02Reaper

iTrader: (2)

I have resorted to this to get your attention. . Why is it that with all of the people and sponsors on here, no one can figure out why the ls1 series engines make lifter noise. No one has really solved it, sponsors dont give a *****, we are the ones who suffer. Turning the radio up or getting a louder exhaust system doesnt cut it. I asked a simple question for anyone who knows how to PROPERLY build an ls1 based engine and I get no answers. Makes me wonder how many sponsors and people on this site can actually build an engine any better than your average joe. I have posed the question to a few sponsors on why more preload on lifters is supposed to make for a quieter valvetrain. Guess what? no replies. I have also Asked at what point is a taller lifter body necessary? Or a higher oil ring? Here is a statement pulled out of a morel lifer post.

Morel4 shows the height. This is what I bought them for. Note the middle smooth "ring" is higher on the Morel than it is on the Crane. My low oil pressure (currently) was being caused by the small base circle of the cam (1.265" base circle). The lifter was travelling down on the heel of the cam, and oil was shooting past the ring on the Crane lifter. Oil shouldn't be able to shoot past the ring on the Morel.

What is the smallest base circle you can have before this becomes necessary? Are most of us with problems already running cams with a small enough base circle to need this?

Here is another quote I pulled off of the design of the 02 ls6 cam compared to the other ls1 engine series cams.

The ’01 base circle reduction did not require a change in dimensions of any other valve train part, however, the 405-horse cam was a different story. "I wasn’t comfortable reducing base circle that much," Hicks told us, "without compensating for it somehow, because the position of the plunger within the hydraulic lifter is not optimal any more–you’re too high in the lifter.

What is optimal to GM? Every sponsor on here has a different opinion. Ive even asked some of them what gm's preload is stock. No one knew. SO SOMEONE PLEASE answer some of my questions. I think that the sponsors are full of crap when they put performance parts on our vehicles or sell them to us and then tell us. LS1 valvetrains are just noisy. I call bullsh-t.

ssheets

iTrader: (1)

And when you get them to flow lots of air they whistle

gollum

iTrader: (1)

Stock lifter preload is equal to 1 1/2 turns past the point when pushrod cannot be spun between fingers. The new Crane roller rockers are quiet because of the OEM 1 1/2 preload setting. Sometimes when swiching to an aftermarket cam that has a smaller basecircle, if you use the stock length pushrods you will have less preload. Less preload equals louder valvetrain.

Use of the correct length pushrods should allow compression of lifter plunger 1 1/2 turns of the nut till tight. If you use adjustable rockers, compress the lifter plunger 1 1/2 turns and then tighten lock nut.

Some engine builders say an engine will make more horsepower with 1/2 turn of lifter preload. But valvetrain noise will be louder.

soundengineer

iTrader: (16)

actually...they have figured out what the lilfter noise is...
most valvetrain noise is caused because of improper preload and improper valvetrain geometry.
you buy an aftermarket cam... it has a .030 smaller base circle...
you can get "cheap" pushrods at 7.400 or 7.450... difference of 0.20....
or a few more dollars and get it real close with 7.425 (only off by .005)
If you spend way too much money you can get custom length 7.430 pushrods and you solve your problem.....and thats only if you actuually measrue it as that.... to be perfect you would have to measure each individual lobe's base circle and get custom length pushrods for every singe rod...possibly having 16 custom lengths to make it really perfect(big bucks like the big boys do it on that route)
problem # 2...also answered.... with fast high ramp rates the valve gets a very quick up and back down again motion...and the reseat on the head WILL make a small click..... unless you go with a low profile cam...and then you wont get huge Horsepower gains....

I cant answer your morel / cam problem exactly ... but I always make sure to check all specs on a cam before I put it into an engine....and my guess is that the morel was designed to stop the oil blow by problem you experienced because of a smaller base circle cam

unfortunately I do not have a # on this... but those who sell the cams needing a morel lifter and those who sell morel would be able to tell you...but I wold start with morel technical support as they will have the most knowlede because they designed the lifter that way for a reason


of course its going to be a custom deal to get to 405 HP on an ls1 engine so the valvetrain would have to be changed to make the geometry right...it doesnt say he didnt compensate....he probably had to put in different length pushrods....or different lifters...or shimms underthe rockers...or any # of possibilities.... but without reading the entire article you only have a small snippit of info...its like saying the tortoise beat the hare without telling that its because the hare was goofing off instead of focusing on winning therace....or like saying....baeball game.....mets vs dodgers...blah blah blah...13-3...blah blah blah...and jimmy ended up in jail.......???? youcan see how that could leave too much open

call GM...talk to a tech person at GM...sponsors are not GM Design people... dont ask a lumberjack to perform brain surgery....
and I thought that lifter preload is supposed to be .060-.080(on ls1's approx 1.5 - 2 turns usually with proper valvetrain geometry)...but I am not 100% sure...again...I'm not GM....


play nice.....

02Reaper

iTrader: (2)

Soundengineer,

You make some good points, but if you go by the turns method of preloading lifters, you are only guessing what the preload is. Stock preload from what I have measured and from what some have measured on here is anywhere from .090 to .110. That is a good bit off from what most manufactorers will tell you, which is .020-.060. Some say .030 max. Then again, its all supposed to be (drop in replacement). Who really knows what is going on. From what I have seen in my own experience. More preload equels more noise. The less I have on there, the less noise I have. As of right now I have about .020 of preload on the base. I am using 7.300 pushrods. 7.350 pushrods and it gets a lot noisier. 7.400 pushrods and it sounds about the same as the 7.350's. the plunger in the stock and stock replacement lifters bottoms out at .192 thou. The more preload you put on them, the closer you become to bottoming out the plunger, the less preload and you have more room to travel. I would think more cusion would be quieter, hence less preload. The lifter is supposed to compensate a decent amount anyway, Right? I really hope some good info and possibley an answer to our noisy valvetrain problems cam come out of this post.

soundengineer

iTrader: (16)

I didnt say I did the turns method...and again...I was not 100% sure...just trying to remember some #'s that I cant seem to find in paperwork anywhere at the moment.....
and it sounds to me like you went the wrong way with the pushrods unless you have shaved/milled heads...
if you have a smallewr base circle then you need a longer pushrod...meaning you might need to step up to a 7.450...not the 7.300 you have now....
have you measured the actual langth you need with any tools???

02Reaper

iTrader: (2)

7.400" pushrods equated out to the stock preload as far as turns go (.085 measured with dail indicator), with my smaller base circle cam and my heads milled .030. The noise was there though. You can mostly hear it around 2000rpms -3300rpms, and at Idle. when cruising, it is less heard. The shorter I have gone on my pushrods though, the less noiser the lifters are, compared to what others opinions are. That is why I asked what putting more preload on them is actually doing.

02Reaper

iTrader: (2)

look, already 111 views and only one person helping.

mrr23

iTrader: (3)

well let's see what i can add to the mix for you. some rockers and springs are just inherently noisy by design and materials. rockers give you the sewing machine noise due to the oiling design of hte roller part. here's vinci/crane's take on how they handle that situation. even marc_w can post about how much quieter his rockers are after he installed them and did the proper preload sequence. he did post in a thread about the rockers when he was having adjustment procedure issues.

this taken right off vinci's tech and tuning page you will find much more useful information there as well.

mrr23

iTrader: (3)

roger told me that GM uses a .090-.110 preload from the factory. there have been threads bout how much preload is needed. as the engine warms up, the aluminum expands significantly faster than steel. and if you do not have enough preload, you may end up with less than optimal to NEGATIVE preload as in the .004" preload issue. negative preload is a gap between the rocker and valve. now you have the clatter noise. now this applies to hydraulic cams. solid cams REQUIRE valve lash or negative preload.

hope this helps to clear up the reasons why and how to cure.

02Reaper

iTrader: (2)

I pm'd mark a week ago or so, but he did not respond back. I remember reading on one of his posts that after he had adjusted the second time around that a noise was coming back (maybe coming and going). The sewing machine noise that I always hear some talk about is not a tapping noise. If someone would host it, I would gladly record the noise I hear. It is definately something going on with the lifters ( per mechanics stethescope) I even have footage of the engine running with the valvecovers off. Still not the lifter tapping noises.

Nobody has answered my question yet about what more preload is actually doing, and also the question about the morels and base circle.

02Reaper

iTrader: (2)

Believe me, Ive tried to cure it with more preload, with less preload, changed lifters twice. The only thing that has helped is running a lot less preload. I am currently running .0195 hot settings. This is why I ask what putting the plunger closer to bottoming out is actually doing.

ssheets

iTrader: (1)

So you're complaining about nobody answering a question that you yourself can't answer???

There is a good thread in here that describes proper valvetrain setup. Starting with push rod length, wipe, rocker shimming and preload. I thought I had it on this machine, but it's not where I thought it was and I've got other things to do right now.

I'm with soundman, the right tech people should be able to explain proper valvetrain setup. If you're worried about PR length Summit sells adjustables for about $12. You can get an accurate measurement of what you need before you buy.

mrr23

iTrader: (3)

more preload is pushing the plunger deeper into the lifter body. as i was saying about the less preload and heat expansion, the aluminum expands quicker than the steel engine components. so this will raise the rockers further away from the lifters. thus creating LESS preload. just to throw some numbers around (not actual measurements) lets say the aluminum head and block once up to temp raises the rockers .050". now some say set cold preload to .030". as you can see, you would end up with a -.020" preload on the lifter. now you have a tapping noise. also, as rpms climb, all the components have less time to move. so, with not enough preload, the lifter can 'jump', ot 'loft' off the cam. now you have a tapping noise further inside the motor because as rpms climb, the lifter is more prone to jump off the cam at peak lift. then 'slam' down on the cam. this can cause valve float as some people have been talking about as well. then people blame the spring for not having enough seat pressure.

mrr23

iTrader: (3)

ok there's the difference. you are using HOT settings. most people are refering to COLD settings whe nwe talk preload.

02Reaper

iTrader: (2)

Exactly. I am not a sponsor. I dont do this for a living. I am sure a few sponsors have read this by now, but they dont dare post. Is it because they dont actually know themselves? It seems to me that they could come up with some better answers than ls1's are just noisy creatures. The lifters werent noisy from the factory. What is causing the lifters to sound like they are collapsed is the question. I know I am not the only one who wants to know.

soundengineer

iTrader: (16)

typically a smaller base circle (lets say smaller by .030) and milled heads (also smaller by .030) means you are right back at 0....
I would get a pushrod length checker to check your true length...
I thought the radius of the base circle was .776" or 19mm on stock ls1 cams for 02...and you said yours measured???1.265 where did you get this #??? is this a rocker ratio math thing??? that would put you at .744 which is .032 smaller.... meaning you need a 7.4 pushrod for your setup

get a puhrod length checker...and find out for sure....
try one of these
http://www.jegs.com/cgi-bin/ncommerc...81&prmenbr=361
or just about anybody's length checker for that matter...
use it to check with your current rockers/cam/heads setup

then check preload....
http://www.cranecams.com/?show=hydraulicLifters
about half way down is a pretty good way to check preload on hydraulic lifters(like our ls1/ls6 engines)

if you have a pretty health cam lift and duration...you will always have some noise from the valves reseating afeter such a large lift.....

Lvmyz28

iTrader: (1)

How about the fact that it's an aluminum block! Aluminum does a lot of things that cast iron dosn't do! An alumnum block will transfer sound from the inside of the block to the outside were a cast iron block will insulate the sound more! So a little tick will be heard on an aluminum block, where that same tick on an iron block proly won't be heard. It's life. Live with it! Or get a 6.0 LQ4 block!

02Reaper

iTrader: (2)

This sounds like a very good explanation. I thought the hydraulic lifter was supposed to adjust itself within a good margin though, so why would preload affect this?

ssheets

iTrader: (1)

Well it would seem to me that noise is secondary to performance and as for sponsors...it is Saturday.