verano29

For those of you with comp cams 850-16 OE style lifters what preload are you using and what cam are you using it on?

verano29

Nobody running this sweet potato of a lifter?

PREDATOR-Z

I run these on my 370 cid with a 224/222 .609/.581 117 LSA (463 rwhp)
.085 preload hot

verano29

How about your lifter preload cold?

verano29

Just two of us running these phenominal lifters?

verano29

I can't believe there are just two of us running this shizzle. I realize the comp cams 850-16 owners are probably busy tearing up the track but I would hope they would make time check the forum.

PREDATOR-Z

.070 cold

verano29

Any excessive valve train noise with that preload?

PREDATOR-Z

why would I recommend to you anything with excessive valvetrain noise?

verano29

I didn't think you would. Seems that many people have valve train noise when they run less than .100" preload.

PREDATOR-Z

where did you hear that, .080>.100 is pretty quiet, but that is relative to lobes of cam used, (ramp rate), less than .060 is where it starts to tic more

verano29

I'm going with a 228/230 .571/.573 112 cam. Do you think I'll have any problems with a .075" preload (cold)?

PREDATOR-Z

if you measured correctly, NO no issues

verano29

Based on the fact that this gentleman is successfully running the same lifters as myself with a .070"-.075" preload I've decided to go with the 7.4" pushrods which should give me a .075"-.080" preload. If there is excessive noise (I don't anticipate this) I'll go with the 7.425 pushrods and I'll sell my 7.4s cheap (they are the comp cams Hi-Tek pushrods).

PREDATOR-Z

Either is fine, you cannot go wrong with either p-rod size (if your measurements are correct).

koolrayz

iTrader: (26)

I used those lifters with a 244 cam and a 6.35 lift. used about .080 preload cold

verano29

That makes 3 of us running these lifters!! And all of us are going to be running similar preload. Will all three of us be able to pull our front tires off of the ground too....I see a pattern here.

Pray

iTrader: (7)

I have run them for years with no problems. What do your preloads translate into turns? i.e. Is .080" preload equal to a full turn? I know you are going to say measure it, but alot of people don't have a dial indicator at the house, and you had to turn the the bolt a certin amount to get .080" preload.

verano29

I don't have adjustable rockers so the pushrod length will determine the preload. First I determined zero lash with an adjustable pushrod, then I'll add .080" to that and order that size. As far as number of turns: With the push rod checker each turn = .050" so to achieve .080 it would be 1.6 turns. I assume this is similar with the adjustable rockers as well.

Pray

iTrader: (7)

I was referring to how many turns past zero lash you have to turn the lock down bolt till you get 22ftlbs on a non adjustable system. When I had my stock rockers on my car it took about 1 1/4 tuns from zero lash to 22ftlbs. Then with my YT RR's it takes only about half a turn to 22ftlbs once I shimmed them for the propper valve train geometry, both with a 7.350 push rod. So I was wondering if there was any correlation between full rotations of the lock down bolt and thousand's of preload. Now I have a good number to go off of I am going to use my dial indicator and measure mine.