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I was doing a time attack race and maybe I didn't notice my AFRs going desperately lean but all I know was that mid-race my engine shut off. crank crank crank, nothing; not even a sign that combustion was trying to occur. I got my car towed back home and immediately pulled the plugs to see all four of them melted.
Next I did a compression check
Cylinder 1: 90
Cylinder 2: 60
Cylinder 3: 0
Cylinder 4: 30
Sad day.
While tearing down my engine to see how badly I fucked up my engine I noticed that all four of my fuel injectors had this strange goop on them. It felt like and resembled wet RTV gasket maker. Obviously thats not what it is but it's just so you can get an idea of its consistency.
These are Deatschwerks 450cc Ev14 that I bought new and have used them for about 10K miles and have been running straight E85 through them for about 5K miles.
Besides setting my engine failsafes what negligence lead to this disaster? Where did all that goop come from? I would like to never make this mistake again.
Damn. Looking at the fuel lines attached to my fuel rail are the generic fuel lines I had lying around in my garage and the fuel lines I have in my "**** I may need later" box are my ethanol rated fuel lines.... Looks like I got two two mixed up when I installed my injectors.
Well that sucks.
If my injectors look like this do you think my fuel pump is also getting pretty gunked up?
That's the underside of the injector, not the top. That stuff reminds me of the junk that gathers on the transmission drain plug magnet. I bet that's a mixture of oil sludge and aluminum from the pistons. I see at least one solid fleck of pepper on the plug, which indicates the same.
The goo is normal even with alcohol rated lines. It helps to run a bottle of seafoam in the gas a few times a year or run regular fuel. The evo crowd Is very familiar with it.
Got a build thread or parts list/plans for the vvt build?
Not in the near future. The idea is to continue to learn a bit more about Miata engines and tuning through trial and error; maybe destroy another 1.6 or two. Continue boosting lava with my M45 SC.
It's evident that I have a lot more to learn. I would much rather make these learning mistakes on a cheap $200 1.6 than a built VVT engine.
Although, I will slowly start building my bottom end while I continue my learning adventure towards Miata engine enlightenment.
Manley Rods, Wiseco Pistons, ARP bs, and Fluidampr balancer is the idea for now.
Looks like I almost detonated myself a new piston! Why would one cylinder have so much detonation and the rest have minimal signs of det?
Now I don't know a lot about the Miata engines in general, and I may be looking at the engine backwards (fairly sure I'm not), but the worst cylinder is #4, no? Isn't that the cylinder that gets the least water flow and tends to run the most hot?
4 is hottest if no coolant reroute. It can also be hottest with a reroute but flow and the temperature gradient can be significantly improved. This has been common knowledge on Miatas for 10 years plus.
Pics are low-res but it looks like #1 isn't far behind. The detonation will breach the gas boundary layer, erode the piston over a large surface area at first, and then it will pick up on a single hot spot and go to town. Once that hot spot forms, it causes even more detonation, compromises the rings, oil gets into the chamber, reduces octane levels, causes even more detonation, and you're off to the races. It snowballs so quickly that there's typically only catastrophic damage to one piston, even though there's evidence in all four cylinders.
12-03-2018, 11:09 PM
Injector Goop
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