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Posted

Yesterday I read a really good article on Bob Johnstone's site on R3 Avantis.  Here is the link:  http://www.studebaker-info.org/MAA/SIA1286/sia1286p30.html

The article said that R3 Avantis had only mechanical advance for timing.  Is that correct?    

Since I know nothing about this subject, I googled it and read that having mechanical advance only is OK for racing when acceleration from a standstill isn't that important, but that having vacuum advance along with mechanical would help from a standstill?

In another article (Road & Track?), I remember that the magazine guys did pretty extensive testing on an R3 Avanti -  on both 1/2 & 1/4 mile tracks.  While they were impressed with the overall performance, they couldn't get the Avanti to launch strong.  I realize that one reason an R3 wouldn't launch like a Hemi is it's smaller cubes and the fact that the supercharger didn't really kick in until about 3000 rpm, but I am wondering if the mechanical advance only may also have contributed to that problem?

My other question is:  Let's say I was building a Stude engine hoping for R3 power, and I wanted to modernize the timing, what would be the best way to go?

 

  

 

 

   

Posted (edited)

 ( My other question is:  Let's say I was building a Stude engine hoping for R3 power, and I wanted to modernize the timing, what would be the best way to go? )

Modify an electronic distributor to fit the R3 and pair up with a Holly, FAST or other EFI system that has a higher than 1 atm MAP sensor and let the EFI learn/control it's way to maximum performance. I know you can buy an electronic unit that will fit but I'd want the one that the EFI controls.

Edited by Avanti83
Posted (edited)

I'm doing just that. Took a Pertronix from Dave Thiebault, and eliminated ALL advance, both vacuum, and mechanical locked out. Then got a phasable rotor from MSD, and set the initial advance of the dizzy to 15deg. Then center the rotor on the #1 tower. Hooked the distributor pickup to the Holley Sniper Electronic Fuel Injection, and that triggers the MSD 6Al ignition box. Timing is completely now programable and even boost retard if desired, and also nitrous oxide if so inclined. 

efi gauge.jpg

Edited by brad
Posted

X3 on going electronic.  Carburetors and distributors are crude mechanisms which don't have the ability to manage a supercharged engine to maximum output.  Take an R2 or R3 and run it flat out up a long mountain pass.  Guaranteed a terminal meltdown several minutes into the run.

Today, there are 2-liter turbo engines making 335 horsepower with a warranty.  With a computer to control ignition and injection, adding an intercooler, a good R3 might make 500 horsepower and live.

jack vines

Posted
On 10/16/2019 at 12:38 PM, VtMike said:

Yesterday I read a really good article on Bob Johnstone's site on R3 Avantis.  Here is the link:  http://www.studebaker-info.org/MAA/SIA1286/sia1286p30.html

The article said that R3 Avantis had only mechanical advance for timing.  Is that correct?    

Since I know nothing about this subject, I googled it and read that having mechanical advance only is OK for racing when acceleration from a standstill isn't that important, but that having vacuum advance along with mechanical would help from a standstill?

In another article (Road & Track?), I remember that the magazine guys did pretty extensive testing on an R3 Avanti -  on both 1/2 & 1/4 mile tracks.  While they were impressed with the overall performance, they couldn't get the Avanti to launch strong.  I realize that one reason an R3 wouldn't launch like a Hemi is it's smaller cubes and the fact that the supercharger didn't really kick in until about 3000 rpm, but I am wondering if the mechanical advance only may also have contributed to that problem?

 

  

 

 

   

To try and answer the first part of your question, R3 and R4 engines had 'bigger' (longer duration ) camshafts than the ones used in R1's and 2's....These bigger cams do not really let the engine develop enough vacuum at cruise for a vacuum advance system to work properly.....The timing could possibly bounce around all over, so it's better to rely on mechanical only advance in engines with "hot' cams. (Mechanical advance comes into play when you have your 'foot in it'!!:o:D)

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