Due to the lead time involved, the first thing I looked into was the cylinder head. Using Mandy’s 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. I’m 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 Kevin!
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.

 
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