Due to the lead time involved, the first thing I looked
into was the cylinder head. Using Mandys contact at
her work (an engine building firm) I made contact with someone
who would port my cylinder head for me. Then I first got
my hands of the head I had bathed it in some degreaser which
removed nearly all of the soot and dirt. I had also been
able to borrow a valve compression tool and strip out the
valves and old stem seals (which would be replaced). The
head had then been sitting in my loft for several months.
The head and valves were dropped off and I had a few weeks
to wait. The valve seats would be re-cut with 3 angles and
the valves would be modified to match.
After about a month I got the call to say the head was
ready and I arranged to collect it on a Saturday morning.
At the same time I had arranged to buy the Jenvey
throttle bodies and arranged to collect them at the same
time, as I would be in the same area. The head work looked
great, consistent and the area behind the heads of valves
had been opened up quite a lot. Im no expert, but
it looked good to me.
The last thing to do before I could assemble the head was
to get the head skimmed. This was to achieve two things.
The first was to ensure the mating surface is perfectly
flat for the head gasket and the second was to increase
the compression ratio slightly. The process of porting the
head involves removing material which effectively increases
the volume of the combustion chamber. By skimming the head,
you reduce the height of the combustion chamber and therefore
readjust the balance. I decided not to go too far with the
skimming and only had 0.012 (or 12 thou) removed by
an excellent engine machine shop called Roe Engineering
(01234 5678910) in Fleet.
Rebuilding the head was pretty straightforward. A friend,
Kevin, had very kindly lent me his valve compressor to use.
The additional benefit of a trip over to see Kevin was that
he had been running a MS ECU for about a year and I was
able to get a lot of my questions answered and to see how
things fitted together in a working solution. Thanks again
Each valve had to be lapped to match the valve seat. I bought
a regular kit of a sucker on a stick and two grinding pastes,
course and fine. I spend a happy (although tiring) few hours
with the head positioned on a table in front of the TV,
lapping each valve in turn.
Once each valve had been lapped (making sure that they were
kept in their respective positions) it was simply a case
of fitting new stem seals but placing them in place and
then using a suitable socket and gently tapping them into
their recess. The valve could then be passed through and
the spring fitted. Brent had kindly given me a spare set
of valve springs which I used. I believe these were from
the K-series but the difference was that they went to coil
bound (in a vice) almost 2mm smaller than the standard spring,
at around 24mm. This meant that they could cope with the
extra lift that the up rated cams would give. Thanks again
Brent much appreciated.