Thread: 454 Rebuild Startup Problem

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I have just completed a rebuild of a 1970 Chevy Caprice.
454.
bored, balanced, new pistons, new cam, new exhaust valves seats and seals, valve springs, headers....
I started the engine for the first time today.
After only a few minutes, the header tube for #3 cylinder started getting cherry red.
The engine runs smoothly and doesn't backfire.
What the heck did I do?????
Please help me.

Budly,

It sounds to me like you engine is running lean. Have you tried enriching the fuel mixture at the Carb? I know that glowing header pipes is supposedly a tell-tale sign of a lean mixture. This can also be caused by bad gas...Since you're just putting the rebuilt engine into the car, my question is, has the car been sitting for a while? (not running?) And has the gas been sitting for a while too? This just happened to my '55 about 3 weeks ago. The fuel had schlacked so bad that it caused the carb to gum up and start running lean. That caused my number 3 header pipe to glow red hot, and I found out later that it also burnt the header gasket at the number 8 cylinder. Anyway, thats my suggestion. Lots a luck.

Firechicken

Had this problem on a 350 sbc. I had adjusted the rocker arm nut too tight. I went a half of turn after I could feel no play in the pushrod. Talked to my neighbor who runs a bbc in his stock car. He said never go over a quarter turn. The valve was being held open. Readjusted the roccker arms and the problem went away.

I also heard the lean theory but that wasn't the case on mine although it does happen like Firechicken said.

Thanks for the respones....

It actually turns out to be both carb and lifter.
I had the rocker arms way too tight.
Changed them all to 1/4 turn and they are fine now.
I had always adjusted them the Old School way
while the engine was running in my younger days.
I also know that my carb is running a bit lean but
that's easy to fix with a pair of screwdrivers.

This engine is in a 1970 Chevy Caprice Classic Sport Coup.
73k original miles. 454 (30 over now )
I've had her on jackstands for 3 years and just now
finished with the rebuild.
Although I switched to headers, I am trying to keep it
somewhat stock looking from the outside.
You can't see most of what's been done.

New: Keith Black pistons, GM Performance cam and lifters,
new timing set, oil pump, water pump (GM cast from YR1),
p/s pump, full length ceramic coated headers.
block magnafluxed, bored 30 over, fully balanced.

I'll have her road worthy by the weekend .

Thanks for the help.

BudlyUSA

Glad you got it all sorted out!

Cheers,
Firechicken

Glad you got her going. Club Hot Rod has helped me alot with my project so keep visiting this site.
Toolow