Volvo's supercharger + turbocharger

This afternoon I was listening to the crew of a machine of similar complexity, the B-29 bomber "Fifi". They had removed the turbos and replaced the direct mechanical injection with carbs to cut down the enormous maintenance, since they don't need the original high performance.

-jsw

The Detroit Diesel engine had both roots blower and turbo, in some instances. And yes, I know what it as for but the roots "blower" did give an intake pressure higher than atmospheric, thus was a "supercharger" by definition :-)

And didn't VW market a car that had this system? Called the GT TSI, or some such name. Back in 2005, or thereabouts.

Add variable valve timing (which is old hat now-a-days_) and Viola! A NEW Design :-)

I have a forklift with a 2 stroke detroit engine with a roots blower.

They need to be supercharged, because of the nature of two stroke diesel.

i

When the Soviets built the Tu-4, based on interned B-29 they studied, they're tech was not up to replicating the Wright R-3350, so they installed a carbureted radial which meant the Tu-4 had much less range.

When my Dad flew B-29 missions out of Tinian, they never flew with all new or rebuilt engines, at least 2 were engines that had already proved they were reliable.

David

Nothing like experience to instill confidence. An "experienced" engine statistically has a lower chance of failure than a freshly rebuilt one.

Pfhhht.

Ohhhh, yeah. That one disappeared in a hurry, didn't it? I had forgotten all about that one.

I'd like to drive one, just to see how it feels.

I should let John explain that, but the blower on a two-stroke diesel is not there to supercharge the engine. Basically, it's just there to "blow" air into the cylinders, at normal atmospheric pressure, because the engine can't aspirate itself without the blower. This is inherent in the engine design.

But, as he hinted, in can do a little supercharging while it's at it. It's first a matter of port timing.

A fellow NYer built a "Pro-Street" J-2000. Had 2 blowers and twin turbochargers. Plus nitrous and injection for the extra fuel required.

The crew said WW2 B-29 pilots tended to have more 3-engine than

4-engine time. By the 1960's the R-3350 engine had become very reliable. Fifi's R-3350 engines were custom-built from A-1 and C-119 components, derated for reliability since the airplane now flies only VFR below pressurization altitude.

-jsw

I've heard they had some problem but it's still around as an option AFAIK. Nissan did this on the Micra Superturbo back in 1988, and Lancia in the Delta S4 but that wasn't really a production car.

So they turned her into a cranky old bitch in the morning, did they? It probably cut out 75% of the maintenance, though, so I'll bet it was a mixed blessing.

I remember the difference between my old 302 Ford engines. The '68 Ranch Wagon had a 2bbl carb and the F-150 had an EFI system. The performance difference was astounding. The EFI added what felt like

100hp and gave it instant performance from startup to shutdown.

That little carb was a darling compared to Holleys and Rottenchesters, but it still wanted some time in the morning to warm up. I certainly don't miss carbureted engine tune-ups, lemme tell ya. Especially interim and post-SMOG engines from CA. I built a special bending tool for choke pulloff rods to be able to adjust them better for cold performance.

That engine sounds like a flaming bitch in any config. "Altogether, the R-3350 went through tens of thousands of design changes during its early development."

Indeed. Could you imagine the conditions their old wrenches experienced on a Pacific island back then? Heat, humidity, blowing dust, etc. I doubt we newer wrenches would have liked them at all, and I applaud the job they did.

I hate to tell you but the article you reference is a bunch of bull.

The first B-29's, if I am not mistaken, were equipped with carbureted engines and the change to fuel injection was a move to increase power and reliability. The B-29's were equipped with twin turbos and an internal supercharger and with the waste-gates open you could get about 30" at full throttle stationary on the ground at just a bit over sea level.

The engines ran perfectly well in summer temperatures on the ground in Japan during the Korean "Police Action" and in fact the cowl flaps were partially closed at take off as full open cowl flaps would over cool the engine on take off as well as adding drag.

No pilot or flight engineer would have even considered doing a mag check on take off roll. Take off was with the turbo waste gates partially closed so manifold pressure was probably 10 or 15" over 30 inches and God only knows what switching off half the spark plugs would do.

In addition the brakes on a B-29 were famously poor and if you had a bad mag check aborting while on takeoff roll with a bomb load and max fuel aboard would result in running off the end of the runway. Not a recommended practice although exactly that did happen at Yokota AB in about 1952 or maybe 53 for exactly that reason. An engine backfired on take off roll and an inexperienced pilot pulled the throttles back. The airplane went through the fence, sheered the landing gear off, the center wing fuel tank ruptured and it caught fire. With a full load of bombs aboard.

The compound engines that they talk about were a later version of the R-3350 and added three small power recovery turbines to the engine. Not used on the B-29 but were used on at least one version of the Lockheed Constellation. I did talk to some of the mechanics that maintained those airplanes and they cursed the engines but none of them had worked on the B-29 :-)

How do I know all this? Because I worked on the things for nearly 5 years both at Randolph Field in Texas and Yokota AB in Japan during the Korean set to and after that was settled in a reconnaissance squadron at the same base.

Sometimes the "cutting edge" cuts both ways :-)

I had a friend that bought one of the first Wankel engine Mazda cars imported into Thailand..... A year later he replaced the rotary with a piston engine :-) He told me that he had it done at the Mazda shop and it was literally a "drop in". Although that was likely an engine-transmission package drop in.

(Years later he died of alcoholism but I'm not sure if the Mazda or the woman he married caused that :-)

For sure, I like my old truck with mechanical diesel. The manual windows go up/down, no air conditioner to break, no computer... you get the idea :)

Did you see what Land Rover did, an app to control/maneuver the vehicle?

I can hardly wait for that to get hacked and it will be for sure...

I always enjoy wretched excess, especially when it's chromed and nicely polished.

My two favorites over the years were a small-block Chevy-powered unicycle, which I saw at a Miami hot rod show in 1963, and Jay Leno's tank-engined car, which I actually got to fondle when I was out there last year:

(Although I spent more time fondling his Grand Prix Bugattis from the

1920s and 1930s.)

Oh, that's great. And because it's on a smart phone, nothing can ever go wrong...go wrong...go wrong...

I'm a gizmo person, so I really like what that can do. Can you imagine hooking up a trailer with that gizmo, cool! But it's going to be hacked. Only question is what will the hacker command the vehicle to do?

Hackers sometimes have vivid imaginations.