Building up the crank or oversized bearings?

[85LaserXe]

hey guys.. i gotta a question.. is it better to build the crank back to standard size or to polish it down to oversized bearings in a 2.2L turbo

[god910]

Build it back to standard size? Can't say I've ever heard of that, can't say that if it was possible it'd be very easy. I'd just turn, polish, and go oversized bearings.

[GLHS0658]

Yes you can build it up back to standard. Although it is not cost effective or wise. When you do have it ground for .010 bearings, ask the machine shop what they will charge to build it back up to standard...very expensive!

[god910]

Quote:

Originally Posted by GLHS0658 Yes you can build it up back to standard. Although it is not cost effective or wise. When you do have it ground for .010 bearings, ask the machine shop what they will charge to build it back up to standard...very expensive!

Seems a little rediculous unless you had a custom forged crank and took a big chunk out of it.

[Reaper1]

Or you stroked a 2.2 crank to 3.75"

[LancerShelby]

Or you de-stroked a 2.2 to a 2.0

[god910]

But it would still be cheaper to get another and turn it to where you want.

[puppet]

They weld them up. I'd only consider it for one journal though. Anymore than that just isn't worth the trouble/money.

[3.0Duster]

sounds like you need a more reliable car, you should buy a hyundai

[omnious]

LOL +1 3.0Duster

i would suggest going oversize bearings as stated, more cost effective

[sleeper_1]

I wouldn't built up the crank by welding, its only a short term solution. Welding weakens it. If you only intend to run it for a year or so, might be OK. The fatique resistance to progressive cracking is reduced to a fraction of it's original design. Going to oversize bearings is a much safer route.

That is, a tiny crack will start at the weld and and gets bigger and bigger till it breaks the crank, a lot earlier than originally designed!

[glhsken]

Nothing wrong with a .010 crank... I just had 3 done!! one is for a 400whp engine.

[Moparmonster]

Quote:

Originally Posted by sleeper_1 I wouldn't built up the crank by welding, its only a short term solution. Welding weakens it. If you only intend to run it for a year or so, might be OK. The fatique resistance to progressive cracking is reduced to a fraction of it's original design. Going to oversize bearings is a much safer route. That is, a tiny crack will start at the weld and and gets bigger and bigger till it breaks the crank, a lot earlier than originally designed!

I've never heard of a good weld causing any problems with the crank. And no, it's not a temporary solution. The new metal is bonded to the existing metal, and then the weld is ground to match the size of the other journals. The hole is then chamfered and the journals polished. I don't know where you got your information, but it's incorrect. I worked in a crank shop for a while and there were never any returns due to bad welds, or welds causing problems.

[Andre Parker]

It would depend on what type of material was used when it was welded. I am not sure for the auto world, but in the plastic mold injection arena, they have a chrome plating they use for friction that builds up the surface of the screws used for injecting hot plastic. This stuff is cheaper than having it welded and is designed to reduce wear. Cheapest would be have it turned down. They can only turn it so far due to heat treating. some of them are nitrided and may only penetrate the metal .020-.100 or so depending on the parent metal.

[Koreth]

I personally wouldn't worry about having the crank turned too far. With how commonly 2.2s and 2.5s can be found in junkyards, I would think replacement cranks would not be difficult to find.