R&T Lost Art: The Valve Adjustment

slantvaliant wrote:

Knurled wrote:

jimbbski wrote: My first car was a Capri with the 2.8L V6 and it had solid lifters. Easy to adjust, you just had to do it in the correct order as you rotated the engine over.

Exhaust opening, intake closing, and follow the firing order. If you're smart, you have an underhood momentary switch to bump the starter hardwired into the car. I understand Porsche did this, small wire in the harness near the generator. Tap it to the battery feed on the generator to bump the starter.

You mean that you don't do it with the ENGINE RUNNING? Amateurs ...

Not me, but the techs at the forklift place would adjust Continental flatheads with them running. You just stuck the feeler gauge in then adjusted the lifter screw till that one got quiet and back it off just a smidge. They swore that was the only way, if you set them to either the cold or hot spec with the engine off it was nearly impossible to get them right and the engine would be noisy. I know it was messy as hell.

In reply to slantvaliant: If you want oil all over your exhaust manifolds you can do this or get an extra set of valve covers to make oil shields to keep the oil in the engine. No thanks! Either to much of a mess or to much work.

For some phun "quality time" wrenching, try adjusting the valves on a Lotus 910 motor (Esprit, etc.) You pull the cam towers off the head. The cams run each in their own tower that is separate from the head. You measure the clearance, pull the front of the motor off, cam towers off (hopefully without snapping off the Torqx bolt holding them down), see what shims you have in there, do teh maths to see what shims you need, buy your new shims, buy the super-special Loktite sealant (pookie) that only a Lotus specific place will even know what you're talking about, put it all back together. Some people do this with the motor in the car, but personally, I think it's probably easier just pulling it. Oh, and do that every 20K miles.

When I was running a big block Chevy engine in our modified there was a procedure where you could adjust all the valves with two rotations of the engine. May have been cam specs.

The Ford Zetecs were like that. Early ones had shims, later ones had sized buckets. Luckily, the only time you had to adjust the clearance was if you did a valve job or change cams.

Knurled wrote: Then you float the valves and bounce a shim out and all SORTS of money falls out of your wallet.

I would hate to think how hard you over revved to do that.

jimbbski wrote: In reply to slantvaliant: If you want oil all over your exhaust manifolds you can do this or get an extra set of valve covers to make oil shields to keep the oil in the engine. No thanks! Either to much of a mess or to much work.

First: On my car it's "valve cover" and "exhaust manifold". Singular, each. Gotta love the Slant Six!

Second: It's not very messy at all. With the engine warmed up and the idle turned way down, there's really very little splash. What there might be is usually on the passenger side, away from the exhaust. As a precaution, I roll up an old Army brown towel and stuff it alongside the head above the spark plugs. It doesn't get soaked. There's no need to sacrifice a valve cover. Probably as much oil drips off the valve cover as splashes off the rockers during the adjustment.

Third: hot and running is the method prescribed in the factory service manual.

I've done it both ways, and prefer it running. It's easier, not having to bump the starter or rotate the crank by hand. It's more consistent across all the valves, as they don't cool off at different rates while I'm futzing around. The first one is pretty close to the last, temperature-wise. Besides, it's more fun!

FWIW, that's not my video. I use a socket on a flexible handle, not a ratchet, so I don't have to flip the switch back and forth.

Engine designs and mechanics' preferences vary. Do what works for you and yours.

Keith Tanner wrote:

stuart in mn wrote: There's an article in the latest Hot Rod magazine about the Offenhauser engines they used to use in Indy cars. To adjust valve clearances you actually had to file down the valve stems - go too far, and the valve has to be replaced.

Actually, we do that with our Miata valves. Ever priced a full set of shims? A good machinist can measure how much is needed and take just that exact amount off.

This brings up a funny story... because most valve jobs do shrink the gap between tip and cam, and in some cases this has slowed my turn around time relying on others on getting the right shim. I've been researching the equipment needed to just tip the valves. So I go to another forum, one allegedly "more professional", post my desire... and within 20 posts, they had me investing 10s of $1000... when all I NEED is to tip the valves.....

likely going to make myself a simple jig, mount a digital caliper and a diamond (800-1000) disc on a rotary tool. Should cost me $50?? That includes the digital caliper ($20 @ HF)

Not a lost art to the Brit car contingency. Pretty much routine maintenance between drives.