat in langley(these here parts),man was he right.

I talked with someone else who knows the boat well and he spoke a little about the lightweight materials and all the little aluminum braces and such on the inside built to be strong and light weight.

Next time i will try to write down some of these details or get a friend of this guys to post with a few specs,thats if i dont get lynched he doesnt know i am sharing this project with you guys.

Jeff i will do my best to get some more pics.

If he is having any problems mabye some of you guys can help him get this party started, unless theres a bunch of vintage planes that need engines i dont see it as a sin

[BHOFM]

The 38's had counter rotating engines to off set the torque. Some were
fitted with the RR engine, but there were no opposite rotation engines
available and the planes did not handle as well even thought they could
operate at higher altitudes.

There were many variations of the P-38 including one of the first radar
equipped night fighters.

My Dad flew 38's in WWII. Shot down 14 trains. They were one of the
best rocket launch bases we had.

[Jimbo1490]

Originally Posted by BHOFM

The 38's had counter rotating engines to off set the torque.

The CR was not done for this reason AT ALL. We know this because they spun them WRONG WAY, making for torque augmentation into a turn on a bad engine, meaning the P38's had TWO 'critical' engines instead of one. So this was a very unsafe airplane as the loss of either engine made it difficult to fly. So why did they do this? SPEED! With the props spinning so the blade tips are going upwards past the fuselage, airflow is greatly improved, and drag reduced making the plane very fast. The P38 could exceed 500mph in a dive.

Jimbo

[Ilan Voyager]

Oooosh, with the money gotten from the selling of an Allison or Packard or RR V12 engine, you can buy 3 turbines.

If you add the 145LL gas needed to feed these thirsty engines, the tight and expensive maintenance, and the 100,000 US bucks (it's the price I heard 12 years ago) to overhaul that short lived engines (around 150 hours), I would stay away...nice pieces but but for very big wallets. Even the museums have the worst difficulties to maintain them.

Indeed the Turbomeca were unbreakable. The french navy had a small prototype patrol boat made in the fifties, and the engines outlasted the aluminum hull. On the Ecureuil helicopter they lasted longer than the transmission. The turbines have also the great advantage to use a cheap carburant.

[Jimbo1490]

It's very difficult to even source 145 any more. 100 LL (LL means Low Lead, which 145 is NOT) is the only avgas you can find now. You could buy some racing fuels by the drum which will work. Most race fuel companies would be more than happy to blend a drum of whatever you need, but it will cost $8-10 per gallon, and that engine is going to burn about 75-100 gallon/hour at full load. 50-60 GPH is probably a typical fuel burn in that boat.

If you use 100LL, you are going to have to tune it for the lower grade fuel, else risk serious damage due to detonation.

We've not yet mentioned the very real health risks of working with the fuels that these engines like to burn. There is SO MUCH lead in them that even brief and occasional exposure to the smoke or getting liquid fuel on your skin is a serious matter. There is about 20X the lead in these fuels than was EVER in automotive premium, back when it contained lead.

Jimbo

[Ilan Voyager]

My mistake. 100LL for low lead (an euphemism...), 145 with lots of lead. The problem with these old engines is that they were designed for this amount of lead which acts also as lubricant of the valves and cylinders. So trying to use a different gas is pretty difficult, as the problems of sizing will become acute. Apart of the problems of toxicity of such amounts of lead.

Even the 100LL is not so easy to find and now all the modern engines (Rotax, Jabiru etc...) are using common car gas like the 87.

It's very old engineering of 60-70 years ago...Museum pieces which are harder and harder to maintain. Again I say that it would be better to sell a such piece and to buy a turbine, simpler, lighter, using turbosine or kerosene, more reliable and cheaper. OK no so nice noise.