More Stromberg questions! My '53 Special has turned two of the exhaust clamps slightly blue...my exhaust guy said that's not right . The plugs seem to be burning well...and it seems to be running well. It did have an overheating problem, and a fuel pump problem that have both been solved...anyway, is there a way to jet this thing up slightly? It doesn't have typical looking carb jets and they have those lead gaskets...Do jets exist for this thing? Just exploring all avenues in case I want to try some things with it...thanks again! Aaron
Virtually all parts for the Stromberg aerotype carbs are available. Some are more expensive than others. Jets have a "double D" head; and require a special wrench. If one does not have the special wrench; one may be made. To make the special wrench: (A) acquire a piece of steel bar just slightly less is O.D. than the I.D. of the passage holding the jet (there are three different diameters used). A bolt may be used (grind off the threads) if a bar cannot be obtained. (B) mill a slot in one end of the bar (a hacksaw/file may be used if one does not have a mill). (C) Drill a hole in the other end of the bar and insert a smaller rod for a "tee" handle (this operation not necessary if one uses a bolt, as the hex end of the bolt may be used). You now have a special wrench. Jon.
I need some jets! Carbking, After a 100 mile round trip in the car, the plugs have some deposits on them, and the insulators seem like they have strange slots in them...anyway, from personal experience it seems like the plug is getting hot. I'm going to try a few things--jetting a few stages richer is one...I'd like to buy the jets from you, if possible! Since I don't want to pull the jets before getting jets because of those lead gaskets...do you know what is stock jetting on an Aerotype 7-90B? I'd like to try about 2 steps richer to see if that helps. If you have any other suggestions, I'd appreciate it! Thanks! Aaron
Great...I'll call your shop later in the afternoon...I'm thinking probably a set of .049s will do the trick, but we'll see. Thanks!
OK, change of plans...I realized the new plugs that came in the trunk when I bought the car that I put in about 500-1000 miles ago were J18YC Champions (aka real hot). I replaced them with some AC R45 plugs...so I'm going to hold off on the jet change til I see how these guys fire...I did get a homemade jet wrench going, so I should be all set if it needs a little more jet...but I'm guessing that super hot plug was part of the problem....glad I caught it!
Aaron - assuming the engine is basically stock, then the stock jets should work well with gasoline. If you are trying to run E10, it MAY be necessary to rejet slightly. If you are trying to run E15, a jetting change will be necessary. With the E-15, both idle jets and main metering jets will need replacing. Jon.
Hey Jon, It's all E10 in my area. I'm going to run the car for a few hundred miles with the new plugs and check them out...I made a jet wrench for my carb, so a jet change shouldn't be a problem at all when and if it's necessary. The idle is adjustable without having to go very far out, so I think I'm OK with that. Thanks for all your help! I'll call you if I need to step up the jets.
Hey again Jon, Well, after about 100 or so miles with my new plugs, I think the car's lean with the .047 jets, because my plugs were very white, like they haven't been in an engine, except for a flat black ring around the base of the plug. Soooo, I got a .049 drill and drilled them out and drove it about 15 miles...a touch better, but still white. (I've drilled jets before sucessfully, and I have two pairs of .047s). I'm thinking I'll need to go to a .051 or .052 to make it burn correctly. Is this strange to need to jet up that much? The car seems to run well, and I can set the idle mixture screws well within parameters. Could today's gas cause that much of a change in jetting? I've fixed any vacuum leaks I could find (minor ones, mainly in the windshield wiper system). On my other old cars, the plugs burn gray to tan...just wondering out loud...thanks for any wisdom! Aaron
Aaron - before going larger than 0.002, I would suggest going over everything again: (A) if you don't have a vacuum meter, get one, and check vacuum at idle (B) check timing, etc. (C) check fuel pump pressure and capacity (D) check fuel valve in carb, if double ball type - replace it Typically, E-10 will not require more than 0.002. My guess is something else is causing the problem. Jon.
Well, I adjusted the timing to get vacuum from 17 in. to 18.75 or so inches at idle. The gauge had only a very slight quiver, but all cars I've tested had that on my gauge. The plugs, after about 8 miles of driving, have turned more flat black around the base, but the insulator is still whit...I think more driving may show that it is close on tune...I don't want to go any richer because the base of the plug is getting blacker...I'll keep you updated! Thanks for your help--oh yeah, the float needle in the carb is a viton tipped needle. If results are inconclusive, I will tee a fuel pressure gauge in while I'm driving...
Well, another 25 miles down the road, and the plugs are now what I expect... (at least the one I pulled). Tan insulator, even all the way around. So, .049 jets, 18.75 inches of vacuum, R45 AC plugs gapped at .028 seems to be a good starting point for anyone with a '53 Special. Carbking, thanks for your help. I've found that you are pretty much one of the only men on the internet who knows Strombergs in and out! Hopefully, the car will hold it's tune in the summer when it gets warmer out, but I still have a set of .047s if it gets too rich!
