The Stovebolt Site Forums The Shop Area Engine Shop Holley Weber carbs - questions

Hi Stovebolters!

I have never been much of a carb guy. I've never tried anything beyond the simple kits you can get from any parts store. My father on the other hand is a carb-maniac. He will take 4 or 5 apart and get some jets and stuff from gawd knows where and start drillin' and tappin' and bendin' and cussin' and buy the time he's done he'll have a carb that works perfect for whatever he had in mind.

I said that to set up for this:

I'm getting one of those old Holley Weber carbs that were used on the old Pintos out of the local wrecking yard, and I am going to use a bunch of info I found online to try to build a super carb for my 250 inline. (I can always fall back on the monojet if I need to, since it is a new remanufactured a got a few weeks ago.) I'll keep ya posted on how things go.

Bob

Good for you, that is about how I figured out how to work on carbs. I started with a lawnmower, then went to a Rochester 2GC, then a Quadrajet, then a Rochester B, and now I can synchronise and tweak the 4 Keihins on my motorcycle without worry.

Carburators are pretty straightforward once you figure out what all the passages and jets do.

I talked to Tom Langdon about the adapter he sells, and ordered one. The guy at the wrecking yard said he will get me a carb for sure at $50, but said to get the adapter first so we are absolutely sure to get the right carb. It's a model 5200 I need, but the guy at the yard is just very cautious. Anyway, I'm looking forward to this experiment. According to some articles I read there are lots of ways to jet and adjust these carbs so you get exactly what you want. Plus Tom Langdon said mpg and drivability are far better than with the Monojet.
Bob

Update
I'm picking my carb up today, and hope to install it over Thursday and Friday.
:rolleyes:
Bob

I took the Holley/Weber apart and cleaned everything. It all looked good except for some marks on the float I didn't like. I put it in a big jar of water, and it did not sink or leak, so I guess it's okay. I also made an air cleaner out of two mid 80's hub caps, and the stock filter. Now I have a cool weber air cleaner with a Chevy Bow Tie emblem. It will be Wednesday of next week before I get a chance to actually try the carb.

Progress not Perfection!
Bob

Now, there is an idea. I like that. I'd love to see pictures of that... if possible...

-W

Someday soon I will post a bunch of pictures of when I first got my truck, and the progress I have made. I have a bunch, but I keep forgetting to get them developed. I am going to get a digital camera soon since the prices are down to reasonable!
Bob

Test hollow floats by dunking them in hot water. If they have cracks or holes, the heated air will generate a stream of bubbles from the flaw.

Joe

It is 4:49 PST, 2/4, and within the hour we shall see if the motor goes VROOM-VROOM, or hach-hach-spppp!

It started right up and ran good; I mean REAL GOOD. Then I screwed around and lost an adjustment screw. I'll have to go to the wrecking yard tomorrow and get another. I can't wait to start posting some pics. you guys are gonna luv this set-up
Bob

Are you expecting some performance gains form swaping out the old carb?

I like the hubcap to air cleaner idea!

Tab; Yes, you gain performance, mileage, and drivability, or so they say. I'm going right now to get the screw I lost, so I can find out if it's true!
Bob

Keep us posted Fleet! This sounds like a neat conversion.

The carb i bought from the wrecking yard turned out to be junk. I only paid $25 for it, so I ordered one from Langdon's, and I'll keep these 2 wrecking yard reprobates for parts!

Never Say Die :mad:
Bob

Yeah, never throw away a carb, ya never know when you will need a part. The 'b' in my truck is sporting a few parts from the junk QJet I had for a parts carb for the Buick 225 in my jeep. I have a box full of Holley type 94 2bbls for my sixpack manifold project and I got three good ones out of four.

Thanks for the posts Fleet. I'm still on the fence about the progressive 2 BBL, so good (or bad) reports will help sway my opinion. No offense to the vendor, but I'd rather get the reports from folks who don't make money from it .

I am going to be running this carb on a mildly built 250. I have heard flow ratings from 280 to 330 for these carbs, and that is not surprising. Tom langdon told me there are, without exagerration, about 500 different versions. I personally saw at least 4 versions at the local wrecking yard. They had 5 carbs and only two were the same. They were used on everything from really small 4 cylinders up to some pretty good size V6 engines like the 231 inch motors in the old Skyhawks. The long and the short of it is you can jet them for many different applications, and they are supposed to be an excellent choice for a stock or mildly built 230, 250, or 235. They are not big enough for a 292, or a radically built motor.

My only previous personal experience was a friend had one on a Skyhawk and I had one on a Dodge D50 truck. I was very favorably impressed. that's why I want to get one working right on my current project.

I'll Keep ya posted. On Monday 2/16 I should be taking a shot at this again with the one I ordered from Langdon's.
Bob

Okay here's the deal! IT runs LIKE A SCAULDED CAT!!!! Or, as my dear old dad would say, "It goes like stink"
The bottom end is so strong that when I accidently took off in second gear I really didn't realize it until I reached for the gear lever. The top end is great. Cruising at 80 mph I can step on the gas and accellerate even though I have 411 butt gears. (Remember, this is a 250, not a 235.)

This is the wrecking yard carb I'm using. I finally got it working GOOD! I ordered one from Langdon, but I had to postpone for a week, so it will be here the middle of next week. Then I'll have two which means when I do my rebuild I will use stock manifolds to build a dual carb - dual exhaust set-up that utilizes the stock heat risers and looks way cool retro! !

HEEE HAW!
Bob

How about posting the jet sizes used along with the mods (if any) you made .

Remember , the local Pick-A-Part yard will always have dozens of these carbies lying around .

Usually less than $20.00 each .

Fleet: Just want to confirm, these Holly-Webbers bolted up without modification to the carb base or(stock) Intake manifold? If so, I'm there! Oh and to paraphrase Nate: Cough up the specs, Dude!
I stink at carb work so any help would be great!
Dave

I bought two of these carbs out of the wrecking yard. One for $25 and one for $5. The one I have coming from Langdon's Stovebolt is one that Tom rebuilt. I paid $65 plus $10 shipping.

The jets were a 132 on the primary side and a 140 on the secondary side. I put the 140 on the primary side, and took a jet from the $5 carb and ran a 1/16 drill bit through it. I also drilled out the secondary idle circuits and idle jets to 1/16.

I don't quite get it with the jet sizes because the carb I am using had a 132 and a 140 with the 132 being the smaller one. The other carb had bigger numbers but smaller jets, and the jet with the bigger number was the smaller jet! There were many variations of this carb so there must also be some variation in the way jets are numbered. I read one article that said you can drill and tap the holes with a 1/4 by 20 tap and use regular Holley jets. I may try that just for kicks and grins.

Bob

Pal, you need a $15 adapter from Langdon's Stovebolt. And you have to fabricate a linkage set up or buy one from Tom Langdon. I think the linkage is $30. Even if you buy the linkage your still looking at a conversion that costs less than a remanufactured monojet, and the Weber is seriously superior to the monojet.
Good Luck,
Bob

We put a pair of them on my friend's 200+ hp 261. They work great. Only problem is with the manifold, which is an Offy for dual one's. The ports aren't big enough for the 2 bbl carb to flow properly.

He has a Saginaw 4 speed with 3.90 gears, said he was doing burnouts with a friend the other day. About halfway through 3rd gear the tires were still smoking, and his friend about wet his pants, so he shut it down.
[img]http://www.myoldtruck.com/forums/themes/tabmenu/smilies/3gears.gif[/img]

Hey Fred, Your buddy's 261 sounds like my buddy's 261. His is in a 52 sedan and runs like a rocket. He's using a 390 Holley on a set-up he fabbed himself.

Now here's food for thought. Those offy manifolds do not have that big square box built into them like a stock manifold. I'm talking about the box the carb sits on and the heat rising comes up against. That is one of the reasons I am going to fab my own set-up. I think the factory had a good basic design that works well with one carb. So, double it up and it ought to work well with two carbs. Just take the box and heat riser with exaust outlet, and put one up front between 1 and 2 cylinders and put one at the rear between 5 and six, and then use some of the cut away tube to fill in the space between.

The King of Mickey Mouse,
Bob

Ok Fleetside, you win! This conversion just got #1 priority in my new garage (estimate 3 months). I'll start putting together the cash. Can't wait to see me SSgts face when we go to lunch afterward..... :o
I already have the fresh 250 (.30 over) and the sm420..... Can we say Torque?

Well - well - well; my other carb came from Langdon's much earlier than I anticipated. It came in a factory Holley box, so I guess I was wrong about Tom rebuilding it. It is a new Holley Reman. It works great right out of the box. I did zero mods, just bolted her on and away we went. I'll hook up the water heated automatic choke tomorrow. That'll be a nice addition!

If you read down through this whole thread one must conlude that, like grand-pappy said; "Chase a rooster 'round the barn enough times, your bound to catch 'im!

Bob

Sounds like that Weber conversion is working OK! Is it the progressive-linkage 2-barrel that works like half a 4-barrel? I've worked with them a long time ago, but nothing recently. It seems it might be a little small for an engine close to 4 liters in displacement, if you're doing much high-speed operation.

Here's a suggestion for another approach. We're required to run a carb on the round track with no more than 350 CFM airflow, and Holley makes one for this application. It's a 2-barrel like the Blue Oval V-8's ran in the 60's and 70's, with smaller venturis and throttle plates. The Holley List # is 7448. JEGS sells them, in either manual or automatic-choke versions, I believe, and it will take a Chevy 350 to 6,000 RPM or so before it starts to strangle off the airflow. With a little adapting, it would be ideal for a hi-rev 292, and wouldn't over-carburate a 235 or 250. There are lots of jets, power valves, and other parts to tailor the mixture to your particular application.
Jerry

"There are lots of jets, power valves, and other parts to tailor the mixture to your particular application"

The same is true of the Holley / Weber 5200. you can make it flow to 330 cfm, and it only uses half at low speed. The way I plan on building my motor it ought to be a great carb. With the motor in its current stock / worn out form it is actually a little to much carb as it bogs if you slam it open at low speed.

Someday I may build a radical 292 and at that point I'll use two webers. That is no better than a 390 holley, but let's face it, dual carbs get more ooo's and awes!
Bob

AAhhh Yes! It's a beautiful thing!
I just hooked up the water heated automatic choke and my 34 year old stovebolt fired up with a bump of the key and idled cold. A little rough until the oil pressure built up, then it smoothed out and purred nicely on a stone cold motor!


Bob

does langdon have a website?

I think it's www.stoveboltengineco.com . It's on the Links page, you can check there to make sure.

Yeppers, that's the place. They really friendly in answering the "Dummy" questions I had to ask too.
Fleet: great topic!

Fleetside, I've been thinking about this conversion myself, for my daily driver '64 Biscayne. One of my concerns was height/hood clearence. I don't have quite as much room as you truck guys! Anyways, how much taller is the holley/weber with the adapter vs your stock monojet/rochester b? maybe measured from the manifold to the surface the air cleaner mounts on?

Thanks,

MayDay,
I'm not sure about that. The Weber is shorter than the Monojet, but the adapter is pretty tall. I'll get you an exact measurement this weekend!
Bob

So a 70's M!@#$%g V6 would be a good place to start,even jet-wise??

This is a cheap carb conversion I did on the stock 261 in our 51 Chevy truck.The carb is a Holley 2300 off a 68 IHC scout with the 266 V-8.I removed the top of the stock intake where the old one barrel to match the Holley,made an adapter from inch thick phenolic material, bored 2 holes to match the new carb throttles, tapped and drilled a few holes to secure the adapter to the intake manifold, fabricated a linkage.Nothing fancy,did it all with common tools.The Holley flows about 220 cfm when rated like a 4bbl(310 cfm rated as a 2bbl)It has far better response than the single barrel with slightly better fuel mileage.
Fleetside, who told you a Holley - Weber can flow 330 CFM??Rated like a 4bbl, they flow 200 cfm according to Holley specifications.
Holley on a 261

Flow rating on the Holley Weber is in fact 200 cfm if rated like a 4 barrell and 270 rated like a 2 barrell. That's according to Tom Langdon. The 330 figure came from god knows who or where.

The conversion sure does work good on my 250, I'll say that for sure!

Now about height; it is 9 1/2 inches from the tube part of the manifold to the top of my home made air filter. The filter is about 3 inches. I do not think there would be a problem doing this conversion to the Biscayne.
Bob

Thanks for the info. Any chance of some pictures?
I'd like to see that homemade air cleaner!

Everybody flips over my air cleaner. When people see it on the truck I ask if it looks familiar, and they always say no, and in some way indicate that they do like it. When I tell them what it is made out of they always smile and say something like "OH, okay, I get it," and then chuckle.

The one I have now is actually a little rough because I did it in a hurry. When I go through my engine in May I am going to make a new top (I have just one of those hub caps left.) At that time I will take tons of pictures and I PROMISE to post the best of the lot.
Bob

O-O-O-O-O-O Rock-On!
It just keeps gettin' mo-betta!
I've run the Holley/Weber long enough that I know it works really well, and I do-o-o-o Luv ta tinker, so today when I was suppose to be mowing the lawn I took the carb apart, changed the setting on the accelerator pump and put in some big ole main jets from an older carb. I put a 140 on the primary side and one that I ran a 1/16" drill bit through on the secondary side. And yep indeedey -- 3600 pounds of yellow and primer antique scoots down the hiway real good, and pulls hills like a Pick Up Truck ought to. Now if my 16 mpg does get lost in the shuffle I'll be in great shape.

I think this set up is going to work super good with my rebuild. Funny thing though, I ended up advancing the timing a bit to make everything work well both at an idle and under hard acceleration.
Lots of fun today :p
Bob