z99ls1

iTrader: (12)

I have been reading this method and it seems like it is very accurate for almost all motors and alot of people love this method. All you have to do is when you see your exhaust valve start to open your lifter on your intake valve will be on base circle and you can adjust your intake side. And it goes the other way to when your intake valve is just about to close your exhaust will be on base circle and you can adjust it. This seems very simple and I can't beleive I haven't heard of it before. Anybody use this method or know if its is 100% accurate or not?

01ssreda4

iTrader: (96)

Adjust valves? I don't get it. We don't adjust valves on these motors.

z99ls1

iTrader: (12)

Basicly yea. You are saposed to make sure you are on base circle of the cam before you tighten down the nut to 22ft lbs. This is what I am refuring to as adjusting the valves. I just got the cam out of my old lt1 and tested the eoic method and it is spot on. As soon as the exhaust side starts to open your intake side on that cylinder is on base circle and can be "adjusted" or torqued to 22ft lbs. I can't beleive more people don't use this method

PREDATOR-Z

It has been advised and discussed many times.

z99ls1

iTrader: (12)

Ha I just think it's awesome. It's so simple and it works perfect. I went and got my old cam from my lt1 and sure enuf right when the exhaust lobe start you look on the intake lobe of the same cylinder and it is on base circle. And right before the intake lobe is done the exhaust is perfectly on the base circle. Does this method pretty much work on any engine?

z99ls1

iTrader: (12)

Do you have use this method pred z? What do you think about it?

vettenuts

iTrader: (4)

Why not just use the GM procedure, which tightens the rocker when the lifter is on the base circle. Of course you can't use the GM procedure or the one you are asking about for installation of some aftermarket rockers like Yella Terra's.

z99ls1

iTrader: (12)

That pic doesn't make sense to me. What the hell is 1:30 postion? I thought when the dots were alined with the cam dot at the bottom and the crankshaft dot at the top it was at tdc? That's the only part that is confusing me

Bramlok

iTrader: (7)

You don't adjust these rockers like an LT1 or typical sbc. The rockers sit on their pedastal and torqued down to spec.

KCS

iTrader: (20)

Its the same for just about any four stroke Otto engine out there. Its a good dummy proof method to check lash or preload in a lifter.

z99ls1

iTrader: (12)

I know this... My post above I stated that when I say adjust the valves I am refering to puting the lifter on base circle of the cam to torque it down

z99ls1

iTrader: (12)

Can someone help me understand this pic? I thought when the camshaft sprocket dot was at 6 o clock and the crank was at 12 is when your were at #1 tdc? I don't get where 1:30 is at?

redbird555

iTrader: (14)

It means that if you look at the crank sprocket you ill see a key where the sprocket slides on the crank rotate the engine so the key is in the 1:30 time position just like in the picture. Here's the deal though with that the book tells you to do it this way and it is the correct way but no shop that I actually know that works on ls engines does it like that. They simply tighten the rockers to 22ft lbs and rotate the engine and recheck. Even the ls1howto website tells you just to tighten them down and a lot of people do it like this. In this thread at the bottom I didnt use the procedure and was paranoid about it so I took the valve covers off 2000 miles later and used the correct method and they were all still in spec 20k later the motor still ran fine. Also with the ls6 I just assembled I checked it both ways just for giggles and it didnt make a difference either.
https://ls1tech.com/forums/generatio...rm-torque.html

vettenuts

iTrader: (4)

The only way to re-check torque is to back off and re-tighten. If you set the torque wrench to 22 and then check it, it will be tight even if you originally tightened to a lower value it will still be tight to 22 lb-ft because you are comparing static torque to dynamic (running) torque.

slt200mph

iTrader: (42)

People have been using this method to adjust valve lash that the OP "just discovered"....since the internal combustion engine was invented. Welcome to the real world of the 4 stroke internal combustion engine sir. It does not really apply to the LS series using hyd roller lifters as it would to a solid lifter engine application.

KCS

iTrader: (20)

I use it to check preload on hyd. lifters the same way one would check lash on a solid lifter.

01ssreda4

iTrader: (96)

OP, EVERY time the crank dot comes to 12 o'clock it is TDC. Most refer to TDC as the intake stroke. So thats when the top dot is 6 and the bottom dot is 12 (when they are closest). But when they are both at 12, that's TDC also but for the exhaust stroke. TDC refers to piston position, intake or exhaust stroke refers to the cam position. The cam is the brains of the engine after all.

z99ls1

iTrader: (12)

Yea I understand all that. I just wasn't understanding that pic he showed because I didn't know they were talking about the keyway.

z99ls1

iTrader: (12)

I guess all you would have to do is look for #1 intake valve to open and when it closes than you would close to bdc and be close to coming up on compression stroke and than the dots will be pictured above so you know right when your tdc on compression stroke when you turn it another 180 degrees

vettenuts

iTrader: (4)

It is the intake TDC on another cylinder (#6 I believe) so the procedure is tightening the rockers whose lifter is on the cam base circle. You can view the GM procedure as similar to the EOIC because it is ensuring that each rockers is tightened when it's lifter is on the base circle of the cam. The LS1howto.com procedure doesn't do this and some rockers will be depressing the valves during tightening of the rocker bolt.