Just installed btr stg 3 turbo cam. Stock 01 5.3, stock rockers, btr springs and hardware. Like the title says, when the rockers are snugged with the valves on the back side of the lobes (full open valve + one full crank rotation), I have a couple valves hanging open. They are hand snugged, no where near the 22ftlb spec. When rockers are full lose the valve rests where it should. Help?

Ps, how should this engine run na for a while untill the winter turbos? Th400, turbo converter (3500), 3.25 gear, 3500 lb through manifolds. Hoping at least 12s.

Back on topic. Help!

Thanks!

 

This happens with what size pushrod?

 

How did you tighten them? This doesn't really make sense, if you tightened them off of base circle they would be too loose on base circle. How do you know they are hanging open? You should follow this guide to tighten them and see if you have the same problems.

Straight out of the repair manual:

1. Rotate the crankshaft until number one piston is at top dead center of compression stroke. In this position, cylinder number one rocker arms will be off lobe lift, and the crankshaft sprocket key will be at the 1:30 position. If viewing from the rear of the engine, the additional crankshaft pilot hole, non-threaded, will be in the 10:30 position. The engine firing order is 1, 8, 7, 2, 6, 5, 4, 3. Cylinders 1, 3, 5 and 7 are left bank. Cylinders 2, 4, 6, and 8 are right bank.

Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.


2. With the engine in the number one firing position, tighten the following valve rocker arm bolts: Tighten

Tighten exhaust valve rocker arm bolts 1, 2, 7, and 8 to 30 N·m (22 lb ft).

Tighten intake valve rocker arm bolts 1, 3, 4, and 5 to 30 N·m (22 lb ft).

Rotate the crankshaft 360 degrees.


3. Tighten the following valve rocker arm bolts: Tighten

Tighten exhaust valve rocker arm bolts 3, 4, 5, and 6 to 30 N·m (22 lb ft).


Tighten intake valve rocker arm bolts 2, 6, 7, and 8 to 30 N·m (22 lb ft).

 

Not all cams have the same size base circle. Compare it to the stock cam, and adjust pushrod length.

Its either that, or you are not on the base.

 

I saw the guide, oddly enough, I know it's rare, I searched lol. I was just snugging them down for the night, playing since I don't have a torque.

Doesnt make sense? Why not? Correct me if I'm wrong, crank rotates twice the speed the cam does (2:1 crank being the 2). With the valve fully extended into the cylinder, one full rotation of the crank would equal 1/2 rotation of the cam, yes? So one half rotation from full open should be fully closed (from lobe to base circle?) May be misusing my terminology. I know its not as efficient as the TDC method, but I can't believe it to be less accurate.

7.4 pushrod.

Again, in no way are the bolts near 22ftlb.

I'm looking down the exhaust ports with a light. Visible seperation. At least there was....

Now they all appear to be fully closed. Could the lifters have been 'pumped up'? Again may be some terminology issues.

 

Also, it wasn't all the valves, only a few. Weird stuff that they are all closed now... Damn hydraulic stuff

 

I wasn't saying your method for base circle was wrong, I was just saying if you tightened the rockers when the cam was on a lobe the rockers would be loose when you were on base circle. If you have the same heads,valves, lifters and gaskets and you have a cam that has a smaller/larger base circle you need different length pushrods to make it work.

 

Oh ok lol. I'm on the train now with what your saying. Thanks for the advice everyone

 

When you tighten the rocker arm, it will depress the valve until the lifter bleeds down. It will take a few minutes for that to happen. Not sure I understand exactly what happened but it sounds like you tightened the rockers and noticed the valves open. Next morning they were closed.

 

you pretty much summed it up. wasn't the next morning, just a couple hours. but seems to be pretty accurate as to what happened. I just wanted some peace of mind, i'm a nervous kinda cat.

 

Common, the lifter should bleed down pretty quick.