dwtjr3

I found a 4.6 2v block that has 105,000 mile and it has a spun rod bearing on it and the guys is asking $75 for it and he is negotiable, so my question is would it be worth getting it and forging it and building it up? or would it just be beter to go with MMR? And roughly how expensive will it be to build the block up?

Xemeth

You can get an MMR rotating assembly, which is just like buying a MMR 600 or 900 or whatever minus the block, for like $2,000. It comes with everything minus the block.

jvog

Is this rotating assembly balanced already?

Whether or not to go with an MMR shortblock or buy that block and use it all depends on how much shops charge to bore/hone blocks, balance rotating assemblies, and assemble the shortblock.

Personally I'd buy an mmr shortblock if I were to do it again, I tried doing what you did except I bought a rotating assembly with 1000 miles on it. I got raped on machine shop work. They charged me $1800 for bore/hone, balance, and assembly. The price also included rings, bearings, and arp main studs. I ended up paying $3000 for my shortblock.

WannaBeGearHead

I would definitely buy that block, reuse the cast crank, buy lightweight pistons and rods and you'll be in a total of maybe $1500 depending on machine shop costs.

But that is assuming you assemble it yourself.

dwtjr3

i would assemble it my self but how much machine work do you guys think it will need? I know you have not seen pictures of it yet but ihavnt either, but what do you guys think will need to be machined?

jvog

Well I would definately bore the block .10 or .20 over if its spun a bearing. Other than that I don't know what else would need to be machined. If whatever rotating assembly you buy isn't balanced you will have to pay for that also. Call around and get some prices from local machine shops.

Buy assembly I was referring to installing the crank, pistons and rods into the block. You are gonna do that? If so, where in PA are you because I want to gets some hands on learning experience in that field.