micro polishing crank, engine rebuild

[aznbmxxxer]

i want to boost my b18b and i asked a local mechanic what they would do if they rebuilt my engine since i melted the pistons the 1st time i boosted. he told me that they would hone, deck and hot tank the block, and micropolish the crank. what does it mean to micro polish the crank and deck the block? is it necessary if i am replacing the pistons and rods or could i just install the pistons and rods without it? my goal is about 250hp is that safe on the stock sleeves and crank?

[Retard324]

i'm pretty sure you dont need any engine work done to replace the pistons an rods. i've never heard of anyone having to do that.

[killah_xft]

alright as for micropolishing is pretty-much putting your crank on a machine that polishes the rod journals. making them smooth for the rodbearings reducing friction, and reducing temps on the crankshaft. decking the block means taking the head off, removing the piston sleeves and installing sleeve decks (machine steele plates with breath holes for coolant to flow) which reinforces the sleeves so they do not "walk/warp" under high boost. both are good suggestions buy if you are using this car for a daily driver you don't want to boost much over 8-10PSI. It will give you plenty of power, and still keep the car driveable. most I would suggest is lower compression pistons, maybe stronger rods if you ever want to turn up the boost for the track. sleeving and decking the block might not be a bad idea.. but it's entirely up to you. word of warning about decking the block can/will increase engine temps, and may force you to install a larger radiator/fan). installing the pistons and rods will help, but there are the words "might as well do it while you're in there" decking and sleeving the block is almost overkill for a daily driver. I'm not sure what "hot tanking" the block is. but hopefully someone else knows.

[casperGSR]

hot tanking the block is pretty much a way of cleaning everything off of it in a tank that contains a solution/chemical that will desolve whatever crap is on or in the block, can't remember if it's heated or not but I wanna say it is but don't hold me to it.

[Schister66]

Hey i would say that if you melted a piston with your last set up, that you need to do a little work to the engine.

What i would do:
1.Get the block and heads decked. The machineshop puts the head and block on a special grinder that takes a little bit of metal off of the head/block in order to make sure they are flat. This prevents compression loss due to a blown head gasket. I would say that since you melted a piston, you should consider decking the block since it may be a little warped.
2. Sleeve the block. I personally would do wet sleeves, but since you're not planning to run high amounts of power, you should do a conventional dry fit sleeve.
3. Micropolish the crank. They will polish the journals on the crank and all of the main bearings. I would replace all of the bearings on the bottom end of the engine, and by the sound of it, you need new piston heads (i would also get new high strength I-beam rods).
4. Have the bottom end blueprinted and balanced. The shop ensures that all of the parts are in exact clearances and that all of the parts are rotationally balanced...this enables safer travel into the redline.

As to honing the cylinder, all that means is taking a honing bit (the big brush-like thing with all of the balls on it) and cross honing the cyllinder so that there aren't concentric circles in the cylinder walls. Concentric circles trap oil and lose compression. Don't cheap out on this build up otherwise you'll probably end up doing it all over in the near future.

[Schister66]

A couple of other things i forgot to add. I would also check all of the valves, their guides, springs, keepers/retainers, rocker arms, and lifters. I would also neuralize the valve guides in order to make them perfect.