VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1940 valve clearnce question

hello, was not here half a year, but now the season did start.
First the good news. Had to pass the technical check by law, which all vehicles must pass every two years here in germany. The ingeneer who had to check my chevy was frustrated. "Hey, fellow, you are unfair! Alwys you bring us cars to check where we cannot find anything! To check your cars is no fun at all for us!" I said, ok, dont cry too much, drive a round around the block and you will be happy I guess" So he did and came back with a big grin "....I did not expect it could be so much fun with a 77 year old car!"

Now my question: To check and adjust the valves was one part of my comlete service I did just now. I did set the intake valves to 0,006 and the exhausts to 0,013 as written in the book. As written there while engine is hot.

But, as you may imagine, it is really no fun to work at the hot engine.

Just now I did check the valve clearence of the adjusted valves at cold engine and found intake: 0,009 and exhaust 0,017. After heating up the motor it is again 0,006 and 0,013 as adjusted before.

the question is: would it be ok, to adjust the valves in future with cold engine to 0,009 intake and 0,017 exhaust to get 0,006 and 0,013 when hot? I dont like burnt fingers and hands after adjusting the valves.
How do you do that job?

Regards
Stefan from germany

While you could do it cold it will be more presise to do it hot. When you say cold running the engine jst a few minutes can change the setting, When stone cold before it is started it would probably be close to the hot setting After a few minutes the block enconds but the push rods, etc. are still cold and need to expand.
You may notice when you first start the engine the valves are quitet, get noisy during warm-up and quiet down when hot.

Now that they are "set" if you drive a long distance so the engine gets really heated up completely and if the idle is rough they are too tight. Back of the exhausts about .002".

Hi Stefan,

Glad you and the Blue Whale are doing well. Carol and I will be in Salzburg on May 24, 25. Why don't you and the Blue Whale join us? We all could pretend to be American tourist or German tourist for a couple of days.

Best wishes, always, Mike

P.S. Could I entice you if I bring some 40 parts?

hello Chevgene, hello Mike,

#Chevgene:
Sorry, did never adjust valve clearance at a running engine.
You adjust at the running engine?

How can you do that? At the running engine everything is moving, fidgeting and shaking, I cannot imagine how to do a high precision job like valve adjustment under that conditions.
How can you hold the screw driver at the srew if it will be kicked out with each rotation of the camshaft?

I know that old Chevrolet advertisment movie from YouTube, "master hands" from 1936, where a worker adjusts valves at the running engine and did never understand how that could come to any good adjustment...

#Mike,
I will check that date, as I know it is during a 14 days orchestra holiday, normally I would not be at home, but I will include your Salzburg visit into my holiday ideas.

the car runs perfect at the moment, in case of anything in need I would contact you. What I have in my mind just now, is just two screws. You know my car is converted to 12 volt but I am still using the 6 volt starter. In case of any unexpoected problem I have a 12 volt (converted) starter in spare. But there are two small screws to mount the starter switch. These I dont have and the european metric screws I cannot use. maybe I find some other parts too to fill up my spare parts box, but in case of I would do an order at filling station or anywhere else and let the stuff send to your adress. Is it still the same adress I know or did you move to any other place since 2011?

Hi Stefan,

I have the same address. Let me know what you need. I should have the screws. I will post a picture tomorrow.

Best wishes, Mike

Stefan
I know your problem adjusting valve clearance with the engine running but with LOTS of practice it isnt that hard. Sometimes when I dont know the specified clearance or the rocker arms are worn I will adjust by ear only (without feeler guage), loosen the adjuster until it rattles then tighten until no rattle then a further .25 to .5 turn of the adjuster. May not be recommended method but in 40+ years I have not had any problems resulting.
Tony

Stefan, here are some more hints on adjusting valves with the engine running. First, make sure you are using a box-socket wrench, not an open-ended spanner type. Second, "crack" each nut before trying to hit the slot in the screw head with the screwdriver just enough that you will need to apply hardly any force on the wrench to turn it. Third, try to avoid gripping the screwdriver like a baseball bat. keep a rather loose hold onto it as you bring the blade close to the bouncing slot. When the blade hits the slot "ride with it" until it is fully seated, then grip it enough to hold it firm while you loosen the nut some more with the wrench. As Tony says, you'll get it with a bit of practice.

And use a stubby wide balde screw driver.