Is my valve stem wear pattern OK

C

C0V3R

Member

Feb 14, 2003

524

0

16

Australia

Jun 8, 2006

#1

• Jun 8, 2006

• #1

I'm in the middle of a buildup (302w with trickflow heads) and just want some second opinions about the valve stem wear pattern I am seeing after adjusting my lifters. It doesnt look too terrible (in my limited experience), but its not quite on the center of the valve after rotating the crank through 4 rotations as you can see from the photo. What do you guys think?

 

Attachments

• stemwear.webp

  34.9 KB · Views: 380

thehueypilot

Active Member

Feb 25, 2004

1,084

0

37

Medina,Tennessee

Jun 9, 2006

#2

• Jun 9, 2006

• #2

No, they are too wide and should be more centered or just slightly inboard. The width should be about 1/16" wide max. Buy an adjustable pushrod to determine the exact length you will need otherwise you will wear out your valve guides real quick.

 

D

D.Hearne

New Member

Sep 29, 2000

11,730

6

0

south louisiana

Jun 9, 2006

#3

• Jun 9, 2006

• #3

Can't tell from the pics but you either need longer or shorter pushrods. What cam, lifters and pushrods you using now?

 

C

C0V3R

Member

Feb 14, 2003

524

0

16

Australia

Jun 9, 2006

#4

• Jun 9, 2006

• #4

Twisted wedge heads, 6.70 pushrods, trickflow cam ("Stage 1") and proform rockers. I'll post some more pictures tomorrow - what angles do you need to see?

 

C

C0V3R

Member

Feb 14, 2003

524

0

16

Australia

Jun 9, 2006

#5

• Jun 9, 2006

• #5

thehueypilot said:

No, they are too wide and should be more centered or just slightly inboard. The width should be about 1/16" wide max. Buy an adjustable pushrod to determine the exact length you will need otherwise you will wear out your valve guides real quick.

Click to expand...

I measured the wear pattern at less than 0.080 (which was spec'd as the maximum by trickflows manual)

 

D

D.Hearne

New Member

Sep 29, 2000

11,730

6

0

south louisiana

Jun 9, 2006

#6

• Jun 9, 2006

• #6

The pattern maybe OK, but it needs to be centered on the tip of the stem. You really need to use a set of "checking pushrods" to find out the length you need. Just off hand ( I may be wrong on this, visualizing it in my head) If the wear pattern is closer to the intake side, I think you need shorter pushrods, toward the exhaust side, longer ones.

 

thehueypilot

Active Member

Feb 25, 2004

1,084

0

37

Medina,Tennessee

Jun 9, 2006

#7

• Jun 9, 2006

• #7

The trick is to clean the end of the valve stem with carb cleaner. (use on rag) And clean the roller the same way to get all the oil residue off. Color the end of the valve stem with a black magic marker. Place the roller lifter onto the rocker arm stud and push down on the rocker arm firmly and twist back and forth about four to five times. Pull it back off and you should have a perfect witness mark to judge where the roller is touching the valve stem.

 

C

C0V3R

Member

Feb 14, 2003

524

0

16

Australia

Jun 9, 2006

#8

• Jun 9, 2006

• #8

Top of the picture is center of the engine.

I am probably not testing it the best way - I tightened the lifters (normal, not solid or modified) to a little beyond zero lash with the pushrods I have available. I am thinking that when the lifters pump up the pattern may move inward more as the lifters are probably compressing during valve lift. Does this make sense?