When restoring a typical NH type carburetor I am very happy to use a torch to heat the cast iron, breaking the corrosion bond thus releasing the brass parts. What I am not sure of is the opposite situation presented by a recently acquired Stromberg LF.
What is the best/safest way to get iron/steel corroded screws out of a brass/bronze body? I would hate to ruin this carburetor.
Also, what are the small and large venturi tubes made of? I hope not pot metal. Any advice on getting it apart safely?
Stan Howe has all the answers, he is the expert on these and OFs.
Wish Stan was my neighbor. So what about the heat question? makes me nervous.
Erich, if I was your neighbor your wife would call the cops because of all the junk in my yard that I think are valuable parts but she would think was junk.
However. When they are nasty or even half nasty like this one I bead blast them first to get the slots in the screws clean, see what is really there and get rid of the stench of old gas and bird crap.
I usually try the screws, a lot of them will come right out. A little heat may help. Then I dump it in my ultrasonic cleaner for an hour or so to clean the inner passages. Then with LF's I take the float, the float cover, the float cap, the choke parts I can use and throw the rest of it in a box of brass carbs that I might do some day but will probably be in my estate auction someday.
If you really want to rebuild it, you need to carefully remove the arm that goes from the throttle arm to the mixture adjustment. Then press down gently on the arm under knob and work it loose so you can turn the knob while holding the arm. Carefully turn it out. The arm will hit the choke intake and if it doesn't turn easily will break the shaft so HOLD the arm and work the adjustment screw out gradually. Some have a steel shaft, some have a brass shaft. The brass ones break off really easily and the steel ones wear the body of the carb so neither is really better. If you look really closely you will see that there is a tiny piece of rod that keys the knob to the shaft. If all the adjustment piece is good you don't need to remove that pin and unscrew the knob. Usually the spring is so rusty you need to remove the knob to replace the spring. You have to drill that pin out to unscrew the knob. If you drill it out it is easy to not get all of it and when you try to unscrew the knob it will break the shaft. I have extras. Some broken, some not.
Everything else is straightforward, take it apart, clean it up, look for wear, straighten bent, fix broken, put in a new needle and seat because the old one will most likely leak, put it all back together.
I have a manual somewhere for these but it is about adjustment, not repair, which is what most of these are.
If you don't have an Untrasonic cleaner go buy one. I pay 100-140 bucks for the little ones they use to clean brass for bullets. The Hornaday cleaners seem to work best for me, the Lyman brass goop is $25+ bucks for a big bottle, works a long time. Put a little citrus based cleaner in along with the brass cleaner. Make sure you get one with a year long warranty. Save the receipt because if you use it much the Chicoms have to replace it. I make them write on the receipt that it is in-store replacement guarantee for a year and then keep the receipt. Mine have lasted from three days to six months. You might have to find a new store and buy another one after they have replaced two or three of them. Sportsman's Warehouse here has the Lyman on sale for $110. My last one from there lasted 3 days of 2-3 hours a day of use. The Hornaday has lasted a month this time of almost constant use since I got back from Chickasha.
If you get on ebay you can find all sorts of Ultrasonics with better transducers, more features, etc. My experience, which is pretty limited with them is that about $300 will buy you a good one. I just cleaned a gun today that I have been going to do for years. Cleaning some things out of the house and shop today, ran across that gun, took it out and threw it in the goop, blew it dry and laid it in front of the furnace. Easy to get them pretty spiffy. Goop for the steel parts is different from the goop for the brass parts. I did a Victornox Swiss army knife, three Starrett thread gauges and the gun parts all at the same time.
I have two cleaners, a gallon and a half size for brass and a one liter for the steel. The goop doesn't seem to wear out, it just gets dirty, I just pour it in a clear plastic jug, let it set and pour off the clean goop, throw the rest, add water and a little more goop from the bottle and it works fine. I also put a cap full of Sea Foam cleaner in the brass one. I dunno if it really helps but I think it does.
After it is clean, blow the passages, you might need to bead blast it again, goop it again, etc., then polish the brass, powder coat the steel parts, put it together and it should be good to go.
Cool, I will get to spend some quality time with it later this week (wife going out of town). Will be taking lots of pictures. Thanks again.
Are you talking about the vibratory brass cartridge cleaners? I need one of those anyway. Wonder what breaks on them? is it the little electric motor?
No, Ultrasonic. Water based. All the vibrator type do is get crap in the passages to plug them.
I stand corrected. I just looked at the box the last one came in and it is an RCBS. It's lasted a couple weeks now running hours and hours a day. I've been working in the shop a lot trying to get caught up a little before warm weather gets here, probably ran it 5 hours steady today.
From my reloading days, it always seemed the RCBS products were a little more money, but better quality than many competing products?
So far, it is mostly apart with only 2 small screws busted. Dang corrosion. Very little wear on the shafts or seats/needles.
A lot of the time there is brand new brass under all that dirt and "patina" -- which is usually just dirt anyway.
I dunno about RCBS as I'm not much of a gun guy but this was the most expensive one they had and looked like it was better built and more features for only about $20 more. I still want one of the better small ones. My big one is good for bodies but I need a better small one. They are kind of a mess with all the water and all but they do a nice job on cleaning passages which is what most carbs need about as bad as anything. I run them through the cleaner, blow the passages, run them through the cleaner, blow the passages, run them through the cleaner again and they are usually shiny like new.
Well, I should start a new thread after I get all the photos loaded up. My "new" Stromber LF is done and on the car. I like it.
So where's the photos???????????
Pictures almost done. Will post them on the separate thread called "stromberg LF rebuild".
Stan -I hope my Breeze carb hasn't blown up your ultrasonic cleaner -I didn't think it was that dirty -Karl
Karl: No, but it's all clean and getting ready for a trip back to Oz.
I wish I'd have got yours done while Phil's was still here and I'd have had the one I got at Chickasha. I'd have had the only photo in the country of three Breeze carbs in one shop. All clean and shiny.
Stan thats good but don't send it to Oz
Australia is three hours away from New Zealand over the Tasman Sea -Karl
That's why I write the addresses down instead of relying on bad memory. I do have one here from New Zealand but it's for a 1924 Dodge, not a Hupmobile. It's a Stromberg OD-1.
I should post an after photo to go with the above photo of how it looked when I got it.
I have been driving around with it and like it a lot. Notable improvement and smoothness over the NH. More power up hills too (at least less power fade).