2X4 Problems
#21
Burning Brakes
John, Tom and Frank are great resources on these WCFBs. I see you rebuilt them yourself which is good, they are straight forward. Download that manual that Frank suggested.
Check the pump pressure as Frank suggested.
Take the little cover off over the metering rods while the engine is running. At idle the 'T' bar where the metering rods hang should be DOWN (pulled down by the vacuum). As you accelerate (vacuum decrease) the ''T' will raise the rods to expose the smaller diameter on the rod in the jet.
If the spring is too stiff, the 'T' will not lower at idle. There are two different springs for the 'T'. One for std cam vacuum and weak one for low vacuum more radical cams.
Just to reinforce others comments these WCFB 2 x 4s are great set-ups. I have run mine for 48 years and 200,000 miles. It starts and runs like it was EFI. A couple of years ago I did a STEALTH engine by putting a DART 400 and DART HEADS with all my original 1961 components back under the hood including the WCFBs. It dynoed 496 hp and 460 ft lb.
Best is the WOW factor when people see those old WCFBs
Joe
Check the pump pressure as Frank suggested.
Take the little cover off over the metering rods while the engine is running. At idle the 'T' bar where the metering rods hang should be DOWN (pulled down by the vacuum). As you accelerate (vacuum decrease) the ''T' will raise the rods to expose the smaller diameter on the rod in the jet.
If the spring is too stiff, the 'T' will not lower at idle. There are two different springs for the 'T'. One for std cam vacuum and weak one for low vacuum more radical cams.
Just to reinforce others comments these WCFB 2 x 4s are great set-ups. I have run mine for 48 years and 200,000 miles. It starts and runs like it was EFI. A couple of years ago I did a STEALTH engine by putting a DART 400 and DART HEADS with all my original 1961 components back under the hood including the WCFBs. It dynoed 496 hp and 460 ft lb.
Best is the WOW factor when people see those old WCFBs
Joe
#22
Instructor
Thread Starter
Here is a PDF file of the fix actually installed in one of my carburetors (the red circled bushing)....this COULD be your turning/stalling problem but do NOT confuse it with your over rich running condition. They are most likely two different things....
Again, I'd check fuel pressure, float levels and ensure the floats are exactly centered in the bowls.
This manual will guide you through the process: http://handbook2.com/c/carter-wcfb-service-manual-e4402
Again, I'd check fuel pressure, float levels and ensure the floats are exactly centered in the bowls.
This manual will guide you through the process: http://handbook2.com/c/carter-wcfb-service-manual-e4402
#23
I had a running rich problem on my 61 with 2x4's. The way I
figured it out was with an IR heat gun. The rear cylinders 6-8 5-7 were
running at 500+ degrees on the exhaust manifold. Fast idle (1000) rpm
The front 4 cylinder were running at 200+ degrees. I cranked down
the idle screws on the front carb until the were closed. The temp on
the front cylinder came up to the 500 degree level. I backed off the
front idle screws until the temp on the front cylinders started to go down.
The final setting on the front carb was about 1/16 turn from closed.
Hope this helps...
Ray
figured it out was with an IR heat gun. The rear cylinders 6-8 5-7 were
running at 500+ degrees on the exhaust manifold. Fast idle (1000) rpm
The front 4 cylinder were running at 200+ degrees. I cranked down
the idle screws on the front carb until the were closed. The temp on
the front cylinder came up to the 500 degree level. I backed off the
front idle screws until the temp on the front cylinders started to go down.
The final setting on the front carb was about 1/16 turn from closed.
Hope this helps...
Ray
#24
Burning Brakes
I had a running rich problem on my 61 with 2x4's. The way I
figured it out was with an IR heat gun. The rear cylinders 6-8 5-7 were
running at 500+ degrees on the exhaust manifold. Fast idle (1000) rpm
The front 4 cylinder were running at 200+ degrees. I cranked down
the idle screws on the front carb until the were closed. The temp on
the front cylinder came up to the 500 degree level. I backed off the
front idle screws until the temp on the front cylinders started to go down.
The final setting on the front carb was about 1/16 turn from closed.
Hope this helps...
Ray
figured it out was with an IR heat gun. The rear cylinders 6-8 5-7 were
running at 500+ degrees on the exhaust manifold. Fast idle (1000) rpm
The front 4 cylinder were running at 200+ degrees. I cranked down
the idle screws on the front carb until the were closed. The temp on
the front cylinder came up to the 500 degree level. I backed off the
front idle screws until the temp on the front cylinders started to go down.
The final setting on the front carb was about 1/16 turn from closed.
Hope this helps...
Ray
Joe
#26
Drifting
My problem .. .pretty well much solved .. foumd anyway
I've had similar running rich and high idle problems and could not for the life of me work it out. So had a friend over today (and a second pair of eyes and ears make a big difference). What we found is a number of vacuum leaks - as follows:
1. Secondary carbi small leak under the gasket - replaced gasket
2. Secondary carbi rather large leak around the secondary butterfly shaft on the left side where the shaft does extend out past the base casting (shaft sits about 1/8" inside the housing) - fixed this by cutting a small round disk out of gasket paper and placing this against the shaft and filling the remaining 1/16" with metal set.
3. Remaining primary and secondary butterfly shafts are all a bit worn where they rotate in the base casting and suck in air I WILL NEED TO GIVE THIS SOME ATTENTION .... going to a machinist mate of mine and talk bronze bush inserts ... which means machining out the base casting at the shaft points.
How did we find all of these leaks ... with a garden hose and a good stream of water over the carb bases. I had done this before with a spray bottle but water quantity is the key. Had the motor running and allowed the water to run over the carbi base and manifold and everytime the idle dipped new vacuum leak was found. Runs better now already with the fixes made (points 1 and 2) but still running a bit rich and the idle screws are almost backed completely off. In fact some of the vacuum leaks past these shafts are so big the engine practically stalled when the leaks was momentarily stopped by water.
Also still runs a bit hot ... may need to change the thermostat or drill some holes in it.
Never the less a productive morning.
I'd be interested in hearing how others are fixing the wear issue between butterfly shafts and base.
Garden hose and water cheapest fault finding tool I'll ever use or buy..... I would give this a go before you talk about what type of engine cam you have and if the floats in the crabs are set up correctly or if the needles and jets are right etc. It was a 10 minute diagnosis .... bit longer to fix ... but finding the problem is the challenge.
1. Secondary carbi small leak under the gasket - replaced gasket
2. Secondary carbi rather large leak around the secondary butterfly shaft on the left side where the shaft does extend out past the base casting (shaft sits about 1/8" inside the housing) - fixed this by cutting a small round disk out of gasket paper and placing this against the shaft and filling the remaining 1/16" with metal set.
3. Remaining primary and secondary butterfly shafts are all a bit worn where they rotate in the base casting and suck in air I WILL NEED TO GIVE THIS SOME ATTENTION .... going to a machinist mate of mine and talk bronze bush inserts ... which means machining out the base casting at the shaft points.
How did we find all of these leaks ... with a garden hose and a good stream of water over the carb bases. I had done this before with a spray bottle but water quantity is the key. Had the motor running and allowed the water to run over the carbi base and manifold and everytime the idle dipped new vacuum leak was found. Runs better now already with the fixes made (points 1 and 2) but still running a bit rich and the idle screws are almost backed completely off. In fact some of the vacuum leaks past these shafts are so big the engine practically stalled when the leaks was momentarily stopped by water.
Also still runs a bit hot ... may need to change the thermostat or drill some holes in it.
Never the less a productive morning.
I'd be interested in hearing how others are fixing the wear issue between butterfly shafts and base.
Garden hose and water cheapest fault finding tool I'll ever use or buy..... I would give this a go before you talk about what type of engine cam you have and if the floats in the crabs are set up correctly or if the needles and jets are right etc. It was a 10 minute diagnosis .... bit longer to fix ... but finding the problem is the challenge.
Last edited by mickatbp; 10-11-2014 at 12:56 AM.
#27
Team Owner
Carb starting fluid, propane (unlit) or even a cigar are excellent ways to find a vacuum leak without dousing the engine with water. Many mistakenly think carb throttle shafts are supposed to be air-tight - they aren't or they couldn't move...if they are TOO loose then re-bushing is the usual fix....this isn't a job for the amateur though.
If your carb was sucking air I would think the mixture would be lean....fixing the leaks may have enrichened the idle mixture even more... I'd be looking hard for incorrect parts bad needle/valve seat, sinking floats or float height/drop levels way off... Bear in mind these WCFBs HAVE to have the floats EXACTLY centered in those small float bowls. Sticking to, or rubbing against, the sides of the carb body will make things squirrley as hell..
Your running hot problem is probably unrelated to your carb issues (unless you are running REALLY lean). Could be cooling system, timing/vacuum advance, sticky T-stat or a host of other issues...also check your bottom radiator hose for collapsing...it should have a spring in it to prevent this and some aftermarket Bubba hoses do not.
If your carb was sucking air I would think the mixture would be lean....fixing the leaks may have enrichened the idle mixture even more... I'd be looking hard for incorrect parts bad needle/valve seat, sinking floats or float height/drop levels way off... Bear in mind these WCFBs HAVE to have the floats EXACTLY centered in those small float bowls. Sticking to, or rubbing against, the sides of the carb body will make things squirrley as hell..
Your running hot problem is probably unrelated to your carb issues (unless you are running REALLY lean). Could be cooling system, timing/vacuum advance, sticky T-stat or a host of other issues...also check your bottom radiator hose for collapsing...it should have a spring in it to prevent this and some aftermarket Bubba hoses do not.
Last edited by Frankie the Fink; 10-11-2014 at 07:33 AM.
#28
Instructor
Thread Starter
Here is a PDF file of the fix actually installed in one of my carburetors (the red circled bushing)....this COULD be your turning/stalling problem but do NOT confuse it with your over rich running condition. They are most likely two different things....
Again, I'd check fuel pressure, float levels and ensure the floats are exactly centered in the bowls.
This manual will guide you through the process: http://handbook2.com/c/carter-wcfb-service-manual-e4402
Again, I'd check fuel pressure, float levels and ensure the floats are exactly centered in the bowls.
This manual will guide you through the process: http://handbook2.com/c/carter-wcfb-service-manual-e4402
I appreciate all the advice and support everyone has given me on this problem. This is a great resource.
#29
I have a 1960, 283 bored to 302, 68 302 heads, Crane cam (sorry can't give too many specs on this but like early Duntov), and 2 Carter wcfb's. The carbs have given me months of fits. The car runs rich and no one, including several mechanics, can get it to lean down. The car hadn't run in 40 years when I got it, but PO's had tinkered with it so I have no idea how it started it's life. But it came with the 2x4's and I got it running with them, but it ran rich. I got generic rebuilding kits and went over them and reinstalled. Still ran rich. Finally got the car on the road and took it to a local respected old car mechanic. He could not get them to lean down and thought they should be rebuilt. I sent them to a recommended rebuilder who did a thorough job on the carbs. They looked beautiful and the rebuilder bench tested them on his motor before sending them to me. Ran rich so I took it to another recommended mechanic who fiddled with everything from valve lash to timing to mixture. Ran rich. I contacted the carb rebuilders and sent them back. They went over them and found a little dirt in the back carb. I changed the filter, and cleaned everything possible and reinstalled. Car ran better, but still rich. Since then I've reset valves, played with timing, tried tuning the mixture and it still runs rich and has idle problems when I run it on the road then come to an idle. I do notice that if I blip the throttle on the rear carb it sounds different than when I do this with just the front carb. When I gas just the front the engine sounds better. It seems to take the gas with less effort. Sorry I can't be more descriptive as this is a sound issue. When I gas the rear carb it is has a more restricted sound and feel, not pronounced, but it's different. Help!!! I am at wits end on this.
Last edited by PAmotorman; 10-13-2014 at 04:55 PM.
#30
Team Owner
I don't know that he ever said he had 270hp carbs but perhaps.
One other thing that may help is to run NGK-XR4 plugs....they are a slight heat range hotter than the ACR45S and what I run in my dual quad '61 and split window coupe...
One other thing that may help is to run NGK-XR4 plugs....they are a slight heat range hotter than the ACR45S and what I run in my dual quad '61 and split window coupe...
#32
back in the day chevy supplied a stainless pieces to block the heat riser crossover in the intake manifold to make the 2X4 setup run better by reducing the exhaust heat to the aluminum intake manifold . they were in a package in the glove box of the corvettes. never saw them supplied with the full size cars.
#34
that is there to quiet the exhaust as blocking the heat riser crossover makes the exhaust louder. back in the day we used to used copper pennies hammered into the heat risers of flat head fords to make the dual exhaust louder
#35
Drifting
I was speaking to Bob Kunz (via email) seems like a great guy and very helpful as well. He put me on to Smith and Co. also a great bunch of people and extremely helpful with WCFB parts ... could not do enough for me ... quick email reply ... and above all excellent prices, spoke to Lana (via email), can't praise her can do attitude enough. Apparently Chuck gets new throttles arms for wcfbs made especially and that is where Bob gets his parts from. Tell you what, you guys have some great niche operators over in the US.
Lana Smith
Chuck Smith
Smith & Company
29081 Fruitvale Lane
Valley Center, CA 92082
760-749-5755
http://www.chucksmithandco.com
Fax 760-749-5355
olsmoothie@sbcglobal.net
Lana Smith
Chuck Smith
Smith & Company
29081 Fruitvale Lane
Valley Center, CA 92082
760-749-5755
http://www.chucksmithandco.com
Fax 760-749-5355
olsmoothie@sbcglobal.net
Last edited by mickatbp; 11-06-2014 at 05:21 PM.
#36
Team Owner
Bob & Rob Kunz, and Ron & Tim at Daytona Parts are the only people that touch my carbs - although I've heard nothing but good about Chuck Smith's work as well...just haven't used his services myself..
#37
Team Owner
Member Since: Mar 2003
Location: Greenville, Indiana
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#38
Drifting
Frank, just stating that they get their replacement shafts from Smith and Co.