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Is it possible my numbers arent accurate because of the fact that im using the designated exhaust rocker per each cylinder.
I oraganized them when i took them off and didnt think that it could effect my measurments. I also did the CHE trunion upgrade on em....
I don't think your numbers are inaccurate, only you had an issue with the measuring technique. I thought you were now getting consistent values of around 7.283".
The firing order is 1-8-7-2-6-5-4-3. Note how I marked up your sheet below. Since you rotated the motor only once, you can actually only measure 4 of the 8 cylinders. Of those you measured, only 6-5-4-3 are valid measurements with the piston at TDC of the firing stroke (1-8-7-2-6-5-4-3). The other measurements are being taken at the top of the exhaust stroke so the exhaust valve is closing and the intake valve is opening. As a result, the measurements being taken with the lifter off of the cam base circle so in reality you don't need to measure these which will cut your measurements in half.
Here are your valid numbers again:
Cylinder 6I: 7.283
Cylinder 6E: 7.283
Cylinder 5I: 7.271
Cylinder 5E: 7.309
Cylinder 4I: 7.306
cylinder 4E: 7.267
Cylinder 3I: 7.325
Cylinder 3E: 7.242
I think you might still have a minor issue with the measuring method as I wouldn't expect that variance of measurements on untouched stock heads. Sorry to be a pain and ask all these questions.
What do you mean by slight spin and medium spin?
Have you been using a stock pushrod to push the lifter down against the cam prior to each measurement?
When you rotate the motor, do you only rotate in one direction, i.e., if you rotate past 90 degrees you don't spin it backwards to get back to 90?
Were you using the feeler gauge at all to verify the lifter plunger wasn't depressed?
Is the motor currently in the last position, i.e., measurements on cylinder #3?
This is a description of the movement of the push rod checker. Once the rocker bolt is tight, the rod can spin just a little(medium spin) in its location. I'm always trying to spin counter clockwise so the push rod checker doesn't get smaller...
Have you been using a stock pushrod to push the lifter down against the cam prior to each measurement?
No, I have been using the push rod checker to seat the lifter onto the cam
When you rotate the motor, do you only rotate in one direction, i.e., if you rotate past 90 degrees you don't spin it backwards to get back to 90?
NO, when I'm trying to get exactly at 90 degrees,
sometimes I go past and have to come back. I do so by turning counterclockwise...I'm guessing this is wrong?
Were you using the feeler gauge at all to verify the lifter plunger wasn't depressed?
Only once when you told me to try. I've improved my procedure by always being on the short side and increasing the length of the checker by very small increments. if I miss handle the push rod checker( dropping instead of placing it onto the lifter) Id wait 10 minutes before trying to measure.
Is the motor currently in the last position, i.e., measurements on cylinder #3?
Rotate 90 degrees and check only cylinder #1 which is the next in the firing order. Don't rotate backwards if you can help it so the chain is tight on one side.
I had some time to think about this and the rotating the pushrod to check for zero lash may be the issue. Below is a different way to get zero lash, you can try this and see how the numbers compare for cylinder #1. This is an abbreviated version of something I wrote back in 2008 for measuring pushrod length. The key to lifting the rocker tip is to be very gentle so you don't push on the lifter plunger and depress it.
1. Shorten the adjustable pushrod to 1/4-1/2 turn less than you just measured so there is a bit of slop when the pushrod is installed with the rocker
2. Install the rocker and snug down the bolt as you have been doing
3. Gently lift rocker tip up and down, if it "ticks" the pushrod is too short. If you can't easily move the rocker and there is no "tick" "tick" the pushrod is too long. You really want to start with the pushrod slightly short so the rocker tip will "tick" against the valve stem when you lift it and let it drop.
4. If too short and you get a tick on the rocker tip, adjust the pushrod a little longer and try again.
5. You are trying to get to the point where the lifter doesn't "tick tick" with the pushrod in place nor is the rocker snug. When you get the pushrod length such that you just barely get rid of the "tick tick", you have found "zero lash".
6. When you have found zero lash, carefully remove the rocker and pushrod without rotating the pushrod.
7. Measure the pushrod.
I had some time to think about this and the rotating the pushrod to check for zero lash may be the issue. Below is a different way to get zero lash, you can try this and see how the numbers compare for cylinder #1. This is an abbreviated version of something I wrote back in 2008 for measuring pushrod length. The key to lifting the rocker tip is to be very gentle so you don't push on the lifter plunger and depress it.
1. Shorten the adjustable pushrod to 1/4-1/2 turn less than you just measured so there is a bit of slop when the pushrod is installed with the rocker
2. Install the rocker and snug down the bolt as you have been doing
3. Gently lift rocker tip up and down, if it "ticks" the pushrod is too short. If you can't easily move the rocker and there is no "tick" "tick" the pushrod is too long. You really want to start with the pushrod slightly short so the rocker tip will "tick" against the valve stem when you lift it and let it drop.
4. If too short and you get a tick on the rocker tip, adjust the pushrod a little longer and try again.
5. You are trying to get to the point where the lifter doesn't "tick tick" with the pushrod in place nor is the rocker snug. When you get the pushrod length such that you just barely get rid of the "tick tick", you have found "zero lash".
6. When you have found zero lash, carefully remove the rocker and pushrod without rotating the pushrod.
7. Measure the pushrod.
I'm at the point where I just feel like slapping in the TSP rods and getting the car going....
But I know I didn't do all this to do it wrong.
I'm pretty sure I'm measuring correctly.
I'm getting a tiny bit of "tick" when the rocker bolt is at 5 ft-lb, but when i torque it to 20 ft-lb, the tick goes away, and I still have lateral movement of the rocker and the push rod can still lightly spin.
When I'm too long, the rocker does not move laterally( side to side) and the push rod does not budg.
I've really fine tuned this. I'm a pretty meticulous guy. I don't think I was depressing the plunger while checking for "tick tick"..
In comparison, what your saying is that the rocker should have lateral movement and NO tick once barely tightened (hand tight with socket) ??
That would mean when you do torque it down to 22 ft-lb it will FOR sure depress the plunger in the lifter!
Also the previous questions you asked me, does it make a difference if i seat the lifter onto the cam with the pushrod checker VS the stock pushrod???
Last edited by Georgies; Jul 29, 2017 at 08:58 AM.
I'm at the point where I just feel like slapping in the TSP rods and getting the car going....
But I know I didn't do all this to do it wrong.
I'm pretty sure I'm measuring correctly.
I'm getting a tiny bit of "tick" when the rocker bolt is at 5 ft-lb, but when i torque it to 20 ft-lb, the tick goes away, and I still have lateral movement of the rocker and the push rod can still lightly spin.
When I'm too long, the rocker does not move laterally( side to side) and the push rod does not budg.
I've really fine tuned this. I'm a pretty meticulous guy. I don't think I was depressing the plunger while checking for "tick tick"..
In comparison, what your saying is that the rocker should have lateral movement and NO tick once barely tightened (hand tight with socket) ??
That would mean when you do torque it down to 22 ft-lb it will FOR sure depress the plunger in the lifter!
Also the previous questions you asked me, does it make a difference if i seat the lifter onto the cam with the pushrod checker VS the stock pushrod???
The stock rocker will have lateral movement unless loaded so you can ignore that other than if it gets removed it is loaded. On a stock running motor if you remove the valve covers those rockers with a lifter on the base circle will have lateral movement.
Based on your measurements in the prior post, your variation between shortest and longest is over an 1/8" which can't be correct.
Do you have access to a dial indicator?
Line up the timing marks again and measure. You should be able to get your 7.283" length again. Once you do that, remove the adjustable and install a stock pushrod. Spin the bolt down with your fingers just until the "tick" "tick" goes away so you have no lash. Then use a torque wrench and tighten to 22 lb-ft. Count how much rotation it takes to reach that value. Note the valve will open when you do this.
Measure the length of the stock pushrod. Don't move the motor when you finish.
Note, only do this on the cylinder where you got the 7.283, not the others as it may force the valve into the piston if the cam has the valves open. It is critical that you only work on that cylinder which is at TDC on the firing stroke.
If you have the dial indicator, then set it up so it is in line with the pushrod set on the oil hole in the rocker and zero it once you remove the "tick" "tick". This should provide a direct measurement of the preload. It will take a few minutes for the dial indicator to stop moving.
One other note, if this is the MS4 cam, you really need to check PTV before doing any of this. That cam is very tight on clearance so if you haven't measured, do that prior to anything else. Also, not sure on the year of your car, but you will need to keep the rev limiter in check. That cam spins high and without rod bolt replacement you can get into trouble.
Last edited by vettenuts; Jul 30, 2017 at 07:30 AM.
When you say to do it only on the cylinder that got 7.283 thats either 1 or 6 correct? Or just 6, meaning i should turn over the motor twice till the dots line up?
ok i got the cam dot at 12 o'clock and the crank dot at 12 o'clock.
I put the push rod checker at 7.283 and put it in the exhaust in cylinder # 6. I tightend the rocker bolt with only a socket and my hand. The tick tick went away.
Now, do I take out the push rod checker and put in a stock pushrod?
If yes,
Next do I line up the dial indicator to the oil hole in the rocker and torque to 22 ft-lb?
I understand i need to depress the plunger of the dial indicator some befor zeroing it.
Wheres a good place to mount the magnetic base?
Last edited by Georgies; Jul 30, 2017 at 12:13 PM.
Ok I got the cam dot at 12 o'clock and the crank dot at 12 o'clock.
I put the push rod checker at 7.283 and put it in the exhaust in cylinder # 6. I tightened the rocker bolt with only a socket and my hand. The tick tick went away right as the bolt stop turning by hand.
I then put in a stock push rod (7.393) and tightened the rocker bolt with a socket in my hand until the tick tick went away then zeroed the dial indicator on the oil hole of the rocker and started to torque down the rocker bolt to 22 ft-lb.
About 10 minutes later I took out the stock push rod and put back in the push rod checker at 7.283 and re hand tightend the rocker bolt with the socket and the tick tick went away just as the bolt stopped turning...
Last edited by Georgies; Jul 30, 2017 at 05:36 PM.
You could do a quick check on the intake of the same cylinder if you are up to it although since you measured these before and got the same value you are likely OK. I'm sure you are sick of measuring at this point.
You got around 0.090" of preload with the stock rocker and pushrod. So you probably want a bit less preload with stock lifters, around 0.080" is a good value. Since you measured your stock pushrods at 7.393 overall length, or around 7.380 gauge length (which is very close to what I have measured for gauge length in the past), the 7.375" pushrods should work bringing your preload to 0.0835". If you do a search with the MS4 on some of the other forums, I think you will find that most of the guys have found the 7.400" pushrods to be too long and have gone to 7.375" gauge length for off the shelf pushrods.
If you are going with a Comp or Trend pushrod, than use the 7.375" value as these are measured in gauge length. If you are going with Manton, then tell him 7.383" overall length (end to end as you have been measuring). In either case your preload should be in the neighborhood of 0.080". The hydraulic lifters are forgiving so a few thousandths either way will work. (Please double check my math)
Don't forget to check your PTV if you installed an MS4 cam as they can be tight on clearance.
