Comp R???
08-06-2009, 04:44 PM
#3
08-06-2009, 06:11 PM
#7
I have them, and they're a PITA to get set correctly, so to speak. I spoke with a Comp tech rep, and he was ADAMANT that you add no more than 1/8 turn of preload. He was also adamant that you don't set them with the car running, as most of us do...(you know, get them close, fire up the motor, back them off till they click, slowly bring to "zero lash", the point where the get quite, then go 1/8 turn more)
Here's my issue...The heads are aluminum, the block is iron, I think the lifters are some form of steel, as is the cam. They all expand at different rates, and getting the lash set accurately (because the tech rep said is it IMPERITIVE for correct operation)at full operating temperature is an insane balancing act. I wound up doing it two different times, for various, unrelated issues. The one thing I've noticed is that they are "clickey" but the Comp rep says that it's normal.
Long story short, the Comp rep says to set them by hand, feeling the "zero lash" point by the spinning pushrod method, with the engine off, and probably cold. I did this the very first time I installed them and they were really loud. The last time I set them, I initially got them close, fired up the engine, let it FULLY warm up, then set them with the engine running, as described above.
Here's my issue...The heads are aluminum, the block is iron, I think the lifters are some form of steel, as is the cam. They all expand at different rates, and getting the lash set accurately (because the tech rep said is it IMPERITIVE for correct operation)at full operating temperature is an insane balancing act. I wound up doing it two different times, for various, unrelated issues. The one thing I've noticed is that they are "clickey" but the Comp rep says that it's normal.
Long story short, the Comp rep says to set them by hand, feeling the "zero lash" point by the spinning pushrod method, with the engine off, and probably cold. I did this the very first time I installed them and they were really loud. The last time I set them, I initially got them close, fired up the engine, let it FULLY warm up, then set them with the engine running, as described above.
Trending Topics
08-07-2009, 08:15 AM
#11
Spinning the pushrod almost always results in way too tight for valvetrasin newbies. With a polylock like you will have on the roller rockers you are undoubtedly using with these lifters you can just spin the nut down till it contacts the rocker using no force.
The spin the pushrod thing might have some slight merit when used with stock rockerarm nuts since you can't just spin them down by finger. Even then though with oily sockets in the lifter and rocker there is a fair amount of pressure on that pushrod before you feel any drag spinning it. IMO that method shouyld be ignored completely causes a LOT more trouble for folks than it is worth.
The spin the pushrod thing might have some slight merit when used with stock rockerarm nuts since you can't just spin them down by finger. Even then though with oily sockets in the lifter and rocker there is a fair amount of pressure on that pushrod before you feel any drag spinning it. IMO that method shouyld be ignored completely causes a LOT more trouble for folks than it is worth.
08-07-2009, 05:52 PM
#15
To my experience, setting the valve lash in scenario "A" doesn't give accurate adjustments, however it was the way I first set my "CompRs". I'm reasonably certain that's why they were pretty loud when I started driving the car in summer temps.
08-07-2009, 10:47 PM
#16
I have only used stock lifters which have a really wide range of reasonable adjustment. By cold I mean -10f to +90f I have adjusted stock lifter in those extremes and had no troubles. I HATE working on cars when it is below zero but a couple years ago I took on a charity case and ended up yanking an engine and doing a cheap rebuild on a knocker, literally pulled the engine at -14f.
Unpon further thought the Comp Rs I would probably do cold, warm up the engine under light useage and redo since their range of proper adjustment is so narrow.
Unpon further thought the Comp Rs I would probably do cold, warm up the engine under light useage and redo since their range of proper adjustment is so narrow.
