I was doing some reading the other day and came across this advice, when changing to roller rockers you need to check the push rod length, to make sure the tip of the rocker is moving across the center of the valve tip. Using an adjustable pushrod checker.
Got a chance to work on it Sunday, and went through the whole adjustment using a different sequence. This one is where you turn the engine until the #1 intake/exhaust are fully open, then adjust the #8 intake/exhaust. Then continue following the firing order. I think that's how it went, I had to print it out! Anyway I used 1/2 turn preload again but I added about another 1/8 on the 5/8 adjusting nut until tight. Shazzamm...It's a lots quiter and runs much better! A lot better throttle response, was a good bit lazy. I checked the pushrod clearance and they are real close to the heads, but I could spin several of the rods on valves that were closed before I began adjusting? So I'm going to drive it some and see how it's going to act. Thanks guys for all the help, that 'ol truck sounds like a AA/FD!
The new mo a friend had the same issue when he went to 1.6 in a new create motor. the holes for the push rod were to small
As another said check the under side of one rocker see if its scuffed from hitting the spring ratainer, or the retainer for marks, you changed the ratio, maybe a problem there, also cast covers will be more quite, is the roller tip running across on the valve tip, with out extending over the valves edge at one point
That's a good possibility, they look close but can't tell if they're actually touching. They still clatter a bit, but not near as bad.
Didn't have any of them off Sunday to check, but no they don't move excessively, but you can twist them a bit?
Do these heads on this crate sbc engine require "self aligning" rockers? If so and your new rockers are not, you need guide plates to successfully run them. Just a thought.
When you changed the rocker ratio you changed the spring requirements.Chances are the springs were designed to work best with 1.5 rockers.. I am assuming you checked and set height on the springs? If not the spring lbs. may be low if the spring is installed at a greater height. So many things to check for a simple change. Dumb question from me, why didn't you just buy the cam with the specs you wanted with the 1.5 rockers ?
An issue I had with a pushrod checker tool, Went thru the steps and measured the tool and ordered new push-rods, installed the new PR's and they came up .050 long, did it again and measured the tool and the PR's and they were the same but installed in the motor and they were .050 long. Come to find out that since the PR's were Chevy (oil thru the PR's), because of the oiling hole, the tip was machined off each end and they measure those off the flat, but the tool has a full radious tip which amounted to the .025 per end difference
The Jalopy Journal
