Rebuilding carburetors at home

[eldubb440]

wow, is that why every Holley I ever ran turned out to be a pos?

 

[RemCharger]

Excellent point. Thank you.
There are no vacuum leaks, no fuel leaks but it runs rough and a bit rich too.

There can be vacuum, and fuel leaks internally from the warped main body AND metering block.. which can't be visually noticed outside

wow, is that why every Holley I ever ran tuned out to be a pos?

Could be.. often the culprit is someone did not use the right PV, or some issue thereof, which does not allow the metering block to sit flush to the body. And then cranked the bowl screws down to " tighten er up!"

 

[Kern Dog]

Almost every Holley that I've had has been excellent. These cars can sit for weeks and start up almost as fast as a new car.

There can be vacuum, and fuel leaks internally from the warped main body AND metering block.. which can't be visually noticed outside

I agree, Hawk's suggestion may be correct. I just forgot to check that. I thought that maybe I had a gasket flipped and was maybe blocking a passage.
I first had the carb partially apart to replace a couple of gaskets. It didn't puke gas after that but did run rough. It smoked black and smelled really rich, leading me to believe that there are internal leaks of some sort. I don't have a spare air/fuel meter to confirm but the smell and blackish smoke sure tells me it is too rich.

 

[Kern Dog]

I replaced the metering block with a known good spare and the car idles much better and isn't smoking from running rich.
I don't know what was wrong with the other metering block. All the passages were clear. The one in there now has new jets and a new power valve. It doesn't rev up as clean as it should so there is still something amiss inside. The spark plugs are 17 years old. The plug wires are older than that. Remember, this car was pieced together starting in 2007 using a lot of junkyard parts. I did set the timing to 10 degrees BTDC since it has a MP reproduction 340 cam. Back when I first got it running, the dude ran pretty strong.
At least now it will start and run. I can drive it and it won't buck and belch smoke.

 

[MarPar]

 

[RJRENTON]

View attachment 1699600

10X.......btw.....in a ' 63 Plymouth Valiant with a stroked 750 inch BB, 727B trans, 250 hp nitrous system, 12.0 pistons, Marvel-Shebler carbs, 7-1/2" 2.73 rear gear and 7.50 x 13" tires....three questions: what oil to use, best cam for street use and most importantly, what's the best wax to use on a bbq black rattle can flat black paint? My buddy said use Rustolium...he also said use BERU spark plugs because they're the best ...just curious.....
BOB RENTON

 

[MarPar]

10X.......btw.....in a ' 63 Plymouth Valiant with a stroked 750 inch BB, 727B trans, 250 hp nitrous system, 12.0 pistons, Marvel-Shebler carbs, 7-1/2" 2.73 rear gear and 7.50 x 13" tires....three questions: what oil to use, best cam for street use--for these first two, whatever @dvw says--and most importantly, what's the best wax to use on a bbq black rattle can flat black paint?--bacon grease My buddy said use Rustolium...he also said use BERU spark plugs because they're the best ...just curious.....
BOB RENTON

Answers above in red

 

[Kern Dog]

Mopars never came with a 2.73 axle gear. Chevrolets did though.

 

[Photon440]

Perhaps he meant 2.76?

 

[493 Mike]

10X.......btw.....in a ' 63 Plymouth Valiant with a stroked 750 inch BB, 727B trans, 250 hp nitrous system, 12.0 pistons, Marvel-Shebler carbs, 7-1/2" 2.73 rear gear and 7.50 x 13" tires....three questions: what oil to use, best cam for street use and most importantly, what's the best wax to use on a bbq black rattle can flat black paint? My buddy said use Rustolium...he also said use BERU spark plugs because they're the best ...just curious.....
BOB RENTON

Are those Marvel-Shebler carbs off a tractor? I rebuilt several for tractor restorer buddies. How many are needed to feed 750 Cu In?
Mike

 

[RJRENTON]

Are those Marvel-Shebler carbs off a tractor? I rebuilt several for tractor restorer buddies. How many are needed to feed 750 Cu In?
Mike

At least 8 but possibly 10, but should be an even number.....tight fit on a tunnel ram manifold....but great street performance.....a little touchy to get them all synced...?...

 

[RemCharger]

Are those Marvel-Shebler carbs off a tractor? I rebuilt several for tractor restorer buddies. How many are needed to feed 750 Cu In?
Mike

My buddies 750 ci Hemi has 8 beer can size holes feeding it.

 

[RJRENTON]

My buddies 750 ci Hemi has 8 beer can size holes feeding it.

But what was the most important consideration.....was it a full body laugher, a wheat, an ale.....but hopefully not a tight......how about FAT TIRE?......and only one can?
BOB RENTON

 

[RemCharger]

But what was the most important consideration.....was it a full body laugher, a wheat, an ale.....but hopefully not a tight......how about FAT TIRE?......and only one can?
BOB RENTON

 

[Photon440]

But what was the most important consideration.....was it a full body laugher, a wheat, an ale.....but hopefully not a tight......how about FAT TIRE?......and only one can?
BOB RENTON

Always a full body laugher, Bob.

 

[1STMP]

On the transfer tube....
Install the "O" rings on each
end and apply a thin coat of
vasoline on them. Insert one
end into the metering block
first, then the other into the
carb. This will help with
positioning the pump arm.
Push the tube ends in slowly
so as not to nick the "O"
rings.
Also check metering block
gaskets so no holes are
covered up.

 

[Kern Dog]

I replaced the metering block with a known good spare and the car idles much better and isn't smoking from running rich.
I don't know what was wrong with the other metering block. All the passages were clear. The one in there now has new jets and a new power valve. It doesn't rev up as clean as it should so there is still something amiss inside. The spark plugs are 17 years old. The plug wires are older than that. Remember, this car was pieced together starting in 2007 using a lot of junkyard parts. I did set the timing to 10 degrees BTDC since it has a MP reproduction 340 cam. Back when I first got it running, the dude ran pretty strong.
At least now it will start and run. I can drive it and it won't buck and belch smoke.

I pulled the spark plugs to do a compression check. All the plugs were sooty black. Most of the cylinders showed 133-140 psi. The lowest was 130. That is a pretty close spread.
New plugs, gapped at .035....new cap and rotor. It idles like new, revs clean and sounds great. Now to do a road test!

 

[gtx6970]

It has been awhile since I did a full rebuild on a carburetor. I’ve changed jets, power valves, metering blocks, accelerometer pump cams and such but it has been years since I did a full tear down.
I have these cars out back:

View attachment 1585747



















Ive been advised to try a Sonic cleaner and simple Green on my next one. Not as harsh of plated surfaces

 

[RJRENTON]

It has been awhile since I did a full rebuild on a carburetor. I’ve changed jets, power valves, metering blocks, accelerometer pump cams and such but it has been years since I did a full tear down.
I have these cars out back:

View attachment 1585747


View attachment 1585749

They both have mild 360s with the most basic of all Holley carburetors, the 600 4 barrel manual choke, list 1850.
Sort of like this one:

View attachment 1585755

I bought these rebuild kits:

View attachment 1585746

Since it has been awhile, are there any tips or short cuts anyone has to offer?
I'm going to get a can of that Chemtool carb solvent to dunk the parts into and I have a few cans of carb cleaner.
I thought maybe I've missed out on some tips since the last time I did this.

great looking white porch railing.....what does it have to do with rebuilding carbs?
BOB RENTON

 

[Photon440]

great looking white porch railing.....what does it have to do with rebuilding carbs?
BOB RENTON

Did you even read what he had posted?