I recently installed a 215 Buick engine in my 31 coupe, and because the car has a perfect cowl tank I decided to keep it. I've driven the car 40-50 miles since the engine swap, and it runs great in every aspect except hot restart. after sitting hot 5-10 minutes it floods itself to the point of being very hard to start again, so I'm wondering if the gravety flow of the cowl tank might be a problem others have had. I'm running from the cowl tank to a stock Buick fuel pump (with good fuel filter in the line) and then to a Holly pressure regulator set to 3.5LB to feed a brand new Edelbrock 500 carb sitting on a 1" phenolic spacer plate. the rest of the motor is totally stock. I've checked the carb float level, and it's good, so I'm just wondering if other have had any issue like this with the cowl tank besides me......... or should I just buy a Holly carb . Thanks for any input, Russ
I have heard of others although few having similar problems with fuel leakage from the gravity fed gas tank. Not especially the same engine as yours. Originally on the model A's the gas tap was supposed to be turned OFF when the engine was shut down, so I guess if you follow that rule you should be OK. To expect anything different would be ambitious, although you could possible find a electrically actuated in line tap/switch control that could be turned ON when you turn the igintion key, which would work. I have always found on original model A's that it is so easy to forget to turn the tap OFF and hence same problem as you are experincing. I was told to regularly flood and try to start an engine was not healthy.
Check your needle and seat. Gravity is less than 0.4 lbs. Should not flood. The shut off was just in case. A good banger carb would hold against gravity.
Turn the petcock off before you shut the engine off and turn it on after you start the engine back up. That's the procedure I use with my flathead powered '30 sedan.
Gravity is a strong force. Just ask us 60+ people. You need to shut off are run the line back under the car to make a longer fuel line.
Then what keeps the fuel from constantly pushing the needle off the seat when the car is running? Fuel pressure doesn't change in this case if the engine is running or not. Edelbrock carbs I've had were always susceptible to heat soak, but the spacer should cure that. How is your fuel line routed? Are the throttle blades wet with fuel 5-10 minutes after shutdown? (signs of percolating or flooding)
Throttle plates do usually show some fuel when sitting hot. An electrical shut off sounds like a great idea. there must be something out there that could be wired in to open with "key on" and close with "key off". I'll have to investigate that further. If not, the "line under the car" idea would actually allow for an easier way to have a valve in the line under the floorboards with a shaft coming up inside the cab. I'd be much more likely to shut off the fuel with an in cab shutoff lever than I would to open the hood and shut off the factory valve each time. would make a nice theft deterant also I never expected the cowl tank to cause this problem, but it's sure interesting to hear that I'm not the only one with the problem. One would think that the float valve would do the trick, but apparantly not, for whatever reason. Thanks for the input so far guys. you've already given me a couple ideas to test out. Russ
On my car I shut the fuel off. With the hot sun the gas expands and will over power the needle and seat and fill my little banger with gas.
I found an electrical shutoff solinoid at Snider's antique auto parts that looks promising. I think I'll give it a try, and will post how it works out. http://www.snydersantiqueauto.com/4008 Cheers, Russ
I am running a cowl tank with my strombergs I have never had a problem with the tank. I have only shut the valve once to replace the filter that is mounted on the firewall. RustyNCA
I use one like the snyders one. It works so far. seems its gunna piss me off if it leaves me stranded. Ive had problems with the needle and seat on edlebrock carbs. One was so bad it would fill the motor oil up with gas, took me a while to figure it out. well 8 hours 600 miles and 4 oil changes, then i hit the carb with a hammer and all is well. If you didnt double check the float, you should. Enough could leak through carb then the float goes down, then more gravity fed fuel.
I'm curious what type of fuel pumps (if any) the guys are using that aren't having a problem. I'm thinking it's the residual pressure in the line between my stock type fuel pump and the carb that's being bled off into the motor. it seems like once that pressure is used up, mine doesn't continue to flood over. I'd guess that just a gravity feed by itself would feed a very mild or stock motor, but I've never tried it. I did order the Snider's solinoid already anyway, so that's my plan at the moment. It will be mounted near the carb to keep residual pressure upstream. Russ
I always use the fuel shut off on my dads 28. Not sure if it is needed to keep the 97's from flooding? It may keep a dumb thief from getting to far if he gets it fired.
Installed the electric shut off wired into the ign. that helped a little. installed a 1" carb spacer. that helped a bit also. installed a fuel presure regulator set to 3Lb. installed new needle and seat kits and double checked the float level. didn't chang a thing. still has some percolating issues, especially on hot days. think I'll buy a Holley carb next time. Russ
The Jalopy Journal
