Frankie the Fink

I am wearing this forum out with questions - but I am getting different advice on this topic. I have been told that you can set the solid lifter lash at .010 intake and .016 on a cold engine and be close to the correct hot setting of .012 and .018 after the engine warms up. But near the bottom of this page: http://www.cranecams.com/?show=techarticle&id=2 it says,

"You can take the "hot" setting given to you in the catalog or cam specification card and alter it by the following amount to get a "cold" lash setting.

With iron block and iron heads, add .002"

So do I add or subtract .002 for the 283ci solid lifter motor when setting lash cold ?

Injected Stingray

You subtract the .002". I did this on my car hot then when it cooled i checked a few and recorded it for future adjustments. cold .010" = .012" hot

MikeM

I wouldn't add or subract anything. Set 'em .012/.018 with the engine warm and off.

Many people will have .001/.002 thou variation anyway when they set valves. Also, several have confirmed there's little or no gap change on the valves between a hot and cold engine.

If there was a change due to heat, wouldn't you think the exhaust would change more than the intake? It runs hotter. Why would Crane recommend the same windage on both valves?

What I told you to do works well for me.

If you want to confirm what Crane says, set your valves stone cold and then check them hot just as quick as you can snap a valve cover off. I think your measurement error will be more than any actual change.

Frankie the Fink

How do you rotate the engine to adjust the individual cylinders...I really don't want to have to take the plugs out.

62Jeff

Then you'll have to pull the coil wire off (so it won't start), and carefully bump the engine over with the ignition key.

Frankie the Fink

I'm pulling the plugs & adjusting at .010 and .015 cold using the following procedure:

"Method #1: For a small block Chevy (or any engine with a firing order of 18436572) you can set the valves by turning the engine over just two times. Bring the engine up to #1 firing (both #1 valves closed and the timing mark aligned with zero on the timing tab) and adjust as follows: exhaust valves 1,3,4,8 and intake valves 1,2,5,7 bring engine up to #6 firing(rotate engine one complete revolution) and adjust as follows: exhaust valves 2,5,6,7 and intake valves 3,4,6,8."

I'll let you know how it goes and how close I get. This way seems the simplest to me and the least messy.

Injected Stingray

This way is the simplest that I know of just did mine last week.
Set Intake as Exhaust closes
Set Exhaust as Intake opens.

Ironcross

Is it not true that the correct settings are 8 and 18? And not 12 and 18.

Frankie the Fink

I've actually done some research into that. Some claim that in the early '60s a recommendation came out to set the lash to .008 from the previous .012 for increased high speed performance. However I have a vette 1956 tune-up guide that recommended .008 even back then for "sustained competition". I live in Central Florida with lots of stop lights and slow country roads so I prefer to have the car behave better at low speeds - hence I'm going with .012.

Frankie the Fink

MikeM is in that camp too. I may do that once I get down to it and feel comfortable with my ability to recognize what is closing and opening and when. Its been a while since I've been under valve covers - try 25 years or so. I just hate 'bumping' the ignition to get to the right transition point and missing it and going around again and all that crapola. So I'll just pull the fresh plugs again and make it easy. Some day I'll find the guy that designed the ignition shielding though and it won't be pretty.

MikeM

I made a slight error I want to correct. You can't depend on adjusting the intake when the exhaust "starts" to open. You can get in trouble with some cams that way.

When the exhaust is FULL open, you can adjust the intake. When the intake STARTS to open, you can adjust the exhaust.

Plasticman

I don't want to start a debate, but just wanted to let you know of a way that has always worked for me (for adjustment with the engine stopped), and Crower Cams recommends it. This works on hydraulic, solids, and roller cams.

Basically, you need to adjust the valves when they are on their cam lobe base circle, and the only way I know of adjusting that valve is when you know that it's opposite cylinder's valve is at full lift. If #1 intake is at full lift, then on a SBC, #6 intake can be adjusted (and can be assured that the cam lobe is in the middle of it's base circle).

Take your firing order for any engine. In the SBC, it is 1-8-4-3-6-5-7-2. Put the 1st four numbers over the 2nd four.

1-8-4-3
6-5-7-2

This is simply giving you the valve that is 360 degrees of crank rotation (180 deg. in cam rotation) away from the opposite valve. 1 & 6 are the opposite pair, so are 8 & 5, 4 & 7, and then 3 & 2. In other words, adjust #7 exhaust only when # 4 exhaust is at full lift, and adjust #4 exhaust when #7 exhaust is at full lift, etc. More time consuming, but much more accurate to see a valve at full lift, than see it when it is just starting to rise (especially with Chevy long shallow cam lobe ramps). I use a magic marker on the each rocker (or wherever adjacent to that valve), to indicate each valve I have adjusted.

Note that once you start on a series of valves (say you start the adjustment process on #1 exhaust valve - when #6 exhaust is at full lift), continue doing all of the exhaust valves going to #8 next, then #4, etc., following the firing order. Then do the intakes the same way. That minimizes how far the engine needs to be rotated for the next valve. Total rotation of the crank would be ~4 turns (2 turns for exhausts and 2 for the intakes).

Plasticman

Frankie the Fink

I had read about that method before Plasticman - but I stuck with my 'two position' technique and it went quite smoothly this morning. Set the lash and checked and rechecked. Nothing really way out of whack but seemed all were off some small amount. Car starts right up fine with nice consistent whirring so I think I pulled it off.

Earlier, I was told by the C1 gurus to run hotter plugs so now I am up to AC R45S and the car runs much better. But I have only driven two miles to the gas station and back and spent an hour or so run time at idle adjusting carbs, etc.. and the plugs are pretty sooty already (but plug condition is consistent for all 8). Is it just because I haven't had the car out for a good hard run yet to clean the carbon out ? I hope so. (The bronze-looking stuff on the threads is anti-seize compound)

Plasticman

My aftermarket Offenhauser dual AFB engine always runs with carboned up plugs (especially at low RPMs). It is primarily due to the poor mixture distribution of the dual quad intake manifold. Some cylinders are running lean due to the manifold, and therefore the carb settings have to be on the rich side to ensure they don't get too lean!

Have to assume your OEM intake has the same mixture distribution issues.

Plasticman

Frankie the Fink

I think that is the case with my setup - I may try a hotter coil down the road just for grins. For now I just have to retweak the carb idle settings and I've done my first tune up on the car and will feel pretty good about it if that goes well.

MikeM

As I said in the other thread, it's been 40+ years since I fooled with a factory 2 x 4 setup but I recollect the rear cylinders ran rich, the front lean while running on the single rear carb.

The plugs in the photo all look like an over rich problem. You may have a high float issue or your idle mixture is way too rich. It's obvious from the photo why the 43's didn't last.

Plugs don't color up like they did with lead so I get a little lost there.

Frankie the Fink

Yeah - I like to see a nice tan, even color. If the Florida monsoon will stop for an hour or so I'll get on the turnpike and blow her out and then we'll see... I may have had a rich idle mixture before I figured out the correct tune-up procedure for the dual quads but that should be better now. (I would suspect jets or metering before a high float issue - but I'm not a carb guru either.)

Plasticman

I agree that your plugs are a lot blacker than mine, and therefore richer than necessary (even with the poor distribution of the intake - unless the distribution is a lot worse than my Offy intake!).

However, when I tried going just one step leaner on the primary rods, I quickly saw lean surge. So I am stuck with the black plugs and poorer mileage that results. But the performance is terrific, and the dual AFB bling look great as well. And my Bosch Platinum plugs have never fouled nor "missed", using the stock coil and points with a rev limit of 6500 that I test out often.

These days, with unleaded fuel, you may never see a "tan" look. Most engines have plugs looking like new after many thousands of miles (with white insulators).

Plasticman

GCD1962

Plasticman has the correct method. All others can lead to inaccurate settings. He saved me having to list all that info, Thanks!

Frankie the Fink

I'm thinking of trying to go up one more heat range (AC R46S) with a hotter coil before screwing with the carbs - does anybody see a downside to that ?