Howdy, My Chrysler Flathead 6 has on and off valve train ticking/clacking. I have adjusted the valves per book exhaust .012 and intake .0010 some days my valves are quiet. More often than not they clack at high speeds. How may I go about making my Flathead quiet and smooth? Adjust for tighter clearances? I drive the car daily. Thanks!
Yes. My stethoscope says otherwise. The engine has been timed with a light and was also timed using a vacuum gauge.
I believe you should leave it at stock settings, is it rebuilt or still original motor. Camlobe going bad spring getting weak two things I would think of first
I'm surprised you can hear valve noise at high speeds. I'd expect you to be able to hear piston or connecting rod noises at high speed. Like he said, what's the history of the engine? and tired valve springs are a likely culprit, if it is indeed valve noise.
I chased a lifter / valve noise for a few mouths, It would come & go , some times about every 10 seconds , some times up to a minute or so , It turn out to be a A Bad valve guide & a worn spot on valve stem ,when the valve would rotate to Bad spot , it was the Valve ,when closing was trying to center itself on Valve seat .
did you notice any oil blow by/running issues? Do tappets adjusters “cup” causing excess clearance? The car starts and runs great. Took it on a long road test today and once the engine is hot, I do not notice it. But in-town driving they click pretty loudly mid to high rpm range.
When you say "cups" are you referring to Spring retainers , lash caps or cups shims like a over head cam set up) If over head , I have heard of cup shims making noises , Vale lash Increases when engine heats up ,( expansion ) most think valve lash get tighter . I have also had a broken spring make noise , Yes , (blow bye ) but not from the valve/ guide , I built the motor around 1984 ran it until a few years ago. 5 different cars & in same cars multiple times & around 10 bottles of 200hp in spray . The noise was @ idle & cruising, if it was making noise @ WOT (7,500rpms) was unable to hear over Exhaust . That engine is Old Faithful, I replace that guide ran it for another year or so Its on engine stand to be Freshened, but by the time I get around to doing it, I will have to figure out how to make my Hot Rod 32s ""GO GREEN""
Since your later comment indicates that multiple lifters are noisy, short of having gotten some bad lifters I would look at the common denominator............which is the oil. It says it has a high zinc content which should be good for cam break in. I would try changing oil to something less than a 50. Maybe a 30 at most. Also, as mentioned above, it could be the valve springs if they are the old ones. Does it make the noise when cold and idling, or only when warm? Also if its exhaust valves, you could point an infrared heat gun at the exhaust manifold and compare cylinder by cylinder exhaust temperatures. There are some people who swear that new lifters should be disassembled and cleaned internally before installation due to trapped manufacturing debris inside. I'm sure that happens sometimes due to the millions of lifters produced. Whether its relevant here or not, I don't know.
Worn guide Sticking valve Weak spring Bad lifter don’t go tighter with the valve adjustment, noise is better then the damage a valve that’s to tight will cause. are you sure your adjustments are done hot and not cold ? It’s been a while since I worked on a Chrysler flathead six. And when you say “ High speeds “ how high ? In stock form these engines do not like to rev to high and anything more then 75-80 mph with the stock trans is pushing it . This is what I noticed with my 53 Chrysler with flathead 6 and fluid drive. The one time I pushed it to 90-100 mph for a few minutes a valve quickly stuck. Luckily no damage replaced and lapped a new valve in place and no other issues. Lesson learned.
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