Pushrod question

5.02GO

Founding Member

Jun 26, 2001

308

0

16

Ky, Blue Sky Country

Oct 10, 2006

#1

• Oct 10, 2006

• #1

I had my head machined. The machine shop took off .010.

I started my car up the other day and my rocker arms chattered for like 5 minutes befor they shut up. This has happend twice on cold start up. I may need to go back and retorque, but i dont think that is gonna be a problem.

Is the .010 machining causing me a pushrod length problem?

I would think if anything that the pushrods would be longer and it wouldnt be making any noise.

Crane energizer roller rockers 1.7
Original lifters
Edelbrock Performers with the "O" ring machined out
Stock length pushrods (6.27 i think)
Compression 140 to 150 psi

 

Aryan15

Member

Sep 22, 2003

236

0

17

CA

Oct 11, 2006

#2

• Oct 11, 2006

• #2

The -.010 head would bring the pushrod farther into the lifter, possibly collapsing it, causing noise. You might try a different viscosity oil or you can shim the rockers. It says in your profile that you have edelbrock heads. Or is it a different vehicle?

 

Aryan15

Member

Sep 22, 2003

236

0

17

CA

Oct 11, 2006

#3

• Oct 11, 2006

• #3

Never mind, you got the o-ring groove machined out.

 

bullitstang1313

Member

Jan 21, 2003

713

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16

Indianapolis / Columbus, Indiana

Oct 11, 2006

#4

• Oct 11, 2006

• #4

Did you check to make sure you had no piston to valve clearance? This surely has nothing with the chatter, but I see you went with 1.7's, stock length push rods, and machined heads. This means you valves are opening more than ever. You should probably get a pushrod length checker.

 

8

8950HO

New Member

Mar 31, 2005

658

2

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Oct 11, 2006

#5

• Oct 11, 2006

• #5

Did you take the time to set the correct preload on the lifters?

 

EDC

Founding Member

Apr 25, 2001

342

63

58

In the new shop... 24/7

Oct 11, 2006

#6

• Oct 11, 2006

• #6

8950HO said:

Did you take the time to set the correct preload on the lifters?

Click to expand...

There's the real answer...

A .010" cut on the heads shouldn't make that much of a difference in the noise of the valvetrain. If it's noisy, you have a dead or dirty lifter.

Ed

 

5.02GO

Founding Member

Jun 26, 2001

308

0

16

Ky, Blue Sky Country

Oct 11, 2006

#7

• Oct 11, 2006

• #7

whoopsy........

did not check the preload.

honestly............

i dont see that it makes a real difference. I mean, 21ftlbs is 21ftlbs. However, if it pushes the lifter down slightly then torque them........maybe it does make a difference. I dont know....... Explain.

I downloaded a installation instructions from crane. Gonna take the valve covers off friday and re-adjust.

If need be, i have some shim stock and i'll shim them .010.


Is there anyway to troubleshoot lifters?

Thanks guys!

 

EDC

Founding Member

Apr 25, 2001

342

63

58

In the new shop... 24/7

Oct 11, 2006

#8

• Oct 11, 2006

• #8

5.02GO said:

whoopsy........

did not check the preload.

honestly............

i dont see that it makes a real difference. I mean, 21ftlbs is 21ftlbs. However, if it pushes the lifter down slightly then torque them........maybe it does make a difference. I dont know....... Explain.

Thanks guys!

Click to expand...

Preload is the amount of depression you are putting on the plunger of a hydraulic lifter. Ford allows roughly between .050" and .080" for a quiet valvetrain. More racy application want less.

If you put too much, you "may" bottom out the lifter and make the hydraulic properties of the lifter useless. Too little and when the engine heats up, there is "clearance" and no preload so the lifters will tick.

When a lifter is gone, the internal valving acts up or fails, and the oil drains out of the body causing the hydraulic properties of the lifters to cease to function. Similar to a shock absorber which leaks all it's hydraulic fluid out. It can no longer dampen.

Ed