LarryD

Anybody tell me the procedure for valve adjustment on these engines?? What's the best way to "prime" new lifters before setting the adjustment??

Dale

iTrader: (12)

To prime the lifters, chuck up a IIRC 5/16 socket on a long entension and put it on the shaft in the dizzy hole and spin the oil pump. A cordless drill does not have enough power to do this, you need a full power drill.

The gm manual says 1.5 more turns after lash is removed, but I find that to be to much. Last time I left them at just .5 turns.

BTW, what brand/weight oil are you running?

LarryD

Thanks for the info... Not familiar with IIRC?? I haven't decided on what to run after I put it back together... Was running GTX 10/40..

Dale

iTrader: (12)

IIRC=If I recal correctly... meaning I'm not sure, but I think it was a 5/16 socket.

firstfirebird

iTrader: (3)

To adjust the valve lash :
1 . Put cylinder one to TDC (compression stroke)
2 . Adjust one, five and six intake valves
3 . Adjust one, two and three ehxaust valves
4 . Rotate the engine until cylinder four is TDC
5 . Adjust two, three and four intake valves
6 . Adjust four, five and six exhaust valves

To adjust the valve, slowly tighten the locking nut (make sure the pointed side of the nut is up) while you rotate the pushrod in your fingertips. When you feel the slightest resistance stop. Tighten the nut 3/4 turn, I like to go about 5/8's of a turn because more damage is done with them too tight that loose (can always re-tighten if needed).

When locating TDC of either cylinder four or one, make sure the timing mark is at "0" on the compression stroke.

Firing order :
(0) <----distributor
5 6
3 4
1 2
[iiiiiiiiiiiiii] <------radiator

LarryD

Thanks for the info.. Now that I have the rockers off, I see that on some valves (3 or 4), the top looks beat up... I'll try to post a pic but it looks like they were beat with a hammer and kind of mushroomed with cracks across the top.. There isn't really a ridge around the top edge so it didn't really mushroom out but the cracks in the top look a lot like an old chisel that has been beat on.... Never seen anything like that... So, it just got deeper.. Thinking about going ahead and pulling the heads for a valve job... Running out of money though for this project....

firstfirebird

iTrader: (3)

You're better off going on e-bay, they have 60* V6 iron heads rebuilt for less than $200 (including the gaskets) all the time (that is if you are going to have them rebuilt by someone). Either way, while you have them off you should port/polish them.
I don't know where you are, but there is a 3.1 for sale in Mass. on the site here somewhere. I saw it this morning for $300 obo.

firstfirebird

iTrader: (3)

Hey Larry,
What kind of noise were you getting that made you think the lifter was collapsed? I'v adjusted my valves twice now and am still getting a tap. I'm getting a turbo cam soon anyways, so I'll put new lifters then - just curious.
Thanx
-John

LarryD

Been gone for a few days... I pulled the heads off and took them to a good machine shop... The guy hot tanked them and said the valves look pretty good and that they just needed resurfacing and clean up.. He has some good used rotators for the exhaust valves.. The cracks on the top are because they aren't rotating.. Total for both $125... Should be done this morning and since he didn't call yesterday, that should be all they needed...

LarryD

The noise I was getting was classic lifter rattle until the last 50 miles, then it started banging pretty loud on one of them... Guy at the machine shop said they probably put a reground cam in it and that is why it failed.. Typical for those "production" rebuilds, cheap and dirty... The two bad lobes were almost bad enough not to be opening the valves at all.. Those two lifters had been worn into a concave shape on the bottom making it even worse.. Good news was that the main cam bearing surfaces looked pretty good and so did the middle two bearings... I can't see the back one but the front one shows some wear... Going to replace the front bearing if I can figure out how to pull it out...

MrEd

I have tried these instructions to the T and I am still getting chatter when I start up the engine. Could there be something else wrong that I am not aware of?

I have replaced both heads, using the old push rods and hydraulic lifters.

I have performed the adjustment process twice, and still get chatter when I start up the engine.

Any help would be greatly appreciated. The engine is a 1992 3.1 V6 in a 92 Sunbird Convertible.