The Stovebolt Site Forums The Shop Area Engine Shop 1954 235 Rochester Carb

I just got a 51-3100 from California. Do I need a different jet size in the Carb since I live at 7150 feet in Taos NM. If so How many Jet sizes are available, and from Whom--Thanks Bill

The altitude means you'll need a leaner jet (because of the lower air density).

Is the engine all original or has somebody changed the carb to a later model? This was discussed about a month or so ago, but I believe the poster had a Carter carb. Jon (CarbKing) has jets in whatever size you need. I'd contact him. You might look inside your carb to see what jet is there first. Most of these I've seen lately have been 57 or 58 and one was a 59 size. In Taos you'll be getting only ethanol gas, yes? I know that's the case in Ruidoso. You may or may not need a slightly richer jet for that, so there will be a little see-saw thing there and Jon would be the ideal advisor...

Jon--do you advocate ethanol free gas in a rebuilt 1954 engine??Thanks Bill

Yes, I'm convinced ethanol free gas is better in any engine that was designed for it. Isn't easy to find now, though. Can you get it in Taos? As I said, there's none in Ruidoso and there certainly isn't a drop of it for sale around Dallas.

In a very recent post I showed three vials of ethanol gas. 2 had been unused for apx two months. They were the color of strong urine and burned more slowly with great amounts of black sooty smoke which reminded me of a wellhead fire. A tarry molasses looking sticky residue was left after burning. One vial was just out of the pump. It burned with less smoke and seemed to burn a bit more quickly with less leftover residue. Point being if you drive your vehicle infrequently, don't keep a lot of gas in it and don't expect it to start easily nor run very well. There is nobody anywhere who could convince me running ethanol gas which had aged for 2 months or more (as my test vials had) would not produce sooty exhaust and nasty deposits in a stovebolt or other similar engine. This crap is a ticking time bomb.

After the experiment of burning the 2 month old gas, I started searching for data. I found a short Road & Track article which sort of sums up what I thought. They said gas starts going bad in 30 days and exposure to air worsens the situation (even the air in your gas tank or can).

I've found more info and it all pretty much says the same thing. So what is the answer? A lot of people are convinced you should add Sta-Bil into gas immediately. I haven't used it, so I haven't made any decisions about it yet. Sta-Bil is about $50 a gallon. A gallon equals 128 ounces. 1 ounce of Sta-Bil per 2.5 gallons of fuel means if you have a 15 gallon tank, you will need to add 6 ounces of Sta-Bil per fill-up. This means your gallon will last you for about 21 fill-ups. This means $50/21 = about $2.40 extra cost per fill-up or a little over 16 cents a gallon extra so your gas doesn't turn to worse crap than it already is. Years ago when unleaded gas first appeared, there was a product you could add to gas which was supposed to solve the problem for vehicles/machinery not designed for unleaded gas. All it did was successfully transfer your money into somebody else's pocket.

Jon--The only ethanol free gas in Taos, is a mile from my house 90 Octane--Thank you Bill

That's convenient and good for you. I'd use it. Everything I've read tells me non-e gas should be ok for up to 5 or 6 months...a lot longer than 30 days.

Aside from aging, which the industry seems to have improved, the problems with using ethanol in old vehicles are two-fold. First is with the carburetor gaskets. If rebuilt with a modern kit, the gaskets are okay. Second is with exhaust valves, which get hotter with ethanol. A valve job with hardened exhaust valve seats takes care of that. I quit using Sta-bil a while back. As long as I burn a tank of fuel about 3 times a year it isn't needed.

Here is the image of the 3 vials of gasoline...the more or less clear one on the left is fresh out of the pump at the gas station. The other two are roughly 2 months old. One from the (new) gas tank on the pickup. One from a heavyweight plastic gas can used with the lawnmower.

http://i1154.photobucket.com/albums/p535/JonGoodman/MVC-727F.jpg