What have you done today/recently to your 5?

LiteIsRite · Postby **LiteIsRite** » Sat Mar 30, 2019 11:16 am

3gress wrote:Just out of Eltham (nsw).
The road through Eltham follows the rail line out of town and there is a lengthy trestle with this farmer's road ducking underneath.
There is a neat looking defunct rail depot near the roundabout in Eltham village too. A few photogenic spots around the area worth investigating.

Got it. Thanks mate!

3gress · Postby **3gress** » Fri Apr 12, 2019 10:22 am

Pulled it's heart out to tend to leaky oil pan.

Pic shows electric water pump reverse flow plumbing.

3gress · Postby **3gress** » Fri Apr 12, 2019 3:27 pm

...and found this!!!

A decent crack in the fidanza cam gear there!
So much for a simple oil pan reseal.
There's a couple of Toda cam gears about the place so I'll have to swap one in for now, but Dang how did that cam gear crack!?
Any ideas?

StanTheMan · Postby **StanTheMan** » Fri Apr 12, 2019 3:31 pm

Wow!!!!
Something shock the earth. Did you hold down the cam with a screwdriver while tightening or loosening the cam bolt?
But that’s really a totally outthere idea

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3gress · Postby **3gress** » Fri Apr 12, 2019 3:38 pm

They Were adjusted for offset due to head shave and set for clearance but were treated with kidd gloves, bright, shiny and new as they were.
I will be checking again for valve float piston contact again i guess but otherwise can't think of what would cause the crack in that spot.

StanTheMan · Postby **StanTheMan** » Fri Apr 12, 2019 3:40 pm

just realised they are cracked on both sides of the hole.... :shock:

bruce · Postby **bruce** » Fri Apr 12, 2019 3:52 pm

Overtightened? I know it's a bit obvious to say that.

3gress · Postby **3gress** » Fri Apr 12, 2019 3:56 pm

Let's hope so, that would be the cheapest repair!

bruce · Postby **bruce** » Fri Apr 12, 2019 4:05 pm

Put a torque wrench on it and see what they were tightened to (I've never used one so don't know if it measures while undoing?)

StanTheMan · Postby **StanTheMan** » Fri Apr 12, 2019 4:07 pm

bruce wrote:Overtightened? I know it's a bit obvious to say that.

I'm not sure....one of my Fedenza bolt just broke by over-tightening the nut. It wasnt that hard to brake the bolt....so Ive been super careful since

hks_kansei · Postby **hks_kansei** » Fri Apr 12, 2019 4:12 pm

bruce wrote:Put a torque wrench on it and see what they were tightened to (I've never used one so don't know if it measures while undoing?)

Depends on the wrench.

The ratcheting ones normally measure both ways.
Deflective beam ones only measure one way

In saying that, you can't get an accurate reading by un-doing a nut/bolt since the torque will peak briefly before it give and then drop to nearly nothing.
Compared to tightening, where the torque slowly grows as the bolt pulls against the surface.

The closest way to check torque is to set it to just above the max needed and try to tighten them a bit more.
If they move a little, it means they were under whatever torque you're set to. If they stay still, they're tightened to something higher.
But, that still isnt accurate, since a bolt tightened to X at install may well take more torque than that to shift a few years down the track as the threads gum with rust etc, and the washers do that weird thing where they grab a surface.

These look pretty overtightened at a visual inspection anyway, the crack for starters, and the one on the left appears to be tight enough that the washer is galling the alloy under it.

3gress · Postby **3gress** » Fri Apr 12, 2019 4:14 pm

They Were tightened to the specs included with gears, pretty sure this was the reason for finally investing in a smaller inch-pound torque wrench. If it were an overtightening issue I'd be to blame. That said i carefully torque everything in an OCD-like manner.
Researching fidanza failures has revealed a heap of threads with similar failures. :evil:

RS2000 · Postby **RS2000** » Fri Apr 12, 2019 4:29 pm

If a nut was over torqued, you would think the crack would be either side of the nut/slot.

3gress · Postby **3gress** » Sat Apr 13, 2019 3:55 pm

Looking about the head internals i can't see any issues (thankfully!). There is no scoring or bluing on the cam lobes, no worries with clearance, the lifter faces are neat with good lubrication evident. The plugs all showed a good burn and ports don't have excessive carbon build up, stem seal leakage or heat charring. Everything looks good.
The cam gears are not galled about the nuts and no other cracks apparent.
I can only think the design of the gears lend themselves to failure when spinning above factory rev limits. I have a hard cut at 7800rpm but it's never been anywhere near that, bounced off the cold 4000rpm limit a few times, never misfired etc, etc.