1SWT95Z

Hey guys just trying to see if anyone has done or heard of this. I have Sealed Power HT2148 lifters in my LT1 and I currently have them set with between 1/4 and 1/2 turn preload(best I can tell with a hydraulic lifter). They have always made some noise and I've been running them about 6 years now with the same preload. I just checked and re-set them over the weekend again at a 1/4 to 1/2 and they seemed a little better but only for about a day. Does anyone know if going to 3/4 or 1 turn would quiet them down? I have heard of setting them while running but how do you do that with a polylock loose and the rocker not moving around?

96capricemgr

iTrader: (1)

What rockers are you running? Those are usually what is noisy.

Far as a running adjustment you loosen them individually as you reset them so you do a static adjustment first, Then loosen each one and reset it individually.
Honestly though I have always been fine with static adjustment, played around with everything from about 1/8 to 5/8 or so and never found much difference in power, looser was maybe slightly louder but tighter was never all that quiet with roller rockers.
Have you considered a heavier valve cover?
Maybe play around with different brands or weights of oil?

1SWT95Z

Thanks for the reply. I have CAT Power (Ebay 1.6 rockers). I was not sure if I went back and put 3/4 to 1 turn if that would make it any quieter then it is now or if the rockers were what was making the noise. I have the stock valve covers. So you can adjust a polylock while it is running? I thought about going to 10W-40 oil as well.

Adam1203

iTrader: (5)

I ran those sealpower lifters and had nothing but problems with them. They always made a ton of noise no matter how much I adjust them. I constantly heard a ticking with them to. I also tryed different brands of oil as well as regular and synthetic and it didn't help. I didn't change weights though bu. At the beginning of the summer I switched to ls7 lifters and that made a huge difference. I

96capricemgr

iTrader: (1)

There are only a couple lifter manufacturers out side the very high end stuff.
That CAT stuff is rock bottom of the barrel junk. I bought a set of the 1.65 SA rockers to try on the intake side when I had a ZZ4 cam only setup and they measures 1.6. Vendor could not be bothered with the complaint because they knew there were selling garbage, seen a handful of cases of the SA washers spinning and chewing things up too.

Basically I would worry more about those rockers than the lifters. Do you have the original lifters sitting around?
IMO people are way way too quick to buy lifters, the stock stuff works great.

1SWT95Z

Yeah I know I should have spent more $$ on some Crane or Comp rockers but at the time I needed to get it put together and was nearly out of $$. As for the lifters, I'm thinking they will probably still make noise but do you think going to 1 full turn of preload might help some?

SoxXpupPeT

iTrader: (34)

If you were low on money you should of stuck with stock lifters for awhile until you were able to save for Quality rockers. As far as the preload is concerned id be extremely careful cranking them to 1 full turn past zero lash. Idk how they stack up to the LS7 lifters, but when i went more then half a turn past zero with them. You could feel the engine dumping fuel into the exhaust because the valves werent sealing. If you go to far you run the risk of putting a valve through a piston. id leave them at half a turn at most and deal with it until you can swap it out for something more serious.

RamAir95TA

iTrader: (2)

I think the CAT rockers are your problem. I would trust stock lifters FAR before that Chinese junk.

whytryz28

iTrader: (28)

I always set my lifters with the engine running. Keep turning til the ticking goes away and its set.

1SWT95Z

So basically both the rockers and lifters could be the cause. I did not want to reuse the stock lifters because they had 140,000 on them. So when I got a rebuild kit it had the 2148 Sealed Power lifters in it, so I used them. I figured they were probably an ok set of stock replacements. But now I'm not exactly sure if it is the rockers or the lifters since it continues to make some noise at around a 1/2 turn of preload. That was why I was asking if anyone had done 3/4 to 1 on a stock replacement lifter.

96TransAmboosted

iTrader: (8)

I run 1a turn pre load and the car ran much better, the 1/4 turn and 1/2 turn did not work well for me. But after the 1 full turn car had much better throttle response, and the idle improved. This was with comp 306 camshaft, sealed power lifters, 1.6 atlantic speed cheap rocker arms.

When i rebuilt the top end a few years later i replaced rockers only to comp pro mags non-SA and ended up gaining a more stable high rpm valve train and gained 6-7hp with the same tune pre-load ect.

And who ever said 1the turn will cause piston to valve issues is incorrect, not even close to being a consern with his cam or even a bigger one.

1SWT95Z

96TA did you have a lot of rocker/lifter noise and then go to 1 turn preload to fix it or did you just start with 1 turn to begin with?