bayer-z28

iTrader: (14)

ok. From what I know and understand, also from what I have heard..... You cannot adjust lifter preload on stock rockers. -W/o modification.

We did an MS4 H/C install on -=Modified=-'s car. LS6 Stage 1 heads, stock .054 GM head gaskets (I'm pretty sure on the thickness)... We started w/ 7.400 PR's... Ticked like crazy... TSP said we needed 7.425's... we installed them.. Still ticking. We just installed 7.3-somethings tonight... STILL TICKING!!!...

This time, it was quiet until it warmed up, it was babied until it warmed up then a couple small pulls w/ it... (SMALL pulls).... then the ticking started again.

Lifter preload could be established w/ longer pushrods, correct? If they are shorter than the length that is needed, the rocker can only be tightened to a certain point. THe way they are now, we can spin the pushrods, but no vertical play. The rocker tip can be slightly lifted off the valve tip by hand. Prolly 1/16".. not even (WTF is the point of HYD lifters then?!?! Make up difference in valve lash w/ hydraulic pressure. ~.020, tho.). then you can feel the lifter plunger getting tight. How much trow do the lifter plungers have anyway?? 1/2"??

What makes sense in my head, longer pushrods would push the lifter plunger into the lifter for the needed preload, before the rocker fulcrum is TQ'd to spec (seated, tho)... -Was advised on another board... (similar terminology)


THis is taking every bit of theory I can dig up in my head from school to try to figure this damn problem out! It's getting really old! Wouldn't stock length push rods work w/ stock head gasket thicknesses?? Lifter preload should be accounted for w/ pushrod length and rocker TQ specs... .... ???..

heavymetals

iTrader: (3)

You need to get an adjustable pushrod.

You don't have 0.500" of throw from "off the retainer" to bottomed out.

About 0.250".

Your ticking noise is because they are to loose.

I set mine for 0.016-8" before the lifter bottoms out but I have adjustables.

None the less, yours are set too loose.

Go up another 0.050" in length.

The reason to go adjustables is so you can set them all the same, something you can't do easily on non adjustables.

Besides, adjustables give you something else to adjust!

PREDATOR-Z

Theoretically speaking with your setup you should run 7.450 on intake and 7.425 on exhaust. Reason being that you have a cam with dual lobes, LSK being smaller than XE-R in base circle.
You can run 7.450 on all valves with no issues if that doesn't quiet it down then you ticking is not preload related.

bayer-z28

iTrader: (14)

Why does it just seem to come from the same side #3 or #5 cyl (driver's side)

I've heard a lot of people having lifter problems. I thought LS1 lifters were quite durable.

mvvette97

iTrader: (18)

I had one fail. Had to pull the heads and put new in. I also had the same ticking as you and tried everything to fix it but nothing worked except for new lifters

cantdrv65

iTrader: (3)

If you do not hear ticking across the board then it is not a preload issue....

Jrp1978

iTrader: (10)

Good thread !

Dandy Don

Just got my head cam and headers done on my Z06, much louder valve train noise than stock. Stock 64cc heads with .045 head gaskets, used 7.4 push rods, lots of ticking but in particular when I wind it up and then come back down to between 1500 and 2000rpm, I have what sounds like to me, a lifter that is not pumping back up. Very loud clacking noise that last for several minutes and then begins to blend in with the rest of the slight ticking noise from all the other valve train components.
Does this sound like a weak lifter, and will it do any harm to the engine?
Thanks
DD

-=Modified=-

iTrader: (3)

You know after reading numerous threads here, CamaroZ28 and LS2 I believe it to be a bad lifter as well. I am going to order new lifters and 7.450 pushrods to see if that is the cure. To be continued...............

bayer-z28

iTrader: (14)

How would lifters just up and fail like that?? To much pressure from the heavier dual valve springs??

-=Modified=-

iTrader: (3)

I wonder if I would be safe going with GM LS7 lifters or spend the extra $$$ and go with something Comp Cams offers?
Suggestions?

DaddySS

If your lifters quiet down with right preload (probably will), stock lifters are fine. If the lifters fail - upgraded LS7 etc. lifters are a good choice.

-=Modified=-

iTrader: (3)

That is just it, does that loud knock mean they are failing?
I really want to avoid taking those heads off. They are such a pain in the *** due to my headers being in the way off the bottom head bolts. The exhaust could be cut again then rewelded but I would really like to avoid all that.
I had a budget on this project and so far have went way over.
I guess that has to be expected.

bayer-z28

iTrader: (14)

IF it's only on 1 or 2 clynders, it's not a preload issue. I've nailed that down.

DaddySS

Not true. If the others are only marginally OK, and a few are out of spec, getting them all within spec will help. I had a couple of noisy ones but they were all around .050 to .060 preload, added 7425s to bring preload to about.075 .085 and they all got nice & quiet. My valve train is really quiet now and it runs like a champ.

-=Modified=-

iTrader: (3)

Well there is definitly no preload with 7.425s as we can spin them even while torqued down 22 ft lsbs. Going to try 7.450s.

Cop Car

iTrader: (14)

you just put a big cam in there, expect the lifters to make noise. they make noise with the stock cam, let alone something with over .6 lift!

-=Modified=-

iTrader: (3)

This is not a normal noise. The sewing machine sounding rockers I can handle but not this constant knock coming from a lifter.

triblk6spd

iTrader: (2)

more on this please. i just hada new set of AFR 205's put on and the ticking is driving me crazy.

-=Modified=-

iTrader: (3)

I suggested to Jason @TSP that I try 7.450 pushrods because I can't even get to zero lash with 7.425s. I have tried 7.400 (got noise) and 7.425 (got noise but not as much). Then went backwards and tried 7.350s (noise is worse than ever). This noise is not the normal sewing maching noise rockers tend to make but a ticking/knocking type noise that gets louder and faster with repective rpms.
Before puttin in the 7.350s the 7.425s were in. We torqued them down to 22' lbs with valves open and closed and didn't really worry about preload. Before trying TSPs suggestion of going with a shorter pushrod (7.350) we checked the 7.425s and although they would not move up and down you could spin them. Basically they were torqued at 22'lbs and right under zero lash.

Going to put the 7.425s back in with some new LS7 lifters. (Possible collapsing lifters)
To be continued...................