Thread: 454 exhaust cherry red

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alright fellows i've just done some mods to my 454,got problems.this is a stock bore 454,i put some later model sqaure port heads on itwith new stainless valves matching valve springs and liftersa 268 voodoo cam ,a mallory 5500 rpm hei coil,and put an GM factory alum. intake,which by the way is a marine intake, and a 850 holley which was used when I got it have no history on it.I've got this in my 72 chevelle,just fired it up last night idled it up to break in the cam let this thing run for about 3 min. the headers are cherry red shut it down quickly, WHATS GOING ON

Either the carb is too lean , or the timing is late.

I agree.

To add to the above, I've seen a dull orange coloration to the headers when breaking in a cam about twilight.
Took about 5-10 minutes to get there and the carb & timing was very close to where it should have been.

Cherry red sounds a bit much though.
I'd pay attention to what R.Pope and techinspector1 have said above.

Too rich, you're continuing the burn outside the cylinder into the header. More fuel + More timing = more heat in the exhaust, engine temps will be ok though.

Too rich on the cruise side, you're continuing the burn outside the cylinder into the header. More fuel + More timing to compensate = More heat in the exhaust. Engine temps should be ok though. If you lean it out too much and or advance the timing too much you will get predetonation. Too little timing and too much fuel will result in high engine temps. Slightly richer is better for breaking in, as you said the dull orange is just right. Thats the fuel/ timing combo to shoot for. The headers show heat because of the thinner metal than the cast manifolds.

so are telling me that i need to advance the timing and riching the carb? and this wasn't a dull orange with no exaggeration these headers were cherry red like a stove pipe almost all the way down to the collecters,if it would have been just a light discoloration it may have been ok but these babies were hot,hot never happened to me before thats why I'm looking for advice and appreciate all advice given. SO DO I NEED RICING AND ADVANCE OR LEANING AND RETARDING?and if the carb needs jetted what size do ya'll recomend on this 850 to start with? I was afraid that this joker was about to melt my headers off in a real short period. Oh by the way this carb came off a 427 stroked{540 ci} motor that was in a boat and 2 of the pistons were detnated if this helps any for giving advice.

"Too rich, you're continuing the burn outside the cylinder into the header."

Not likely. A fat mixture will cool things down. The main problem he's facing right now is retarded timing. When the mixture is fired late, it burns late and is still burning out into the manifold/header.

wjr, make certain you know where TDC is and put 8-12 degrees in at the damper, with another 20-24 degrees centrifugal for a total of 32-36 degrees.

If you're uncertain about whether or not the damper ring has slipped, use a top dead center piston stop and find TDC for yourself so that you absolutely know.

if the headers are getting red up next to the motor then that's lean, if its got converters and its getting red down at the inlet of the conv, then the motor is either running rich and the gas is collecting at the inlet of the conv. or the conv. is 1/2 stopped up and causing a fire in the pipe at the conv. inlet. if you don have conv. then forget you ever saw this. set your timing and richen up your carb. a vac. leak will lean it out also. check your timing if its right leave it alone. up the primary jets a couple # and try it, untill you get it right. make sure you dont have a major vac. leak.

Fire it up and choke it slightly, watching the headers. If choking reduces or eliminates the red, richen the carb. Advance it and do the same, no lights or anything needed, just move the timing and listen to it run. Retarded it will be labouring, when it runs free, the glowing should stop.

thanks r pope that makes pretty good sense,I think i'll give that a shot, I just don't want to be destroying any pistons before we get this thing figured out. techinspectator 1 when I had the motor out I found tdc on 1 and when I put the balancer on I marked the timing chain cover in relation to the balancer I'm useing,but I probably did a no-no in ya'lls book I didn't degree this cam in and I really never have never had this problem that's why I coming to you fellows for some good sound advice,and I thank ya'll. please keep it coming if any other suggestions.

Hey I've got another question I've always considersd advancing the timing with the distributor as moving the vaccum pod towards the front of the car and retarding the timing as moving the vacum pod towards the back of the car, is this what you consider advance and retard or do you have somethingelse in mind?

WJR....thats right, or clockwise to retard, counter clockwise to advance. You need more timing, as opposed to running rich. Rich wont make the headers glow, it will actually make the exhaust cooler. Dont do more than one change at a time either, you wont know what fixed it....do one thing at a time..start with more advance.

thanks johnnyO for the confirmation, I guess I've always lived in the danger zone because I've always set my timing by ear and this has always worked well for me.When the motor is starting easy no kick back no labour knocking under load not running to hot and has that great throttle response then to me thats always been good to go. and right now this motor where the distribitor is setting is hitting it off at the strike of the key move her back just alittle and she is to retarded and won't do right. thanks again.

Are you sure your valves are adjusted properly? I had this problem , cherry red headers, on a small block I rebuilt. The rocker arms were adjusted too tight making the valves stay open. The book I used said put a half turn on them after all the play was gone. I readjusted them with a quarter turn after the play was gone and the cherry red headers went away.