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Carbs rebuilt
- Thread starter don62
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Hap Waldrop
Yoda
Offline
Alec, I don't like counting flats, I think it's not a very acurate way of doing things, instead I measre jet heights with dial caliper, I think it a truer way of doing things, I seen plenty of example how 7 flat on carb when compared to another carb don't net the same results.
Rob, first off, I first clean the dashpots, this is really a multi step process, if really dirty, gummy, greased up, I dunk them in a carb cleaning bucket for a day, then solvent clean them in the parts washer, then palstci media blasted them, then clean them with scalding hot water and dish soap.
Cleaning the aluminum as good as you can get it, is the first step to getting a good polish, when you polish all the grime in the pores of the metal will come back to the surface. I then use a handle I made form 1/2 nut and bolt to hold the dashpot, also double as a way to chuck it up in a lathe ot drill press, where I then start my sanding process, if a dash pot is stratched up, I may start of with 100 grit and sand it as it turns at low speed, then move on to 180 grit, then to burgundy scotchbrite, then to 400 grit and wet sand it. I'll skip the rougher sandpapers if the dash pots are in pretty decent shape and not all stratched up. After all sanding is done, I clean it agin in scalding hot water and soap, now I ready to polish. I use the whit rouge, and a polishing pad mounted on a bench grinder, the secret here is not to force the piece hard into the buffer pad or you'll just end up slaming the dashpot on the grund as you lose your handle on it, light contact is all you need, It norammly take about 5 minute to get the first result I'm looking for, then I hot water and soap wash them last time, then go back to bench poliser one last time for about another 5 minutes, then buff by hand with a realy soft, clean cloth like a micro polish cloth, diaper cloth etc., then I clen the inside off one last time with the burgundy stotchbrite, blow everthing down with air, and well you see the results, the polishing wheel is the key to getting a mirror polish, the more you polish the shinier it will get, I seen people with way too much time on their hands and only one set of carbs to worry about ( at any given time I'm doing 2-3 sets) get even more shiney results.
Rob, first off, I first clean the dashpots, this is really a multi step process, if really dirty, gummy, greased up, I dunk them in a carb cleaning bucket for a day, then solvent clean them in the parts washer, then palstci media blasted them, then clean them with scalding hot water and dish soap.
Cleaning the aluminum as good as you can get it, is the first step to getting a good polish, when you polish all the grime in the pores of the metal will come back to the surface. I then use a handle I made form 1/2 nut and bolt to hold the dashpot, also double as a way to chuck it up in a lathe ot drill press, where I then start my sanding process, if a dash pot is stratched up, I may start of with 100 grit and sand it as it turns at low speed, then move on to 180 grit, then to burgundy scotchbrite, then to 400 grit and wet sand it. I'll skip the rougher sandpapers if the dash pots are in pretty decent shape and not all stratched up. After all sanding is done, I clean it agin in scalding hot water and soap, now I ready to polish. I use the whit rouge, and a polishing pad mounted on a bench grinder, the secret here is not to force the piece hard into the buffer pad or you'll just end up slaming the dashpot on the grund as you lose your handle on it, light contact is all you need, It norammly take about 5 minute to get the first result I'm looking for, then I hot water and soap wash them last time, then go back to bench poliser one last time for about another 5 minutes, then buff by hand with a realy soft, clean cloth like a micro polish cloth, diaper cloth etc., then I clen the inside off one last time with the burgundy stotchbrite, blow everthing down with air, and well you see the results, the polishing wheel is the key to getting a mirror polish, the more you polish the shinier it will get, I seen people with way too much time on their hands and only one set of carbs to worry about ( at any given time I'm doing 2-3 sets) get even more shiney results.
Hap Waldrop
Yoda
Offline
As for a as needle selection and jet hieght, read my above post, most of my customer just bolt thier cars on and don't even touch the jet setting. All HS4 jets are the same except for being left and rights. Oh get your parts from Joe Curto, he's forgot more about these carbs than the rest of us will ever know, he's who taught me stock carbs.
Hello Hap,
I agree that a caliper is more accurate, but counting flats or turns is also a good method. (after all that is the principle of a micrometer, basically counting turns or part turns of a thread).
I think that where the variations can come from is setting the jet tube to the full up position, usually by eye.
What you say about people just fitting your carburettors is how it should be, they are precision instruments and the manufacturer went to a lot of trouble to get the settings correct. I haven't used S.U.'s in many years and run a Lucas fuel injected Triumph saloon( sedan). The metering unit for these engines can also be bench set and as long as the rest of the engine is in good condition and tuned correctly the metering unit will be right straight off.
Alec
I agree that a caliper is more accurate, but counting flats or turns is also a good method. (after all that is the principle of a micrometer, basically counting turns or part turns of a thread).
I think that where the variations can come from is setting the jet tube to the full up position, usually by eye.
What you say about people just fitting your carburettors is how it should be, they are precision instruments and the manufacturer went to a lot of trouble to get the settings correct. I haven't used S.U.'s in many years and run a Lucas fuel injected Triumph saloon( sedan). The metering unit for these engines can also be bench set and as long as the rest of the engine is in good condition and tuned correctly the metering unit will be right straight off.
Alec