After I did all of the modifications, you are right, I should have been right back at stock, and I had the 7.4" pushrods in there and measured preload to be .0855 and approx 1.75 turns after zero lash torqued to 22 ft lbs. Tap, tap tap tap, is the noise I heard. The shorter on the pushrods I went, the more the noise faded ( I think because of more cussion and now I have about .170 before the lifter plunger bottoms out in the lifter). From what I gathered, it would appear to me with the plunger closer to bottoming out, when the lifter comes off of the lift and slams down on the base circle of the cam, you have less distance and oil to cussion the fall onto the base circle. remember if you go by the stock settings which are approx .100 from what people are saying, you only have about .092 before the plunger bottoms out in the lifter.

 

I dont want to think that. Why are some quiet then. Sponsors still lurk on saturdays.

 

its basically a "shock" setting or a "seat pressure" for the little spring inside....
you have to have some pressure at start or it would travel till it has enough pressure to do its job...too much preload and it binds...not enough and it has slop before actually pushing up on the the pushrod...same deal as with installed heigth on valve springs.

 

What are your cam specs and valve seat pressures?

My engine makes very minor sewing machine noise. I believe the more radical the cam the louder the noise will be. Example: Faster ramp, higher lift cams, larger than mine in signature below.

Factory OEM uses much slower ramp speeds.

 

He has an iron block.

 

I am running a cammotion 221/221 .586 .586 112

.006 271*
.050 221*
.200 135*

and comp cams 918 valvsprings.

 

Yes, its a 5.3 liter truck, with an iron block.

 

My car made all kinds of strange sounds when I had 918 springs on my stock heads. They all went away when I changed to the tea heads with comp double springs.

 

Springs could be a possibility.

 

with the 918s I had false knock from 4500 & up. I had to run with the sensors off. With the double springs I have no problems.

 

Maybe it's just me but when start off with "ignorant" I'm not inclined to try to help.

This forum is made up of enthusiasts, some with lots of experience, some with less and some with none - that goes for the sponsors too - some are more retailers and others have lots of experience and talent.

Dealing with the LS1 and it nuances is not always easy and in some cases requires a good deal of research, analysis, trial and error, etc. which very few of the enthusiasts have the time for and the same goes for the sponsors - even the talented, knowledgeable and caring ones.

None of that however makes them or us ignorant, it just means most of us haven't figured this problem out yet.

 

ok here is the easy fix if all the problems are with preload and not knowing exact pushrod length, get adjustable rockers and you won't neet to worry about the pushrod being to long to short is it to much or to little preload casue of the pushrod??? adjustable rockers problem solved. i think someone correct me if iam wrong plz

 

The topic was used to get the attention to the thread. My last thread didnt even get one statement. Theres one thing about customer service, if you got one person sitting quietly waiting for you to do something and then one person breathing down your neck, which one are you going to be trying to get rid of? The whiner gets the attention, and the one who sits back seems to always get put on the back burner.

 

Problem may or may not be preload related.

 

I said that about 4 posts in to this thread. Although I better clarify; you use an adjustable rod to measure the correct length for your valvetrain geometry. As someone else mentioned already, "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..." So it will help, but you still need to do some set up work.

I'm with DaddySS, pretty hard to get excited about helping someone that starts with an insult.

 

The insult got you posting didnt it? Maybe you will help me, maybe you wont. No one posted in my last topic, so If no one posted in this one I still have nothing to lose do I? If No one with any knowledge wont help me, still, I have nothing to lose do I? the problem still exists.

 

yes an insult was probably the wrong way to go...
get over it...you're in here posting and reading too....

and I said that in post #4...which I started typing before post #2 and post #3 were even there....and I also stated that he should measure to find out for sure....

if you are not going to help...then get lost...and quit bitching.


now back on topic....

really the noise comes from valvetrain geometry mismatch....
we definately need to fix your geometry and put in the proper length pushrods first...(buy a checker like I talked about above) after that then it becomes important to get the proper preload..... try setting them for around .080 preload(factory ls1 preload spec??? ish???)....and then get the engine warm....stop it and check where you are at.... being that it is IRON it will not change a whole lot.... after is it hot...
what I dont know is what the hydraulic lifters preload should be for an Iron engine.... but we could do the same math for it too once we find out for sure...

and I guess we could try to find out what the stock hot ls1 preload actually is...and set it for that...that would most likely yield the best "quiet" results

my guess is that it is supposed to be around .030-.060 hot

the threads are M8 x 1.25
and count your turns.....

.080 [in->mm]
2.032mm (preload of .080 = approx 1 & 5/8 turns)
.030 [in->mm]
0.762mm (preload of .030 = 219* = just under 5/8 of a turn
.060 [in->mm]
1.524mm (preload of .060 = 439* = almost 1 & 1/4 turns)

.100 [in->mm]
2.54mm (preload of .100 = 2.54mm or 2.032 turns)


1.25 [mm->in]
0.049212598425196850393700787401575(1 full turn = preload of .049)
1.25 [mm->in]*1.5
0.073818897637795275590551181102362(1.5 turns = preload of .074)
1.25 [mm->in]*2
0.09842519685039370078740157480315(2 full turns preload of .098)
0.3125 [mm->in]
0.012303149606299212598425196850394 (1/4 turn = .0123 preload)


sorry about all the math.....

 

Wow what a thread but you know what i just got chewed out the other night on here for trying to educate some one on this board about stuff like this.

Sound man you are wright about your feelings most of the time people don,t care about how to fix it or find the cause of the problem.

I better stop why i,am a ahead.





Mike Rogers

 

teh key is that I keep trying to help..... and I back it all up with facts when I can

i try not to flame... but I dont have any problems putting out the fires coming from those who do...

sometimes I wonder why we cant all just get along.....
If I stressed like some people on here do sometimes...I'd have been dead by 25 form heart failure or an anurism or something medical

 

It sounds like your Cammotion cam is causing all of the commotion.

Websters definition of Commotion: noisy or turbulent disturbance; agitation; turmoil