Shadey_MF

After weeks of driving in snow i found some dry pavement and decided it was time to floor it. She was redlined for the only about the third time in this engines 10,000km life.

The next day I'm driving her nice and suddenly i notice I have to push the pedal 1/4 of the way to get the tires to spin on the wet road, then when i let off I heard a loud ticking and the engine tried to stall. Very similar to when I spun all the bearings, or just blew out the egr gasket like i do every 2000km. The full gasket set game with three base egr gaskets but do any fit..nooo. I have become good at cutting new ones from exhuast gaskets.

Upon pulling the rocker covers I was able to pull the number 5 intake pushrod out. Then i pulled the rocker arm to find a broken spring which screwd into itself. Until this day I've had a 100% sucess rate with "Sealed Power" brand engine mounts, lifters, etc.

I went to the place that rebuilt my heads and they gave me two brand new springs. They have been installed, but I'm scared to bolt them back together, because of something I was told by the head place. I was wondering why a spring would break and I brought up valve lash. To which he immediatly replied, you don't set valve lash on second gen 2.8L, you torque it down. What??

He decribed a typical 350 rocker stud, which is threaded all the way down, and a 2.8l stud that is treaded but half way down the stud and there is a neck on the stud. He tried to show me on a 3.1l sitting there, but it was wrapped in plastic and I couldn't make it out very well. The studs on my car are as he described.

He pointed out in the parts listing, under 87 it said that these engines have non-adjutable rocker arms. My engine has 1986 stamped on the block and a single belt set-up (87+). I wonder if this makes a dif.

I can't find any torque spec for the rocker arm.

What do you guys think of this situation. I don't want to put this thing back together until i found a few more sources of info. I don't want have to replace a cam in -40*c weather, it just isn't as fun as it should be.

also whats the record for reusing intake gaskets, I've reused them four times going on five. I have big plans brewing (i'll be asking in valve train performance Q's in another post) for the top end to be redone in april, I will change them then.

Later

big_al_47

All v6 camaro/firebird engines require the valve lash to be set, just like the v8s. The gen II engines w/aluminum heads in front wheel drive applications had non-adjustable rockers that were torqued to a specific setting. Your valves are adjustable.

Shadey_MF

Thanks for pointing me in right direction! I remember now that when I was peeking at his parts book it said W-code. I just checked my collection of vin codes and seen that all have an S in the 8th digit.

I'm thinking W-code refers to FWD 2.8L. And it also means Aluminum head, right?. i'm a bit shaky on that because I think i bought an s-code thermostat gasket and had to return it for a w-code, but memory is foggy.

I called the parts store and asked if they had valve spring for an 1987 firebird V6. They asked "S-code or W-code?" I said S-code, but I asked if W-code was different, they are. So i have to wait till wednesday for them. I'm thinking the rebuild shop rebuilt them as w-code.

Does anyone know if this is a big deal?. My new w-code springs looked like the springs that were in there. But if they were different, I think it wont be obvious.

If this is a big deal. I may have to find some rock-hard sources of info to get my heads re-rebuilt for free. and if i pull the head and see damage from the valve, well all hell's gonna break loose. At least this shop has a good reputation that they won't want ruined.


thanks

Dale

iTrader: (12)

All my RWD 2.8/3.1/3.4l have adjustable valves buy spinning the pushrod when you tighten. Then you go (books very) 1/2 to 1 1/2 turn more.

Sounds like you do need to do some major research. May be getting a new head job.

Other then info above, im no help, sorry.


But anyway we can convert our studs over to "non-adjustable"?? I would like that more

Gumby

sounds like you may want to contact a lawyer before you go much farther. Sounds as if the shop that rebuilt it didnt bother too check the right specs and your whole engine could be a timebomb waiting too go off.

Friend went through that with a rebuild shop, he then realized he should of called the BBB first, cause he would of found out about the 100's of complaints the shop had aginst them for shoty work.

You may find your self getting a new engine. I would not let that shop work on it again, if they are found at fault and must pay to rebuild it again right, just like fastfood , you complain at one store then goto another for new food, unless you like spit on your burger.

Denis.V

All the opinions here make sense. I 've a 2.8 V6 FWD with alum. heads (1988) and my problem was the same. I did a search and the 87-88 studs are non-adjustable (If you see a parts catalog you will see the following: "Non-adjustable. Replace for 85-86 adjustable studs".

O.K.?. Non adjustable use a 13mm. nut. Adjustable studs use a 15mm. nut. I changed all the studs and nuts from www.partsamerica.com and ready.

The only problem was: Some rocker arms can't be installed with the intake manifold in place an the news studs. You will needs remove the intake manifold or to put the new stud with rocker arm included and then thigten the stud using double nuts until 35 lbs. (For this I bought 15 nuts for the 12 valves).

Whit this job done, the valve adjustments will be the same for all the cars. (You can check my post for "valve adjustment" at "Tech General Engine" thread.


Denis V.

Shadey_MF

I found my reciept for getting the heads done, and the part numbers for the rebuild kit and gaskets are for a firebird. I checked that out at the shop that rebuilt the bottom end shortly after I installed the new heads.

I think I'll be okay using my s-code spring's i ordered. From the info denis gives me I'm sure i have ajustable rockers because i do have 15mm nuts I will be setting the valve lash with a compression tester, i should still be able to set all cylinders to 150 lbs.

I will just avoid 6000rpm shifts until spring.

In spring my goal is going to be to make this engine feel (but not sound like) my mom's 95 3.1L achieva. By this I mean, in nuetral, if hit the gas it instanly redlines.

My car feels lazy, it's faster than the Achieva, but after 2000rpm is climbs slowly. I think its like this because the cam i put into it has a flater torque curve (generic equivelent of that 2030 cam people here talk about). But I don't have enough experience to say that for sure.

I've been told that 3.4l heads are much better. I remeber someone here saying that those heads are a direct fit to a 2.8l. I must find these, and determine if i can pysically use the 3.4l intake. There are no emmision laws here, they just take your car away if its too rusty, or otherwise unfit. I will find the strongest springs possible and research the benifits of roller or performance rockers. I will find out if i can buy set of high quaility pushrods meant for an LS1 and use em. I'm impressed with my heavy-duty silent timing chain, i will proly re-use it because it was expensive and only has 10,000km on it. When I set the min air, timing, tps i was able to get the engine down to 200rpm and you can barley hear/see it running.

I will also learn the art of the dremel and do my first port/polish job, or most likely send it to a shop.

After I'm confident with the valve train it's going to be time to make use of my over-priced forged pistons and NEW crankshaft. Open up and say.. NOS

I'm gonna need new arm rests too, my g/f already digs her nails into the arm rests. She would have liked my old gold/black 6.6l '78 T/A named Smokey.


Later all

TomP

Woah, don't torque those rocker nuts down. Unless you've changed something that you didn't mention, our v6's (2.8/3.1) have hydraulic lifters. You don't set lash manually with a feeler gauge, and you don't go torquing anything down all the way, either!

A hydraulic lifter has a spring inside. You torque the rocker nut down until "zero lash" is reached, and then you turn the rocker nut an additional 180 degrees. This preloads the rocker. This is the non-expensive-gauge way to set up the hydraulic lifters. By going an extra 180 degrees on the nut, you start pushing the pushrod into the hydraulic lifter. Because of the threading of the stud, every little bit you turn the nut, the pushrod presses into the lifter by a certain measurement, for example, 0.010". So by turning the nut 180 degrees, you set the lifter up so it can be self adjusting- as all hydraulic flat-tappet lifters are. This information is directly from the 1986 GM Service Manual, and applies to all 82-92 motors, since they all used the same lifters.

You can't just go tightening for zero lash; you need to rotate the crank in order to get the valves to close. By bringing certain pistons up to TDC, you ensure that some valves are closed- and those are the ones you'd set. From what I remember, it's a four-step procedure (need to turn the crank 4 times before all are set up properly.) The end result of the procedure is the same- all pushrods are "sunken" into each lifter by the same amount. When the lifter "pumps up" with oil, the oil each lifter absorbs allows it to self adjust.

Zero lash is felt on a pushrod when the valve is closed, and the rocker nut is loose (or off). Start tightening the rocker nut as you jiggle the pushrod up and down. If there's play in the pushrod, you'll feel it "tap" against the rocker arm (upward motion) and tap against the lifter. Once that pushrod won't jiggle up/down anymore, you're at zero lash. Another way to find zero lash is by lightly spinning the pushrod- at zero lash, the pushrod will stop spinning since it's sandwiched between the rocker arm and lifter top- but this isn't too hot of a method- say you've got a heavier grip on the pushrod than I would, you might spin the pushrod for longer, and go past zero lash.

I'd do a search and bring up all my old messages, but search is still down. Hopefully Dirk has good luck with the server, we use those Ultra 160 cards in some of our servers at my job; they're pretty good.

I have to wonder if your shop torqued all the nuts down all the way, instead of following GM procedure. Yipe. I'm 99.9% sure that the lash adjustment for FWD aluminum-head splayed-valve 2.8's/3.1's is the "torque down all the way" method. I bet they confused your iron-headed Gen I motor with a Gen II engine.

Randy82WS7

what Tom said: follow his info, its zero lash plus one turn on hydraulic lifters when the lifters are at the bottom of travel in their bores.

good luck

badandy247

Tom, sometimes i think you know too much

Shadey_MF

300km and so far so good. I'm using 18* timing this time. More pull, and oddly the gas milage got even better. Good thing gas prices went up or i would be driving more. 90 cents a liter It ran rough until the computer until (i'm guessing) the computer figured things out.

One wierd thing though, sometimes when I floor it and let off, the engine makes a wierd rattling noise. Is this knock from the timing? I'll be trying 12* again tomorow to see.

I noticed the drivers side of engine made a metal/on/metal (there's a good 80's tune) claking noise that went away after it warmed up. I should have taken the other rocker cover off.

A tad bit more than 1/2 a turn is where the compression was best.

lets hope she holds till spring.

Sierra6

Digging this old thread up, because I need to know if the lifters need to be primed before doing all this? Unless I missed it, it doesn't say. I see a lot of contradictory info on whether they should be primed or not.

drdave88

iTrader: (3)

I always did it. Drown them in an oil bath and then push the plunger down a few times. Then install.

Sierra6

I called COMP and they said it's easier to not do it. Like it's not required nor beneficial. Also, my 1985 service manual doesn't mention doing it at all.