Engine Questions

[pjmopar]

Hi guys,

Today I finally started the engine I have two questions.

I am running roller rockers, hyd lifters there is a slight tapping. Is this normal for roller rockers? They are adjustable and I adjusted them before putting the engine in.

The header tube (TTI) for #8 hole gets red hot. What's going on?

The engine is a 71 383 HP using Hughes Cam .523 lift on intake. Bored 30 over; rpm performer intake, Speed Demon carb. 850

Hope y'all can help

[darktone]

how did you adjust them?

[pjmopar]

rotating the engine every 90° check pre-load for each valve .015/.020. I made sure there was no play between the lifter and push rod.

[bobr]

Adjust them again. No, roller rockers do not make the noise you describe when adjusted properly. A red hot header tube usually means late ignition timing and/or a rich carb mixture. What happens is the mixture continues burning inside of the header pipe. Start by checking your timing an bump your initial up a bit. Read your plugs to see if they are dark meaning a too rich mixture. One other cause could be a header leak. This could also be the noise you are hearing. -Bob

[crisser]

Sometimes a new lifter will tick for some time, then stop. But, it wouldn`t hurt to re-check the adjustment. The red tube is either late timing, as stated above, or a lean mixture. Check for a vacumn leak on that runner. You could have a fuel distribution problem if no leak is found. Make sure the carb is clean and adjusted properly.

By the way, check for a clean, white plug on #8 to see if it`s lean.

[thatwasfunny]

Could be different things that will make a header tube glow.
too lean , way too much timing. 'rich' would normally cool things but not if the air is thin/hotter than shit, the engine temp would reflect this.
On the plugs make sure your heat range isn't too hot and look for a full turn of color on the base ring[top of threads] about 2 threads down, also look for tan/grey at base of the porclin where it meets down in the inside of the plug. If you have a bright light u can see this [magnifying glass would help]
Look to c if the ground strap is clean and kind of rainbow'd in color that will tell u it's probably been glowing [too much heat] from 1 of the above.
Hopefully u haven't begun melting a piston.

www.4secondsflat.com/Spark_plug_reading.html

[dave5711]

Originally Posted by pjmopar

rotating the engine every 90° check pre-load for each valve .015/.020. I made sure there was no play between the lifter and push rod.

SO are you saying you have .015-.020" preload on the lifter?(can't preload a valve) Did you check this with a dial gauge?

Usually the procedure is to adjust the rocker until there is zero lash(no play between the pushrod, and the lifter or rocker) then add preload by tightening the rocker adjuster 1/2 to 1 turn.

I usually do 1/2 but up to 1 turn seems to be the norm, varying with personal preference

Or is there some confusion here, and you actually have .015 to .020 clearance at the valve tip? You only need clearance on a solid lifter setup

[pjmopar]

Yes this is the clearance between the rocker and valve tip.

I have been working on this car for 2 yrs. so I have forgotten some of the steps that I took. I went back to the instructions (if all else fails) for setting the proper rocker arm geometry. I used a checking lifter sent by Hughes along with an adjustable push rod. Also I went with a chart which states what application I am using. The application I used was for street/strip which states 1/4 to 1/2 turn the preload is .015/.020. This chart says that engine may tick when cold. The chart also goes down for "record attempts"; 0 to loose; .000/+.003 this says engine ticks all the time.
The truth is it's been so long since I've set it, I can't remember what my measurements were. And being so smart I didn't write down the readings.

I started the engine up a little while ago and I placed my breather on the carb. and noticed that the header tube did not get hot.

[darktone]

Pre-load and clearance are just the opposite. You put a clearance of .015-.020 when it actually should be tightened down that much after the valve train has no slack. Easy enough to remedy this problem.