What is the tightening sequence on the lt1's? I made it into a splayed 4-bolt from a two bolt.

 

There is no sequence for main caps, unlike heads, the intake, etc. The guy I learned/am learning engine assembly from always does the inner caps on each cap before the outer though.

Rich

 

In most cases it would be inners torqued before outers. But sometimes with a plate girdle on a 4 bolt main the line hone job will be done with the outers torqued first before the plate is installed, in this case you need to replicate the torque procedure that was used when the line hone was done because the main housing bore distortion will change.

I would assume that your machinist torqued the inners before the outers when doing the line hone but it would be a good idea to confirm.

For each cap - tap it into it's register then snug all the bolts to ~20lb. Take them first to 40lb, then to final torque as specified for your fasteners and lube, same principal applies here - if your machinist used ARP lube then you need to do the same thing, if oil was used that needs to be replicated.

 

here is what most do:
start at cap number two, three, and then four. then move to the centre cap, and then the first cap at the front of the block, and then finally to the number five cap at the rear side of the block. go through the same sequence for every tightening pass.
if ur having the 4bolt caps make sure u tighten the inner bolts first before the outer ones for each cap

 

Hmmm...never seen that procedure before.

Most machinists, actually all that I know torque the thrust first.

I thought we were talking about torque on each cap - now if you want to talk about order, then the thrust cap always gets done first. This is so that you can properly seat the thrust bearing front to rear and check endplay. Lay the crank in place and measure endplay with none of the caps in place - this is written down as "block end-play". Then you will put the cap in place and lightly snug the bolts - now you will use a prybar or old screw driver and tap it in to place between a counterweight and main webbing in the direction the pushes the crank backwards against the thrust bearing to align them rearward...then you will do the opposite motion to drive the thrust bearing evenly forward and now torque the cap. This is done so that the loaded thrust face on the back of the bearing is evenly seated and will support the load of the crank against it. Now you will again measure end-play and write this one down as "crank-endplay". The reason for the two different measurements is purely problem solving should there be no endplay on the last measurement but without the cap in place end-play was ok. In this case you would know that adding the cap caused a binding situation and that something is wrong there such as a badly ground cap after a line hone job.

After that I simply torque the innners front to rear, then the outers.

Re-check end-play and you're done.