pushrod length help

lunetick

Member
Dec 28, 2010
9
1
13
Illinois
HELP pushrod length ,did the marker trick with stock PR 6.272 its riding high on valve used a tape measure and its 16th inch to center from the top of the scrub mark.. What im coming up with is 6.272+0.625= 6.3345 plus .030 for using hydraulic lifter for a total of 6.3645 so the PR i need is 6.350? is that correct or am i doing it wrong??
motor is 331 stroker x303 svo heads 1.7 rockers unknown if block or heads have been milled
 
  • Sponsors(?)


90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
5,889
4,989
203
43
Make or buy an adjustable push rod. A cheap method is to take one out of the junk yard or an old one. Cut a piece out, tap threads in it and screw a stud in there. A long bolt can be cut to make a stud also. A tap and die kit is about 20 bucks at most part stores. Would be easier to buy one of these. I have everything to make them so I do. Cheap way out for me.


A measuring tape isn't precise enough. You need one of these. It has to be more than 6 inch reach...I have this 8 inch reach one from HF.


This will get you exactly what you need. You can adjust the rod to get the pattern you need. Then remove and measure it. .010 is very hard to see with the eye.
 
  • Useful
Reactions: 1 user

Bird76Mojo

Member
Jul 12, 2018
46
24
18
44
Central Illinois
From what I've been reading, a better way to achieve the correct pushrod length is by using the adjustable pushrod tool, but using a dial indicator, finding mid-lift (by checking total lift at the valve tip) and when you're set up at at mid-lift on the valve, the rocker should be exactly 90 degrees to the valve. I understand it may not yield the best, most centered pattern on the valve tip, but the pattern will be as narrow as it can be by using this method, which is the most important thing to look for.

Am I wrong here?