Do Solid Crank Pulley or Harmonic damper Lead to Crank Failures? Can anyone find one?

[Digsy]

Sure, But if that was true why did Toyota make an engine that could systain more the twice the original power, they could have fitted alot lighter crank/rods/pistons But they dident. Afaik

 

The most likely answer to that has alredy been posted, but there is a possibility that Toyota might have had a plan to do future variants with higher outputs that never got made.

 

Obviously they put it there for a reson. But that still dont in anyway say that the crank Will snap, or shoot bearings. Could be But we cant know for certain

 

No, there's no way of knowing, but inline 6 engines do have (by definition) long, bendy crankshafts which suffer from torsional vibrations. I'd be surprised to see an I6 without a damper.

[Hellstrom]

The most likely answer to that has alredy been posted, but there is a possibility that Toyota might have had a plan to do future variants with higher outputs that never got made.

 

 

 

No, there's no way of knowing, but inline 6 engines do have (by definition) long, bendy crankshafts which suffer from torsional vibrations. I'd be surprised to see an I6 without a damper.

 

Yes i agree with what you have said. inline6 has the longest crank and also the biggest need for a dampner i totally agree with this. But imo there really is not way in telling wether crank will be failing or holding up. Like i said i would never recomand anyone to not use one. but i do think that there will not be a huge difference in terms of wear.

 

Still would make no sence imo to upgrade the bottom end (or keep it that meaty) from the 7M as i said the bottom end is a verry well built

Edited April 20, 2012 by Hellstrom (see edit history)

[skyludeboy]

this may or may not be relevant but when my big ends went, I had a bent crank shaft as I was told by an engineering shop, a month later I sold my stock pulley to someone off this forum, I always thought my pulley was a stock supra one I had never seen one before but, when I posted the pulley out, the guy that brought it told me it was broken and had a ring missing, showed me pics as well to prove what was missing as I did not believe him, turned out since the car came from japan it always had a broken pulley running with a different aux belt which kept the car going for 2 years plus with 560bhp daily, when my engine died on the dyno due to oil heating up, I think that the dampener pulley may have been the cause for my bent crank which only got realized when I took the crank to get regrind.

[Swampy442]

That's why I like this forum, it's full of really smart mofo's

 

Bearing wear is mainly down to oi film thickness which is related to the in bay-balancing of the piston and rod (i.e. the crank counterweights). However, what everyone misses with the 2JZ (no matter how many times I mention it ) is that its crank damper is two-mode. It has a torsional AND a bending damper. Crankshaft bending would affect bearing edge loading so in this case I would say running without one may promote bearing wear.

[GMan]

Last week my stock crank pulley let go, outer ring just gone, fortunately it was at low speed in town and the only damage was it tearing the plastic under tray cover on its way down out of the engine bay. I'd hate to think what it would have done to my fluidyne radiator had it decided to go that way.

It also sounds like I also have to change the aux belt tensioner as it stated making noise on startup, perhaps the pulley hit it on the way out or more likely the bearing is done after 19 years and a quarter of a million kms.

new one ordered from the U.S. for $139

 

Since I plan on doing a tt swap as soon as one becomes available I decided to use mine as a guinea pig and fit the solid aluminum pulley I got with my full set of lightweight non under drive pulleys but was afraid to fit due to the information on the web. I intend to put updates on here about the life of the motor. the way i see it a replacement NA wouls only cost me fractionally more than a ati or titan pulley, and after this, I'LL NEVER FIT A STOCK ONE, just too much risk with all the failures I read about. I read that some dragstrips in the us won't even let you on with a stock pulley!

As it stands:

225,654 kms on the clock, have done about a 100 since the replacement. so assuming that was the original it lasted 19 years and probably hasn't dampened squat in the last four I owned the car.

my only complaint about the new one is that it doesn't have that large ring with the timing mark, I was able to put in a timing mark on the new but it sits fairly far back from the marks on the cover.

Lets see if it blows up!

looks like i also have to change the aux belt tensioner as it stated making noise on startup, perhaps the pulley hit it on the way out.

new one ordered from the us for $139

Edited June 18, 2012 by GMan (see edit history)

[Swampy442]

I don't get this, those pulleys are a service item and do have a finite life. If it was 150+ thousand miles old it's no surprise it let go. If it had been changed on spec you wouldn't have had that problem. But glad it didn't cause more damage though.

[machman]

You have to ask yourself the question 'why put a damped pulley on there in the first place?'

The answer is the engineers recognised the need probably after extensive testing. I guess when the engine disintegrates due the adverse harmonics\resonance you'll wish you had spent the extra money on a stock pulley!