93 K2500 Suburban 454 Holley Sniper Upgrade

[Frank Enstein]

Technically yes, but the cam was 180 out first for compression stroke on 1. The Holley hyperspark has a tool. Says go #1 compression tdc. That means the dots both 12 o clock on the 454. It is a clear cap, it marks roughly where #1 cyl is on the cap to be phased per instructions. Mark it, slap the sniper on and it should fire up perfectly without a timing light at first. If the dots are 6 and 12, then its 180 out and not on 1 compression stroke.

Over and over on the internet I keep seeing the same message on why I did it wrong all these years, need to be 12 and 12 after lining up at 6 and 12 dots so its on 1 compression.

https://www.chevytalk.org/fusionbb/showtopic.php?tid/198828/

http://www.crankshaftcoalition.com/wiki/How_to_install_a_distributor

Here is the procedure to adjust the valves on a new 8 cylinder engine:

Turn the crank clockwise while watching the number one cylinder pushrods.

Watch the exhaust pushrod go up and down and then the intake pushrod go up and down.

Continue to rotate the crank after the intake pushrod goes all the way down until the timing marks

Line up on 0 degrees.

(This will be LESS than 1/2 turn of the crank after the intake pushrod is all the way down.)

Install rockers and tighten the nut while rattling the pushrods up and down until the rattle just stops.

At this point you are at ZERO LASH.

Tighten further to add your preload ( typically 1/2 turn after the rattle stops ).

Do this to both rockers for number 1 cylinder. Cylinder number 1 is DONE!

Now turn the crank 90 degrees ( 1/4 turn) and set the rockers for the next cylinder in the firing order.

After the second cylinder in the firing order turn the crank 90 degrees and set the third cylinder in the firing order.

Repeat this procedure for the remaining cylinders, one for each 90 degrees of crank rotation

ending with the last cylinder in the firing order.


After the last cylinder in the firing order's rockers are set turn the crank until the timing marks

line up with 10 degrees BEFORE top dead center (BTDC).


Install the distributor aligning the rotor with the cap location that you want to put number 1 spark plug wire.

Line up the magnetic pickup with the reluctor and then rotate the distributor opposite the direction of rotation

JUST SLIGHTLY until the points are BARELY misaligned. Tighten down the distributor.

You are now pre-timed for 10 degrees Before TDC. And the engine should start right up!

 

[LC2NLS6]

The Holley, I set the balancer to 0 tdc compression #1, then slap the plastic clear cap aligner on, tighten down dizzy. Then lock timing to 15 in the programmer, and then verify its 15 on the timing light, adjust as needed to match 15. My trouble was resetting preload after wiping the cam on breakin and bending the pushrods. I have my first cam, but don't trust slapping it back in, roller from now on.

 

[Christian Steffen]

New pistons, shooting for 9.5 maybe 10 - 1 compression ratio. Full roller rockers - trunion and tip and short poly locks to clear stock valve covers. Hopefully makes 550 lbs-ft and 425+ hp at the crank at 3000-4000 rpm or so on pump 93. I'm hoping the 1yr old 1996 spec vortec delphi fuel pump can support that. I think its a 35 gph pump at 58 psi, not sure, if so, then not enough fuel pump- would explain the high fuel trims already experienced in learn mode. I need to plumb and monitor/log fuel pressure.

This should be a lot of fun! FWIW a walbro 255 will fit in the stock pump basket.. Might be cheap insurance.

 

[LC2NLS6]

Engine's back in the garage. Ended up at 9.2:1 comp ratio. Didn't need a bore or crank turned, all mic'd out, just honed, new dome speedpro pistons and lighter pins. Polished crank, all new bearings, line honed, full roller rockers and short poly locs to fit the factory Gen V valve covers, ditched the factory rotators, reused the 911 springs, ARP rod bolts and head bolts. Got it all done for only $3800 quickly, intake to pan assembled. Hopefully I can drop it back in this weekend.

 

[LC2NLS6]

Bolted in, radiator in, oil lines on, oil is primed, starter wired up. Going to set the hyperspark distributor in while I know its at 0 compression. All that is left is exhaust, torque converter bolts, bellhousing cover, water pump, and plug the harness in. I would have had it done this weekend but too much other stuff going on to play in the garage. I put studs on each end of head to hopefully make it easier to put manifolds on.

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[CrustyJunker]

Knocking on wood for ya!

 

[LC2NLS6]

I fear the gov-lock in the 14 bolt isn't long for this world.

 

[Christian Steffen]

I fear the gov-lock in the 14 bolt isn't long for this world.

Burnouts in your future?

 

[LC2NLS6]

Northern Michigan is my winter special rally stage. All that's left is exhaust, water pump, coolant, plug, wires, and slap the harness connections back on. These things are fairly simple, no turbo plumbing or intercoolers, just an engine with fuel in/out and 2 oil lines. When I got the engine sitting on the mounts, I walked away, and I looked at it, and it fell the final 1 inch into the dowel pins and right on the holes for the mounts. That was easy.

 

[LC2NLS6]

Fired right up first key on.