The Stovebolt Site Forums The Shop Area The HiPo Shop Headers are cherry red hot

My 63, 292 doesn't seem to be getting much oil to the rockers. I reved the engine up porbably about 2500 RPM and held it there for about 3-4 minutes. I noticed that the headers particularly on 5 and 6 were cherry red from heat. I never noticed this before, is this normal?

Larry
68 C20 327 daily driver
63 C20 292 Camper truck
65 C10 ? Custom Cab AC,PB,PS,$flasher - Long term Project

Red hot header runners are an indication of running lean on those cylinders. Do you have an O2 sensor that you can check your mixture with?

I don't have an O2 sensor. I richened up the Monojet as part of this tuneup(?). This is a used 292 I put in till I can another rebuilt. The intake and exhaust are off the 292 I had been running for several years. This is the first time I've ever held the RPMs up while watching the motor. I'm hoping it is normal for the headers to heat up cherry red like this. 4 and 5 do seem to redder that 2,3 or 6. The fan cools off 1,2,3, but 6. I don't know.

Larry
68 C20 327 daily driver
63 C20 292 Camper truck
65 C10 ? Custom Cab AC,PB,PS,$flasher - Long term Project

since the 5and 6 cylinders are fed by the same intake runner, maybe there is a vacuum leak at the intake manifold gasket at the head, causing the 5 and 6 to run lean.hope this helps. good luck.

The lack of oil to the rockers is a separate issue, usually due to plugged lifters.

Check for the vacuum leak by squirting around the intake with a can of carb cleaner. If the engine speeds up, you've found the leak.

You may also want to check your timing--it the timing is retarded the engine will have to burn more fuel to produce the desired amount of power. I have '70 Chevy Impala that the P.O. set the timing with the vacuum advance hooked up. It just never seemed to run right--I even rebuilt the carb thinking there was a passage plugged up somewhere limiting the fuel available. I ended up checking the timing on a whim and was VERY surprised to find the timing (with vacuum advance UNHOOKED) to be 3 degrees AFTER top dead center. I set the timing to 8 degrees BTDC, and reconnected the vacuum advance. I was then able to set the idle mixture and speed properly and let me tell you that car runs MUCH better--LOTS more power and much easier on fuel. I also used to tighten the exhaust pipe donuts at the manifolds (ram horns) every month and I couln't figure out why they kept getting loose. After the timing was set correctly, the donuts have not leaked since--and that was 4 months ago. My guess is that the manifolds were getting VERY hot, which was deteriorating the donuts.

Good luck, hope this long winded answer gives you some ideas.

Now I'll have to take the Impala back down to Fred T's neighborhood and show my cousin's friends how a properly tuned small block in a beat up brown Impala will really run.