Most of these entries have covered portions of the track car preparation that take hours of time and often a modest amount of engineering. But there are many other things that need to be worked on that don’t really take too much time to accomplish so I thought I would touch on a few of them.
One change from 1994 to 1995 models of the Miata was to turn the oil pressure gauge from an actual reflection of oil pressure to something that still looked like a gauge, but really was just a pointer instead of an idiot light. When the engine was running the pointer would sit in the middle and when the engine shut off or lost oil pressure it would go to zero. I like having a real gauge so I purchased a used one out of a ’94 car and swapped it out for the ’96 one. I also had to remove the oil pressure switch by the oil filter and replace it with an oil pressure sending unit (otherwise the oil pressure switch would have blown the “real” gauge).
The radiator’s overflow tank is an important part of the cooling system. As pressure builds in the normally closed cooling system the radiator cap will open and allow excess pressure and coolant to flow to the overflow tank where coolant can also be “inhaled” by the system when needed. Unfortunately the factory expansion tanks are a known weak item. I could just replace it every year or so, but instead I opted to get a little functional “bling” into the engine compartment by replacing it with a Moroso unit. It is welded from aluminum and should never need replacement.
The valve cover is a nice and important item that keeps a lot of oil from blowing all over the engine compartment. Most people would be happy know that it is serving that function, and so am I, but it also provides me an opportunity to add a personal touch to the Miata’s engine compartment. It has become sort of a trade mark of mine to coat the valve cover of my cars with black wrinkle paint. And so goes the Miata valve cover.
It takes a while to clean the old valve cover. On the inside are three screwed on metal panels that I removed and cleaned up along with the rest of the valve cover. I used a product called Purple Power which can be really nasty to your skin and lungs so use it with respect. It also does a great job ridding the part of nasty oils and tars in preparation for paint. When everything was clean and dry I reinstalled the three metal plates with a modest amount of RTV for sealant and then masked off the areas of the valve cover that I didn’t want painted.
It takes three coats of paint with a five minute wait between coats. Then I put it under some hot lights and wait for the wrinkling to magically happen. The resulting finish is durable and puts up with most liquids a valve cover comes in contact with.
The headers by Racing Beat are beautiful to behold. The flanges are all cast and the welds are to envy. But headers radiate a lot of heat and that is not so good in an engine compartment. It is also believed that keeping the heat in the exhaust header enhances the flow characteristics. So I picked up a couple of rolls of DEI’s Titanium exhaust wrap. It is not real titanium, but it does look very pretty and has excellent insulating qualities. It will easily handle 1500 degrees F.
The fuel injectors had 150,000 miles of use and probably had spray pattern problems and poor flow characteristics. Since I had already replaced the fuel filter I picked up a refurbished set that came with a printout of the flow stats. One less thing to be concerned about.