if you have a different cam, you cant go wrong with the way pat described
i did it the way my FSM told me to do it
Last edited:
Info: Duramax Valve Lash Tutorial.
- Thread starter McRat
- Start date
if you have a different cam, you cant go wrong with the way pat described
i did it the way my FSM told me to do it
No advantage, and it takes a couple more minutes. The "one cylinder at a time" is how I've always done it on all engines. That way I'm 100% sure I got them all. If it's at TDC compression, those two valves are as closed as their ever going to get, regardless of engine design.
unsure
so I bought a 03 2500 and I was told it needed injectors but once getting the valve covers off I found all the exhaust push rods bent so i bought all new push rods put the new injectors in and it fired right up idles great but it wont rev over 1500rpm and it feels like its miss firing and makes a sound like predet. I checked to see the that the coolant wasnt leaking into the cylinder i also checked all the balance rates and they all look great im at a loss right now no clue what else to check.
so I bought a 03 2500 and I was told it needed injectors but once getting the valve covers off I found all the exhaust push rods bent so i bought all new push rods put the new injectors in and it fired right up idles great but it wont rev over 1500rpm and it feels like its miss firing and makes a sound like predet. I checked to see the that the coolant wasnt leaking into the cylinder i also checked all the balance rates and they all look great im at a loss right now no clue what else to check.
Reviving an old thread here
First off-
This is an excellent write up! It's helped me to have a slightly better understanding of what's goin! Only slightly cuz I had. NO idea before reading this...:roflmao:
:baby:
My big question here is;
Is all the info provided in this post accurate for an LBZ engine?
Then the only other question I have is;
If I line the marks up on the balancer and block, I start with the #1 cyl, right? But shouldn't there be other cylinders on the odd bank that the rocker to bridge clearance is tight?
Cuz I have the marks lined up now, and all the rockers of the "odd" cylinders (passenger side) are free and have play between the bridge and rocker tip EXCEPT the intake rocker on the #7 and the exhaust rocker of the #5
Right now I'm just tearing down this used engine I got to fully inspect it (the best I know how) and clean the heads cuz it's had an EGR for it's whole life and the intake tract from the EGR valve to the intake runner going to the chamber is totally caked with sludge
So I'm trying to get a good understanding of how this needs to be set up how it looks, how it works and how it moves before I take the heads off so I'm not trying to figure it out when I go to install them
First off-
This is an excellent write up! It's helped me to have a slightly better understanding of what's goin! Only slightly cuz I had. NO idea before reading this...:roflmao:
:baby:
My big question here is;
Is all the info provided in this post accurate for an LBZ engine?
Then the only other question I have is;
If I line the marks up on the balancer and block, I start with the #1 cyl, right? But shouldn't there be other cylinders on the odd bank that the rocker to bridge clearance is tight?
Cuz I have the marks lined up now, and all the rockers of the "odd" cylinders (passenger side) are free and have play between the bridge and rocker tip EXCEPT the intake rocker on the #7 and the exhaust rocker of the #5
Right now I'm just tearing down this used engine I got to fully inspect it (the best I know how) and clean the heads cuz it's had an EGR for it's whole life and the intake tract from the EGR valve to the intake runner going to the chamber is totally caked with sludge
So I'm trying to get a good understanding of how this needs to be set up how it looks, how it works and how it moves before I take the heads off so I'm not trying to figure it out when I go to install them
Last edited:
My method works regardless of firing order on all 4 stroke 8 cyl engines.
When the timing marks line up, only 2 pistons will be TDC. And only 1 of them will have play in the rockers.
Rotate 90, and the same. 2 will be TDC, 1 will have play.
You don't even have to know the cylinder numbering scheme, or firing order. Hence why I've done it that way since I was 16 years old.
With 4 cyl, the only thing that changes is you turn the engine 180 at a time.
6 cylinder, you turn it 120 at time.
10 cylinder, you turn it 72 deg at a time.
But yes, there is a two move pattern for most engines. Lord help you if you get confused by the firing order or INT/EXH.
One of the major reasons to do it a bore at a time is DOHC engines. You ABSOLUTELY do not want to write down the wrong numbers. The first time you do that, you will learn a very hard and possibly expensive lesson.
With them, you write down all the lashes. You pull the chain, the trunions, the cams, the buckets and the shims. You mic the shims, put in the right shim to get target lash, put the buckets back on, the cams, the trunions, the chain, and get them sequenced. The procedure can take 4 hours in some engines, so if you screw on up, it takes the same 4 hours to correct 1 bad lash.
Based on which rocker moves next if you keep going. If you are at #1 TDC Exhaust and keep going the intake valve will start to open next. If you are at #1 TDC Compression and keep going you will have to go a long ways, then exhaust will open.
So, when you first put the rocker arms back on. How do you adjust the screws over the push rods before starting the adjustment cycle?
