Want your input on R1 Carburetor upgrade

[Jim 63R3984]

I would like some input on upgrading the carburetor on a 63 R1 to an Edelbrock.

First off do I go with a 500 {1405} or 600 {1406} CFM? This is not a race car but a driver that I would like the best snap with out upgrading everything else on a stock engine. Some swear by the 500 and others say a 600 is the way to go.

How thick of riser does one recommend?

I'm sure the four studs that fasten the carb down will need to be lengthened as well

How does one switch from a manual choke to an electric?

How about the vacuum plumbing on the Edelbrock? Do you switch from the back which is the current setup on the 3589S to the front?

Thank You

Jim

[Gunslinger]

The best for a R1 is the 500 cfm Edelbrock. Not the the 600 can't or won't work but a stock R1 cannot use all the air the 600 can suck in...plus the 500 will be better off the line as too much cfm can cause it to stumble on acceleration.

I'm nor sure a riser over stock height is needed but there's nothing wrong with a higher insulator between the intake and carb base depending on whether it hits the hood. A thicker insulator helps to cool the fuel charge.

An electric choke is simple to hook up. Its hot lead goes to a source connected to the start/run side of the ignition switch. Some will connect it to the ignition side of the coil...some elsewhere. I'm not sure which is the best power source.

The Edelbrock has two small vacuum ports...full-time and ported vacuum. I believe you want the ported side.

On the AFB the PCV valve threads into the rear. Edelbrock recommends you have the front of the carb tapped and threaded for the PCV. Not that you can't use the rear like the AFB, but the front mount solves some problems with burning crankcase fumes.

Another thing you'll find is your AFB has a 4 1/4" air cleaner base and the Edelbrock has a 5 1/8" diameter. You'll need to buy a replacement base from Studebaker International (others may carry it as well) or the entire air cleaner assembly to fit the Edelbrock.

I don't know whether the studs need to replaced with longer ones...if you install a higher insulator that may well be necessary. They're easy to find at any speed shop.

[silverstude]

Just some $.02 I have some notes on. Some older correspondence between myself and the factory indicated that the Edelbrock 500 CFM (1403/1404) is jetted for performance from the factory, while the 600 CFM (1405/1406) is jetted for economy. However, I don't know what the differences would be if they were installed on the same engine

[mfg]

I believe that the original Studebaker Avanti R1 carb had a CFM rating of between 600-625.

[PackardV8]

You'll find any riser or insulator addition will put the air intake against the hood.

Either the 500 or 600 works well. As mentioned, the OEM was a 625 CFM. Have you investigated having the original carb rebuilt. It aint rocket science and should cost about the same as a new carb.

jack

[Jim 63R3984]

I've just heard or read in this case that the Edelbrock switch has been great for those that have gone this route. I haven't check the clearance but again I've read in the forums that a 1/2 inch rise is needed and I haven't seen any issues from the articles about air cleaner hitting the hood. I will have to get the playdough out and see what the current clearance is.

Jack, I have gone through and cleaned it really good. It looks like new. I have not changed any of the jet or meter rods. Now having said that I've thought about doing that but I haven't seen the same specs twice on those.

Also the baffle in the choke was missing, I have no idea how this car ever ran for the previous owner? I have not been able to locate that baffle anywhere yet. I'll probably just fabricate one.

[Gunslinger]

I'm not sure but I believe the reason some say a 1/2" rise might be necessary is due to the throttle bracket on the Edelbrock hits the intake so either a spacer is needed or an alternative method is to grind off some of the bracket to eliminate the problem. Even then, I'm not sure that applies to a genuine R-series intake but to Studebaker 2-barrel intakes modified to a 4-barrel. Some claim both have clearance problems and some say only the converted intake needs it.

[abasile]

I remember reading that the Avanti R1 Carter Carburetor was model number 3506S and it

had a rating of 637 CFM.

[64studeavanti]

Gunslinger is correct about the clearance issue. I just cut off the extra part of the throttle bracket so it matched the original. BTW, The original AFB used manifold vacuum to control the spark modifier. So, I used the drivers side vacuum port on the Edelbrock. I posted a picture of the original AFB on the SDC site to confirm this. In any case, it does not really matter once you are off idle. Some have reported good results using the ported or timed side.

[JWL1940]

Using full manifold vacuum for the distributor advance may help in keeping the engine temp down during idle. Set the timing to spec with the vacuum line disconnected and the engine rpm at normal idle speed. Connect vacuum line and reset engine idle speed and mixture. This worked well to cure idle over heating in a 283 SBC with an Edelbrock carb. Engine also runs more smooth coming off idle. Worth a try.

(o[]o)

[mfg]

Using full manifold vacuum for the distributor advance may help in keeping the engine temp down during idle. Set the timing to spec with the vacuum line disconnected and the engine rpm at normal idle speed. Connect vacuum line and reset engine idle speed and mixture. This worked well to cure idle over heating in a 283 SBC with an Edelbrock carb. Engine also runs more smooth coming off idle. Worth a try.

(o[]o)

This is a GOOD TIP!!