meteor Posted May 21, 2014 Share Posted May 21, 2014 How do most of you adjust the valves? I have been told to do it while running or with the engine off and just at operating temperature. Thought I would ask all you guys who have done it and would know the best method. I did a compression test and had 90lbs on 5 cylinders 95lbs on 2 and 110 on 1. Seems an adjustment is in order. Thanks, Meteor Link to comment Share on other sites More sharing options...
Bob Engle Posted May 21, 2014 Share Posted May 21, 2014 I get best settings by adjusting when the engine is hot, and running at idle. Use two feeler gages, one for correct setting and one thicker as a no-go gage.Bob Engle Link to comment Share on other sites More sharing options...
Buicknutty Posted May 21, 2014 Share Posted May 21, 2014 Adjusting with the engine running at idle is the best I've found, more difficult to do though. The problem I've had, is that as soon as you shut it down the rockers start to cool, and by the time I'm finished all 16, they've cooled enough to throw the adjustment off. However, that may not be why the compression is down, that kind of spread could be due to normal wear. Did you test "wet", ie., with some oil in the cylinder, to see if there's a difference? Keith Link to comment Share on other sites More sharing options...
Mark Shaw Posted May 21, 2014 Share Posted May 21, 2014 If I am starting an engine on a newly acquired project, I first make adjustments on the engine that is not running & just bump the starter or turn the crank to adjust all the valves. I mark each one with chalk so I know which ones are done. This insures that they are close to correct and will not bend a push-rod or break a rocker. Then I check all adjustments with the engine running. Link to comment Share on other sites More sharing options...
Marty Roth Posted May 22, 2014 Share Posted May 22, 2014 When adjusting valve clearance on my "Straight-Eights", and if adjusting while NOT running, I also use two (2) feeler gauges ( go and no-go).When the last one is rocking, the first can be adjusted;when 2nd from last is rocking, then 2nd from first can be adjusted;and so on until all 16 are adjusted.The same method works for a 4-cylinder, at least in my experience, but there may be exceptions depending on firing order Link to comment Share on other sites More sharing options...
pont35cpe Posted May 22, 2014 Share Posted May 22, 2014 Meteor, when I had my engine apart, I marked the flywheel every 90deg, so after I warm the engine up to operating temp., I kill the engine and start with #1 and work thru the firing order turning the engine manually 90deg after each intake and exhaust adjustment per cylinder, takes two complete revolutions and you`re done.. No oily mess.. Tom Link to comment Share on other sites More sharing options...
meteor Posted May 23, 2014 Author Share Posted May 23, 2014 Thanks everyone, Lots of good advice. Think I will try to adjust while running and see how it goes. No easy way to crank the engine. Like the go-no- go method. This is a great place to learn from all your experience. You guys have some really great cars. I will let you know how I make out. Meteor Link to comment Share on other sites More sharing options...
Buicknutty Posted May 23, 2014 Share Posted May 23, 2014 Make sure that you don't have them too tight, as that will cause the valves to burn. If during the adjustment, the engine gets a "roll" it, that's a sure fire sign that one at least is way too tight. The other point, is that a valve adjustment may or may not have any effect on the compression, if there're only off by a couple of thou it won't make a difference. If you have a lot of "clatter" then for sure it needs an adjustment. Let us know how you make out. Keith Link to comment Share on other sites More sharing options...
DonMicheletti Posted May 23, 2014 Share Posted May 23, 2014 What I do on the '38's is take the little cap off the relay on the top of the starter solenoid. If you push down on the top of the relay contact you can very easily and accurately "bump" the engine around to get the rocker arms in the right position for adjustment. You do not have to have the ignition on to do this. Don 1 Link to comment Share on other sites More sharing options...
Pete Phillips Posted May 23, 2014 Share Posted May 23, 2014 Don,What a great and simple idea! I never would have thought of taking the cover off the starter solenoid relay. Makes perfect sense.Pete Phillips, BCA #7338 Link to comment Share on other sites More sharing options...
Bob Engle Posted May 24, 2014 Share Posted May 24, 2014 If you adjust valves a lot, there is a special tool, looks like a 3/8 drive ratchet handle with a large knob on the top. This turns a slotted screwdriver end inside the socket. It's much easier to tighten the lock nut while the rocker arm is bouncing up and down. This is a great flea market tool to look for.Bob Engle Link to comment Share on other sites More sharing options...
meteor Posted May 24, 2014 Author Share Posted May 24, 2014 Hey Don, The solenoid trick seems perfect, thanks. Bob, I just found that tool at the AACA show in Flohram Park. 2 bucks and a snap-on no less. I will check those valves as soon as I get the chance. Thanks to all, Roger Link to comment Share on other sites More sharing options...
rjengelhart Posted September 26, 2014 Share Posted September 26, 2014 Hi. Don't have clatter, but valves are very quiet, and on downhill, lots of light back firing. I'm wondering if my valves may be too tight.Thanks.Bob Link to comment Share on other sites More sharing options...
meteor Posted September 26, 2014 Author Share Posted September 26, 2014 Hi Bob, I think that backfire is typical for these older cars. My Model A does this too, but if I enrich the mixture a little it ceases. Can't do this on my Buick, but you can increase the idle a little bit or pull your throttle out slightly. With a little more gas it will usually stop the backfiring. It will backfire more when slowing quickly from a high speed or downhill. Hope this helps. Roger Link to comment Share on other sites More sharing options...
hidden_hunter Posted September 27, 2014 Share Posted September 27, 2014 i know the book says to adjust them while idling, but how do you do that without mashing your feeler gauge? Link to comment Share on other sites More sharing options...
meteor Posted September 28, 2014 Author Share Posted September 28, 2014 I used 2 gauges and started out at .012 to see if any were that tight, then I worked my way up to .015 Idle the engine real low. Only a few seemed a little tight and I was able to adjust them. Roger Link to comment Share on other sites More sharing options...
DonMicheletti Posted September 28, 2014 Share Posted September 28, 2014 If the engine has many miles on it, the rocker arm may have a slight indentation where it has been wearing on the valve. 2 things happen, you get a smashed feeler gage and an incorrect valve setting (the feeler will "bridge" the wear on the rocker). If I run into that I usually live with the slightly noisy valves rather than take up the lash by ear - that is lessen the gap until there is no noise.One solution to that is to disassemble the rocker shaft and grind the depression out of the rocker and make it flat again, but Buick says not to do that - but I know that many do just that.Anybody have better ideas on this? Link to comment Share on other sites More sharing options...
Guest Grant Magrath Posted September 28, 2014 Share Posted September 28, 2014 A bit OTT, but you could have your worn rocker arms welded and ground back to spec I guess. As an aside, a wide screwdriver with a slot ground into the blade makes the adjustment easier with the car running if you don't want to spring for the flash tool!CheersGrant Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted September 28, 2014 Share Posted September 28, 2014 A bit OTT, but you could have your worn rocker arms welded and ground back to spec I guess. As an aside, a wide screwdriver with a slot ground into the blade makes the adjustment easier with the car running if you don't want to spring for the flash tool!CheersGrant Good idea, Grant!! I have never heard of that, but sounds like a no brainer. Ben Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now