The Ford Barn - View Single Post

G.M. · 03-02-2012, 07:46 PM

I just blocked mine a few weeks ago. I used .020 SS 1 1/8"X 1 1/2". Bent a tab up 3/8" on the 1 1/2" side to hold it when sliding in place. Punched a 1/4" hole in the center 5/8" from the other end. Loosen the intake bolts and slide them in centering on the heat riser humps. Tighten the bolts and your done. This will provide some heat and not completely block it. This along with a 1/2" vented phonolic spacer and longer studs from Bob Shewman [email protected] will completely solve the gas boiling in the carb. I just installed one of Bobs spacers. Before the heat riser block and the spacer the heat on the manifold where the carb mounts was 157 degrees + and the base of the carb the same. After the heat riser mod and the spacer today when it was 85 degrees out after close to 2 hours of driving the manifold away from the carb area before was 157, at the base where the carb mounts and 140 today which is a 17 degree drop. The big differance is the carb base above the spacer 107 and bowl of the carb where the fuel is stored was 115. The gas is heated in the fuel pump from the 157degrees of the intake manifold 3/4" below the fuel pump to 122 degrees and loses a little heat from the cooler gas flowing through the pump from the tank. The longer it sits at idle or slow speed the more the gas in the pump is heated. I'm rising the fuel pump next week with a 1" phonolic spacer and a longer push rod I started making today. Threaded the push rod 3/8-24 1 3/8" long, 1/2" hex steel drilled 1 1/16" deep and tapped 3/8-24. Turned the hex beyond internaly threaded area down to 3/8" OD like the push rod. Will screw a 3/8 24 jamb nut on the threaded push rod then the new hex part. and with a little locktite, adjust the push rod to the length I want and lock it in place with the jamb nut. Now I will be able to adjust the pump pressure if require. I'm pretty sure this will take care of the heat on the pump which is maybe the biggest problem. If you ever saw the gas boil in the glass bowl this is what its from. Just a few bubbles in the bowl leads to lower pump pressure that pulsates. Also you can see the pump pressure drop as the pump gets hotter. G.M.

03-02-2012, 07:46 PM	#11
G.M. Senior Member Join Date: May 2010 Location: Florida and Penna. Posts: 4,471	Re: Blocking Off heat Risers I just blocked mine a few weeks ago. I used .020 SS 1 1/8"X 1 1/2". Bent a tab up 3/8" on the 1 1/2" side to hold it when sliding in place. Punched a 1/4" hole in the center 5/8" from the other end. Loosen the intake bolts and slide them in centering on the heat riser humps. Tighten the bolts and your done. This will provide some heat and not completely block it. This along with a 1/2" vented phonolic spacer and longer studs from Bob Shewman [email protected] will completely solve the gas boiling in the carb. I just installed one of Bobs spacers. Before the heat riser block and the spacer the heat on the manifold where the carb mounts was 157 degrees + and the base of the carb the same. After the heat riser mod and the spacer today when it was 85 degrees out after close to 2 hours of driving the manifold away from the carb area before was 157, at the base where the carb mounts and 140 today which is a 17 degree drop. The big differance is the carb base above the spacer 107 and bowl of the carb where the fuel is stored was 115. The gas is heated in the fuel pump from the 157degrees of the intake manifold 3/4" below the fuel pump to 122 degrees and loses a little heat from the cooler gas flowing through the pump from the tank. The longer it sits at idle or slow speed the more the gas in the pump is heated. I'm rising the fuel pump next week with a 1" phonolic spacer and a longer push rod I started making today. Threaded the push rod 3/8-24 1 3/8" long, 1/2" hex steel drilled 1 1/16" deep and tapped 3/8-24. Turned the hex beyond internaly threaded area down to 3/8" OD like the push rod. Will screw a 3/8 24 jamb nut on the threaded push rod then the new hex part. and with a little locktite, adjust the push rod to the length I want and lock it in place with the jamb nut. Now I will be able to adjust the pump pressure if require. I'm pretty sure this will take care of the heat on the pump which is maybe the biggest problem. If you ever saw the gas boil in the glass bowl this is what its from. Just a few bubbles in the bowl leads to lower pump pressure that pulsates. Also you can see the pump pressure drop as the pump gets hotter. G.M. __________________ www.fordcollector.com Last edited by G.M.; 03-02-2012 at 07:52 PM.