Helping Nilao out with an inframe ...

[Rawze]

We got rained out on Sunday and part of Monday. Such is life in my driveway, kept everything covered really well.

Day Four (Monday) ...
We needed to determine how that failure occurred and if it was a liner issue as well. The liners all checked out good with no signs of dropping. they were all 0.009" tall and seemed to be nothing wrong with them. I do not trust this method so well for checking if a liner dropped because many times, they only do so on one side (the exhaust side) and you cannot see this by checking liner height.

I use a better method for detecting this. Here it is...

To check to see if a liner has dropped only on one side, we polished the underside of the head where the liners sit. We looked for a stepped wear pattern. For those who do not know, as a liner drops to only one side in an engine, its overall height will check out just fine, but it will also ride hard against the under-side of the head as it bounces. This creates a step in the under-side of the head as it does this. Here is what we found...

This is the under-side of the head above a good liner that has not dropped. Basically cylinders 1-4 looked similar to this ...


On the other hand, at cylinder number 5, it looked like this on the under-side of the head above where the liner sits...


It is very clear that liner number 5 was dancing on the exhaust side. This is what most likely caused the fire ring to get distorted as well. Maybe some people who build engines can learn a new trick from this technique?. It seems to be very effective in determining if someone should pull liners on an engine that the liner height checks out ok. This is also one of the reasons that you cannot re-use a head, as the few thousanths wear here will allow the new liner(s) to eventually fret again due to uneven crush pressures.


Day Five (Tuesday) ...

We pulled pistons and liners and did some running around for some stuff so that we could prepare. We also ordered liner shims and a few other items. He got with his bank and got a loan approved to pay for it all. It looks like he will be needing a new head (not reman), overhaul kit, rod and main bearings, one new injector (we found a bad spray pattern in the number 6 piston), a new air compressor (his is going out), a new crank shaft damper, new oil pump, new thermostat for coolant, new coolant filter, and a few other things.

We can only do limited things until the shim kit gets here. I will counter-bore his block for him, and we will raise the liner height to 0.015" instead of the 0.009" it was set at. This will help it tremendously. As well, we are using brass shims just like I did on my own truck. This will make the liners tighten up as they expand in the heat and allow for the extra height.

Tags:

liner issue, liner dropping, liner wear, liner fretting, underside of head, under side of head, step from liner in head, liner step