charcold-bowtie

iTrader: (10)

My brother pulled the head off the 496 to have them cleaned, and its about time to put them it back together. Its a pivot water well motor, not your normal motor or set up.lol.

Does anybody have a manual on torque specs for theheads and intake...etc?

Kerr you listening? lol....

1Bear

iTrader: (1)

Even for 8.1L engines; do not reuse the cylinder head bolts. NEW cylinder head bolts must be used. The cylinder head bolts are torque-to-yield bolts and cannot be reused once the initial torque is applied. During the initial torque of the cylinder head bolt the cylinder head bolt is stretched to achieve proper clamp load. Proper clamp load will not be achieved if a used cylinder head bolt is torqued again.

Due to production 8.1L engines not having blind tapped head bolt holes in the block, thread sealer must be applied to the new head bolts. Apply the sealant to at least the 1st 8 threads of the bolts, unless you are using new bolts from GM that already have the sealant applied.

Notice
The cylinder head bolt tightening sequence must be followed. The final angle tightening sequence of the cylinder head bolts varies depending on the length of the cylinder head bolt. Failure to angle tighten the specific length bolt the proper number of degrees can lead to cylinder head bolt failure or improper clamping load of the cylinder head gasket. Cylinder head bolt or cylinder head gasket failure can lead to extensive engine damage.

Important
The long bolts are used in locations 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16, and 17.
81LHeadBoltPattern.gif?t=1298063351
The medium length bolts are used in locations 15 and 18. The short bolts are used in locations 4, 5, 12, and 13.
1. Install the cylinder head bolts. Tighten
a. Tighten the cylinder head bolts a first pass in sequence to 30 N•m (22 lb ft).
b. Tighten the cylinder head bolts a second pass in sequence to 30 N•m (22 lb ft) then an additional 120 degrees using a torque angle meter.
c. Tighten the bolts (1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16, and 17) an additional 60 degrees, bolts (15 and 18) an additional 45 degrees, and bolts (4, 5, 12, and 13) an additional 30 degrees a final pass in sequence using a torque angle meter.

Rocker Studs and Guideplates
Tighten the valve rocker arm studs to 50 N•m (37 lb ft).

Rocker Arms
Install the valve rocker arms, the valve rocker arm *****, and the valve rocker arm nuts and then tighten the valve rocker arm nuts slowly to 25 N•m (18 lb ft) while guiding the tips of the rocker arms over the tips of the valves.

Valve Covers
1. Tighten the valve rocker arm cover bolts in sequence using two passes.
a. Tighten the valve rocker arm cover bolts to 6 N•m (53 lb in) a first pass.
b. Tighten the valve rocker arm cover bolts to 12 N•m (106 lb in) a final pass.

Water Crossover
Tighten the water crossover bolts to 50 N•m (37 lb ft).

Intake Manifold
1. Tighten the intake manifold bolts in sequence, using four passes.
a. Snug the intake manifold bolts in sequence to 5 N•m (44 lb in) on the first pass.
b. Snug the intake manifold bolts in sequence to 5 N•m (44 lb in) on the second pass. Inspect the intake manifold joints for signs of intake manifold shifting. Correct as required.
c. Tighten the intake manifold bolts in sequence to 10 N•m (89 lb in) on the third pass.
d. Tighten the intake manifold bolts in sequence to 12 N•m (106 lb in) on the final pass.

thundert56

don't forget to put the head gaskets go on the correct way.
the holes in the head gasket for the water jacket goes to the back of the block.
fail to do this the engine will over heat

charcold-bowtie

iTrader: (10)

1bear lays down the info yet again. I really do appreciate it.

thanks for the heads up thunder.

Kerr

damn... ask and you shell get!

you port and polish or do anything to the heads.. Im still impressed with how big those ports are for a freaking stock motor... everyone talks about how the LQ9 heads on the denali and esculades are awsome and im sure they are but man the look so small compaired to our "junk" 8.1 stuff

charcold-bowtie

iTrader: (10)

You gotta be faster Kerr! hah.


No they were just cleaned and inspected, not sure what all they are going to get. These motors run at around 2500 RPM for days on end. Usually we kill them to change the oil, especially towards the later end of cotton season. They run on natural gas as well.

hog

These rae the industrial versions that use teh same intake manifold, but the injector holes arent machined, therefore no fuel rails are used. It uses some sort of t-body injection.

They dont rev very high 224hp@2650rpm/452lb/ft torque@1800rpm with natural gas.

http://www.bucksengines.com/Data/37.pdf

8.1 parts list
http://www.bucksengines.com/Data/23.pdf


peace
Hog

charcold-bowtie

iTrader: (10)

Yup they are bucks, your exactly right. I just guessed at the rpm lol. You stand by an open headered 8.1 and tell me how many rpms it turning lol. He just revs them up or down based on water pressure he sees.

xx_ED_xx

iTrader: (17)

I spent a small chunk of change on the reusable ones. I hate them torque to yield POS's