Change engine rotation direction with firing order

[Surestick]

I hate these click-bait style "top ten" lists. Every once in a while I click on one and am reminded why I hate them. #8 "The engine direction was reversed on one engine by simply changing the firing order of the spark plugs"... Who needs proper valve timing? 17 Things You Never Knew About the P-38

 

[440Magnum]

But its on the internet... it MUST be true! Its really getting scary how much not just wrong, but STUPIDLY wrong stuff pops up as "cool facts" or "things you didn't know" (for good reason, if you ask me) lately. And when you read the articles, the use of grammar is so bad that it comes as no surprise that the rest of the facts are not there either. Now you went and got me spun up.... :-p From what I've read, of the hardest aspects of keeping a P-38 flying is finding parts for the "left handed" Allison engine (which has its own part number). The cams, the water and oil pumps, the supercharger drive, the magnetos... pretty much EVERYTHING is affected by the reverse rotation. Sheesh. But there were some nice pictures of the restored "White Lightnin'" (now the Red Bull P-38).

 

[440Magnum]

And did you see "fact" #10? Stainless steel skin. What a hoot.

 

[FowVay]

And all of these years I thought a P-38 was a tiny can opener that you carried on your key ring. Go figure,,,

 

[simple_gifts]

My understanding is the ones that were sold to England during WWII did not have counterrotating engines or a supercharger, just to keep the advantages of the plane close to our chests.

 

[440Magnum]

Originally Posted By: simple_gifts

My understanding is the ones that were sold to England during WWII did not have counterrotating engines or a supercharger, just to keep the advantages of the plane close to our chests.

The RAF Lightnings had the Allison's single-stage superchargers, but no turbos like USAAF Lightnings got. Most of the post-war racing Lightnings ( like N25y, now the Red Bull p38) deleted the turbos since they did no good below 10,000 feet anyway. I'm pretty sure ALL Lightnings had counter-rotating engines, but I could be wrong on that.

 

[Oldmoparguy1]

Originally Posted By: 440Magnum

But its on the internet... it MUST be true! Its really getting scary how much not just wrong, but STUPIDLY wrong stuff pops up as "cool facts" or "things you didn't know" (for good reason, if you ask me) lately. And when you read the articles, the use of grammar is so bad that it comes as no surprise that the rest of the facts are not there either. Now you went and got me spun up.... :-p From what I've read, of the hardest aspects of keeping a P-38 flying is finding parts for the "left handed" Allison engine (which has its own part number). The cams, the water and oil pumps, the supercharger drive, the magnetos... pretty much EVERYTHING is affected by the reverse rotation. Sheesh. But there were some nice pictures of the restored "White Lightnin'" (now the Red Bull P-38).

Well not quite. http://en.wikipedia.org/wiki/Allison_V-1710#Technical_description

Quote:

Another feature of the V-1710 design was its ability to turn the output shaft clockwise or counter-clockwise by assembling the engine with the crankshaft turned end-for-end, by installing an idler gear in the drive train to the supercharger and accessories, and installing a starter turning the proper direction. There was no need to re-arrange the ignition wiring, firing order, or the oil and Glycol circuits to accommodate the direction of rotation.

Wiki has a good section on the P-38. Wayne

 

[SteveSRT8]

Originally Posted By: 440Magnum

And did you see "fact" #10? Stainless steel skin. What a hoot.

Quoting Wikipedia is not high on my list. Anyone who really works on an engine knows reversing rotation is tricky, remember when serpentine belts first came out? Get the wrong water pump and things get interesting...