lifter issue and rock arm registration

[Scott Danforth]

if your rocker studs look like this, then the head is set up for non-adjustable valve train. you tighten the nut until it bottoms out and then torque to 20 ft-lb (27 Nm)/ you have just a nut and the rocker on a trunion



if the rocker studs look like this, then they are for adjustable valve train. then each cylinder is brought to TDC and you tighten the nuts to 3/4 turn past zero lash. this will have a ball, nut, and rocker.

 

[Lou C]

And the rocker arms themselves are different, the ones you have are for the adjustable system.

 

[alldodge]

And the rocker arms themselves are different, the ones you have are for the adjustable system.

Lou
I checked the serial number and part shows those style rockers item20/21

The lifters are item 10 roller type

Push rods should be 7.25 inch

 

[Lou C]

GM changed the rockers in later production, look back at the pix I posted, you can see that the rockers appear to have needle bearings. However, that is what Michigan Motors supplies in their reman engines, it's possible that the later style design can be used on the early engines that came with the net lash system....I think they were trying to reduce friction in the valve train.
I think Scott is right, the only way to tell what the OP has, and what he should be using is to see what the studs in the cylinder heads look like.
PS
I blew up the pix the OP put in the beginning of this thread and from what I can see, it looks like he has the studs for the adjustable system, with no shoulder like the one you see for the non adjustable system.
The question is why he would have the adjustable system if it's a '95, and it could be so because while the engines built in Tonawanda NY switched to the net lash (non adjustable) system in '92, but engines built in Romulus Mi. didn't switch till '95. If the serial # on the front of the block shows an R for Romulus, then that's the answer.

 

[alldodge]

Pic from his vid

 

[Lou C]

those are screw in rocker studs instead of the earlier pressed in rocker studs.
look at his pix again, there is no shoulder under the rocker arms.

 

[Lou C]

look under the rocker arms on the far side cyl head....

 

[ste80]

Good morning and tks for feedback recieved sorry for delay but diference of time between italy and usa

@Scott Danforth my roket studs are like your first picture see attached photo

I put the picture of my studs and components that i got in the box with heads
I also have got one new studs in the box that has right pn and is like all other 12 that i've got ( don't know why there is one more)

Last picture are roket studs before cleaning and assembling.

 

[Lou C]

Well I stand corrected it looks like you do have the non adjustable system

 

[ste80]

Well I stand corrected it looks like you do have the non adjustable system

thanks, and thanks for the page of manual. actually your manual helped me a lot..not for the procedure but for what is mentioned in that ( that i higlight here



as i said yesterday i checked this data, and my lifter has an excursion of 5 mm more or less
if i do 0 lash and 3/4 of revolution, with dial gauge i can see that copression of the lifter springs is 0.95 mm
if i du 27 nm the compression of the spring is 2.35mm so lifter in this condition is working in the center of its travel as it is mentioned in your manual as well

now i have to find how to load the lifter of oil ( when lifter is full of oil compression will be just 0.1 mm or something like that to compensate the thermal expansion 8 and not 5 mm like now that they are emty. but i thing this can happened only after motor switch on and when i have pressure inside..( probabilly first couple of second it will be very noisy untill when oil will fill it )

 

[alldodge]

Can pre oil some of them by using a drill to turn the oil pump

 

[Scott Danforth]

as i said yesterday i checked this data, and my lifter has an excursion of 5 mm more or less
if i do 0 lash and 3/4 of revolution, with dial gauge i can see that copression of the lifter springs is 0.95 mm

you do not have adjustable valve train. so you DO NOT GO 0 LASH PLUS 3/4 turn

if i du 27 nm the compression of the spring is 2.35mm so lifter in this condition is working in the center of its travel as it is mentioned in your manual as well

with the adjustable valve train your heads are setup for, you bring each cylinder to top of its stroke and run the nut to the step in the stud, then torque to 27 nm. or simply run the nut to the stop on all cylinders

now i have to find how to load the lifter of oil ( when lifter is full of oil compression will be just 0.1 mm or something like that to compensate the thermal expansion 8 and not 5 mm like now that they are emty. but i thing this can happened only after motor switch on and when i have pressure inside..( probabilly first couple of second it will be very noisy untill when oil will fill it )

get a priming tool

OEMTOOLS GM V6 and V8 Oil Pump Primer

Shop for OEMTOOLS GM V6 and V8 Oil Pump Primer with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

or

https://www.amazon.com/Primer-Replacement-Chevy-Small-Priming/dp/B0CFKRK8ZG?th=1

or make one from an old distributor

 

[ste80]

you do not have adjustable valve train. so you DO NOT GO 0 LASH PLUS 3/4 turn


with the adjustable valve train your heads are setup for, you bring each cylinder to top of its stroke and run the nut to the step in the stud, then torque to 27 nm. or simply run the nut to the stop on all cylinders


get a priming tool

OEMTOOLS GM V6 and V8 Oil Pump Primer

Shop for OEMTOOLS GM V6 and V8 Oil Pump Primer with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

or

https://www.amazon.com/Primer-Replacement-Chevy-Small-Priming/dp/B0CFKRK8ZG?th=1

or make one from an old distributor

Thanks so much i will try to find the tools or i will use my old efi distributor in case ( but if i can keep as it is i can sell it ) but will use something to do it.

I will go for torque and i will update

And i hope that this good technical discussion will help also other with my same doubt in future

 

[Scott06]

Thanks so much i will try to find the tools or i will use my old efi distributor in case ( but if i can keep as it is i can sell it ) but will use something to do it.

I will go for torque and i will update

And i hope that this good technical discussion will help also other with my same doubt in future

If you cannot get the tool easily in Italy - not as elegant but you can also put in the distributor as is (need intake bolted down) and turn the engine over with the starter to prime it, leaving spark plugs out.

 

[ste80]

If you cannot get the tool easily in Italy - not as elegant but you can also put in the distributor as is (need intake bolted down) and turn the engine over with the starter to prime it, leaving spark plugs out.

Thanks,
yesterday i tight all the roket arm to 27 nm now lifter are all empty so spring doesn't give right strenghts so valves open only when studs are totally inside the lifter.
So i was thinking if it is safe to rotate all the engine with valves only half open but i have the disributor from my efi i can use that one (i sow someone in some video use just flat screw driver but i think it will not work because presure can not increase if distributor hole will be open.

I hope valves lifter will become hard after this because now they are not working at all

 

[alldodge]

A screwdriver won't work, but the lifters will pump up when started

 

[ste80]

A screwdriver won't work, but the lifters will pump up when started

Thanks so much i will preload a bit with the efi distributor and then i will make some rotation with starting motor. ( Also because i need to check piston compression so in that periods i hope it will be fine )

 

[Lou C]

When I did mine, I didn't take the lifters apart since they were working fine before I took the heads off (blown head gaskets, cracked cyl heads from a past overheat) and I inspected each one visually, and just put it back in the bore it came from. When I reassembled the engine it was about 4 months later, I set the hydraulic valve lifter lash as per the manual and when it started, no odd noises, sounded like it did before the repairs.
I think if you set torque your rocker arm nuts as per the spec for the system you have, and then crank the engine over with the starter for about 10 sec, then let it rest, then repeat, they will pump up. Just make sure to coat the cam lobes, and rollers with motor oil, same for the studs where the rockers pivot on them and use new self locking nuts....

Dropbox

www.dropbox.com

this is the first run after the repairs from back in 2017....

 

[ste80]

When I did mine, I didn't take the lifters apart since they were working fine before I took the heads off (blown head gaskets, cracked cyl heads from a past overheat) and I inspected each one visually, and just put it back in the bore it came from. When I reassembled the engine it was about 4 months later, I set the hydraulic valve lifter lash as per the manual and when it started, no odd noises, sounded like it did before the repairs.
I think if you set torque your rocker arm nuts as per the spec for the system you have, and then crank the engine over with the starter for about 10 sec, then let it rest, then repeat, they will pump up. Just make sure to coat the cam lobes, and rollers with motor oil, same for the studs where the rockers pivot on them and use new self locking nuts....

Dropbox

www.dropbox.com

this is the first run after the repairs from back in 2017....

Thanks. Yess i cover all with motor oil.
Actually i left them in oil for 3 days then i puted inside wen they were still leacking oil in order to cover also the came. Then i put oil on the studs and roket arman i tighted 27nm (i put also thread locker on nuts)
Now i have to go for work one week abroad then when i'll come back i will complete it looking forward for that

 

[04fxdwgi25]

Pull the spark plugs out and spin it over with starter (or pull distributor and use an oil priming adapter). Oil pressure should build pretty quickly and pump up the lifters. If pressure doesn't build up, there are some other problems there.

Aint rocket science.