351W Pushrod Length
#1
351W Pushrod Length
I am building a 351W, I have gotten rid of the d8oe heads and pedestal rockers, I am using Edelbrock E-Street 5023 heads and Comp Cams high energy roller rockers with 1.6 ratio and Comp Cams 35-239-3 extreme 4x4 camshaft. My questions are? ( head gasket at time of check .050)
My stock push rods are 8.180
head gasket compressed .047 felpro 8548pt2
1/4 inch clay no compress
3/8 inch clay .329 intake
3/8 inch clay smudged out to much exhaust
Per Comp Cams instructions; zero lash plus 1 full turn
.100 on intake .125 exhaust minimum valve clearance
.329 compressed clay
- .200 I will call free space
=.129
-.003 for head gasket
=.126
+8.180 stock pushrod length
= 8.306 new pushrod length, can anyone tell me is this where I should be Please let me know !!
My stock push rods are 8.180
head gasket compressed .047 felpro 8548pt2
1/4 inch clay no compress
3/8 inch clay .329 intake
3/8 inch clay smudged out to much exhaust
Per Comp Cams instructions; zero lash plus 1 full turn
.100 on intake .125 exhaust minimum valve clearance
.329 compressed clay
- .200 I will call free space
=.129
-.003 for head gasket
=.126
+8.180 stock pushrod length
= 8.306 new pushrod length, can anyone tell me is this where I should be Please let me know !!
#2
The pushrod length has nothing to do with the piston to valve clearance. The length has everything to do with the rocker geometry. Take a magic marker, paint the top of a vavle stem, then bolt on the rocker, adjust as necessary, then cycle the valvetrain thru a full revolution. Remove the rocker then note where the rocker contact lands on the top of the valve stem. It should be as close to the center as possible.
#3
Join Date: Jun 2006
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Expanding on what baddad said, ideally you want the rocker at a height where it is slightly below perpendicular to the valve stem when the valve is closed, and so that it moves through an arc that produces minimal inboard/outboard movement on the valve stem. Use the marker on the valve stem to visually indicate how much the rocker tip moves.. ideally you want to see a narrow line in the center of the valve stem.
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