Push Rod Length?

[CamaroZGuy]

just went out and did some measuring, first tested with a stock push rod and the mark was a bit high on the valve then tested at a 7.250 and got this.



dose the 7.250 look like the proper length?

[Bersaglieri]

Looks almost like it has two patterns on it, is the old one towards the top?

Did you do a full sweep? Is this rocker in the middle or on either end of the head? Did the plunger in the lifter depress at all as you turned over the motor or did you mock it up as a solid lifter?

Which aftermarket heads are those, AFR?

Ok enough questions, if you checked all those things I'd say that middle line looks pretty much spot on.

[CamaroZGuy]

re colored the lifter after each test, and did 2 full turns of the crank (1 turn of the cam), set the rockers at 0 last then 1/2 turn preload, they are AFR 210's with a spring recommended by LE (not sure the make, bu i think a Lunati).

but i set my calipers at a 7.250 (cause i saw that Call911 was selling a set) and tested, as far as the stock size i could have probable gotten away wiht but the 7.250 looks better.

[chile]

it looks good. According to comp cam you want the pattern close to the center but leaning on the inside of the valve.

[CamaroZGuy]

it looks good. According to comp cam you want the pattern close to the center but leaning on the inside of the valve.

that is the method i used.

[Fastbird]

I think that looks good.

[96LT1355Z28]

Good video, here's what was sent to me by Lloyd Elliott years ago with pictures of how the pattern should look:

The following is a method of verifying proper valve train geometry. After you have estimated the required pushrod length using a Pushrod Length Checker, use this method to verify that the valve train geometry is correct (using the rockers you are using in your engine):

1.jpg

1
The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker


2.jpg
2
Install your rocker arm and set it up with zero lash.

3.jpg

3
Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.

4.jpg

4
Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.

5.jpg

5
Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.

6.jpg

6
Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.

[CamaroZGuy]

Good video, here's what was sent to me by Lloyd Elliott a years ago with pictures of how the pattern should look:

The following is a method of verifying proper valve train geometry. After you have estimated the required pushrod length using a Pushrod Length Checker, use this method to verify that the valve train geometry is correct (using the rockers you are using in your engine):



1
The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker



2
Install your rocker arm and set it up with zero lash.



3
Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.



4
Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.



5
Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.



6
Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.

pics are broken...but good info!

[96LT1355Z28]

Pics work for me can anyone else see them?

[CamaroZGuy]

Pics work for me can anyone else see them?

i just checked with IE, Fire Fox and Chrome and pics dont work.
adskjhfakjsldhfkjalshdlfkahdskljfahsdkjhf.jpg