Rebuild - 2013-2014
After having the car on the road for a couple of years, at a track day at Blyton Circuit, the engine suffered from Detonation, blowing the head gasket & damaging the Pistons.
Rather than Just fix the engine, I decided to do a partial rebuild, based on some issues I had found in the last two years...
On the List of things to do were:
Increase the fuel Capacity
Improve the Gear linkage / change the Gear lever, as I was never happy with the MR2 lever/linkage
Replace the twin Davies Craig water pumps with a better setup & install a remote thermostat.
Tidy up the Charge cooler piping under the front clam
Make space for a Water Injection Tank
Replace the broken solid State battery isolator with a conventional one.
Replace the Zero 360 electric extinguisher with a Mechanical one.
Look at installing Traction Control & extra logging for the ECU...
BLOWN HEAD GASKET
Lets start with the Blown Head Gasket.
This happened on a track day at Blyton Park, somewhere the car had been before without any issues, It was a nice day in August, so quite warm when compared to other track days I had done - First session on track, as I was changing from 3rd to 4th, I was hearing a Knock, which I though was from the transmission, but as it turned out it was detonation..... anyway a few laps later i returned to the pits followed by a cloud of steam from the exhaust & a blow head gasket.
Why did it fail, well due to the logging memory being full, and not having any data to analyse, it could be a number of things, but given it was a warm day, I am thinking that it could be high inlet air temperatures causing the problem, possiby a lack of correction in the map. Not helped by the fact that the Davies Craig pmps were run by controllers that vary the speed and so were probably not giving enough flow to avoid local hot spots.
Anyway its a case of doing some propper logging when its back on the road and making sure there is sufficient safety built into the map. If there is a charge temperature problem, then I have made space to install Water injection, but this will only be used if needed.
The results can be seen in the photos below.
The gasket had blown on 3 or 4 cylinders & the detonation had damaged 4 of the pistons with the rings stuck in the grooves on two pistons. The head was marked, but that has been cleaned up with an 8thou skim, so it wasnt too bad...