Engine: R-3 Engine Size

[rbisacca]

The R-3 engine is considered to be 304 cubic inches. However, on the back cover of the latest issue of the Avanti Magazine there is a copy of a Studebaker ad from 1963 which states 299 cubic inches for an R-3. Why the 5 cube discrepancy?

[BobPalma]

The R-3 engine is considered to be 304 cubic inches. However, on the back cover of the latest issue of the Avanti Magazine there is a copy of a Studebaker ad from 1963 which states 299 cubic inches for an R-3. Why the 5 cube discrepancy?

There is no discrepancy; there were two legitimate R3 engines.

The early 299 was used to set some records but as far as anyone knows, none were actually released as production-line engines.

The later engine, with a slightly larger bore, was the more common R3 and the one you see in cars today that have "genuine" R3 engines in them. BP

[bezhawk]

There were two types of R3s'. Early and a few made .060 299 were called series A and the more familiar .093 over "production" B series engines. The first records were the Series A engines. from what I understand.

[PackardV8]

The R-3 engine is considered to be 304 cubic inches. However, on the back cover of the latest issue of the Avanti Magazine there is a copy of a Studebaker ad from 1963 which states 299 cubic inches for an R-3.

Yes, No, Maybe. The short life of the R3 had several iterations. According to urban legend, the prototype 299" R3s (.060" overbored from 289") were built by Paxton Products using pretty much California hot rod parts and ported regular heads. Again, legend has it the engine used in the 171 MPH record-setting Avanti was the highest horsepower R3 Paxton ever tested.

The production 304.5" engines (.093" overbore) had R3 heads and were all built to the same specifications.

Then, after Studebaker V8 production ceased, there were the Paxton-sourced R3s. The first several they sold were leftover production R3s. Later, after Paxton had used and sold all the R3 heads and connecting rods, to use the remaining blocks and pistons, some R3-stamped blocks were sold with standard rods and R2 heads.

jack vines

[BobPalma]

Jack's additional details are true, Bob. His expanded answer is appreciated. BP

[studegary]

Studebaker Letter no. 103, dated 9/27/62 introduces the R3, "as announced on April 25, 1962". "This is the special 299 cubic inch ... built in conformity with A.M.A. specification dated July 24, 1962."
"This is a modification of the standard supercharged Avanti engine with the modifications being performed at our Paxton Products Division..." "The engine will be installed on our Avanti assembly line in South Bend..."

Studebaker Sales Letter 161, 6-10-63, "The Avanti R3 ultra-high performance engine will be available on or about August 1, 1963." "...Cylinder block with 304.5 cubic inch piston displacement."

[sgriggs]

Yes, No, Maybe. The short life of the R3 had several iterations. According to urban legend, the prototype 299" R3s (.060" overbored from 289") were built by Paxton Products using pretty much California hot rod parts and ported regular heads. Again, legend has it the engine used in the 171 MPH record-setting Avanti was the highest horsepower R3 Paxton ever tested.

The production 304.5" engines (.093" overbore) had R3 heads and were all built to the same specifications.

Then, after Studebaker V8 production ceased, there were the Paxton-sourced R3s. The first several they sold were leftover production R3s. Later, after Paxton had used and sold all the R3 heads and connecting rods, to use the remaining blocks and pistons, some R3-stamped blocks were sold with standard rods and R2 heads.

jack vines

Paxton sold R3-stamped blocks with R2 heads? Were they ported and modified for large valves?

[mbstude]

Just to add to the confusion, there's a gentleman here in Florida with R3 engine B5. It's a 299".

[Studebakercenteroforegon]

Engine displacement for Bonneville classes in measured in liters. Thus, 304.5 cubic inches just fits in the 5 liter class. 61 cubic inches per liter, so 5 liters is 305 cubic inches.

[Hawklover]

Why should that be confusing?.......I know the person, both he and his son have Avantis, one is an R3 the other an R4......no clones.the real deals....he even had at one time a four door Avanti. Back in the day he had his Studes serviced at Trojan Service Center located at 511 NW 79th Street, Miami..Richard Dahl was the owner....used to work at Studebaker Miami on NW 2nd Avenue..when Stude closed shop, Dick purchased the service area and for a time worked with a fellow named Harvey, who later retired around 1970.....Trojan operated until late 1976 or 1977.....sold to a fellow who ran the business into the ground and later scraped all the Stude parts:-(

Just to add to the confusion, there's a gentleman here in Florida with R3 engine B5. It's a 299".

[mbstude]

Why should that be confusing?.......I know the person, both he and his son have Avantis, one is an R3 the other an R4......no clones.the real deals....he even had at one time a four door Avanti. Back in the day he had his Studes serviced at Trojan Service Center located at 511 NW 79th Street, Miami..Richard Dahl was the owner....used to work at Studebaker Miami on NW 2nd Avenue..when Stude closed shop, Dick purchased the service area and for a time worked with a fellow named Harvey, who later retired around 1970.....Trojan operated until late 1976 or 1977.....sold to a fellow who ran the business into the ground and later scraped all the Stude parts:-(

Not the person you're thinking of.

Thought it might be "confusing" since someone said the 299's were all "A" blocks.