Installing a Metric Mechanic HiFlo ST Cylinder
Head
I am replacing the stock cylinder head with a high performance head built by Metric Mechanic, ordered September 24, 2009. I had planned to simply R&R the head gasket (would be the fourth replacement) to finally
stop the oil seepage problem common to most M20 engines, but decided to take the opportunity to enhance my M20 performance
by involving the MM product. Stay tuned, lots of good pictures and information to be posted once I start work on this winter
project.
Details on what Metric Mechanic does to these heads can be seen here. The horsepower gain is about 20%, plus what ever a revised ECU chip can add to it. Dyno runs done several years ago produced
RWHP readings of:
A - 106.5 RWHP with stock ECU
B - 122.3 RWHP with E.A.T chip
I am hoping to see about 147 RWHP (~165 clutch HP), once everything is in place and
fully sorted. RWHP was calculated to be about 12% less than clutch/flywheel horsepower. I will post new dyno results, once
I have them probably early spring, 2010.
UPDATE November 16, 2009
The completed MM head arrived November 4. (see pictures below)
Difficulties in obtaining a satisfactory cylinder head core and the flu bug at MM had caused the delay. Fortunately,
my garage is heated, so doing this project as winter moves in will not be an issue... other then I may not be able to road
test it for a while, until a warm day comes along, due to the ultra high performance summer tires, which can't be run below
a 45F (7.2C) temperature.
I asked Mark D'Sylva to look at the possibility of building a revised "027" ECU chip
to take full advantage of the new MM M20 head and cam configuration, since Mark has worked with MM developing revised ECU
chips to work with MM engine configurations. Mark has not yet advised me on my request, as of this date.
