Driving Sports

Only a week has gone by and already we have an update on the Miata Time Attack project car.

A few days ago I took the car down to the local boys at F.A.M.E. Automotive (I believe they're huge Irene Cara fans) where we did a compression test to check the health of the motor. Unfortunately, cylinder #4 was well outside the normal variation for compression (100psi, versus 180psi in cylinders 1-2-3.) That meant more drastic diagnostics were required: a leakdown test.

For the leakdown the cylinder was filled with compressed air, Tim would then listened for hissing coming from either the intake or exhaust. This would determine which was fouled: intake valve, exhaust valve, or the cylinder itself. From sound alone Tim figured it was the exhaust valve, but pulled out his camera for a look-see, just to be sure. This is a scope similar to what doctors use, only Tim was looking inside my car's cylinder and not up my... well, you get the point. Here, too, the verdict was a slight burn on the exhaust valve. He also commented that there was a really nice cross-hatch on the cylinder walls. Good sign of the block's overall health.

Finally, just to make 100% certain, and so he could show off all of his nifty diagnostic tools, Tim did a smoke test. This pushed smoke into the cylinder and we visually could confirm where the leak occurred. As expected, lots of smoke exited from the rear.

Now that we've determined the cause of the low compression, we can get it fixed while we also refresh the head. For this, we'll be unbolting the top-end and shipping it out to Delta Cams for both a new set of "hot" cams and so they can have their way with the valves.

Why all the attention to the motor? Well, we want to make sure it's running 100% before we strap on the Bell Engineering BEGi-S turbo kit (we optioned for the Garrett GT2860RS "Disco Potato" turbo upgrade), then build it up with a Bell Engineering Intercooler and Engine Management courtesy of the AEM Plug-and-play box.

If luck goes our way, 220 whp is bound to be in our immediate future.