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valve adjustment problem


tcslr
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L-head Chrysler. Adjusted valves and did find some out couple thousands. The valve tap sound DID reduce in magnitude but did NOT disappear. So, What could I be missing?

Should I repeat? Chrysler said 6 on exhaust and 4 on intake. I set everything at 7 and 5 - just want to avoid burning anything. Is that the issue?

Or Could it have cooled off too much? I did heat it up to about 150-160ish and by the end of the work the engine was down to about 140. In normal summer conditions, it can get up to 180 for short periods.

Also, it seems to have one cylinder that misses? it seems to disappear when I retard the distributor - maybe runs/idles a little smoother. Plugs aren't overly carboned but aren't greyish ash either. Plan to get it out on the road and expect it to run fine - it ran well before this with the exception of the valve knock - of which I knew I wanted to tune before winter.

So, any ideas appreciated.

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Thanks C49er. I didn't think about the guides :-(. This is a '29 and the original manual said 0.006" exhaust and 0.004" intake. I added an extra 0.001" using this logic: make sure it is seated and further reduce potential of valve burning.

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If it really bothers you set it to factory specs. I know guys who thought they knew more about their motor than the engineers who designed it, and had the same problem. When they set everything to factory spec, the problem disappeared.

If it is still a little noisy put it down to wear and tear.

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It is a mystery to me why people buy a certain car, convinced it is the best on the market, then think they can improve it, after it was designed tested and proven by some of the smartest engineers in the business.

Even if you are an engineer with a dozen PhDs you still have not done the testing that was done on that car, on the proving ground and through feedback from customers. So why do you think you know better than the factory?

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Just who is trying to change modify, improve the factory engineered design of a car? Better one or two thousands loose on an exhaust than .002" tight IMO.

I have no issue with my cars and trucks setting the exhaust .001" or .002" wider as I know it will never cause any issue and has not with any of my 1946-54 Mopar flatheads. Most of which I have owned for over 40 Years and driven many miles.

I have never had to redo a flathead valve job-ever and have done at least a hundred of them over the years on the flatheads.

The 218/230 engines are factory set at either .008 or .010 depending on year for the 218's.

Back to the OP he asked a simple question lets help him out about his noise issue..

Bob

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First the OP set his valves too loose, on purpose. Then he couldn't figure out why they were noisy.

Thanks for straightening me out on why all those millions of quiet, long living Chrysler flatheads that were set to factory spec, were wrong. What other mistakes did those dough heads at the factory make?

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Rusty you need to be a bit more tame on these boards. You tend to be way too tense and your way or the freeway.

A bit of calmness and be more friendly sure would be nice .

This is just a online board. You are not at work showing your perfection on the job.

I know chrysler corp designed things mostly right-NOT all things.

Can't we all just get along!!:)

Bob

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I thought I was being nice. Times have changed since I worked in garages and body shops. I know it is all in fun, if I caused any offense I apologize. At least you always know where I stand on the issues lol. Often in the wrong but never in doubt ha ha.

Rusty, your doing just fine. Straight talk never hurt anyone, in fact straight talk used to be normal talk in my earlier days and of my parents and grandparents generation. Today it's getting to be un-politically correct as people are so sensitive to their feelings rather that listening to the hard facts. NO offence to sensitive people out there.

Getting back to valve adjustment, I worked in automotive all my life and in automotive engineering there are compromises for reasons. Once I asked a question years ago to one of our engine designers about HOT valve adjustments "ONLY" in service manuals. It was explained that there is not enough time in a dealership or service garage to wait sufficiently for a engine to cool down to do a adjustment, therefore a hot adjustment is given. After further explanation on a inline six cylinder from the beginning of the valve adjustment to the last cylinder done there could be as much as .001 difference due to the cooling effect of turning the engine over to the proper cylinder for the adjustment. In other words as you crank the engine over to the cylinder the cool intake charge changes the size of the valve ever so slightly. It was also noted that if you get out of the service and maintenance section of the factory manual and go to the engine section that gives all the clearances for the engine you will find the COLD setting that the factory sets the valves to when the car was new. If your insistent on setting the valves hot, the only way is to do the adjustment while the engine is running. On a flathead this can be done, but it's a messy proposition.

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Sometimes I would check the valve clearance with the engine running and mark the ones that needed adjusting with chalk. Shut off engine, adjust, restart and check them again. Usually only 3 or 4 would need adjusting and after doing a few, you develop a feel for how much to adjust. This was on slant sixes, which were about the last engine with solid lifters.

I know it sounds nutty but both the slant six and flathead six will idle down so slow you can adjust the valves with the engine running and with solids, they don't throw oil around like a gusher gone berzerk, unlike certain inferior makes (Chevrolet V8).

Edited by Rusty_OToole (see edit history)
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I don't know if anyone mentioned it or not... on Chrysler built flatheads you are supposed to remove the right front wheel then remove a panel in the fender well, and adjust the valves through the wheel well. Not from under the hood.

Pontiac cars from 1933 to 1954 have that removable panel feature for adjusting valves as well. Also many newer cars like my 69 Pontiac have enough room once the rt ft tire is removed to replace spark plugs through the space in-between the inner fender and upper "A" arm....it's a must with a car that has factory A/C as the compressor is in front of spark plug # 2, and 4.

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Sometimes I would check the valve clearance with the engine running and mark the ones that needed adjusting with chalk. Shut off engine, adjust, restart and check them again. Usually only 3 or 4 would need adjusting and after doing a few, you develop a feel for how much to adjust. This was on slant sixes, which were about the last engine with solid lifters.

I know it sounds nutty but both the slant six and flathead six will idle down so slow you can adjust the valves with the engine running and with solids, they don't throw oil around like a gusher gone berzerk, unlike certain inferior makes (Chevrolet V8).

I have a Pontiac valve cover that I cut a long slotted opening to adjust valves on the solid lifter Pontiac V-8. You can also do that with a Chevrolet V-8 and Ford small block V-8. Chevy and Ford use the same type of independent ball over stud rocker arm architecture that Pontiac engineering ( Pontiac engineer Clayton Leach ) invented in 1948.

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