The Stovebolt Site Forums The Shop Area Engine Shop Engine level and carb float bowl

Not sure if I am overthinking this or not, but can the level-ness of the engine/carb affect how the float bowl functions? The reason I ask is that I dropped my front end 6" (3" axle and 3" springs) then dropped the rear 3" with springs which creates a slightly nose down stance. This got me to wondering if that could possibly cause a perfectly well set up carb float to leak fuel toward the front (mine does this). When I checked the engine level it read -2 degrees instead of dead level.

I realize that the leak could be caused by a bad float needle, a warped top, or both and I'm running down those items now with a rebuild kit. The engine is a 1954 235 with a Rochester B.

Yes, the float bowl should be level, or close to it. I'm not sure a 2 degree difference would cause the problems you're having, however. The phenolic spacer that fits between the carb and the intake manifold could be angled slightly on a belt sander to correct the carb position, but be sure you have a spare in case things don't improve. We used to make carb angle correctors for some of the Chris-Craft runabout boats that ran the Graymarine flathead six engines I worked on back in the 1960's when the boats ran with a little nose-high attitude when on plane.
Jerry

Thanks Jerry!

I may be thinking about this wrong (wouldn't be the first time) but I have driven my truck down a 45 degree hill that was about a half a mile long and the carb didn't leak and the engine ran fine. And I have parked on places that were way more than 2 degrees off of level, again with no problem. So how does having the front end of the truck slightly lower than the back cause carb problems?

Tim

I agree with Tim, there are to many cars around setting at the same or more angle without fuel running out.

I suspect the float is a little high and / or the top cover is wrapped and not sealing well. Two or three degrees is not going to make any difference.

Joe and Tim, what you guys describe makes sense, so I can rule out levelness as an issue (Houston is pretty flat so I don't normally think about hills..).

I'm just getting my feet wet in carburetor tinkering, and wanted to know if levelness could contribute any to leaks or carb issues. After poking around I've found that the leak is likely a bad needle/seat, leaky float, warped carb top, too much fuel pump pressure or some combination of them (maybe an issue with gas tank venting?). I don't think my fuel pump is putting out too much pressure as it is just the stock mechanical glass bowl unit that I rebuilt with a new diaphragm and spring.

I'm planning to rebuild the carb, replace the float/needle/seat and see if that fixes the leak and my hard starting issues. I've ruled out ignition as the hard starting issue since I've replaced all of those bits, set the timing and it starts/runs no problem only after I dump a little gas down the carb.

"The ABC's of carburetion- - - - -Always Buy Carter!" That was Carter's slogan foe many years.

Rochester carbs are probably the biggest cause of high blood pressure, falling hair, fallen arches, heart palpitations, and a bunch of other maladies among stovebolters. When General Motors decided to build their own Chevrolet carburetors back in the late 1940's and stop buying Carters, the CEO of Carter vowed to sell a million replacement units for Rochesters. It took a few years to do it, but when the one millionth Chevy replacement carb came off the assembly line, he had it gold plated and presented it to the CEO of General Motors. Quite an advertising coup there!
Jerry

If the fuel pump was just rebuilt, CHECK THE PRESSURE!!!!!!!!!

The fuel pump pressure is controlled by the tension of the spring. There is at least one company selling fuel pump kits with the philosophy that "if the parts fit, they are the correct parts".

Just like carburetor parts, the "one size fits all, works well on nothing, but is cheaper than dirt" can give an enthusiast headaches.

And Jerry, please don't categorize all Rochester carbs with the type B (does B stand for bad ). With the exception of the very earliest 2-barrel Rochesters (AA - Oldsmobile, and BB - 1951 Cadillac), the 2-barrel and 4-barrel Rochester carbs are excellent.

Jon.

Jon, if I check the pressure and it is over 4lbs, Is it best to just install a regulator to correct it, and will any fuel pressure gauge work, or is there one best suited for a mechanical pump? Also, is the fuel pump a possible hard start culprit if it is making too much pressure, or are there just too many other carb related possibilities?

Hard starting has been my biggest issue since getting this thing buttoned up and roadworthy, and I want to get past having to dump a few teaspoons of gas in the carb everytime I need to start it... Seems to run ok once started, but I haven't trusted it enough to go more than a few miles from the house.

Your hard starting problem is probably political in nature, rather than mechanical:

http://www.thecarburetorshop.com/Troubleshooting.htm#Hardstartcold

If the mechanical pump is producing too much pressure, (opinion) the better avenue would be to (if the pump is original) rebuild the pump with the CORRECT internal parts (a plug here for "Then & Now Automotive" in the Boston area). If the pump is incorrect, then acquiring the correct pump.

If you should use a regulator, DO NOT go the your FLAPS and buy one of the $34.95 inline regulators, regardless of what brand is on the box. Find a good speed shop (or a FLAPS that sells Holley regulators) and get one of the expensive Holley regulators.

Disclaimer: I do not own stock in either Holley or Then & Now.

Jon.