Williams/Hinckley timing paper questions

[Gary S.]

I am just about ready to do my first solid lifter adjustment in 10 years. Previously I had done the traditional GM method but I am going to do method as put forward in the mentioned paper, 2008 edition. Two questions come to mind:

1. it is mentioned to start at TDC #1 piston. Is the best method to determine actual TDC to use the timing tab assuming it has never been off and the engine has never been apart?
2. is there even an easy way to mark the balancer at 90 degree increments? If so, how?

I will be using Duke/John's clearances at .016/.023 inlet/exhaust.
Thank you as always.

Gary Schisler
1972 LT-1

[Patrick H.]

Re: Williams/Hinckley timing paper questions

Easy way? Not really. Did this last summer on two LT-1s.

I measured the circumference, then marked 90/180/270 using painter’s tape and a marker. That was close enough for this; 1/4 inch won’t make any difference. I started from the mark on the balancer and went around. Yes, I assumed that it was correct. Ironically, we found that one of the cars was not correct and had the balancer (dampener) rebuilt and reinstalled.

Patrick

[Ron G.]

Re: Williams/Hinckley timing paper questions

Gary, Just curious what are you setting the intake and exhaust at ?

[Gary S.]

Re: Williams/Hinckley timing paper questions

Ron,
First part of the message - from the paper I - .016, E - .023.

Here's what I did - from the Internet 8" diameter x 3.1416 = 25.1328" circumference. That divided by 4 gives me 6.28" per 90 degrees. I took painters tape, marked at beginning line and measured 6.28" which took me back to the initial mark with a pen mark at each 90 degrees. I carefully laid the tape on the balancer starting at TDC and smoothed it in place. I then made the required adjustments based on the Williams/Hinckley paper i- intake at .016 and exhaust at .023.

It wasn't easy but it works (well, I haven't run it yet but every valve was loose.) Did I do OK, all? It is amazing how much of the engine, 1972 LT-1, I disassembled to facilitate the incremental changes.
1. Right valve cover needed the fuel distribution line loosened, AIR back valve removed, both AIR trees removed to ease removal of the spark plugs.
2. All ignition/spark shielding removed
3. Oh, and my "duh moment"? Failing to take the car out of gear when turning the crankshaft! I was amazed at difficult it was until I realized my mistake.
4. Fan and fan clutch

[Duke W.]

Re: Williams/Hinckley timing paper questions

Your method is probably the best if you don't want to put actual marks on the balancer. Using the recommended clearances means you'll probably never have to do it again as it will take many tens of thousands of miles for the clearances to loosen to even the .024/.030" recommended clearances for the LT-1 cam.

You will very likely notice a rougher idle and loss of low end torque, but the top end should feel stronger. The recommended clearances reduce valve train shock loading and rate of seat recession since the valves will be seated at no more than clearance ramp velocity under all engine operating conditions and valve and seat temperatures will be lower under most driving conditions.

Be sure you go through the idle speed/mixture adjustment procedure to achieve the best idle quality.

If you haven't converted the engine to full time vacuum advance with 8" B28 VAC I highly recommend that you do so. This will result in better idle quality, better throttle response, better fuel economy, lower EGT that reduces heat rejection to the cooling system at idle and in low speed traffic. And why you're at it optimize the centrifugal advance, the best starting point being the 365/375 HP 327s with initial timing set to achieve 38-40 total WOT advance.

Of course making this conversion requires going through the idle speed/mixture procedure again, and I recommend a target idle speed of 900.

My 2012 San Diego National Convention Tuning Seminar - an easy Web search- has all the whys and wherefores.

Duke

[Gary S.]

Re: Williams/Hinckley timing paper questions

Thank you for the comments. A while back I converted to full time vacuum using recommendations from you and others, with the appropriate vacuum can and re-routing the vacuum source. This should be the "icing on the cake".

Gary

[Gary C.]

Re: Williams/Hinckley timing paper questions

Simplified method of checking/adjusting valve lash regardless of camshaft style

Logic: where is #6 intake lobe when #1 intake valve shows to be near full open: answer, lobe is ~ 180 degrees away from lifter and lifter is on the cam base circle, Hey, I can adjust this valve knowing that it is on base circle.

Therefore, adjust # valve lash (I or E) when opposite # valve is open. Firing order is: 1 8 4 3 6 5 7 2, thus 1 & 6, 8 & 5, 4 & 7, and 3 & 2 are the opposite pairs. This method also works for any style engine, just break up the firing order similarly.

What I do is make a simple chart on a piece of paper as shown:

E I E I
1 6
8 5
4 7
3 2

When any # valve shows to be open, say #4 E, check & adjust opposite valve #7 E. Once adjusted, I put check mark on #7 E.

I use starter to bump the engine around (with xmsn in neutral) and when I get near the end of filling in the chart, I then look at the valve I want open and bump starter until that valve is open. With the manual transmission starter safety switch cars, I just stand by the driver’s door, push in the clutch with right foot while looking at the valve train when bumping starter so I can see the rocker arm.

Even though the valve starts to move, I strive to get the valve near full open so I can ensure that I am adjusting the valve with the lobe 180 deg away from the lifter.

In this, I don’t have to:
Mark balancer
Move engine by the crankshaft bolt
Remove fan & fan clutch to get access to crankshaft bolt
Remove spark plugs
Also, once I remove valve covers, there are some valves ready to be adjusted (those opposite to the valves currently open) so the process starts immediately.

Been doing this method since the 70’s. It is simple and if there is any particular valve I need to adjust, just get the opposite valve to be open.

Gary

[Patrick H.]

Re: Williams/Hinckley timing paper questions

I have tried the bump method, and it seems like the engine always wants to go "just" past where I'd like it to go.
That's a pain.

So, I reverted to the 90 degree balancer marks. That too is a pain, but once the marks are on it's easy.

[Gary C.]

Re: Williams/Hinckley timing paper questions

For the majority of the valves, I don't strive for any particular valve to bump to, just bump, see & adjust those that are in position and fill in the chart. Near the end, that is when I have to start looking at the specific valves and usually don't have an issue bumping to get them open. I find it much simpler than the 90 deg style.

Also, as long as the valve is open, the opposite valve is on the base circle, cams do not have that large of duration and ramps that would be an issue so it does not need to be exactly full open.

[Duke W.]

Re: Williams/Hinckley timing paper questions

For the majority of the valves, I don't strive for any particular valve to bump to, just bump, see & adjust those that are in position and fill in the chart. Near the end, that is when I have to start looking at the specific valves and usually don't have an issue bumping to get them open. I find it much simpler than the 90 deg style.

Also, as long as the valve is open, the opposite valve is on the base circle, cams do not have that large of duration and ramps that would be an issue so it does not need to be exactly full open.

As I explained in the paper the total "duration" of the 30-30 cam, including the clearance ramps, is 540 crankshaft degrees, which is 270 cam degrees, so only 90 degrees of the lobe is base circle. The Duntov is 450 and the LT-1 cam is in between. I determined this because I have all the lobe lift data from the GM drawings and plotted it all out. The Hickley/Williams method ABSOLUTELY, POSITIVELY GUARANTEES that you are on the base circle for each valve for ANY cam.

The only way to prove that you can "adjust this valve when that valve is open" is to plot it out, but no one ever has that I know of. Also, how do you keep track of all this valve monkey motion and not get lost.

With the H/W method you start at TDC compression stroke #1, then move the crank 90 degrees seven times to complete all in the sequence. I was once timed doing the job (exclusive of removing and installed the valve covers and any other necessary hardware) in two to three minutes. I had a helper with the sequence written out calling out the sequence while I ran back and forth between the sides of the car adjusting the valves and moving the crank with a breaker bar.

I don't recommend you try to set a speed record. Take your time, be methodical, follow the written down sequence, record the data, and it's foolproof.

The procedure is sufficiently forgiving that you only have to be within 5, maybe even 10 degrees of each TDC position, and I've never had to remove the fan/fan clutch to access the balancer bolt with a 1/2-inch breaker bar with a 3/4" socket.


Duke

[Gary S.]

Re: Williams/Hinckley timing paper questions

Patrick,
You leave the marks on your balancer? In what form - tape, sharpie, or ...? My painters tape will strip off relatively easily as you know. The starter bumping hasn't worked well for me in the past. A bit of disassembly, maybe 45 minutes, as I described and a 1/2" drive socket allowed me to turn the engine easily.
Gary

[Joe L.]

Re: Williams/Hinckley timing paper questions

I am just about ready to do my first solid lifter adjustment in 10 years. Previously I had done the traditional GM method but I am going to do method as put forward in the mentioned paper, 2008 edition. Two questions come to mind:

1. it is mentioned to start at TDC #1 piston. Is the best method to determine actual TDC to use the timing tab assuming it has never been off and the engine has never been apart?
2. is there even an easy way to mark the balancer at 90 degree increments? If so, how?

I will be using Duke/John's clearances at .016/.023 inlet/exhaust.
Thank you as always.

Gary Schisler
1972 LT-1

Gary------


Just to make sure you understand, when the timing mark on the balancer and the timing pointer align, it's not necessarily TDC on the compression stroke of the #1 cylinder. It can also be TDC on the compression stroke of the #6 cylinder.

As far as degreeing the balancer, you can get degree tape from sources like Mr. Gasket and available through sources Like Summit Racing. They have it for various size balancers.

[Patrick H.]

Re: Williams/Hinckley timing paper questions

Patrick,
You leave the marks on your balancer? In what form - tape, sharpie, or ...? My painters tape will strip off relatively easily as you know. The starter bumping hasn't worked well for me in the past. A bit of disassembly, maybe 45 minutes, as I described and a 1/2" drive socket allowed me to turn the engine easily.
Gary

No, I removed the pieces of painter's tape when I was done. Our hope is not to have to do it again.
You may want to remove all the spark plugs if you want to move the crank by hand, which we did as we were putting in new ones anyway. Our suspicion is that one of the cars still had its original 1972 plugs in place. If you leave them in place it takes a lot more force to move the crank.

[Duke W.]

Re: Williams/Hinckley timing paper questions

Assuming the distributor is correctly installed, at TDC #1 of the compression stroke, the rotor tip should be pointing about 20 degrees to the right (from the driver's seat perspective) i.e. passenger side of engine centerline. If it's at TDC, compression stroke of #6 the rotor tip will be 180 out from the #1 position.

As far as marking the balancer, there are several methods. If the car is going through judging it will likely be best to use painters/masking tape that can be easily removed. Measure the circumference of the balancer. Assuming it's 8" exactly, the circumference is 25.13" and one quarter of this is 6.28". Cut a piece of tape about 21-22" long. Lay it out on a flat surface and make a mark near the right end, then three more marks spaced at 6.28". Index the RH mark at the balancer notch and wrap the tape in a counterclockwise direction. The tape could also be used to place Sharpie marks on the balancer, and most ink is soluble in alcohol, so they can be removed without a trace, but test first.

If not concerned about judging, commercially available timing tape is fine.

As I previously stated try to get the marks with 5 degrees, but ten might be okay too.

Another way to move the crank is to put the manual transmission in top gear and bump the car fore and aft to align the marks with TDC on the timing tab. I don't find it that hard to move the crank either with a breaker bar or bumping the car with the plugs installed, but it is easier to move with either method if with the plugs removed, so doing a valve adjustment along with a spark plug is a good combination.

As with any procedure, there is a learning, and after doing it a couple of times you will likely find the method specifics that works best for you.

Duke

[Gary S.]

Re: Williams/Hinckley timing paper questions

Duke,
In your paper titled "30-30" SOLID LIFTER CAM VALVE (https://www.crankshaftcoalition.com/...cam_adjust.pdf), no date specified, you stated that the LT-1 valves should be adjusted to .020 Intake and .026 Exhaust. Then in your 9-23-08 paper that number is .016 I and .23 E. Do you recall what made this change necessary? Fwiw, I used the latter to do my adjustment and I am putting the car back together.

Thanks again for the valuable data and assistance that you provide.

Gary