An engine failure..

[Chuck Leeper]

The engine ate #2 rod brg... And possibly other parts, as the engine has not had an autopsy, yet.
I got the Lucas 42# injs pt # 621031, for cleaning/flow check.
The customer relayed that the engine had failed and was removing it for rebuild. During the conversation he mentioned the rod brg failure and subsequently "gassy smelling oil".
My first test was just to see how the injs flowed.
#4 was lacking a goodly amt, and leaked down when I shut the test down, while the other 5 were all within 2 cc's of each other.
I did a "workaround", ran them again, and #4 behaved.
I then cleaned them with heated solution for 2-10 min cycles.
Put them back on the bench and fired them off. PERFECT!.........Until I shut the machine down.
#4 continued with a serious leak. I deemed that inj as being junk.
Given the customer mentioned gassy oil, I pretty much concluded that repeated leakage of a significant volume of gas into the crankcase possibly whacked the #2 brg. We don't know at this point what the rest of the brgs look like.
As a "gotcha" when #4 leaked after I shut down, I waited until the pressure in the bench bled down to zero.
The #4 cylinder had 15CC more fuel than the other 5.
Bottomline: There was possibly as much as 15cc dumped into the oil at every key off.
Be aware of how your systems are behaving!
Fuel pumps with check valves: Why is the fp instantly going to zero?
Why does the car smoke and run rough when starting?
Why does the exhaust stink?
Why do some plugs look different than others?
What's wrong with the Scanmaster readings?

MERRY CHRISTMAS!

 

[Turbo Archie]

Headgasket on #4?

 

[Chuck Leeper]

Headgasket on #4?

Have alerted the customer to check them when the engine is pulled apart.

 

[hensleyt]

thanks for the step by step. as much as most GN set in the garage I bet this could be a problem

 

[GNTIM]

I had a set of 42's cleaned back in the day that worked fine before the service. 2 were dead after I installed them after the cleaning.

 

[Chuck Leeper]

I've not recently "disected" failed injs.
My thot is that the older parts were not intended to be used in ethanol fuels.
Here's a pic of one that I cut open some yrs back.

However, not all failures are internal. Here's 2 pics showing what just a dirty filter basket can do.
Nothing was done other than changing the filters.

last one: This is a set of near new "Shitfire" injs. The owner was having issues tuning. Can't imagine why! They went in the trash.

 

[turbodave231]

Thanks for posting this Chuck!

I have built alot of these V6 engines over the years and I've learned from experience exactly what Chuck describes in his write up.

If the customer supplies new injectors for the engine build, I don't flow test them (maybe I should). If the customer supplies used injectors, the used injectors automatically get sent (to Chuck) for cleaning and flow testing. I run all my engines before they leave my shop. If I encounter a problem on the run stand, I know it's NOT the injectors. I know (because Chuck tested them) the injectors are healthy and will supply consistent volume and pattern across all cylinders.

This simple practice has saved at least one engine from a catastrophic event that would NOT have been related to my workmanship. If the engine failed...............guess who would get the blame!!!!