(modified) – Ah! It is so nice to bring the car home after a big racing weekend and not have anything to fix!

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  • (modified) – Ah! It is so nice to bring the car home after a big racing weekend and not have anything to fix!

I did pull all the plugs and look at how they were burning the fuel. I had put a new set of NGK-7 plugs, gapped at .040″, before Nitro Jam. The front four plugs, #1 & 2 were all very good looking, slightly on the lean side with #3 & 4 being perfect. Numbers 5 & 6 were slightly rich and #7 & 8 were very rich. The King Demon 1090 carb. was jetted at 902 square. My Holley precision jet set has, lean (901), standard (902) and rich (903) in each size. I removed the back jets and put in two 892 jets. I hope that clears up the rich condition in the back cylinders.

I have my EGT probe in the exhaust of cylinder #2. The temp. all this weekend was around 1370 degrees. This is a little lean, which verifies what I saw on the plugs. I am going to move the probe to #8 cylinder to see how the rejecting works, after the first good run. If the weather is drastically different from last weekend, the changes may have to different.

I have had trouble with fuel distribution since the engine (originally a 540 CID) was changed to run a Dominator style carburetor. When the engine was ordered, I asked for a 4150 style intake and the engine was delivered with a BG RS 775 CFM carb., which was changed to 1025 CFM. The distribution was perfect with that carburetor. Since changing to the Dominator style intake, which has been port matched first, then the heads were ported and the intake reworked, the distribution has been uneven. The engine is now a 555 CID running a BG King Demon 1090 CFM carburetor (I also own a Holley HP 1150, which exhibits the same distribution problem). It does make a little difference what fuel I use. I get the best results with VP-C14. It burns a little cleaner. Other fuels burn much richer (plugs are black). The times (ET) with VP are the same as other fuels, but the MPH with the VP is about 2 MPH higher. I only have 14:1 compression ratio, so I don’t run C-16. “Other” racing fuels are available at a much better price!

I cleaned up the outside of the car and put a little wax on the trunk and fenders. I will finish later.

I will turn all my attention to getting Outlaw’s truck ready for this coming weekend. He is installing new 35 spline axles with a new spool, bearings and carrier.

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