R3 vs.R4

[Footer]

I don’t remember ever reading of a factory installed R4 in an Avanti, but theoretically if there was, how would it perform against an R3?  Have there been comparisons done with Hawks and Daytonas?  Mike

[Geoff]

I surmise R4 would have an awfully hard time competing against the boost pressure of R3. R4's bump in compression ratio and additional carburetor can only get so far against a boosted engine.

I've heard Andy Granatelli spun an early R3 engine to 8,000 RPM. [Another / the same] early R3 was regularly shifted by Ron & Doug Crall in the 1970s at the R (of "thousand R P M" printed at the bottom of the 6k tachometer). That's got to be closing in on 7,500 RPM engine speed.

I heard it was shifting at 8k in half-mile drags at Riverside, Andy was able to beat 426 equipped Mopars. 426 Hemi*? Probably not. The 426 max wedge is more likely. The mighty Mopar would have led through most of the first quarter-mile while the R3 was reeling it in, making the pass before the finish.

I hear it ... 8,000 RPM!!?? That's way up there; that's mother effing Hondur vee-tech territory. At that time, and in his position with Paxton Products, he didn't care if the engine went kaboom.

I would love to acquire a basket case R2 Avanti and use some modern parts and practices to build an 8,000+ RPM capable stroked R3 homage. Although I would do what's necessary to back the engine with an M22 "Rock Crusher" 4-speed. Because too much gear whine is never enough 🙂

 

 

* Although, 426 Hemi cars don't do well on the drag strip⬇️
https://youtu.be/ey7WippcuCI?si=1v27SYBm8or__8mO

[mfg]

I think Studebaker, if they had remained in South Bend building cars, should have waited until the 340 CI engine was ready before they used the R4 moniker…..

The 305 inch R4 that we know seems to me to be a ‘ragged edge’ engine… over carbureted… with an astronomical 12.5-1 compression ratio….

Not exactly ‘user friendly’ !!!

[Dwight FitzSimons]

15 hours ago, mfg said:

I think Studebaker, if they had remained in South Bend building cars, should have waited until the 340 CI engine was ready before they used the R4 moniker…..

The 305 inch R4 that we know seems to me to be a ‘ragged edge’ engine… over carbureted… with an astronomical 12.5-1 compression ratio….

Not exactly ‘user friendly’ !!!

Back in the late 1960s a local fellow (central VA) had an R4-equipped '63 Avanti.  The car went through several owners, and by the time the engine failed, ALL the rings were broken and two cylinders were ruined.  Sunoco 260 was the only gasoline adequate for a 12.5 C.R. and not all of those owners knew (or cared) that the engine had to have a very high octane gas.

But, to answer the original question, an R4 should beat an R3 to about 25 MPH, just as an R1 will beat an R2 to 25.  The reasons are obvious.  Above 25 the R3 will reel in the R4 pretty quickly, especially if the R3 has high output pulleys.

--Dwight

[Footer]

So are there 9 factory R3 Avantis and no R4s?   Are there any surviving factory R4 Studebakers?  Mike

[Dwight FitzSimons]

3 hours ago, Footer said:

So are there 9 factory R3 Avantis and no R4s?   Are there any surviving factory R4 Studebakers?  Mike

Correct, there were 9 factory R3 Avantis, but no factory R4 Avantis.  Back in the late 1960s a local fellow had a crate R4 engine installed in his '63 Avanti.  As I recall the reason he installed a hood scoop was for clearance (rather than just for looks).

There was one R4-equipped Lark type.  I believe that car survives.

--Dwight

Edited January 26 by Dwight FitzSimons

[64Avanti]

On 1/24/2025 at 1:56 PM, Geoff said:

 

I would love to acquire a basket case R2 Avanti and use some modern parts and practices to build an 8,000+ RPM capable stroked R3 homage. Although I would do what's necessary to back the engine with an M22 "Rock Crusher" 4-speed. Because too much gear whine is never enough 🙂

 

 

* Although, 426 Hemi cars don't do well on the drag strip⬇️
https://youtu.be/ey7WippcuCI?si=1v27SYBm8or__8mO

Why a stroked engine.  If you want to go to 8000 RPM stick with the stock stroke and get some good rods etc.

[Geoff]

Just to replicate the stroked 299 R3 [3.75" stroke with stock 289 bore]. These days even strokes of 4" and greater can get there, and higher.