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**buddymander** · 07-11-2008, 03:32 PM

If it was a holley, I'd say you had a blown power valve, but if you have a carb with metering rods, I'd say they are stuck in the up position. Your float could be too low as well.

**buddymander** · 07-11-2008, 03:32 PM

oops, too HIGH

**bige** · 07-11-2008, 03:56 PM

I would remove the air horn and look into the carb with the engine idling. Look for dribbles of fuel from the venturis, especially the secondaries. If you see none while the engine is idling I would shut it off, leave the air horn off, block the linkage so it stays wide open and when things cool down look for dripping fuel. There may be more than one casting issue with your carb.

Situations where the secondary throttle plates are not closing all the way could cause fuel to be sucked through the venturis. Even though you are not pushing down far enough to open them.

I'm also assuming the rebuilder assembled the carb carefully and the metering rods are centered in the jets. Easy enough to check by loosening the metering rod covers and pushing down on the piston and rod before they pop out of the bores. They should move up and down easily.

Finally if there are no visible leaks you can re-jet. The primary jets on the 3725S are fairly large at 101+, and you could drop down to a 98 with a 75/47 rod ( from an Edelbrock Jetting Kit )and improve throttle response and economy.

I've heard of boost closing an open choke, and keeping secondaries from opening all the way. I removed my choke plate entirely.

Your ignition system must be up to snuff because it keeps firing those fouled plugs so I wouldn't spend time there.

Did the car run OK before, except for the external leak, or is this the first time you've actually had this carb on the engine driving around?

**Mike Van Veghten** · 07-11-2008, 04:16 PM

As buddy notes, one thing that happens to older Carter/Edelbrock carburetors is that the jet needle (or metering rod) piston wears out the bore in the body of the carb. Well actually both the piston AND body wear out. This causes the vacuum to leak past the piston. This...in turn causes the piston spring to stay extended...in the "full rich" position. Engine vacuum is supposed to pull the piston down...thus effectivly plugging the jets. As the vacuum goes down, the spring under the piston forces the needle up..(where the needle is smaller in diameter) to let more gas thru the main jet.

Despite the word..."professional" rebuilder....he could have rebuilt you "a" carburetor! Are you sure you got YOUR...carburetor back. Not someone elses!
Most rebuilders clean "many" parts at a time. That is...more than one carburetor...
Are "your" jets in, are "your" metering rods back in?

Are the floats adjusted properly? Too high a float adjustment will cause a rich condition.

Are your curb idle mixture screws adjusted properly?

As bige sorta asks...too low a timing will "mask" as...somewhat a rich carb.

There's a few things to look at...

Mike

**studebaker-R2-4-me** · 07-11-2008, 04:42 PM

Ernie and Mike.

I have my carburetor back - no doubt about that. I am leaning toward a timing issue that is masking as a rich carb. I am picking up a new digital timing light tomorrow c/w tach and dwell. I'll check out Ernie suggestions on Sunday.

In the mean time I'll be out tomorrow in the '63 Daytona convertible during the nice hot weather.

Thanks for the replys

Allen

1964 GT Hawk R2 Clone
Oakville, Ontario.

Hamilton Chapter
See you at Niagara 2008 Crossroads Zone Meet July 18-20

**53k** · 07-11-2008, 05:07 PM

I went through the same thing with my '64 R-2 several years ago (sooty, fouled plugs). Turned out the metering rods were bent to where they weren't seating properly. I was able to straighten mine ok, but new metering rods are available individually or in "strip kits" from places like Jeggs and Summit.

Paul Johnson, Wild and Wonderful West Virginia
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine
1962 Gravely Model L (Studebaker-Packard serial plate)
1972 Gravely Model 430 (Studebaker name plate, Studebaker Onan engine)

**Mike Van Veghten** · 07-11-2008, 06:32 PM

Note for all -

If anyone thinks that they can make the metering rods sit and remain "centered" in the jets you are fooling yourself!
Actually, it can be done. You'll need some epoxy or silicone, and some aluminum tape.
First add tape to the needle (rod) until it will just go into the jet. Make sure you can pull the tape off later. Now put some silicone/epoxy on top of where the needle enters the jet...let set. Now remove the tape...OR you can leave the tape on becsuse the silicone/epoxy will have plugged every thing anyway!

Now that the joking is over...I challenge ANYONE....
All they have to do is PROOVE to me that the needle/metering rod stays CENTERED within its jet by anything more than pure accident on a running/RPM changing engine!

This is to say...insert a NEW set of metering rods into a carburetor, put oh...say...2500 miles on said engine. Now remove the needles/rods.
What will you find....you will find that the rods/needles are nice and shiniey/polished where it's been sliding in and out of the jet and possibly from the guide in the body of the carb. if the jets are large enough for the needles to rattle around that much!

$500.00 to the above challenge!
A "stock" Edelbrock/Carter carburetor...with all "stock" internal parts, "no modifications" to any parts (needles, pistons, springs, jets, gaskets or any part of the carburetor body, upper or lower), on a running engine, in a drivable car, after a minimum of 2500 miles (street and freeway driving).

Proper carburetor tuning allowed. And the needles MUST be able to properly move within the body as designed to enrichen and lean the system as the engine requires.

All original machine marks must remain untouched/unpolished/unmolested on the needles/metering rods after the 2500 miles.

Do I have any takers?

All in fun of course! E-mail me if you think you've found a loophole in my considerations.

Mike

P.s. - for what it's worth....there is NO "seating" of a movable needle/metering rod in an American carburetor that uses them!
Bent...yea..that may cause some hassle. My question....just HOW...did they get bent? Can't happen inside the carburetor !!! Isn't like a pushrod !

**bige** · 07-11-2008, 07:37 PM

I use the term centered to describe their proper position, relatively speaking, as opposed to bent up laying outside the jet because the top was put on with the rods in place and then screwed down without making sure the rods were "somewhere" in the jet. I'm sure that's what Paul meant also.

ErnieR

**GTtim** · 07-11-2008, 08:11 PM

Allen, I think the most likely culprit is the carb. First, are all the plugs fouled, or just half of them? If only one metering rod is acting up, only half of the plugs will be fouled. Does your engine have an R2+ cam? If it is the plus variety you need to have the weakest springs available in the metering rods. The plus cams create so little vacuum that the metering rod pistons will not pull down into the lean position with the standard springs. The carb that I have was used by a racer who had used JB Weld to plug the vacuum ports at the base of these pistons. This kept the rods in the rich position all the time. Two rebuilders missed this. You can remove the little plates on the top of the metering rod pistons and observe that they are being pulled to the down position with the engine running. Just don't drop the stuff into the engine.
Now lets back up a bit. These engines were designed to run rich. That was the way they were built. Major black smoke at full throttle is not unusual. The acid test at that point is how does the engine run, is it missing, sluggish, does it seem to wake up if you let up on the throttle a little? I think the smell of gas at full throttle is also somewhat normal. Normal because of the worn state of most of the carbs in service at this time. Choke shafts and throttle shafts have all got a lot of wear on them at this point, so unless you've had all those rebushed I'd expect some fuel mixture to be let out under full throttle.
Tuning these beasts is also something of an art. You have to live with them a while to learn what they can do. It took me two years to get my car so it would run like it is supposed to. Remember also that these cars were designed to run on good 100 octane gas without alcohol and they didn't have all the wear problems when new that we are dealing with now. Stick with it, you're at the bottom of the learning curve. Good luck.

Tim K.
'64 R2 GT Hawk

**buddymander** · 07-11-2008, 09:05 PM

After all is said and done--He's going to check his TIMING. I'm going to go bang my head against a wall.

**53k** · 07-12-2008, 03:01 AM

quote:Originally posted by bige

I use the term centered to describe their proper position, relatively speaking, as opposed to bent up laying outside the jet because the top was put on with the rods in place and then screwed down without making sure the rods were "somewhere" in the jet. I'm sure that's what Paul meant also.

Yes. that's what happened[:I].

Paul Johnson, Wild and Wonderful West Virginia
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine
1962 Gravely Model L (Studebaker-Packard serial plate)
1972 Gravely Model 430 (Studebaker name plate, Studebaker Onan engine)

**studebaker-R2-4-me** · 07-12-2008, 04:35 AM

quote:buddymander Posted - 07/12/2008 : 12:05:21 AM After all is said and done--He's going to check his TIMING. I'm going to go bang my head against a wall.

Buddymander, don't BANG your HEAD yet!

I've got a old timing light and I am using my stock tach to set rpm. (it's useless and inaccurate) 2 weeks ago a friend and I set the timing with his timing light(with advance),that was before I had my carburetor rebuilt and was leaking fuel through the throttle shaft. I assumed the richness was due to the leaking fuel. The leaking fuel problem has been repaired in the carburetor. The new digital timing light will tell me a whole lot more of the story, dwell, degrees of advance and RPM. Right now I don't have a clue where I am at but the new timing light will be at my FLAPS by 10:00 am this morning.

To solve the problem you have to eliminate one thing at a time. TIMING was set and I have not touched the distributor since. The carburetor has now been rebuilt with new bushings, floats, seats etc. So I am not going there until I look at the timing again but you have to OWN or have access to one before you can use it.

I'm leaning on too low of timing and I'll be finding that out as soon as I own that timing light.

1964 GT Hawk R2 Clone
Oakville, Ontario.

Hamilton Chapter
See you at Niagara 2008 Crossroads Zone Meet July 18-20

**bige** · 07-12-2008, 05:27 AM

May I offer a tip when setting the initial timing. Idle the car as low as you can and then check it. If it's so far retarded that the idle increases dramatically when you advance it adjust the curb idle screw to reduce the idle speed and recheck. If you have an R2 spec curve in your distributor centrifugal advance comes in quickly. You want to make sure that all your timing settings are measured without the centrifugal advance coming in. Go back and forth between timing and idle screw. If the distributor is curved properly the initial should be around 4 degrees advanced at idle and 24 at 1600 RPM, vacuum advance disconnected.

Check the timing all the way up to 3500 RPM. An R2 distributor should not continue to advance past the 24 BTC. If it does you could experience detonation in the higher RPM ranges. That's not to say that an extra degree or two might not yield a performance gain but if the advance is approaching 36-40 degrees you need to change things in the distributor.

A by-product of timing that may be too far retarded would be the need to open the primary throttle blades via the idle screw to a point that they create enough vacuum to signal the venturi to start delivering fuel. That will cause a very rich condition at idle. It will also cause the vacuum advance to start if the timed port is exposed to vacuum.

**59r2** · 07-12-2008, 12:25 PM

r2-4-me,
before you go secound guessing the timing,which I'am sure you set right.Years ago I had a pcv valve hang shut, which drove me nuts with the heavy black soot out the exhast.Installed a new one it lean out the mix,worth a check.
JOE

1959 HARDTOP R2 clone
1960 conv
SDC member since 1972

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