The R3/R4 Roster Project....
(.... where knowledgeable people are encouraged to share their knowledge, in exchange for a private copy of the roster as it is updated....Contact Ron Ellerbe )....

The assembly of a roster containing current information on R3 and R4 engine ownership and survival began in the Spring of 1998. The author believes no other equivalent effort has been undertaken in 15 years, with the exception of a John Shanahan work, ending in 2002. Shanahan’s work has been incorporated here. In addition, there is a sense of urgency in that the collective knowledge base on these engines is seriously fading.

The roster product is in three parts.
First, there is a listing of engines by "B"-number. Every B-engine number that we believe Paxton used, is on this listing. Those numbers run from 1 to 117 plus 153, 299 and 300. The most current information we have on every B engine is shown in one row. There are many blank rows, indicating that the engine has never been found or has not been reported by B number. The data for some engines are very fresh and some is 30 years old. The listing exists as an Excel workbook.

Second, there is a larger listing containing every R3 and R4 engine discovered. This listing and segregates engines into 4 parts.
Part A” engines are all known Paxton built engines with identification by factory R3S number, B number or EX number. Factory installed engines for which we have found B and R3S numbers are shown in bold. The B engines reported in the first listing are in “Part A”.
Part B” engines are those reported without identification or other amplifying facts. Most of these were found in club rosters and have been the subject of letters of inquiry to their owners. These “Part B” engines are not known to be owner built, Paxton built or real R3/R4 engines. When we learn enough about one of these engines, we move it to another part of the listing or drop it.

Part C” engines are known owner built clones of R3 or R4 engines. Engines with R3 heads or R4 intakes qualify. There are plenty of these in existence and they have been accounted for to avoid confusion about which engines are Paxton built and which are not.
Part D” engines are those Paxton motors that went into factory cars but did not stay in the car. At least one factory R3S Avanti engine is in something else. Some R3S engines were damaged and had blocks replaced. The B numbers of all of these “part D” engines were assigned by Paxton but are unknown. These Part A / B / C/ D listings are more tabs in the same Excel workbook.

Third is a dissertation on the serialization and marking practices that Paxton and South Bend used on these engines. This is where the roster work has attempted to capture authenticity information. It offers suggestions on what to look for. As with the engine listings, this is a work in progress. The story conveys what has been learned and does not pretend to be the last word on what makes or marks an R3 or R4.

  All of this work has been done with the cooperation of many interested parties and through much letter writing and investigation. Most owners in “Part A” made a contribution when asked to do so. Special debt is owed to George Krem, Shannon Bruffet, Nelson Bove, Gene Rinck, John Hora, and Jon Myer for major portions of the material obtained.
Some owners, engines and cars in “Part B” have disappeared. The work does not have the benefit of any Paxton production records. If they exist, such records have not been found. The work does have the benefit of factory build sheets for the 11 official, R3 and R4 powered cars. These sheets do not show B numbers. We are gathering data the hard way.

Among the projects goals are:

  • Document all surviving and scrapped B engines. (60+ so far)
  • Discover the B numbers of all 11 R3 and R4 engines installed at the factory. (6 of 11 so far)
  • Discover the B numbers of the engines in the 5 Bonneville ’64 Hawks and Larks. (3 of 5 so far)
  • Document the modification of these 5 cars as to what the factory did and what Paxton did to prepare them for Bonneville in September of 1963.
  • Document all Paxton engines that went to South Bend and their numbers.
  • Document the B engines that were 299 c.i.d.
  • Document the engines that were built and sold by Paxton without R3 heads.
  • Obtain an accurate count of the number of complete R3 and R4 engine actually built by Paxton.
  • Document which engines were not fully race prepared.
  • Discover special and experimental engines or blocks besides the R5, Paxton back door projects and how they are identified.
  • Discover when the shift to blue paint for R4’s took place.
  • Learn what happened to the original R4 engine in the unique R4 Daytona, 64V15405.
  • Learn the differences between the production and prototype R3 heads and whether there were any other head variations on the early engines.
  • Document all the variations that Paxton applied to the two engines.
  • Document the assembly and sale dates of B engines.
  • Collect sales orders for Paxton engines.
  • Discover what became of Bonneville #3, the R4 convertible.
  • Find all Paxton conversions of cars to R3 and R4 power.
  •   Follow this link to the Engine marking table