R1 vs R2

[ken1007]

As they were produced by Studebaker, what specifically is the difference between an R 1 and an R 2, beyond the supercharger? Did the R 2 engine block have a unique number for its supercharger? Cam? Intake/exhaust? Any thing else? What is involved in returning an Avanti that left the factory as an R 2 to unquestionable R 2 status, (not a clone)?

[WayneC]

... what specifically is the difference between an R 1 and an R 2, beyond the supercharger?

I'm no expert, but a quick look at a parts manual shows that the short block, exhaust manifolds,

and pan are the same, the heads, intake manifold, and distributor are different (although apparently

the R2 head was available as an option on the R1).

It's the R3/R4 models that differ a lot from the R1/R2. Interestingly, the radiator is used by all.

I don't know whether there are any stamping marks on the engine that tell its type.

And, of course, the paperwork that came with a new R2 would be of interest to a collector, since

it proves the car was originally an R2.

Edited April 5, 2011 by WayneC

[ken1007]

I'm no expert, but a quick look at a parts manual shows that the short block, exhaust manifolds,

and pan are the same, the heads, intake manifold, and distributor are different (although apparently

the R2 head was available as an option on the R1).

It's the R3/R4 models that differ a lot from the R1/R2. Interestingly, the radiator is used by all.

I don't know whether there are any stamping marks on the engine that tell its type.

And, of course, the paperwork that came with a new R2 would be of interest to a collector, since

it proves the car was originally an R2.

Thanks, Do you know if the VIN reflects R1 R2 status. The 2011 AOAI roster shows this but is that part of the factory stamped plate? I'm considering a 63 that used to have a supercharger according to the present owner.

[Gunslinger]

The VIN's don't reflect any information beyond the number itself. VIN's will be either 63R-XXXX or simply R-XXXX. Studebaker dropped the "63" part when they instructed dealers to title unsold Avanti's as 1964 models. You'll occasionally find an Avanti with an "A" or "B" suffix on the VIN plate as a few states required serial numbers with more digits than originally used, so the suffix was added on those cars sent to that state. I believe California was probably the primary state that occurred in. Whether the suffix was added by Studebaker or at the dealer level I don't know.

[brad]

The block will be numbered RS XXXX for R2 engines and just R XXXX for R1s. The Distributor is the same, but the advance springs and curve is different (both dual point) The R2 intake has balance slots in the plenum (or is it the other way around)? either will fit and function. Cam, pistons...everything else in short block is the same.

Heads were different to lower compression on the R2 for use with the supercharger, and are the very same as truck heads. No special porting or manifolds and are not any different than any post 55 Stude.

[JavierB]

This is an ancient thread, so not sure if anyone will still be on here, but I'm curious about the performance of the R2 engine without the supercharger.  I've seen a few 64's or late 63's where the supercharger was removed to install AC, and I'm wondering is this a better or worse engine than just an R1.  Anyone have any thoughts?  This is all as part of my enduring quest to find the right one.  🙂

[studegary]

1 hour ago, JavierB said:

This is an ancient thread, so not sure if anyone will still be on here, but I'm curious about the performance of the R2 engine without the supercharger.  I've seen a few 64's or late 63's where the supercharger was removed to install AC, and I'm wondering is this a better or worse engine than just an R1.  Anyone have any thoughts?  This is all as part of my enduring quest to find the right one.  🙂

IMO, an R2 minus its supercharger is a worse (less performance) engine than an R1. 

[mfg]

I drove a '63 R2 Avanti without a supercharger for a few months (everyday use)...however, I switched over to a non-supercharger AFB carb during that time period, as the supercharger carb was jetted too rich and seemed to really guzzle fuel!

[JavierB]

thanks for the insight, guys.  that makes sense.  

[PackardV8]

An R2 without a supercharger will be slightly slower than an R1 on a cool day and slightly faster than an R1 on a hot day.

jack vines

[VtMike]

I have run across some claims (not related to Studebaker engines) that you can increase the compression by replacing the head gaskets with super thin ones.  I was wondering if you could raise the compression by doing that on an R2 without the supercharger to give it a little more go?  If not, what about having a machine shop take a little off the heads to do the same?  Would either make enough of a performance difference to make this a practical idea?

 

Edited May 25, 2020 by VtMike

[Gunslinger]

If you're not sure what you're doing you're playing with fire...or a grenade with the pin partway pulled out by increasing the compression ratio on a supercharged engine.  Small amounts of CR increase can result in a huge increase in blower pressure...resulting in detonation and a blown engine if you're not careful.  Compression ratios and supercharger pulley diameters have very specific mathematics to get it right.  

The best thing is to keep the engine the way it was designed...it certainly can be improved but it requires lots of machining to the heads and combustion chambers to increase airflow and a better, less restrictive exhaust system...plus improvements to the intake manifold, carburetion and camshaft...and that doesn't even begin to take into account the octane ratings of today's gasolines if you're talking pump gas rather than racing fuels.  It all comes down to how much money you want to dump down the rabbit hole.  

[mfg]

22 hours ago, VtMike said:

I have run across some claims (not related to Studebaker engines) that you can increase the compression by replacing the head gaskets with super thin ones.  I was wondering if you could raise the compression by doing that on an R2 without the supercharger to give it a little more go?  If not, what about having a machine shop take a little off the heads to do the same?  Would either make enough of a performance difference to make this a practical idea?

 

Although Studebaker offered two different type head gaskets for their V8's....a 'thick' composite sandwhich type gasket, and a 'thin' sheet metal type, all domestic R1 and R2 Avanti engines left the factory with the thin, sheet metal type.