I just fired up my 455 with a new hydraulic cam and lifters. Did the typical break in... figured I'd do a fresh valve adjustment. Shouldn't all the adjustment screws be prety much the same height? When breaking in the motor, I did get some header glowing on the #5 cylinders
Header glowing is fuel being burned in the tubes. Various reasons including over rich is most common.
Header glow at break in can be a symptom of a lean condition, too. Usually it's because while break-in rpm being over 1000 rpm and usually higher, there's no load on the engine, thus carburetor doesn't "see" the lower intake manifold vacuum that would normally enrich the mix. Sometimes crutching this with more than usual ignition advance for break-in may help. Regarding the rocker arm adjusters, yes...if all parts are considered equal, they should be really close. Things that could affect them being off, two biggies come to mind. Pushrod lengths? Valve tip heights? I could mention cam lobes, but if the cam is healthy I wouldn't think it's a problem, but I haven't seen exactly how a cam core is machined, and whether or not one master lobe profile follower is used on multiple lobes or just one at a time. Are you sure lifter preload was set on the base circle of all 16 cam lobes? Devon
Makes sense Devon. A long time ago breaking in a sbb, it was an over rich carb that made my headers glow big time.
https://www.taperformance.com/PDF/Roller_Rockers_Installation.pdf The roller rocker arm adjuster should be flush with the bottom of the rocker arm if the push rod length is correct. One thread showing, or one thread recessed is acceptable, but not optimal.
To get each cylinder to TDC I rotated the motor by hand until I saw the exhaust valve start to open then rolled it back until it closed then set the valve to zero and turned it a half turn. Could it be the lifters aren't fully pumped up?
It IS tricky trying for zero lash if the lifter isn’t full of oil. Easiest way is with the intake off so you can see the lifter plunger. What I do with the intake ON is wind out the adjuster till the pushrod is loose, then slowly and with no force on your Allen key, turn it clockwise until it feels like your meeting SLIGHT resistance to turning, back off, do it again, till you get a consistent feel/resistance, that should be pretty damn close to zero lash. Remember you have quite a bit of travel in the lifter plunger, so if your off by .010 or a bit more, no big deal.
If you see or find a few valves that done jive with the rest,as far as adjustment goes,it could also be the seat. If all of the rockers are off,run a straightedge across all the tops and see if they all contact the straightedge the same. You might also have a situation where all the intakes touch,but all of the exhausts are lower,or vice versa. As far as adjusting valves go,some will put one at full open and adjust the opposite one because it’s obviously not open,but isn’t quite right. When the exhaust valve begins to open,adjust the intake. When the intake begins to close,adjust the exhaust.
Absolutely.....but some leak down faster than others...hence the problem with hydro lifters now....I recently took a set I had let the lubricate hardned up on....broke them down and cleaned everything..BUT like a dumass I left the plungers get mixed up...but any way they were machined very well and when assembled the trapped air would keep the plunger up top....cheap shitty lifters the plunger will just zip up and down
Yes 20 minutes is more than enough as long as the engine is running. As soon as you shut the engine off, oil pressure goes to zero, and any lifters under spring pressure will eventually bleed down. Hydraulic lifters are designed to “leak” As long as the oiling system can overcome the “leak” while the engine is running, there’s no issues.
on at least one of my engines i recall between the exhaust and intake there was a difference in adjustment.
