Can't maintain fuel pressure

[SteveJ]

Okay, so I think I am at a good point with this issue. I fabricated a new heat shield and tested it today. Temperatures between the carburetors was around 260 with the old heat shield. Today, after I tried to induce some heat soak, temperatures were about 120.

 I started with a 24x12 1/16 thick sheet of aluminum from McMaster Carr. I used a brake to give the sheet a slight bend where I wanted it and marked off where I thought the PCV would pass by and the holes for the mounting points to the carbs.

I used various cutting tools, grinding tools, and a drill to get my preliminary design. On the first dry fit, I saw I needed to remove about 1.5 inches from the bottom. After that, I had to clear more space for the PCV tube, widen the mounting holes and grind down a couple of corners where the mounting tabs were hitting the carburetor insulators.

When I was happy with shape, I applied a sheet of insulation (adhesive backed), trimmed it to fit, and secured it with bolts and fender washers. I mounted a couple of bolts for the throttle return springs to mount, and then I bolted the heat shield to the carbs, bending the shield a little to keep it off the header.

[Captain Obvious]

Too many words... Pics or it didn't happen.

[SteveJ]

By the time I finished my test drive, it was too late. Maybe tomorrow. Maybe later. Besides, I'll be doing some stop-n-go driving this weekend when I take the car to The Mitty. I want to give it the acid test.

 

[Mark Maras]

 That degree of improvement is very impressive. What insulation did you use? I'd like to see a few pics of the finished shield.

[SteveJ]

Here's the insulation: https://www.amazon.com/gp/product/B00029KC2K

The nice thing is that by applying it to the heat shield, it improved the look of the shield.

I'll take some photos later.

[jalexquijano]

Improvement?? Im still stucked and trying to tackle this heat soak hesitation or whatever it is during traffic jams even after installing an aluminum heat shield extensión as in the picture attached and swapping the spark plugs with NGK BP5ES (hotter) to keep them from fouling during short stops and traffic lights. As the cam i have is a Schneider 274F and has an RPM range from 1800 to 6000, he recommeded to raise my idle to 1100 instead of the 1000 i have it set at.  

We checked the PSI pushed by the Airtex 8012S electric fuel pump yesterday and it showed 2.5 to 3 psi.

Still clueless on how to solve this!! Will test the car again at 1100 RPM idle tonight.

 

 

[Mark Maras]

Did you ever get around to unwrapping the steel fuel lines or better yet bypassing them?

[SteveJ]

I left the fuel lines as is. When I was testing today, I could see they were being subjected to a fair amount of heat, and I could feel it on acceleration. It makes me wonder if it would be better to make a new fuel line that would go closer to the carburetors.

[jalexquijano]

such  nice Steel fuel rail to be dumped in the trash and replaced with cheap fuel hoses? still testing with idle at 1100 rpm which goes down to 900 when ac is activated!

[gwri8]

Can't you just slip one of these in the fuel tank?

[jalexquijano]

why the offense? trying to solve fuel percolation at idle during traffic jams and you come up with this?

[Jarvo2]

Try putting fuel pressure regulators between the metal fuel rail and each carb (2 regulators) and run. Stronger psi through the main fuel line (bigger pump). I would not for for a fuel injector pump as 60-90psi will blow out the fuel lines, but a steady 10psi should prevent percolation


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