Bob's Resource Website (2007)

R3 / R4 technical Data

According to Studebaker, the R3 - 304.5 cubic inch block was bore is..3 - 21/32". The piston people say 3 - 5/8" + 0.093". The original R3 also has pistons manufactured by Forge True and can be identified by either an embossed Studebaker 'S' logo or Embossed Forge True logo on the top of the piston. The R3 cylinder block serial number will start with a 'B' in place of a 'R' or 'RS' My R3 engine is serial number B110 and Carolyns R2 number is RS2117. An R3 engine block has the top of the cyilinder walls relieved, looks like some one at Paxton took a half round file to the front and rear edge of the cylinder wall at the deck. This was done to allow better flow around the larger and wider spaced valves. I hope this answers some of your questions. Doug Crall (314)355-9951 /

R3-R4 power ratings

Engine Specs
R4/R4 engine data
& tuneup specs

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R3/R4 Price List (pp1)

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R3 / R4 Price list (PP2)

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R3/R4 price list (amended later)

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Engine / valve settings

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R3/R4 piston specs
valve timing

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R3 / R4 carb Specs

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R3 / R4 Engine pics, courtesy of Paul Johnson

pjohnsonr3a.jpg pjohnsonr3r4.jpg
pjohnsonr3r4b.jpg r3r4a.jpg

Mike Float, Clone R4

mfloatr4a.jpg mfloatr4b.jpg mfloatr4c.jpg
mfloatr4d.jpg mfloatr4e.jpg r3571m.jpg
r3571n.jpg r3571o.jpg r3571p.jpg
R4 Parts

Lionel Stone R3 Heads

r3heada.jpg r3headb.jpg
r3headc.jpg r3headd.jpg
r3headf.jpg r3headins.jpg

R3 Specific Parts

Control Arms
Upper inner pin

Install kit

R3 Transistor Ignition Blueprints
r3transigna.jpg r3transignb.jpg

R3 Parts
1555713r3.jpg Intake gasket 1561160.jpg Rear drum backing plates 527921r3.jpg Upper control arms
r3.jpg Axles r3bush.jpg Upper inner bushings / pin
r3bushb.jpg r3heada.jpg R3 Head gasket r3man.jpg R3 Manifold
& Headers
r3pistona.jpg Pistons r3pistonb.jpg Pistons r3pistonc.jpg
r3pula.jpg 8" Crank Pully r3pulb.jpg r3pulc.jpg

Nelson Bove's R3 Daytona

bover3a.jpg bover3b.jpg bover3c.jpg
bover3d.jpg bover3e.jpg bover3f.jpe

Read about an R3 Daytona Purchase

531191 NOS pin and bushing kit. Upper inner a-arm 1951 - 1952 All. 1962 - 1964 Y1 - Y3 - P3 - F3. 1963 - 1964 Avanti R3, R4. Can be used on all 1951 - 1966 cars and Avanti 1963 - 1983 if using upper A- arm number 527921

R3 suspension miscellaneous

What happened to the DUO CENTO?

Change to R3 upper control arms

These pages and programming contained therin are © 1996 - , Bob Johnstone and may not be reproduced without the permission of rfjohnstone at (Bob Johnstone) All Rights Reserved.
Some technical opinions are my own from experience, other informational data is from online sources with credits when available and while care has been taken to be as accurate as possible, it is offered only as a guide and caution should be exercised in the application of it.