How come? Is there a difference between setting preload with pushrod length vs. adjusting the rocker arm in relation to the lifter? I'm not arguing, I would really like to know

 

no bashing . . . it's cool


There's been several build threads from a while ago that were done by HKE or LME . . . one of the shops that builds motors in the Hosuton area. They went over their reasons for not using a "stock OEM" lifter vs an aftermarket lifter. It all had to do with setting tollerences. I'd have to look back, but it's been a while, and they stopped responding once the got too popular.

this was all "internet" reading . . . I've never adjusted a set of adjustable rockers myself.

 

So there is nothing wrong with these lifters. In my racing experiences throughout the past 23 years I have always adjusted rockers the same way. I didn't think there was anything special about these lifters. I guess thats why I should stick to my original plan and go with it. Just as exhaust valve opens and adjust the intake and when the intake valve is about to close adjust the exhaust valve. I also put a dial gauge on the rocker to see how much pre load I was getting and with 2 turns I was getting over .120. With the 1 1/4 turn I was getting .065, just where I want them. If it needs more I will adjust while the engine has been running. I am just not use to the GEN III engines yet. This is my first build and I am also in the middle of building one for my drag/street car, twin turbo 404.

 

I think that you'll be OK doing it the old school way Zittman, as you mentioned, it's a cam-in-block pushrod engine with factory hydraulic lifters.

.065 preload is right where you want it, from what Richard at WCCH has told me. It's been posted that .030 to .080 is what you want, with .060, right in the middle, being most desirable.

I've always done it the old school way, but that was on sbc's,...and I usually ended up re-checking them with the engine running while oil was shooting all over the place I used to have a set of sbc valve covers that I cut the center out of for adjusting rockers with the engine running, but it still made a mess lol. If you have a definite .065, button up the valve covers and be confident that you're good to go

BTW, just like many of us here, I'm learning these GENIII's as I go along

 

I just read my instruction sheet from Comp Cams.
Intake valve: turn engine in normal rotation direction, when exhaust pushrod starts to move stop, intake valve is on base circle and is ready to be adjusted. Tighten polylock until all slack is taken out and a slight resistance is felt when turning the pushrod, u r now at zero lash. Tighten the poly lock 1/2 a turn more, then set the lock screw. Repeat the process with the other intake valves.

Exhaust valve:turn engine in normal rotation direction, until intake pushrod goes all the way up, rotate past maximum lift approximately 1/2 to 2/3 of the way down. The lifter is now on the base circle and the exhaust valve is now ready to be adjusted. tighten polylock until all slack is taken out and a slight resistance is felt when turning the pushrod, u r now at zero lash. Tighten the poly lock 1/2 a turn more, then set the lock screw. Repeat the process with the other exhaust valves.

The valves are now at the proper preload.

This came from the instruction sheet for COMP Pro Magnum Roller Rocker Arms.

The comp R Pro Magnum Hydraulic lifters (part #875-16) require a preload of .002" to .004" for proper operation.

 

incase I missed it, what rockers are you going with?

 

Comp. But I am not running there lifters just cam and rockers.