..I thought it was thrust bearings that couldn't hold the crank in place, not the rods where the issue began ...

Your tuner friend seems to have no understanding of how the internal components of an engine are put together and work together. Rods have nothing to do with the latreral movement of a crank. The problem is because the thrust bearing wears out. One theory is because of excessive force applied by a high tention pressure plate. Please have your friend explain his theory in more detail.

it's the thrust bearing going bad, not rods. you're "tuner" friend has no clue what he's talking about. i THINK now you can get revised thrust bearing to eliminate it.

Absit said:

I just heard something from a local tuner today and wanted to get some more opinions on it.

Click to expand...

Tuners generally know nothing about engine function and operation. Actually, I've found that "Tuners" generally know nothing about anything, ever.

Wait a minute....




I retract that statement.

beachbum2185 said:

it's the thrust bearing going bad, not rods. you're "tuner" friend has no clue what he's talking about. i THINK now you can get revised thrust bearing to eliminate it.

Click to expand...

More information please. This sounds interesting and the first I have heard of it.
Got a link to said thrust bearing?

96WhiteTSi said:

More information please. This sounds interesting and the first I have heard of it.
Got a link to said thrust bearing?

Click to expand...

http://www.dsmtuners.com/forums/cylinder-head-short-block/354828-split-thrust-bearings.html

I used the ACL race bearings in my Talon.

The horible fact of the matter is, any motor can crank walk. I thought it was a myth since I had drivin and abused my 7 bolt for 6 years without encountering it. But just in the last year I've seen how just a bad pressure plate has caused the same abused motor to walk, a built 6 bolt to walk, and now my 7 bolt 2.4 is starting to walk. All because of a bad pressure plate. Thats my take on it.

mine walked last month. the thrust bearing looked fine but the thrust on the crank was gone and the crank wore a grove into the block.

crank walk was explained to me by a reputable engine builder and tuner.

Here what he said: As you crank to start your engine with the heavy flywheel such as 2gs it takes certain revolution to start it. As you crank the engine there are no lubrication going to the thrust bearings and overtime it will walk.

Simple put.

dj211855 said:

crank walk was explained to me by a reputable engine builder and tuner.

Here what he said: As you crank to start your engine with the heavy flywheel such as 2gs it takes certain revolution to start it. As you crank the engine there are no lubrication going to the thrust bearings and overtime it will walk.

Simple put.

Click to expand...

Holy shit!!!

You people have no fundamental understanding of how or what is going on here do you?

First things first.

ANY motor can and will "crank walk" under the right conditions.

Cranks do not walk! The term crank walk reffers to excessive end play.

When you build an engine you will check how far the crank can slide back and forth. ALL engines have to have some tolerance here, or they would be too tight to turn.

The procedure for checking this is to install the crank into the block. Hit it with a dead blow to seat the crank up against the Thrust bearing {the main bearing that looks different}. Affix a dial indicator, push the crank all the way in the opposite direction. Note the amount of horizontal slide here. It should be about .005" give or take.

Crank walk is when this slop is excessive, for whatever reason. The thrust bearing could be wiped out. The thrust surface on the crank could be wiped out or mis-machined.

For obvious reasons, manual transmission equipped cars have the largest tendency to crank walk.

Why?

Because ALL of the force exerted by the clutch pedal assembly is translated Directly to the surface of the thrust bearings. This thrust surface is what stops the crank from being pushed out the front of the block when you depress the clutch pedal. It could even be bearing material is harder than the crank surface. Perhaps mitsu forgot to heat treat the thrust surface on batch of cranks? a BIG batch.

That is also why severely crank walked motors tend to push the front seal out the engine, and push off the timing belt.

Crank walk and DSM's. Why do they go hand in hand? Well lets see.

Manual Tranny, Poor Engine Oiling design, Poor oil pan design...the list goes on and on.

When you start a cold motor, you have to push the clutch in. This means the crank is slam up against the thrust bearing on a dry motor.

The oil squirters are thought to be the issue, since where they draw there oil from. It seems to be a volume thing, but more likely is just cheap bearings, wear and people not changing there oil properly.

Oil? did someone mention oil?

So what it all breaks down to...is lack of lubrication. Anything that puts undue stress on a dry bearing is going to take its toll. Turbo cars run richer than N/A cars generally speaking.

Over fueling can and will wash down surfaces. Esp cars that over fuel and idle and have turbo timers. Now you are stripping the engine of all lubrication before you shut it down. Now what do you think will happen next time you start it?

In the end i have only ever personally seen classic crank walk in 2 engines. Both were Honda H22's. Both were totally built for turbo, yet the owners put huge injectors and no management in the car. Thinking it would be somehow OK to idle around on 1000cc and a stock honda computer.

I wouldnt worry too much about crankwalk. And anyone that says they have a solution involving changing the RODS is a ####ing moron.

Oh yeah to blame the pressure plate and such...wow. I say nay. chances are its your tune. Way rich.

The end all solution is to put a torrington bearing between the flywheel and engine. This will move your clutch force away from the crank and its thrust surfaces to a much larger area.

kawgomoo said:

Holy shit!!!

You people have no fundamental understanding of how or what is going on here do you?

First things first.

ANY motor can and will "crank walk" under the right conditions.

Cranks do not walk! The term crank walk reffers to excessive end play.

When you build an engine you will check how far the crank can slide back and forth. ALL engines have to have some tolerance here, or they would be too tight to turn.

The procedure for checking this is to install the crank into the block. Hit it with a dead blow to seat the crank up against the Thrust bearing {the main bearing that looks different}. Affix a dial indicator, push the crank all the way in the opposite direction. Note the amount of horizontal slide here. It should be about .005" give or take.

Crank walk is when this slop is excessive, for whatever reason. The thrust bearing could be wiped out. The thrust surface on the crank could be wiped out or mis-machined.

For obvious reasons, manual transmission equipped cars have the largest tendency to crank walk.

Why?

Because ALL of the force exerted by the clutch pedal assembly is translated Directly to the surface of the thrust bearings. This thrust surface is what stops the crank from being pushed out the front of the block when you depress the clutch pedal. It could even be bearing material is harder than the crank surface. Perhaps mitsu forgot to heat treat the thrust surface on batch of cranks? a BIG batch.

That is also why severely crank walked motors tend to push the front seal out the engine, and push off the timing belt.

Crank walk and DSM's. Why do they go hand in hand? Well lets see.

Manual Tranny, Poor Engine Oiling design, Poor oil pan design...the list goes on and on.

When you start a cold motor, you have to push the clutch in. This means the crank is slam up against the thrust bearing on a dry motor.

The oil squirters are thought to be the issue, since where they draw there oil from. It seems to be a volume thing, but more likely is just cheap bearings, wear and people not changing there oil properly.

Oil? did someone mention oil?

So what it all breaks down to...is lack of lubrication. Anything that puts undue stress on a dry bearing is going to take its toll. Turbo cars run richer than N/A cars generally speaking.

Over fueling can and will wash down surfaces. Esp cars that over fuel and idle and have turbo timers. Now you are stripping the engine of all lubrication before you shut it down. Now what do you think will happen next time you start it?

In the end i have only ever personally seen classic crank walk in 2 engines. Both were Honda H22's. Both were totally built for turbo, yet the owners put huge injectors and no management in the car. Thinking it would be somehow OK to idle around on 1000cc and a stock honda computer.

I wouldnt worry too much about crankwalk. And anyone that says they have a solution involving changing the RODS is a ####ing moron.

Oh yeah to blame the pressure plate and such...wow. I say nay. chances are its your tune. Way rich.

The end all solution is to put a torrington bearing between the flywheel and engine. This will move your clutch force away from the crank and its thrust surfaces to a much larger area.

Click to expand...

Well said... however, I don't think it necessary to call out a members post as you have, implying that he has no idea what he is talking about, and them turn around and say nearly the exact same thing in your post with a little more info.

IMO, You took what could have been an A+ response of a member question and turned it into - just another forum posting from just another kid.

For another long post on the many causes of crank walk see:
http://www.dsmtuners.com/forums/articles-engine-fuel/342560-crankwalk-depth-explanation.html



My own old moldy research found that a stock torque converter could balloon out and put excess pressure on the thrust bearings. That’s why I put a billet TC in my Talon. Yeah that’s it, not because I wanted the 4300 RPM stall speed.

Most people disconnect the clutch safety switch. Having gasoliney oil from overfueling will ruin more than just the thrust bearing. There are other bearings to worry about. I just think it is an overrated problem. Haha no shit cranks don't "walk" but not everyone in the world is a nerd and most people don't prefer to talk like one and use "excessive end play of the crankshaft" in everyday speaking. I work at a web hosting company, and there are so many people here who are adults that don't drive, don't shower or groom, and still talk about magic cards and other stupid crap like that. I know more than a lot of them and I'm not a nerd, and they deserve to get made fun of for being nerds.

Check out this cool read on the subject. There's some nice pics of 6 bolt and 7 bolt blocks cut in half as well!

http://magnusmotorsports.com/?page_id=323

beachbum2185 said:

it's the thrust bearing going bad, not rods. you're "tuner" friend has no clue what he's talking about. i THINK now you can get revised thrust bearing to eliminate it.

Click to expand...

Not trying to jack the thread here or anything, but could one install the revised split thrust bearing on an engine block that did not originally have the split thrust bearing?

I heard of a kit that goes around the oil filter area that keeps the oil pressure up in the system while the motor is not running instead of the oil draining back into the pan.

Thus, it does keep the pressure around the crank bearings so they are not running dry before the oil pressure build up on inital startup.

Maybe someone heard of this device or similar ...

-DSM

90gst_sean said:

Well said... however, I don't think it necessary to call out a members post as you have, implying that he has no idea what he is talking about, and them turn around and say nearly the exact same thing in your post with a little more info.

IMO, You took what could have been an A+ response of a member question and turned it into - just another forum posting from just another kid.

Click to expand...

Yea, basically calling everyone else an idiot, moron, retard, whatever...and giving a long drawn out explanation of something that was already explained. And the whole "you people" statement, is pretty childish. You make it sound like everyone on here has been rambling on about what causes crankwalk, when it was only mentioned once or twice in passing... way to go.

I always thought crankwalk was cause by the crankwalk fairies making their way into your motor through vacuum leaks and molesting your thrust bearing.

That's what my tuner told me anyways.

I don't think that would help much if any. The bearings aren't a sealed item so the oil around them would just leak out. Thats how our thrust bearing is lubed from just leak by on the crank journal.
Maybe this kit holds some oil to help prime the oil pump....maybe.

Torrington bearing between the block and flywheel?

And to answer the original post. the rods won't keep the crank from walking. There is play in the wrist pins and side clearance for the rod bearings. The "thrust bearing " will be in contact with the crank well before the rods do anything.

I think im getting walk =(. My understanding is, replace the thrust bearing. should give me another six months with my act 2600? Just what ive heard.

Holy $#@! The crankwalk fairy is gonna molest your thrust bearing!!! Hes going to....thrust it....

Usually the crank will be damaged on the thrust surface so a new bearing won't fit the clearance problem.

Ive personally taken apart 3 7 bolt engines. One which was a 5 speed awd and none of them had excessive crank play and they were all over 140k with no rebuild. I guess there is a certain percentage that fail. On the other hand, the 7 bolt 4g64 dont have the crank walk issue and it is essentially the same block plus 6mm deck height and a different crank. So......

I beg to differ http://www.dsmtuners.com/forums/newbie-forum/396826-4g64-crankwalk-confirmed.html