Article on R series engines in July TW

[jeryst]

In the co-operator, there is a very good explanation of the differences between the R-series engines, so I had a couple of questions.

It says the the R-3 engine, with a supercharger and single 4-barrel carb put out 355 HP, but an R-4 with higher compression pistons, dual 4-barrels and no supercharger dropped to 280 HP. Does the removal of the supercharger really cause that much of a drop in HP in spite of the other performance modifications?

How much HP does a supercharger add, with all other things being equal?

How does a 57 GH engine compare to the R-series engines? Does it fall in there somewhere, or is it more of an R-0 engine from which the others were improved?

[N8N]

as far as the '57 goes, it's along the lines of an R2 but has none of the oiling system improvements of the later cars, and also is limited by the 2bbl carb mounted in a pressure box rather than the more modern AFB on the R2. I think the R-series cams and valvesprings allowed for higher RPMs than the Golden HAwk engine.

nate

--
55 Commander Starlight

http://members.cox.net/njnagel

[BobPalma]

Originally posted by jeryst

In the July Co-Operator, there is a very good explanation of the differences between the R-series engines, so I had a couple of questions.

Thanks for the feedback, Jerry. 'Glad you enjoyed Jim Pepper's entry therein. We sometimes take for granted, to our detriment, people knowing basic elements of Studebaker history that may be unknown to newer Stude enthusiasts!

It says the the R-3 engine, with a supercharger and single 4-barrel carb put out 335 HP, but an R-4 with higher compression pistons, dual 4-barrels and no supercharger dropped to 280 HP. Does the removal of the supercharger really cause that much of a drop in HP in spite of the other performance modifications?

YES

How much HP does a supercharger add, with all other things being equal?

That's pretty easy to determine.

The 1957 289 engine with a single 2-bbl carb was rated at 210 HP. The 1957 Golden Hawk engine was virtually identical in every respect (i.e., "all other things equal") and was rated at 275 HP.

So, in 1957, the additional horsepower attributed to the supercharger would be 65. Of course, there is speculation that the 275 figure was reported so the engine would have the same horsepower as the unsupercharged Packard 352 it replaced, so who knows for sure?

It does make for an interesting bit of trivia: Unlike many high-performance cars produced more than one year, or with various engine options, every single Studebaker Golden Hawk built had a 275 horsepower engine over the model's three-year production run, despite that run using two entirely different engines!

How does a 57 GH engine compare to the R-series engines? Does it fall in there somewhere, or is it more of an R-0 engine from which the others were improved?

That's a difficult question to answer decisively. Many improvements and engineeering changes were made between the 1957 289 engine and the late-1962 289 engine from which the R-series engines were designed and built.

Then, that late-1962 289 engine underwent considerable high-performance engineering work to produce the R-series engines. Heads, ignition system (dual-point distributor), camshaft, crankcase ventilation system, vibration dampener, etc., etc., were all specifically redesigned/refined for higher-performance. BP

[studegary]

quote:Originally posted by jeryst

In the co-operator, there is a very good explanation of the differences between the R-series engines, so I had a couple of questions.

It says the the R-3 engine, with a supercharger and single 4-barrel carb put out 355 HP, but an R-4 with higher compression pistons, dual 4-barrels and no supercharger dropped to 280 HP. Does the removal of the supercharger really cause that much of a drop in HP in spite of the other performance modifications?

How much HP does a supercharger add, with all other things being equal?

How does a 57 GH engine compare to the R-series engines? Does it fall in there somewhere, or is it more of an R-0 engine from which the others were improved?

I thought that an R3 was rated by Studebaker at 335 HP (not "355 HP").

A general rule of thumb is that a good supercharger adds one-third to the horsepower.

Other items already answered.

Gary L.
Wappinger, NY

SDC member since 1968
Studebaker enthusiast much longer

[53k]

FWIW, when Jon and Mike Myer finished going through the NOS R-3 I sold a couple years ago, they put it on a dyno. It produced 357 hp with the milder cam.



Paul Johnson, Wild and Wonderful West Virginia. '64 Daytona Wagonaire, '64 Daytona convertible, '53 Commander Starliner, Museum R-4 engine, '62 Gravely Model L, '72 Gravely Model 430

[monomaniac]

Paxton, in their literature of the day, used to print:
the addition of a supercharger will add 40% horsepower
to the rear wheels.

[BobPalma]

quote:Originally posted by monomaniac

Paxton, in their literature of the day, used to print:
the addition of a supercharger will add 40% horsepower
to the rear wheels.

There you have it, guys!

'No sense paying all that money for an R2 and getting only 289 HP. According to Paxton, you could order a base 289 with 4-bbl carb, rated at 225 HP, add a Paxton Supercharger, and wind up with a 40% increase: 315 HP![:0]

(Geeze, Art, I wonder why Studebaker didn't just do that to begin with and save all the development cost of the R-series engines, only to produce a puny 289 HP R2? [}] <GGG> ) BP

[Thomas63R2]

The percentage of horsepower increase via supercharging is very related to the percentage of boost measured in atmoshperes of increased breathing via forced induction. There is some simple math to calculate the horsepower increase of a supercharger that will get you close to the technical engineer math: divide the observed manifold boost by 14.7 (one atmosphere), then add 1 and multiply this by the unboosted horsepower. For example an Avanti at 4.5 psi: 4.5/14.7 = .306 atmosphere boost, 1 + .306 = 1.306, then 1.306 x 225 horsepower = 293 horsepower ~ pretty close to the 289 or 290 horsepower figure most often quoted. The engineer math would factor in the horsepower drag of the supercharger at a certain boost level and othe inefficiencies.

The lower the boost and performance level of the engine, the more accurate the simple math will be. On the other end of the scale I had built a BBC with a large D2-R ProCharger centrifugal supercharger. Naturally aspirated it was 481 horsepower. At the 16.9 psi achieved it theoretically would have been ~ 2.15 time the n/a power for 1,034 horsepower. The actual measured horsepower was 953. The 81 horsepower difference was the loss from mechanical friction, belts, etc., and heat energy loss from compressing air.

Thomas

Long time hot rodder
Packrat junk collector
'63 Avanti R2 4 speed

[Laemmle]

Where?...........at the flywheel or the rear end? makes a big difference.

quote:Originally posted by 53k

FWIW, when Jon and Mike Myer finished going through the NOS R-3 I sold a couple years ago, they put it on a dyno. It produced 357 hp with the milder cam.



Paul Johnson, Wild and Wonderful West Virginia. '64 Daytona Wagonaire, '64 Daytona convertible, '53 Commander Starliner, Museum R-4 engine, '62 Gravely Model L, '72 Gravely Model 430

[HNCadet]

[quote]quote:Originally posted by Laemmle

Where?...........at the flywheel or the rear end? makes a big difference.

Originally posted by 53k

FWIW, when Jon and Mike Myer finished going through the NOS R-3 I sold a couple years ago, they put it on a dyno. It produced 357 hp with the milder cam.

At the flywheel........and with stock, non-ported R3 heads. With the Mondello porting, I believe the reported 400HP numbers are easily achievable.

[Thomas63R2]

HCN, I remember when you were having that engine rebuilt (even though technically it was a "new" engine) - I was glad that you wanted a realistic "stock" R3 engine build, rather than a modern tech knowledge max effort build. I remember that some people were disappointed with the final power. I was happy to see your results back up what Granatelli promised for power.

Thomas

Long time hot rodder
Packrat junk collector
'63 Avanti R2 4 speed

[jeryst]

As you go up the R-series, the engines become higher performance, until you get to the R4, which has much less HP than the R3. Why was that?

[53k]

quote:Originally posted by jeryst

As you go up the R-series, the engines become higher performance, until you get to the R4, which has much less HP than the R3. Why was that?

Supercharging (R-3) boosts the horsepower considerably more than dual four-barrels (R-4). Both engines are basically the same except the R-4 had 12 to 1 compression and the two AFBs.

Here are the specs for the two engines-




Paul Johnson, Wild and Wonderful West Virginia. '64 Daytona Wagonaire, '64 Daytona convertible, '53 Commander Starliner, Museum R-4 engine, '62 Gravely Model L, '72 Gravely Model 430

[jeryst]

But why did they offer a less performing engine when the trend was heading toward higher performing engines. Did the superchargers have so much trouble that Studebaker just wanted to eliminate them?

[Dan White]

I believe that this allowed Studebakers to race in certain brackets that did not allow blown engines. Other makes also were using dual quads or three twos for high performance so this was a way to meet that challenge, although it really did not work out that way since so few actually sold. It is also interesting that this engine (R4) was really the first and only Studebaker engine to really make good use of the stout bottom end, which if I remember right was designed for (continuous not just blown) fairly high compression ratios back in the days of its development.

Here is an interesting article on the only R4 factory Daytona made I believe.

http://racingstudebakers.com/R4_page_2.htm

Dan White
64 R1 GT
64 R2 GT