R3-R2?

[mfg]

The supercharger used by Studebaker on its 'R3' engine was adjusted to produce more pressure than the supercharger used on their 'R2' engine......True?

[Gunslinger]

False...I believe the blower was the same but a different pulley was used for an R3.

[mfg]

Agreed!...same blower...I'm not even sure that the pulley was different unless the 'high output' pulley set was ordered....Answer...FALSE!

[GAWen]

When I was working for our local Studebaker dealer in Pa., one of our customers had a 1963 R-2, 4 speed Avanti and he handgernaded the supercharger and the engine. Paxton sent us a replacement engine/supercharger assembly (under warranty). The original setup produced approx. 5 lbs of boost at 3500 RPM, the replacement could produce as much as 12 lbs of boost at 5,500 RPM. What the hell did Paxton send us ??

[mfg]

I'm not sure what Paxton sent you.....But I DO know that I love 'inside' stories like this from folks that were there!!......VERY interesting!

[GAWen]

As an afterbthought. After The new engine/supercharger was installed in the Avanti, Henry (the owner, and 350 plus pounds) took the car to our local dragstrip. I do not recall the trap time or speed, but I do recall that I calculated that the engine had to be pushing in excess of 350 HP on pump gas ( Sinclair, high test).

[PackardV8]

The original setup produced approx. 5 lbs of boost at 3500 RPM, the replacement could produce as much as 12 lbs of boost at 5,500 RPM. What the hell did Paxton send us ??

The boost curve of a centrifugal supercharger rises exponentially with RPM. If one were producing 5#@3500, then 12#@5500 would be expected. Most OEM Paxtons didn't produce 5#@3,500; seeing 2-3#@3,500 would be more usual, maybe rising to 5#@5,500 before the belts started to slip.

Having said that, you might possibly have received a Competition version. Difficult to believe they would have sent one as a warranty replacement, as the Competition version had a lifespan measured in minutes and was sold with no warranty.

The other possibility was a standard supercharger coming with a high output pulley. However, they typically didn't make 12#.

jack vines

[Geoff]

Great explanation! I can only bring the Hot Rod article to support what Jack stated,

"Different blower pulley ratios are used on the R3 and it is supposed to deliver 6 pounds boost at 5200 rpm. Now although we've estimated a horsepower figure of 305 for the R3 engine, we've based that guess on 6 pounds boost at 5200 rpm. The pressure build-up is pretty rapid in a centrifugal supercharger at high rpm's and we wouldn't be a bit surprised if an accurate gage would show about 8 pounds at 6000 and maybe even 11 or 12 pounds at 6500 rpm."

So if they were guessing 11 or 12 pounds of boost at 6500 RPM, and Andy used 8000 RPM for his straight-line feats, how much total pressure are we talkin'? No wonder the engine looked like a WWII fighter's cowling (smeared and oozing with oil) after high RPM operation.

[64Avanti]

8,0000 RPM ???

[Geoff]

Affirmative. Andy Granatelli said he frequently spun RS1021 (engine in 63R1025) to 8,000 RPM.

[mfg]

Wow!..If a 289 (299?) can be wound to 8K, I wonder how high a 259 or even the super-short stroke 224 could be wound out to....all else being equal?

[Geoff]

I should also put it out there (for those who weren't in the 1025 discussion) that we're talking about a 289 stroked to 299, so that's 3.75" worth of stroke being wound to 8,000 RPM.

More rev's is all about sinking money into the engine technology … well that and just making sure things are lightweight and balanced. As of 2006:
A NASCAR cup engine had ~3.25" worth of stroke and they were wound out to 10,000 RPM.
F1 engines (2.4L V8, max bore ~3.85", max stroke ~1.56") were wound out to 20,000 RPM.

Edited April 24, 2015 by GeoffC312

[64Avanti]

The big end of the Studebaker connecting rod is one of the week areas. What happens is the hole becomes oblong pinching the bearing in and potentially spinning a bearing. 7,000 rpm for a brief period is ok but not for a long period of time. However 8,000 rpm with a 289 Studebaker and a stock rod is not a good idea. If 7,000 RPM is ok with a 289 then 7400 rpm should be ok with a 259.

Before anyone says but they were R3 rods, the only difference was the small end that used a press-in pin instead of the pinch bolt. I also have one R3 rod that had a bushing in the small end for a full floating pin.

I hate to say it but you can't believe everything that Andy said!

[mfg]

He really was the salesman's salesman! (RIP ANDY)

[Geoff]

Here's the thread I referenced: http://www.aoai.org/forums/index.php?showtopic=3701

[ron@crall.com]

We have only had the pan off of 63R-1025 once and it was many years ago, however; it was apparant that a lot of work had been done to the rods and crank. At the other end of the chamber there was also a tremendous amount of work done to the heads and the valve retainers are very light weight and obviously hand made items as each is slightly different that the others.

[mfg]

Ron, ...Is 63R-1025 presently in running (operating) condition?....Do you plan on taking it to Warwick next year?....Folks would definitely LOVE to see that Avanti!

[PackardV8]

Wow!..If a 289 (299?) can be wound to 8K, I wonder how high a 259 or even the super-short stroke 224 could be wound out to....all else being equal?

Yes, a shorter stroke takes more RPMs to generate the same inertial loading on the OEM Stude V8 connecting rod weak link. However, the old school valve train goes wonky before the shorter stroke short blocks hurt themselves.

There are many drag race engines with 4.5" strokes turning more than 8,000 RPMs, so it's no longer about stroke length. Changing the build with custom connecting rods and light forged pistons and a 289" will turn the same RPMs; whatever the valve gear will support.

With good rods and pistons, a custom cam profile, titanium valves and race springs, a 289" could turn 10,000 RPMs; whatever RPMs the builder wanted.

However, it's moot, as the iron heads run out of normally aspirated flow capacity to supply a 289"-305" short block way before the high RPMs happen. That's why Stude engineers went to superchargers in 1957.

jack vines

[mfg]

Actually, Studebaker began using superchargers in 1957 because the heavy old Packard V8 was taken out of production.

[PackardV8]

Actually, Studebaker began using superchargers in 1957 because the heavy old Packard V8 was taken out of production.

Yes, agree, once the good engine was gone, they were forced to add the supercharger because that's the only way the Studebaker V8 could produce 275 horsepower, so as not to have a reduction in the advertised horsepower. In real world driving, the '56J was faster and quicker than the '57-58.

No, actually, the Packard V8 isn't that much heavier than the supercharged Studebaker V8. I've weighed both on the same scale on the same day and the difference is less than 20#.

As to "old", the Studebaker V8 came out in '51 and the Packard V8 in '55, so it's the newer of the two.

Maybe, the Studebaker engineers were doing the best they could with what few resources they had available.

jack vines

Edited July 10, 2015 by PackardV8

[Geoff]

Ron, ...Is 63R-1025 presently in running (operating) condition?....Do you plan on taking it to Warwick next year?....Folks would definitely LOVE to see that Avanti!

1025 is not yet in running condition. I am off to Maine starting next Tuesday to vacation at my dad's place; my goal for this trip is to bring the fiberglass back to 100% complete.

Next year's show in Rhode Island is a strong maybe for 1025 to attend, it'll hinge on our progress before then. I plan a return trip to Maine next spring, and a third time a little before the Rhode Island show. Hopefully three times inside 365 days is enough to "finish" the car.

I enclosed finish in quotes because ultimately I would love to get into the engine and have it once again be 8,000 RPM capable. Also, over time it has gone away from its factory turquoise paint / turquoise interior and I'd like to go back to stock appearance. Neither the engine nor the appearance are necessary to take it to the show, but they're on my to-do list.

I noticed 2017's meet is scheduled for a return to South Bend. A lot would have to go very wrong for 1025 to not be finished (no quotations) and to not attend that meet.

[ron@crall.com]

A couple of hours work and the car could be driven, however, we have body work to do after an "off roading incident" many years ago.

My son arrives Tuesday and we will begin the work on the body, however no way to get it done in time for St Louis, however; hopefully in time for Warwick.

Recently Acquired RQB-1703's chassis will be next to 1025 and I'll be starting work on it. It is being built for fun so it will not take as long to get going.

Good chance a color change made 20 years ago will be reversed and it will be restored to original colors.

[ron@crall.com]

Regarding engines, remember that Studebaker was making aircraft engines during WWII (as did Packard). Supercharging and 160 octane fuel was pretty common. When Studebaker developed their V8 there was a presumption that very high octane fuel would be available so high combustion chamber pressures could be used to obtain horse power. GM converted gasoline engines to diesel with poor results. I would expect that a 289 diesel would likely be a good engine; they certainly have demonstrated the ability to absorb high combustion chamber pressures.

[PackardV8]

Regarding engines, remember that Studebaker was making aircraft engines during WWII (as did Packard). Supercharging and 160 octane fuel was pretty common. When Studebaker developed their V8 there was a presumption that very high octane fuel would be available so high combustion chamber pressures could be used to obtain horse power. GM converted gasoline engines to diesel with poor results. I would expect that a 289 diesel would likely be a good engine; they certainly have demonstrated the ability to absorb high combustion chamber pressures.

Can you give us a citation for 160 octane fuel being pretty common? IIRC, it was experimental and more properly referred to as 100/150 aviation fuel.

Wikipedia

Avgas -The particular mixtures in use today are the same as when they were first developed in the 1940s, and were used in airline and military aero engines with high levels of supercharging; notably the Rolls-Royce Merlin engine used in the Spitfire and Hurricane fighters, Mosquito fighter-bomber and Lancaster heavy bomber (the Merlin II and later versions required 100-octane fuel), as well as US-made liquid-cooled Allison V-1710 engines, and numerous radial engines from Pratt & Whitney, Wright, and other manufacturers on both sides of the Atlantic. The high octane ratings are achieved by the addition of TEL, a highly toxic substance that was phased out of automotive use in most countries in the late 20th century.

The octane rating became important as the military sought higher output for aircraft engines in the late 1930s and the 1940s. A higher octane rating allows a higher compression ratio or supercharger boost, and thus higher temperatures and pressures, which translate to higher power output. Some scientists even predicted that a nation with a good supply of high octane gasoline would have the advantage in air power. In 1943, the Rolls Royce Merlin aero engine produced 1320 horsepower (984 kW) using 100 RON fuel from a modest 27 liter displacement. Towards the end of the second world war, experiments were conducted using 150 RON fuel (100/150 avgas), obtained by adding 2.5% aniline to 100 octane avgas.^[4]

jack vines

[Gunslinger]

I had read some years ago in a history of the P-38 Lightning fighter that an experimental load of 150 octane fuel was delivered and tested...I believe delivered to them in England but I might be wrong on that.

More to the point...the 150 octane fuel provided higher performance but was impractical as they found the spark plugs in their Allison V-12 engines fouled in extremely short order and created excessive maintenance problems to an otherwise already high maintenance aircraft.

An aside to the octane discussion...British fuels were generally 80 octane and that's what they flew their aircraft on. During the Battle of Britain just as the air battles were coming to a climax, an American tanker of 100 octane avgas docked and that fuel provided the boost in performance for the Spitfires and Hurricanes over the Luftwaffe fighters to make a huge difference in the outcome.