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Update and another question....

I ordered my AFR gauge kit. Should be here this week.

Question - how important is it to have a fuel pressure gauge inline with the pump and carb? How important is it to have it. I'm currently running a summit fuel pump with max pressure 8psi and 110gph. Seems like a low cost "while I'm at it" that gives additional insight to performance and another touch point for troubleshooting. I think my carb is looking for 6'ish PSI which seems to set itself if you have the floats set correctly.

Thanks
J
An inline fuel pressure gauge is nice to have to effortlessly verify everything's alright. How important is it? It's a good idea but not mandatory by any stretch. What I consider important to have with a pump that puts out 8psi max is an inline regulator. You want to be able to set the max pressure about 6psi for best performance. You will need a pressure gauge to verify the pressure you set is the pressure you want but after that you could disconnect the gauge and not worry about it unless you had a problem down the line.

Fuel can push past the needle if pressure is too high overloading the bowls. I've never had a problem with it, but I do run a regulator and pressure gauge with a Carter 120gph pump. I don't remember max pressure for it, but it was similar to yours. Maybe it's overkill, but it works for me. Your setup is up to you.
 

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Question - how important is it to have a fuel pressure gauge inline with the pump and carb? How important is it to have it. I'm currently running a summit fuel pump with max pressure 8psi and 110gph.
Thanks
J
I wouldn't say its critical but nice to see the #. A FPG convinced me I needed to add a regulator to reduce pressure, solving a carb problem.
 

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I put a gauge on mine and it worked for about two weeks and less than 20 miles. I'd say it's a decent tool to see what's what but once the tuning is done I'd pull it off, put it on a shelf and just a run a plug there. I don't think they can last long under the hood.

Comps recommended CAM:
Looks like a 274h.
 

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Have you thought about switching to a roller cam?

All you need to run one is these:

https://www.andersonfordmotorsport.com/gaterman-hydraulic-bar-link-roller-lifters/

I know it seems pricey but to me it's $400 insurance against wiping a cam lobe and wrecking your engine in the first five minutes. You'll probably also need new valve springs, but as has been discussed, you might need those anyway.

There's probably 3-5 common roller cams that will do what you want and most of them you can find used on Corral.net.
 

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Discussion Starter #88
Quick update team VMF

Installed an AFR Gauge/Bung/Sensor (Wideband). Car is with my mechanic now. AFR during WOT is running at 12.1.

Found this on the google machine:

For typical engines, the range or ratios is:

A/F Characteristics
Ratio
5 Rich burn limit. Combustion is weak and/or erratic.
6-9 Extremely rich. Black smoke and low power.
10-11 Very rich. Some supercharged engines run in this range at full power as
a means of controlling detonation.
12-13 Rich. Best power A/F for normally aspirated WOT.
14-15 Chemically ideal. At 14.6 the A/F is at the theoretical ideal ratio
with no excess fuel or oxygen after combustion. Good A/F target for part
throttle cruise and light to moderate acceleration.
16-17 Lean. Best fuel economy A/F ratio. Borderline for part throttle
drivability (worse than borderline if EGR is used).
18-19 Very lean. Usual lean limit (Driveability).
20-25 Lean burn limit. Varies with engine.

Based on my build - does the above apply or do you all think I'm running to rich WOT. Recall that based on my dyno sheet - I'm dropping off around 5200 RPM and trying to solve that problem.

Thanks
John
 

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Is it 12:1 the whole time, or just on the top end?

My thinking is that it's a little fat. Getting it closer to 13 on the big end would net you some more horses without being dangerous.
 

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Discussion Starter #91
Update guys:

The car was running rich from acceleration all they way though WOT. Idle and start it was running lean as expected.

WOT was running between 11 and 12. Acceleration was about on the low 13s. We are installing smaller jets on secondaries.

More to follow.

Thanks
J
 
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