The Stovebolt Site Forums The Shop Area Engine Shop 235 Valve Lash

I have a '58 235 with solid lifters and have read several valve adjustment procedures in several manuals. They all say to adjust the valves when the engine is hot. No place does it tell me what the lash should be for the initial startup. Will someone help me out?

Kels

Intake .006 and Exhaust .018 HOT

LOL.... I have been through this a hundred times. I have a 62, 235 and a Chevy tech told me long ago to adjust them

HOT .008 intake .010 exhaust
COLD .010 intake .012 exhaust

I adjusted cold and it worked for me. Your 58 probably has different specs though but certainly there HAS to be a cold setting because you have to at least get them in the ballpark to warm up the motor enough to do a hot final adjust. I found that adjusting them hot sucks big time so I always do it cold. I get them to where I can hear a slight ticky tick and I know that they are adjusted properly. People worry to much about these motors. Most of them will still be on the road long after we have worn out. Call the local Chevy dealer and talk to the service manager and see if he has a cold setting. Then if you must, you can fine tune it later.

58 and 62 will be the same, but yer mechanic's not close enuff Tab - the manual sez 006 and 018 HOT, and specifies that HOT means when the oil temp is stabilized for 5 minutes - for initial adjustment the book says "roughly set valve clearance to make sure all valves have clearance", that's the "cold" setting - once properly warmed up, shut it down and immediately set the proper clearance and make sure they're not so tight they don't make any noise or you'll burn'em - should sound like a well oiled sewing machine

Bill

Thruwurkin,

I think the Shop Manual says that the settings could change by .005 (tighter) from cold to hot. If that is the case, you might try:

COLD .010 intake .020 exhaust

HOT .006 intake .016 exhaust

Or, add .004-.005 to whatever hot setting you will use in the hot adjustment.

If you read the various Tech Tips or other postings on setting the valve lash, hot and cold are of equal simplicity/difficulty (it sounds like you have alread read them - I will add suggested settings to my write-up). Just be sure to run the engine for at least 30 minutes after the engine reaches full/steady temperature (this is what the Shop Manuals suggest).

Tim

Are these lash settings the same for a hotter than stock cam? My cam card had every number but the lash on it.

Shipwright,

Your best bet is to call the vendor of the cam and ask for the setting. Or, post the vendor's name and the cam specs here - maybe someone has used that specific cam and can give you settings.

Tim

Valve lash settings can and do vary from one manufacturer to another. The lash is the height of the "acceleration ramp" or slow, gradual lift part of the cam lobe to get everything snug before the actual valve lift begins. If you've got an aftermarket cam with no lash specification, try this trick:

Mount a dial indicator above the rocker arm (over the valve end, not the pushrod), and slowly turn the engine in the normal rotation direction while watching the dial. There should be several thousandths of slow lift before the speed of the dial movement increases. The height of the gradual rise of the dial is the clearance ramp. Set the lash to that height, and you're in business. Generally, the exhaust will have a wider lash than the intake, sometimes twice as much or more. I use this method when dealing with race engines with unidentified camshafts.

Have fun!
Jerry

Shipwright,
Like Tim said call your cam company. For example the Howard M4F solid lifter cam card sais .014 & .016 hot. However after a few mile I reset to .012 & .014 to quiet it down some.

52pu

I called the Cam Co. and asked. They said .018 on both intake and exhaust. They sounded busy and it almost sounded like they pulled a number out of the air. I'll look for the specs and post them. Thanks

red58: Thanks. If I adjusted my exhaust valves at .018 it would sound like a rattle trap. lol.... I will look at the exhaust valves again hot, and loosen them a bit. Maybe this is why my 235 lacks power. :•( But I doubt it....

Thanks for all the interest and quick responses.

Kels