351W Pushrod Length

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Jul 1, 2012 | 09:19 PM

mikepedersen17

Thread Starter

Junior User

Joined: Jan 2010

Posts: 52

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From: Shelby Mt

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 !!

Jul 2, 2012 | 06:58 AM

baddad457

Hotshot

Joined: May 2003

Posts: 11,141

Likes: 25

From: south louisiana

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.

Jul 2, 2012 | 09:19 AM

Conanski

FTE Legend

Joined: Jun 2006

Posts: 31,930

Likes: 1,499

From: Ottawa, Ontario

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.