five7kid

iTrader: (14)

You don't "lose clearance" with one full turn down. You actually decrease slop and increase the ability of the lifter compensate for temperature changes.

You'll have more likelihood of durability issues with lifters adjusted 1/4 turn than you would with them a full turn down like they are intended to be. High RPM operation is absolutely not affected negatively with them a full turn down. That old "hot rod trick" was made moot in the 60's as hydraulic lifter design was improved over the originals.

customblackbird

iTrader: (15)

so u recomend a full turn? even with stock or aftermarket lifters? im still alittle weary of my lifers. i just put in the LS7 lifters and i set them to 1/2 turn lash. but i have rocker ticking/alittle valvetrain noise under the covers.

five7kid

iTrader: (14)

Yes, one full turn down from zero lash.

TunedPort350

On his motor (1990) the oil pressure sender/switch is integrated into one unit, that is located near the oil filter. GM did away with the separate switch by the filter and sender by the rear china wall and made them one. I think the transition year was 88 to 89 for this...

He will have a plug located at the rear china wall, he can remove this to attach a mechanical gauge and also makes a nice spot to connect an aftermarket gauge.

JakeJr

I totally agree. I'm against the 1/4 turn preload (or less) that so many have started using, especially with GM lifters. Crane even warns that lifter failures result from such minimal, 1/4 preload.

I can find the link to the site and post it here if you want me to. I even found a site saying that, after extensive testing, they found LS7 lifters like more preload, too; more than 1/4 turn. Something like .050"-.080". All of the testing results are available on-line; I just used GOOGLE.

The GM FSM for my 96 LT1 says ONE FULL TURN +/- 1/4 TURN which translates into 3/4 TURN to ONE AND ONE-QUARTER TURNS (1-1/4).

As an additional benefit, the valvetrain runs quieter with more preload rather than less.

Jake

rockstar08

Finally got to the bottom of this, it came down to 2 worn exhaust valve guides on #7 & #8 cyls, with seized lifters contributing to the noise problems I was having.

The stuck open oil filter bypass explained the metal shards.

I have no idea how many miles were on the heads, the right side has some minor damage, missing a chunk, where the frontmost intake bolt hole had been tapped to a larger size.

I'm going to replace with some aftermarket heads.

Thanks for all the advice, and help in understanding my engine a little more.

You guys rock!
Rockstar08

JakeJr

Okay. Glad to see you finally tracked down the cause of your problem.

Have you started your research for a new set of heads yet? Just wondering which way you're leaning.

Jake

customblackbird

iTrader: (15)

glad to see u figured it out. i told ya the speed pro lifters are cr@pola!

jake could u post the link i just want to read what your saying. so you are saying GM LS7 lifters like more than a 1/4 turn past zero lash? and they recoment anywhere from 3/4- 1 1/4" turn past zero lash? bc im only running a 1/2 turn and mines still rather noisy. i think i might step mine up to 3/4-1 turn if u say thats correct.

JakeJr

Wow. I've saved a few on the LS7s. What I have to do is log on to the site where it's posted then read the article in order to find what you're looking to read.

I found the one below right off, but I need a little more time to track down the others.

http://cranecams.com/?show=newsLetters&no=112

I was about to head out for dinner, so I'll get back to you after I return.

http://www.strokerengine.com/SBC.html

Jake

Damon

Oooooooo...... I was actually right about something!! Somebody mark the date on the calendar! First time ever for me.

JakeJr

I'm glad you were thoughtful enough to post what the cause of your problem was. Even though the Factory Service Manual lists worn guide(s) as a possible cause, worm guides so seldom shows up on the Forums that we tend to discount it.

Whjat I'll do is keep your situation in the back of my mind and pass it along to other members when I see similar posts.

Do you have any idea on how they could have become worn to that point? Did you make any change in the valve train that could account for it?

Thanks,

Jake

customblackbird

iTrader: (15)

jake, from the first link it talked about the Ls1/LS6 engine and how roller lifters operate best at .050-.080" lifter preload. what does this equate out to in turns? So now u got me thinking that the 1/2 turn past zero lash isnt enough for my engine which is why im hearing valvetrain noise.

I now just read in the second link that they like them to have .060" cold lifter preload which equates out to about 1- 1 1/2 turns past zero lash am i correct? so i should set mine to about 1 full turn past zero lash?

also since i have already set my lash to 1/2 turn, does that i mean i can just loosen the poly lock and just adjust the lash another 1/2 turn? or do i have to do this from the beginning?

thanks again jake, im surprised they say 1 full turn when comp cams said i would surely destroy the cam and lifters and strongly said not to do it. i just want the valvetrain noise to and alittle more vacume as well!

JakeJr

Send me the link where Comp says that.

Jake

customblackbird

iTrader: (15)

I was on the tech line with a comp cams tech guy and he stated not to ever go past 1/2 turn on lashing on a roller lifter setup, he stated that i WILL destroy the cam and lifter.

its also in there cam installation instructions and rocker lash procedure.
go to #11 on the PDF, it states the order to lash the rockers and how much (1/2 turn)
http://www.compcams.com/v002/Instructions/Files/145.pdf

so wat do u recomend, basis of both those links u posted i could step it up to 1-1.5turns past zero lash? and can i just add 1/2 turn to my already lashed lifters or do i have to start all over?

JakeJr

Now I'm wondering where in the world THAT came from. I mean how did that tech guy come up with that. That flies in the face of everything I've ever heard or read; wonder what he was smoking, LOL.

You probably know that I read a LOT, especially CompCams' stuff, since it's MY CAM COMPANY! Yet, I have never, never, read anything like that; that it will destroy the cam and lifter. NEVER.

What lifters were he referring to when he told you that??

I'm definitely going to research what you said he told you. In fact, yesterday I received Comp's NEW catalogs and I'm going to hit StarBucks, have coffee and read, read, read to see if there's anything in there along those lines.

BTW, for some reason, I couldn't get the link you posted to work for me. I do know that the literature I have from Comp says the recommended preload is .030" +/- .010". That translates into 1/2 turn of preload from Zero lash.

Is there a way you can email me that pdf. file so I can read it? jcameron266@sbcglobal.net

HOWEVER, GM's Factory Service Manuals for both the 86 (L98) says ONE-TURN DOWN and 96 (LT1) Vette recommend ONE FULL TURN (+/- 1/4 TURN).

It's not necessary to start over from scratch. Just loosen the set screw (assuming you're running poly-locks) and add the additional 1/2 turn of preload.

Both my son's 96 LT1 and mine are running 3/4 turn of preload on LT1 lifters. LS7s are different though, different from LT1s even though GM claims they're a direct replacement.

Guys have measured them and found the pushrod cup is at a different height; then there's swome confusion about the oil hole being at a different height and there are some other confusing issues too.

One guy posted some photos showing a difference in height between the GM LT1lifter and the LS1 lifter. Whether that height difference translates to the LS7 lifters too I don't know. One guy says LS7 lifters always cause oiling problems. I'll post the link in a few gotta track it down again.

This lifter preload confusion is all over the map. There are so many differing views it's big-time confusing. What I do is set the amount of preload based on the lifter i'm running.

Jake

JakeJr

Here's the link to the photos, etc.

http://www.z28.com/forum/engine-tech...t-motor-2.html

Jake

customblackbird

iTrader: (15)

http://www.compcams.com/Technical/FAQ/FAQLifters.asp

here it states 1/4-3/4 turn past zero lash. i can send u the link for the cam install and valve lash instructions that come with there cams.
http://www.compcams.com/Instructions/Instructions.asp
click that and download the first one (4934) and go to #11. it states 1/2 turn past zero lash.

the guy stated that for stock lifters 1/2 turn is the max and he wouldnt even do 3/4 turn. this was with stock replacement speed pros. I never asked them about the LS7s bc at the time i havent replaced the cam or lifters at that time.

Ive been reading about the LS7 lifters they say .060" cold lash, but most LS guys try to shoot for .080 as the sweet spot. but most like it around .091". Some run them up to .120" without issues. heres a thread on the info of the LS guys. they state also that the LS7 GMPP lifters are an upgrade and are build with lightweight internals and solve the RPM issue with the stockers that allow these lifters to rev to 8000-8500RPMS without issues.... this makes me happy

I also posted pics of the stock L98 lifter height differences of the piston cups. the LS7 lifter cup is slightly higher than the stock replacement speed pros.

heres the link of the LS guys talking about preload.
http://www.ls1tech.com/forums/genera...066-091-a.html

my issue is that i dnt know what .080" of preload equates out to as far as turn on the poly lock. Yes, im running poly locks and if i can throw another 1/2 turn on them i would in a heart beat. The LS guys have to worry about the aluminum blocks and heads they have bc they expand twice as fast as iron, and that changes lifter preload. Im running stock iron block and aluminum heads so where does that put me?

customblackbird

iTrader: (15)

i can tell u that the LS7 lifters that i bought didnt look like the ones he posted on that last link u posted. here is what the LS7s look like from GMPP... they arent stock LS7 lifters they are a performance upgrade that solved the high RPM oil problems. this is the thread i started and i posted pics of the LS7 lifters compared to the stock speed pro replacement L98 lifters. and posted the lifter pocket height differences.
https://www.thirdgen.org/forums/tech...nt-roller.html

customblackbird

iTrader: (15)

i found an old thread that u posted on before jake. on LS1lt1.com

heres the specs for the tightening the rocker nuts to acheive correct lash. How am i suppose to reach .080" preload tht would be roughly 2 full turns to get .080". but i would also need 1.5 turns to get the minimum cold lash of .060". If what everyone is saying 3/4- 1 1/4 turns to get preload then that would only put me at .030-.050" preload.

\This is what preload is using the stock 3/8-24 rocker studs (7/16-20 studs will take slightly less turns to reach the same preload):


.020 = .48 turns (roughly 1/2 turn)
.030 = .72 turns (just under 3/4 turns)
.040 = .96 turns (not quite 1 turn)
.050 = 1.2 turns (over the GM recommendation)
.060 = 1.44 turns (well over the GM recommendation)

this is the link
http://www.ls1lt1.com/forum/showthread.php?t=33184

JakeJr

Here's the latest: I just read info in the new CompCams's catalog that I received yesterday, part # 106-07. On page #21 it states:

"With the cam on the base circle (valve closed) the plunger in the lifter should be depressed .040"-.060".

So Comp has increased its recommended preload setting. I'm going to update the STICKY posts I've put up on a few Forums since I prefer to follow the 'written' word.

Jake

JakeJr

I wouldn't aggravate myself about this any longer. I'd just go one full turn and call it a day.

Jake

customblackbird

iTrader: (15)

why are u getting aggrivated? a full turn would barely meet the minimum of the comp cams specs. im just saying, wats the difference between the recomended .060-.091" recomendation on the LS engines vs a .040-.060" that comp says. i just want to adjust them correctly and not destroy another cam.

CrAlt

Small exst manifold leak?

JakeJr

Aggravated? Not me; I was referring to you. No need to be **** on this, just make sure you have the correct pushrod length, with no binding or interference anywhere. Then set the lifter preload at one full turn and move on to something else.

Whoever told you that one full turn would destroy your cam and lifters has to be from a different planet.

Jake

rockstar08

Not sure of the history of this car before I purchased it, it has 186K Miles on the odometer, a re-tapped intake bolt hole and had felpro gaskets on the intake when I removed it, so its definitely had some engine work done. The valve train was not adjusted by me before the problem came around. The reason I bought the car was because the engine sounded and actually driven really well. I really only wanted to do suspension/brakes/body and interior before this happened. I'm thinking it was just its time to die. There is also a horrible oil leak coming from somewhere at the rear of the block, it's not the rear crank seal or pan gaskets, so it has been around the block a few times.
Also all of the other fixes I found when going through the car were very poorly done, its former owner had some very shoddy work done on it. It had a missing thermostat, bare battery wiring, bypassed fans (using electric lamp wire to the fuse box!) and a bunch of codes that I had fixed with temp and O2 sensors and some really old splitfire plugs that put HC's in the 2's.

I like to get to the root cause of something before I make a choice on how i'm going to proceed. Just throwing parts at it, is not my way, at least if I can avoid it. So I really appreciate the advice, knowledge and the capability of the people on here.

I'd like to get some prebuilt in-expensive aftermarket heads. I'd like them to bolt up to the stock intake/base plate and exhaust manifolds, and keep the stock cam for smooth idling. I want to budget around $800 for all the parts and $200 for a local dyno tune. I don't want to set the rear tires on fire, or to chase performance heads with more performance parts and get on that money train.. i'd like to keep it simple.

Can you advise on any heads that might suit? Also will i have to measure pushrod length with aftermarket heads? Do you know the install procedure for non factory heads?

JakeJr

Based on what you posted, the oil leak seems like it's coming from what we refer to as the rear China Wall. Now, it's possible that it's coming from the oil sensor/sender screwed into the back of the block, slightly to the driver's side, but most often it's the China Wall.

If that turns out to be the location, I posted a STICKY ON LS1LT1.com on how I re-seal the intake. It's on the LT1 Tech board.

As far as heads, new aftermarket heads will probably run a bit more than $800. I don't include Patriot heads in that because I have strong questions about the quality of the casting. Guys gravitate to them because of their price, but I look beyond that and check the quality of the product.

Next in line, price-wise, would be Edelbrocks. i haven't checked lately, but the set I bought for my 86 Vette ran right at $1,000. Beyond that would be Darts and Trick Flows, but now you'll be in the $1,300 range. I paid $1,350 (shipped) for my son's Dart Pro 1s last summer from JEGS.

Air Flow Research heads are, to me, top of the line, but they're more costly and availability isn't that good last time I checked. It may be better now than when the first Eliminator versions were released.

Of course, having your heads ported is an option and you can get around 250ish CFM out of the good LT1 castings, 643s being one of the two. From what I've read from porters on different Forums, the LT1 heads are better to port than the LT4 versions.

If you're going to change heads, that would be the perfect time to repair the oil leak - two birds with on stone. Adding a cam down the road will really wake-up the engine, but you can do changes in stages - which many guys do - because of budget concerns.

The trick to over-come the other guy's shoddy work is to be detailed in your thinking and work. Check all the parts, both new and the ones you're going to re-use - for wear or anything out of the ordinary. Don't be reluctant to ask questions on what you find and what you're considering buying. You may not get universal agreement (what else is new) but there's a lot of good info on this Forum.

Hope some of this helps.

Jake

customblackbird

iTrader: (15)

i Agree on the china wall. i did my engine swap with no leaks first time. i had to do a complete tear down due to a rod contacting slightly with the cam at 5500ish RPMs, not to mention a destroyed cam due to 2 lifters (speed pros stock replacement roller lifters). i put it all back together and installed the engine. ended up having a oil leak that i couldnt trace. figured it was coming out the back of the block but not the rear seal since it was all new and i could see it. it was either from the head or the back of the intake. i tore the intake off but couldnt really tell. i REDID the china wall with MORE than enough RTV but not to much to get sloppy and so far i didnt have the problem anymore. it could be the oil pressure sender at the back of the china wall but i would pull the intake and redo it, again nows the time to do the heads.

as far as the patriot aluminum heads... im running them. i got the 195cc versons. aluminum and ported. came with 2.06/1.6 stainless backcut valves that were .20" taller than stock(this required me to get .100' longer pushrods) i got taller valves bc i upgraded the springs for a high lift roller cam. the stock springs on the heads are good for .525 with a hyd flat tappet cam, they were single springs 1.25". my upgraded springs are 1.45" i think, they are dual springs and good for .720" lift!!! my cam has about .576/.571' lift. they also came with guide plates, valves have a 5 angle valve job, hand ported, partly CNC combustion chamber milling. they come with vitton seals and bronze guides. they are also tapped for centerbolt/perimeter valve covers, and vortec and chevy style intake patterns.

i have no complaints on the heads so far, with my 383 , holley stealth ram, patriot heads and XFI280 cam, 3.55 gears and a posi, 700r4 with 2900stall ive ran a best of 13.5s in the 1/4 WITH A BROKEN ROCKER STUD and a destroyed lifter whos guts were in my lifter valley. that happened at 3/4 the way down and it was still pullin at 5500. the 13.5 is slow bc my 60' is 2.2s bc i cant get traction for my life. this should be a lowwww 12s/high 11s car with these heads. so for the heads quality i have to dissagree. if i could afford AFRs i would get them but these were the right price of 866$ shipped to my door with the upgrades.

Gadp74

Finally this is over, it's been a long time to get to the botton of this problem.

I have the same problem, same noise (first video).

My friend gave me a Firebird formula 1989, 305 CI, TBI, 69.XXX original miles, onw oner, left in my friend's backyard for 10 years, I am not a mechanic but follow instructions very well, changed fuel tank, fuel sending unit, fluids, fuel filter, TBI, filters, timing chain, cleaned fuel lines, valve covers, gaskets, new distributor, spark plugs, wires, turned the engine first after 10 years ( no problems), put some marvel mystery oil in each spark plug hole to lubricate before I start the car.

I turned the key and YES!!!! The car its running ( my first time doing this)...but I have the same ticking noise.

THAT'S WHY I WANT TO THANK EVERYONE OF YOU GUYS, THIS INFO ITS LIKE GOLD.


hmm exhaust valves

JRNYMNDAVID

Could be a worn cam lobe.