[Radman]

Originally Posted by tripwr1964

i ordered a set of 3x yesterday from GSI. Had them by noon today! $4.95 plus shipping.

what's the status on these radman? working ok?

I have had it running in the garage several times. Watching the fuel pressure gauge the pressure changes with temperature. The pressure is going down as the under hood temperature goes up. I set the pressure at 3 pounds when the fuel regulator was at 150 degrees. Cold it starts at 8 pounds, then goes down to 4 to 6 as the under hood temperature goes up to the normal running, the 3 pounds and 150 temperature is only happening after extended running in the garage with the hood down. That is the closest I have got to sitting in traffic. There have been no flooding issues while doing that.
I hope to get the car out this weekend. So far the Saturday forecast doesn't include thunderstorm and tornado warnings. That has been the weather every day here so far this week.

[ahnuld]

Hope it works out, I didn't have these issues with mine, what fuel pump you running. Dan

[Radman]

The fuel pump is a Summit part number SUM-G3137. I have that mounted close to the gas tank above the rear axle. The fuel pressure regulator is a Mallory part number 4309, and the pressure gauge is a Russell part number 650330. The regulator and gauge are mounted on the firewall. I can always adjust the pressure higher when I see the low reading. I do not think it is the pump. Google has shown many different threads talking about pressure changes with temperature. The big debate is if it is the regulator or oil filled gauge that is changing. One suggestion is to drill a small hole in the top of the gauge to vent it. I will try that tonight. I am also using an IR thermometer looking for a cooler spot under the hood to mount the regulator and gauge.
The picture was taken while I was finishing the wireing under the hood.

[gtofreek]

The fuel is starting to bowl in the carb. This causes the float to bounce around and keep letting small amounts of fuel in. This, in turn makes it hard for the fuel pressure to stay even. Insulate the fuel lines, and run a fuel return system if you can. A phenolic spacer under the carbs can help also.

[Radman]

I found this information on fluid filled gauges with a little searching. Good information, do not read the gauge and adjust for your wanted pressure if the gauge is hot. I wish I had found this earlier, it might have saved some trouble.

When reading fuel pressure, keep in mind that a fluid filled pressure gauge will change it’s reading as the temperature of the gauge case changes (Under hood temperature). Because it’s sealed to contain the liquid inside, a liquid filled gauge no longer compares line pressure to actual atmospheric pressure, reporting the difference. Instead, it compares line pressure to the pressure inside the gauge case. As the liquid in the case heats or cools, it expands and contracts, causing case pressure to change as much as 1 psi for every 30 degrees temperature change of the gauge. Will directly screw into any 1/8 NPT female port.

[Radman]

I got some road time in with the car tonight. I did not have any flooding issues in the 55 mile trip. The weather was overcast with a temperature of 68. The drive included city, interstate, followed by stuck in rush-hour traffic. There was an accident in the other direction lanes, so all of the other drivers had to rubber-neck. 3 miles of moving one or two car lengths then sit for a couple of minutes. If it was going to flood, that would have been the place. Also the now vented fuel pressure gauge did not drop after the engine compartment was warmed up. I used the infa-red thermometer as soon as I got home. The temperatures were: engine block 195, right fender well 140, left fender well 150, firewall 140, fuel pressure regulator 114. Pops, I forgot to measure the carb bowls.