The end of another L5-VE
Ref. my previous post ; Any engine installed in my car is living dangerously :-)
This time was a bit different since it was a combination of what I would call bad luck and a serious mistake during calibration of the EMS on my part.
In short:
- Installed and tuned MaxxECU EMS with car in N/A trim to NOT destroy anything
- Added turbo + new injectors
- Third pull when tuning boosted rows on minimum boost the WG signal line ruptured and boost spiked to 1.2bar+
- Permanent smoke out the tailpipe and misfire
- ~Zero compression on cylinder 1
- Later found out that my base timing with the new EMS was +20 deg off… Nice.
Aftermath
Root cause: Base timing was advanced 20 deg… my bad. Although the boost signal line to wg shredding did not help.
Most likely damaged during install when adjusting the vband.
The engine should handle 1.2 bar of boost and what I thought was 12.5 deg timings which turned out to be 32 deg… major error on my part. Used the RX8 36-2-2-2 pattern, but obviously it has the sensor mounted 20 deg offset to a NC.
Head and deck has no signs of damage including top of pistons. But cyl 4 has some vertical markings which means there is some kind of party happening below.
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To my surprise the chain guide had cracked. This explains a ticking sound I could not locate after switching cams even if I had the valve cover off and rechecked everything. Most likely it cracked during the cam lock procedure where the guide is pinched in relieved position by a bolt trough the front cover.
This explains why the knock sensor was reading erratic noise all over the spectrum.
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Piston 4 looks to have had a pretty rough makeover. Some serious knock/pre-ignition has taken place.
The piston cracked all the way down to the pin bore including ring lands and the second ring itself.
Rod is also bent in all directions.
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At first it seemed piston 1-3 did not have any damage. But on closer inspection the second ringland on all three had a small crack.
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The turbo ingested quite a lot of oil from cylinder 4 when I limped the car home at 2K rpm.
Crossed my fingers it was not hurt in any ways as it’s worth more than the engine. (It survived)
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The rest of the engine looked ok and probably could be rebuilt with the crank. But I’ll never own a 1.52 R/S 100mm stroke engine ever again.
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