Replacing Cracked Block - Anything I Should Know?

[brsox88]

I have a 4.3l year 2002 with a cracked block. I ordered a new one and its arriving tomorrow. I have pulled and swapped engines before on cars, but never had to swap all components from one block to another. Is there anything I should know or suggestions being a rookie at this?

 

[cdhunter]

Be systematic. Get two engine stands if you can and set both engines tdc on the compression stroke and mark all ignition components if your working from a short block. If your moving pistons and everything take lots of pictures at all stages of disassembly. Oil is your friend lube. last but not least a good manual and good set of torque wrenches!

 

[brsox88]

Sorry, I should have mentioned it is a Long block with full heads and valves. Should I still mark each spark plug wire and distributor cap accordingly to which cylinder they belong?

 

[Bt Doctur]

Only if you never worked on a GM V6 motor and dont have a manual

 

[cdhunter]

Definitely set both engines to tdc compression, take the distributor cap off and mark rotor position on the distributor body, and mark distributor shaft housing to a common location on the block. I use the timing clamp bolt for reference when you lift the distributor the rotor will move, mark that new location as well for a starting point when you reinstall the distributor it will save you a ton of work during the timing phase at start up. seems anal but its worth it. Should have mentioned before make sure you check the casting numbers to see that the engines and the heads match up with yours.

 

[brsox88]

So if I get the cap to match up exactly on the new block, will I still need to set the timing of the engine? I thought that since the block comes with the timing chain and headers already installed that the timing is already set? I've never timed a v6 before either.

 

[Bt Doctur]

Dosent matter what kind of engine. You put #1 on TDC compression stroke and install the dist with the rotor pointing to #1 position in the cap

 

[cdhunter]

every engine requires some sort of timing after reassembly. The procedure I described for you will have you with in a couple degrees of the final timing. there are some good videos on youtube showing the installation of distributors, they are generic and aimed at automotive guys but the basics apply. Before you put wrenches to motor make sure you have a good manual for your motor, and in todays world lots of pictures that you can reference from every angle. Another trick we used was lots of coffee cans for bolts by assembly ie timing cover in one can, oil pan bolts in another. You have said your self this is your first rodeo so take it slow.