I'm looking for those whom have rebuilt their engines, or at least the top end. I also have a post going on at 60*V6 about this. Okay, I've been experiencing valve noise lately. I had reset the valves after finding out that compression was weak, about 30 PSI short of usual, about a month and a half ago (when the weather was decent on one of those freak "summer" days), and that's when I really started noticing the noise even worse (also after putting decent exhaust donuts in and killing those exhaust leaks ). I had set the valves backing off the stud nuts until I felt lash in the pushrods VERTICALLY, as I've found that the spinning the rods thing is pointless (set the lash so that the rods can't be turned, turn the engine over to check for open valves and there they go spinning again ), and then tightening the nuts a quarter turn after the vertical play in the pushrod was removed. That led to noise ALL of the time (I still run 5W-30 in the winter and 10W-30 in the summer). So, I broke out the FSM. GM FSM states that proper setting is 1 and a half turns after vertical play is removed (again, spinning the pushrods instead of checking vertical play). I'm floating valves now and getting nowhere.

The part where I need help is that I've seen so many blasted numbers as to the number of turns past no vertical pushrod play. I've seen anywhere from 1/4 (my usual spec) to 1 1/2 turns (FSM). I'm looking for someone who has done this recently to see if they can remember how they did this, and for them to maybe get some compression readings. When I set the valves a few years back after head gasket surgery, I had been running about 162 PSI or so (with the exception of the high pressure in #4 due to the valve stem oil leak). I'm caught between being and .

 

We rebuilt my son's 2.8 last year. With the engine on a stand, we tightened the rockers until there was zero vertical play, and then an additional half turn.

After installing the engine and running it, no further adjustments were necessary.

 

i just did mine the other day went 3/4 turn after no problems i would guess you could go anywhere from 1/2 to 1 1/2 ive seen lots of posts on this and all of those difftent turns seemed to have worked for everyone.

 

if your settings are according to gm i dont see how you could go wrong doin it that way

 

is this for your 3.1 if it has rollers it is set diffrent, i had a 3.1 at one time , and cant remember if it was rollers or not

 

if u want a sure fire way to get them right the first time everytime get urself a dial indicator and set it up on the lifter plunger and tighten the rocker till the plunger drops .020-.025 and ur done.

just make sure u do it on the cams base circle for each valve

 

1. No roller rockers. Stock non-roller cam.
2. As posted above, GM spec is not working, I'm floating valves and have about as much compression as my *** .049" model engines.
3. I'm on an EXTREMELY tight budget (if I wasn't, I'd probably be close to completion on the hybrid), and as such, no dial indicator.

I think I'm going to split the difference between half turn and GM spec to start. I have the day off tomorrow, and the only things on my to-do list are to replace the engine crossover pipe and finish cleaning the garage enough to get the car in there. So, I'll have plenty of time to get the compression back up. The battery, on the other hand, will be a factor in the compression testing. I'm going to have to replace that as well, I suppose, sometime, here.

 

start with a half turn and see how it works out good luck

 

now that i think of it i had a motor that would float all the time, turned out that half my valve springs were 1/4 to 3/8 of an inch shorter, they where just junk , changed em over to better ones and problem solved, mine would float at5000. just a thought

 

i dont know just how tight ur budget is but heres a dirt cheap one with magnetic base
http://www.wttool.com/product-exec/p...m_source=froog

18 bucks and they come in handy for lots of stuff

 

You have to make sure the lifter is all the way down into its bore.(valve completely closed) If its riding up on the cam lobe, you wont get an accurate lash adjustment. What I usually do is with the valve covers removed, I manually turn the engine over until I see the rocker arm I want to adjust drop all the way down. I turn the crank about another quarter turn to make sure I am on the base circle of the cam lobe.(If the rocker arm starts going back up, rotate the engine back until it goes back down again.) Then I spin the pushrod while tightening the rocker arm nut until I just start feeling resistance. Then I tighten the nut 3/4 turn more and that valve is done and on to the next. I do this all the time and have no issues with setting lash.

 

That's how I do mine. Wether or not there's oil between the pushrod tip & rocker has a large effect on how soon you feel it start to 'grab'. You want to run the motor briefly before you set lash to be sure everything's oiled up.

 

I was just going to edit that in because I forgot to last time lol. Make sure the lifters are pumped-up with oil. All lifters have a small hole in them that allows the body to fill with oil(hence the name hydraulic lifters). Lash should be set when the lifter body is full of oil for best reults. The perfect time for this is after you just shut the engine off. Id wait a bit for it to cool some then do your adjustments.

 

I've always gone about 3/4 of a turn past zero lash. If you can't get it, I'd back them all off and pull the lifters out to make sure you didn't wipe out the cam. I've seen that happen too many times for no apparent reason.

 

Incorrect lash can wipe the lobes off the cam because the lifter edges ride too sharply against the cam lobes. This over time will turn your cam lobes into fuel pump eccentrics in the not too distant future.

 

Once you start to wipe out a lobe, it gone in no time. They don't typically get gradually worse or anything.

 

Well, luckily for me, I have experienced with this engine mostly loose valves, especially before the head gasket change, and for about the last year or so, I would guess (which is why I'm looking into either getting new nuts or finding a way to use poly locks). I let the engine run for about, oh, five seconds, with the valves overtightened. There was a horrible noise due to the fact that I had neglected to snug down the rocker nut on the #5 exhaust valve, and the valve wasn't opening. Then, I went back in and it didn't even attempt to run with the floating valves, so I went yesterday and backed off a full round on all of the valves, and I'm now at 1/2 turn past no vertical play and running nice.

Besides, if the crap does hit the fan, I have a spare cam.