Needle & Seat - Now with some real data!!
- Thread starter 29 Tudor
- Start date
29 Tudor
Senior Member
Here's the latest.....
Rebuilt carb and timing set correctly and the car runs fine... until the crummy gas we get now starts to boil in the carburetor. When cool, the car runs great. If I have to sit in traffic for a while, it runs poorly until the carb gets filled with cool(er) fuel. I stopped at the grocery store with the wife and shut her down and opened the hood. I could actually feel the fuel boiling in the carb. (It was 86 degrees outside, here in Central Florida) The Motometer was below the bottom and the fuel line and carb were cool enough to hold my hand on but there was no doubt the fuel was boiling!
I suspect I will just have to live with this although I am going to try to fabricate an aluminum shield behind the carb to see if that will help a little.
Overall the car is quite usable now but I sure wish the government would get out of the gasoline business!!
Rebuilt carb and timing set correctly and the car runs fine... until the crummy gas we get now starts to boil in the carburetor. When cool, the car runs great. If I have to sit in traffic for a while, it runs poorly until the carb gets filled with cool(er) fuel. I stopped at the grocery store with the wife and shut her down and opened the hood. I could actually feel the fuel boiling in the carb. (It was 86 degrees outside, here in Central Florida) The Motometer was below the bottom and the fuel line and carb were cool enough to hold my hand on but there was no doubt the fuel was boiling!
I suspect I will just have to live with this although I am going to try to fabricate an aluminum shield behind the carb to see if that will help a little.
Overall the car is quite usable now but I sure wish the government would get out of the gasoline business!!
modela@aol.com
Well-known member
If you tried everything else by now, it sounds like it couldn't hurt to try a shotglass or two per gas fill up of Marvel Mystery Oil mixed in with the gas. It may help with the gas boiling of the gasahol in the carb.
If it does not help with this then just use the same shot glass yourself just with g good tasty alcohol. One or two shots per fill up should keep the Cops busy.
29 Tudor
Senior Member
Now there's a man after my own heart!
I won't use the alcohol in myself if I'm using the car but after that, a little alcohol is not a bad way to finish off the day.
Thanks for the MMO suggestion. I'll try that and see if it helps. Sure wish we could get real gas here!
Streve
I won't use the alcohol in myself if I'm using the car but after that, a little alcohol is not a bad way to finish off the day.
Thanks for the MMO suggestion. I'll try that and see if it helps. Sure wish we could get real gas here!
Streve
29 Tudor
Senior Member
Well, in the interest of a complete thread, here's a bit of an update. One of our members was good enough to send me a spare 1/4 inch phenolic spacer for the carb to isolate the carb from the hot manifold. I added that along with two new gaskets. By the way, some were concerned that the GAV wouldn't line up when using the spacer but it lines up and works just fine. After the spacer, the problem was MUCH better. I replaced a head gasket and drove the car for a few days with no hood and there was NO problem. There was again a hint of a problem after putting the hood back on. That seemed to confirm the issue as heat in the carb.
Then, quite by accident, I discovered something that seems to have made a HUGE difference, to the point that the problem seems to be entirely gone... at least for now.
Here in South Texas, we are not allowed to have "real" gasoline. I think "they" believe we'll hurt ourselves if we have the real stuff. I have been running Shell premium (with the recommended 4 oz of MMO per 10 gal) because I read or was told that Shell premium had the lowest alcohol content that we could get. Over Memorial Day weekend, my wife and I drove the "A" about 50 miles to a state park for a picnic. (LOTS of waves and thumbs up by the way) On the way up and back, if I had to sit in traffic for a few minutes, when pulling away, there was a "hint" of the old starving problem.
Coming home, we were pretty low on fuel so I pulled into an Exxon station and filled with 87 octane regular, just to see how it would run. When we pulled out of the station, it ALMOST stalled as we pulled away. It hardly wanted to run and then .... almost like magic, it smoothed out and accelerated perfectly normally. Since then, I have driven it quite a bit in HOT weather (94 yesterday) to see if the problem is there. Not a hint of the starving!
I HAVE to believe the gasoline made the difference. Maybe the difference is 87 instead of 93 octane. Maybe the difference is the brand or MAYBE, I got lucky and got some with little to no alcohol but at this point, it's running GREAT, even in good old hot South Texas.
I am going to continue with various brands of 87 octane with the MMO and see what happens.
Has anyone else seen that kind of a difference in brands/octane?
Steve
Then, quite by accident, I discovered something that seems to have made a HUGE difference, to the point that the problem seems to be entirely gone... at least for now.
Here in South Texas, we are not allowed to have "real" gasoline. I think "they" believe we'll hurt ourselves if we have the real stuff. I have been running Shell premium (with the recommended 4 oz of MMO per 10 gal) because I read or was told that Shell premium had the lowest alcohol content that we could get. Over Memorial Day weekend, my wife and I drove the "A" about 50 miles to a state park for a picnic. (LOTS of waves and thumbs up by the way) On the way up and back, if I had to sit in traffic for a few minutes, when pulling away, there was a "hint" of the old starving problem.
Coming home, we were pretty low on fuel so I pulled into an Exxon station and filled with 87 octane regular, just to see how it would run. When we pulled out of the station, it ALMOST stalled as we pulled away. It hardly wanted to run and then .... almost like magic, it smoothed out and accelerated perfectly normally. Since then, I have driven it quite a bit in HOT weather (94 yesterday) to see if the problem is there. Not a hint of the starving!
I HAVE to believe the gasoline made the difference. Maybe the difference is 87 instead of 93 octane. Maybe the difference is the brand or MAYBE, I got lucky and got some with little to no alcohol but at this point, it's running GREAT, even in good old hot South Texas.
I am going to continue with various brands of 87 octane with the MMO and see what happens.
Has anyone else seen that kind of a difference in brands/octane?
Steve
Rex_A_Lott
Well-known member
With a low compression motor like the A you're wasting your money buying anything but the 87. Thanks for the info.
29 Tudor
Senior Member
Rex A Lot: I realize I don't need 93 in the "A". I was using that to TRY to get fuel with little to no alcohol.
Mikeinnj: No, no filter but the tank is spotless and I DO have the original cast iron sediment bowl as well as the screen in the inlet of the Zenith. Both are, and stay, clean. As I outlined in my data above, I have plenty of flow when the engine/fuel is cool. The problem occurred when the engine/carburetor was hot. I could actually HEAR the fuel boiling in the carb after I shut the engine off and opened the hood.
Mikeinnj: No, no filter but the tank is spotless and I DO have the original cast iron sediment bowl as well as the screen in the inlet of the Zenith. Both are, and stay, clean. As I outlined in my data above, I have plenty of flow when the engine/fuel is cool. The problem occurred when the engine/carburetor was hot. I could actually HEAR the fuel boiling in the carb after I shut the engine off and opened the hood.