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Mod | | | Forums66 Topics128,169 Posts1,057,041 Members48,458 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Aug 2009 Posts: 311 'Bolter | | 'Bolter Joined: Aug 2009 Posts: 311 | I adjusted my '48 235ci valves using the method outlined here. I originally thought I would adjust my valves while the engine was idling, I recognized immediately this was out of my comfort level. So my question is, how do you adjust the valves while it is running? | | | | | Joined: Jan 2010 Posts: 4,263 Shop Shark | | Shop Shark Joined: Jan 2010 Posts: 4,263 | forward to 3:32 in this video ...YouTube... | | | | | Joined: Feb 2004 Posts: 29,868 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,868 | A running valve adjustment is a poor substitute for doing it the right way, but some folks insist on that method. Get the engine idling as slowly as possible, and get really good at juggling a box end wrench, a screwdriver, and a feeler gauge while getting splattered with hot oil. There are special tools that allow you to combine a socket and a screwdriver tipped knob so the adjusting and jam nut locking becomes a one-handed operation. I see them on Ebay occasionally. search "valve adjusting tool". I've got a couple of those tools stashed away somewhere. Drop me a PM with your email address and I'll send you a picture. I haven't used one in over 30 years- - - -there are much better ways to adjust stovebolt valves.
Edit: The Snap-On part number for the tool is V-21.
Jerry
Last edited by Hotrod Lincoln; 03/10/2014 3:11 AM.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
| | | | | Joined: Apr 2013 Posts: 172 Shop Shark | | Shop Shark Joined: Apr 2013 Posts: 172 | you could try
Pull all of the plugs, hook up a remote starter and pick a cylinder. You can do one cylinder at a time. You can do it according to the firing order. Or you can do it totally random. I use a bright yellow marker and put a dot on the rocker after it is adjusted.
Adjust the intake valve when the exhaust valve opens
Adjust the exhaust valve when the intake closes
even a cave man could do it
1947 M15 Studebaker 454 4x4 1949 Chevy COE In the Stovebolt GalleryMore pix of the COE1950 Harley FL 1958 GMC LCF 455 3x2bbl 1961 Chevy C60 Tilt Cab 327 1966 Chevy C60 Tilt Cab 496 1961 Chevy K10 sb 292 1974 Harley FXE 1979 Chevy K10 sb 2007 Harley Streetglide I'm not that good but I'm slow
| | | | | Joined: Sep 2001 Posts: 29,270 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,270 | Curt, Here are different brands of tools that Jerry referred-to. Why not set the lash using the static method ( another set of instructions is given at the bottom of that link/page)? The static method is easier than the "running engine" method and easier than the "bump the starter for each valve" method; and, the static method is at least as accurate as the running-engine method. You warm up the engine, - set the engine to the timing mark, - adjust half of the valves, - rotate the engine until you line up the timing mark - adjust the other half of the valves No matter which method you use, if you have a groove in the mating face on the rocker arms, you will not get good settings. | | | | | Joined: Nov 2010 Posts: 1,159 Shop Shark | | Shop Shark Joined: Nov 2010 Posts: 1,159 | http://www.stovebolt.com/techtips/valveadjustment.htm Here's the guide,as posted by "Oly". It took me about an hour to do the complete adjustment.Half of that time, was waiting for the engine to warm-up enough. Only 2 settings,do adjust all 12 valves! Thanks, "Oly"!! B.T.W... the way I did it,I only removed #1 plug,to make sure I was on T.D.C. Hope this helps.
Last edited by wetwilly5757; 03/10/2014 3:34 AM.
| | | | | Joined: Aug 2009 Posts: 311 'Bolter | | 'Bolter Joined: Aug 2009 Posts: 311 | Dads50 that video was a the first time I had seen it done while idling. I love the video, and I am so glad my job is not man handling a red hot crank! Jerry I appreciate your advice, I don't need to impress anyone by adjusting it running, I just want my truck to run the best it can! I have seen those "special tappet adjusting wrenches" from Britain, Plumb, and Snap-On. They look like they make things a little easier. Jerry what method do you prefer to adjust them? | | | | | Joined: Feb 2004 Posts: 29,868 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,868 | I use the "companion cylinder" method, something left over from adjusting race engines with very radical camshafts that have a very narrow window of cam lobe position that gives an accurate adjustment. It involves getting one cylinder on "overlap" where the exhaust valve is closing and the intake is just beginning to open, and adjusting the valves on the cylinder halfway around the firing order that's exactly on top dead center. It's similar to the method of aligning the timing mark, adjusting half the valves, turning the engine once and adjusting the others- - - -just a lot more accurate.
Like a lot of stuff old racers do, it might not be absolutely necessary on a street machine. We just do it by habit! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
| | | | | Joined: Jan 2013 Posts: 1,084 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,084 | Dads50 - thanks for sharing this video. What are the guys with the long screwdrivers listening for? Appears they do a front, mid and rear check?
Allen Yeah, well, that's just like, you know , your opinion, man - The Dude
1948 Chevy 3600 - goal Original restoration, Current Stage 1 - Disassembly and getting body in primer 1954 GMC 3100 goal Hot Rod, Current Stage 1 - Get body in primer 1931 Ford Model A 5 window Coupe - Old Skool Hot Rod 1945 Ford 2N Tractor - Runs great 1964 Ford 2000 Tractor - Use it every week 1974 Stingray Corvette
| | | | | Joined: Jan 2013 Posts: 1,084 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,084 | Why are exhaust valves set at 3X clearance as intake valves? And why is there a range (+/-) and how do you pick where you should be in the range?
Allen Yeah, well, that's just like, you know , your opinion, man - The Dude
1948 Chevy 3600 - goal Original restoration, Current Stage 1 - Disassembly and getting body in primer 1954 GMC 3100 goal Hot Rod, Current Stage 1 - Get body in primer 1931 Ford Model A 5 window Coupe - Old Skool Hot Rod 1945 Ford 2N Tractor - Runs great 1964 Ford 2000 Tractor - Use it every week 1974 Stingray Corvette
| | | | | Joined: Feb 2004 Posts: 29,868 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,868 | Exhaust valves run hotter than intakes so the valve stems stretch more. Every time the valve opens it gets exposed to the hot exhaust gas, while the intake is cooled by the incoming mixture. The long screwdriver is a field expedient stethoscope- - - -they're listening for a rattle that indicates the valve adjustment is loose. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
| | | | | Joined: Jan 2013 Posts: 1,084 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,084 | Thanks Jerry. Seems like you would adjust valves with engine cold then, before the exhaust valve stems expand. What's the main reason for adjusting on a warm engine?
Allen Yeah, well, that's just like, you know , your opinion, man - The Dude
1948 Chevy 3600 - goal Original restoration, Current Stage 1 - Disassembly and getting body in primer 1954 GMC 3100 goal Hot Rod, Current Stage 1 - Get body in primer 1931 Ford Model A 5 window Coupe - Old Skool Hot Rod 1945 Ford 2N Tractor - Runs great 1964 Ford 2000 Tractor - Use it every week 1974 Stingray Corvette
| | | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | What's the main reason for adjusting on a warm engine? So your valves will be properly adjusted when the engine is up to operating temp and buzzing down the highway. | | | | | Joined: Jun 2011 Posts: 1,901 Shop Shark | | Shop Shark Joined: Jun 2011 Posts: 1,901 | .... What's the main reason for adjusting on a warm engine? So they are already 'expanded' when you set the gap. If you set the gap (without allowing for the expansion)they are cool but then they expanded an extra few thousands the gap would be smaller by that much... meaning more pressure and heat trying to squeeze through each time it cycles and.... oops the valve burnt. That's why you see a cold and a hot setting aome times.
Give me ambiguity or give me something else
| | | | | Joined: Feb 2014 Posts: 18 New Guy | | New Guy Joined: Feb 2014 Posts: 18 | .... What's the main reason for adjusting on a warm engine? ...but then they expanded an extra few thousands the gap would be smaller by that much... meaning more pressure and heat trying to squeeze through each time it cycles and.... oops the valve burnt. Not exactly. The main cause of burnt valves as it relates to "tight" valve adjustment is that once the gap (your feeler gauge setting) disappears, the valve is no longer seating completely, or seating for as long a period during the cycle. And since the valve sheds most of its heat during this period while it is seated, it begins to overheat and eventually deteriorate and burn, or break, away. | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | Exhaust valves run much hotter than intake valves so they can increase in length more. When adjusting using feelers, it is easier to detect that the next gauge up is too tight or one before is too loose. | | | | | Joined: Oct 2006 Posts: 9,671 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 9,671 | So lets see Aero, if that logic applies then the more we let it clatter the longer the valve stays in contact with the seat and the cooler the valve will run right?? I can see where this thread is headed by page 5 when we start to factor in using sodium valves, engine rpm, air temperature, density and grade of fuel that we're using. Not to mention the fact that the water jackets in most of these old Stovebolt's are so limed up that, that should be the major concern rather than a couple of thousands variation from the nominal valve adjustment. Denny Graham Sandwich, IL
Denny G Sandwich, IL
| | | | | Joined: Jan 2008 Posts: 4,962 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,962 | Inline Jimmies powered our tank wagons into the early 70's. The book calls for 12 and 20. Closer than that would burn valves in a hurry. We converted to "free" valves and the 302 came with "free" valves. We made sure that 12 and 20 was a minimum. A thou or so more didn't hurt anything. And we just didn't worry about the rattling. I still break out the old Snap On tool with a 5/8 socket. I see no sense in changing something that has been working for me for over 50 years. My old 645 Sioux valve machine has a rocker refacing attachment. Refacing the rockers eliminates a lot of the rattle and eliminates false clearance readings. | | | | | Joined: Apr 2005 Posts: 2,832 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 2,832 | I still use my old P&G valve gapper, slow but dead accurate. It takes into account any wear in the rocker, rocker shaft, if the valve stem has cut an eyebrow into the end of the rocker, and even what oil film thickness exists. Still see them offered on ebay but be sure to get the complete kit.
Evan
| | | | | Joined: Sep 2008 Posts: 872 Shop Shark | | Shop Shark Joined: Sep 2008 Posts: 872 | I have one of the valve adjustment tools and setting the lash on a running motor is SUPER EASY.
I do the intakes first.
First, I try and slip the feeler between the rod and rocker. If it will not fit, lash is to tight, if I can get it in its either right or to lose.
With the tool on the rocker, I loosen the nut, turn the adjuster till I can get the feeler in and then tighten the adjuster till the feeler has a bit of drag then tighten the nut.
Takes about 10 seconds per rod.... so yeah.. full valve adjustment in less than 2 minutes.
Last edited by pfarber; 03/11/2014 4:13 PM.
| | | | | Joined: Oct 2006 Posts: 9,671 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 9,671 | Evan, tell us more about that P&G gapper? Lots of ups and downs on the internet. Seems that those that have them swear by them and those that taint think they're useless. Having a machine shop background I like the idea especially since a good portion of the solid lifter engines that I've had over the years have had enough wear on the rockers to make a difference. Bet there taint to many dudes here that have heard of them also.
Two minutes to adjust the valves, heck, you should drop the pfarber and take up the handle speedy. Denny G
Denny G Sandwich, IL
| | | | | Joined: Nov 2006 Posts: 2,544 Shop Shark | | Shop Shark Joined: Nov 2006 Posts: 2,544 | | | | | | Joined: Oct 2006 Posts: 9,671 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 9,671 | That's only part of one Don, there are a variety of inner barrels, base adaptors, springs that are required. All different for different makes and models. You really need a good mix unless you can find just the set for the Chevy 6, if that's what you're working on. The boxed model 300 had the most common sets and came boxed like this: http://www.pbase.com/dennygraham/image/154805833DG
Denny G Sandwich, IL
| | | | | Joined: Sep 2008 Posts: 872 Shop Shark | | Shop Shark Joined: Sep 2008 Posts: 872 | Adjusting the valve lash is not super critical. As long as there is enough clearance to let the tappet/rod rotate as designed in operation you are good to go.
The only real danger is when the lash is to 'tight' and not allowing valves to seat. There is no real danger if you are loose a thou or two (or five). Might tap a bit... but won't hurt much.
The feeler gauge method fails when there is wear on the rocker. You need both the valve stem and rocker nose to be flat and perpendicular... the wear will increase the lash.
Setting lash cold is quick and easy. Screw down till contact is made, then loosen the adjuster as many flats as you need (I did the math in another post IIRC 2 flats for intake, 3 for exhaust). This is probably the best way to account for wear as you are dealing with actual contact not a feeler gauge that requires perpendicular mating surfaces. Many motors that don't give you a lot of clearance to get in with gauges (motorcycles in particular) use this method. I did with my 06 Boulevard. Works fine. | | | | | Joined: Sep 2008 Posts: 872 Shop Shark | | Shop Shark Joined: Sep 2008 Posts: 872 | Here's the manual image of the tool in use.... its a PDF file so you need a pdf viewer. Fasts and easy valve adjustment
Last edited by pfarber; 03/12/2014 8:40 PM.
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