|Safely home after our "If you plan it they will come" road trip.|
That something was compression! Cylinders one, two and four were all up around 125psi with number three at 0! Possible causes are broken piston rings or burnt valve and the only way to tell will be to tear the engine down and have a look. I had been experiencing oil consumption issues even before we went on the road trip so figured it was time for a rebuild anyway.
Before embarking on this project I had to make room in the garage and clean things up a bit. My other project car was moved into the back yard and hidden away under a tarp for the duration to free up space. Cleaning up was mostly putting stuff away and giving the floor a sweep. That task completed I can now move the Festiva in and get to work. I started by removing the hood, bumper, grille and headlights.
|Garage all cleaned up and ready to go.|
|Hood, bumper, grille and headlights removed.|
|Engine out and transmission put aside.|
|I don't think it's supposed to look like that!|
So now I had the problem figured out I had to come up with a solution. I acquired a large stock of Mazda B6T and B6D parts a few months ago and in that inventory was a number of spare valves and a few other bits that I would need. Also included was a short block B6D engine from an early, normally aspirated, Mazda Miata/MX-5. I learned that this particular block had only 125,000km / 78,000miles on it which is at least one third the mileage on the 323GT engine that came out of the car. In addition to the lower mileage the Miata block runs with 9.4:1 compression rather than the 7.9:1 in the 323GT engine.
|7.9:1 piston on the left. 9.4:1 piston on the right|
|New head gasket.|
|Timing belt, cam seals and oil pan gasket...|
|New crank bolt and key, water feed outlet and hose for the turbo from Stoney Trail Mazda.|
|Honed, hot tanked and painted... ready for reassembly.|
|Head shaved by 0.004"|
While the block and head were out at the shop I set about cleaning the pistons and rings. They came up really nice and I was able to reuse all but one ring. Once the block came back it received a couple coats of a flat black engine paint. The crank and rod bearings appeared to be in really good shape. Clearances were checked using Plastigage and the were well within specs so I simply reused them.
|Pistons all cleaned up and ready to go...|
|Media blasting debris in the valve cover...|
|... even more...|
|Oil pan all cleaned up and ready to go!|
|Cylinder head isn't bolted down but you can see how thick the head gasket is.|
With the engine bay empty I noticed that the steering rack boots were disintegrating so took the opportunity to replace them. While I was at it I cleaned up the bay as best I could... a lot easier to do both these tasks with no engine in the way.
|All cleaned up and ready for the driveline.|
|Engine and transmission reunited.|
|Back in the car!|
|A/C compressor all clean and shiny.|
|Exhaust manifold, turbo, heat shields and oil and water lines all hooked up|
Next question... will it start?
|The three cylinder portion of our trip!|
What's the end result? We now have an engine in the car that is not burning or leaking oil and will last a long time. With the higher compression pistons there has been a jump in horsepower. The stock Mazda B6T engine is rated at 132hp, knowledgeable friends estimate that the added compression will boost that to over 150hp. Those numbers are at the crank... it would be interesting to get the car on a dyno and see what the power at the wheels might be.
|First test drive... to the car wash!|
|All clean and shiny.|
Thank you for your continued interest in our little econobox and the adventures it takes us on. What can you expect from the Econobox Cafe moving forward? Show and shine season isn't that far off so you can expect a few posts on that topic, there'll be some road trip tips and tricks, we'll be featuring some econoboxes from Europe, perhaps a hot hatch or two, and lots of other 'stuff'. Let us know what you'd like to see in our blog in the comments section below.