Does the crankshaft HAVE to be resurfaced?

[khartley]

The guy said that he had the car at about 9000RPM's, it started knocking, and he took it right home (less than 1 mile), shut the car off and hasn't started it since. So given this information, do you think the crankshaft will absolutely have to be resurfaced? Cause otherwise I will ony have to unscrew a couple bolts, and take the turbo out. I'm sorry to keep asking these same stupid questions, but I want all the info I can get before I actually start this.

 

[midnght]

The guy said that he had the car at about 9000RPM's, it started knocking, and he took it right home (less than 1 mile), shut the car off and hasn't started it since. So given this information, do you think the crankshaft will absolutely have to be resurfaced? Cause otherwise I will ony have to unscrew a couple bolts, and take the turbo out. I'm sorry to keep asking these same stupid questions, but I want all the info I can get before I actually start this.

There are alot of post lately from people wanting to know what to do with "X" motor. The situations that come about usually require a more indepth look at the block itself. Pics or even testimony (sp) from a reputable shop would help out alot better.

Knock can destroy a block completely or cause less damage than you would expect. The only way to know is if you take the head off and see what is really going on. If you do not know much about what you are looking at then get a set of good DSM eyes to help.

 

[khartley]

Ok, well thanks. I will take some pictures on Monday to show you guys - no one around here really knows alot about DSM's.

 

[midnght]

It's not you man. Just that these type questions have been coming up and it is really hard to tell what is wrong with the engine without seeing or getting an indepth description of what we are trying to fix.


Hope it all works out.

 

[khartley]

I'm sorry!! I didn't mean "around here" as in "DSMtuners". I meant around here in Wyoming. Sorry!! I wasn't ragging on you guys, I feel bad now.

 

[midnght]

I'm sorry!! I didn't mean "around here" as in "DSMtuners". I meant around here in Wyoming. Sorry!! I wasn't ragging on you guys, I feel bad now.

It's all good man.


I knew you meant your living area. If the block is messedup any reputable machine shop that has worked on any type of engine that has cylinders will be able to tell you the severity (SP) of the damage done.

 

[Defiant]

The guy said that he had the car at about 9000RPM's, it started knocking, and he took it right home (less than 1 mile), shut the car off and hasn't started it since.

I don't know how he coulsd have gotten it to 9K.

That aside, rod knock will almost always mean crank damage. But what's done is that you take your parts to a machinist, and he measures things and compares that to specs. Actions are determined after that.

 

[Doubletake]

I had knock, it was 2 rod bearings spun and shreded. Tried to get the crank milled for oversized bearings but i was told it was beyond spec... So i bought a 6-bolt short block and swapped it in.
Still have the 7-bolt components, but i don't know if it's worth the rebuild

 

[sonicnofadz]

Like what was said above, the damage cannot be determined until the engine is fully disassembled. For all you know you have damaged your oil pump or balance shaft bearing (which was making the noise). So you may have no damage, or you may have shredded all of your crank bearings and cracked some pistons. Theres really no way to tell until you inspect the block (and head) entirely. If the engine some how managed to reach 9000rpms (which I severely doubt because of the computer controlled rev limit) there is a GOOD possibility that some valves floated open and were crushed. So there is a chance that there might be head damage as well as damage to the block. Keep this in mind.

 

[blitz43]

so whats cheaper..... a 7 bolt rebuild? or buying a 6 bolt motor and having it installed???

 

[bjones18]

so whats cheaper..... a 7 bolt rebuild? or buying a 6 bolt motor and having it installed???

Cheaper? or less risk? a rebuild of your own parts is generally cheaper. For a 6bolt you have to buy it and then rebuild it also.

6 bolt has less "crank walk" risk associated with it.

 

[TwoLiterV8Eater]

Don't get your crank turned, regardless of what your machine shop may say. What is common practice on V8s, is not on a DSM. If the crank is out of spec, either buy a new one, or pull one from a junkyard and have it checked. 7 bolt cranks are a dime a dozen as no one seems to want them. As long as the thrust bearing is within spec you should be ok. Turning a crank that is out of spec removes the hardened coating, thus leaving it more susceptable to bearing failure.

 

[Anomoly#5]

I would not have put it any other way.