I recently lost the head gasket (sort of) on my custom turbocharged Miata 1.8L. The head gasket failed due to corrosion on the iron block. I used minimal antifreeze to keep the turbocharged engine cool. The result was a hydrolocked cylinder due to water. I have 122,000 miles on the engine.
Anyway I am in the process of a full overhaul. I used Mobil 1 10-30 early on in the car's life and switched to 15-50 after installation of the turbo. The engine is in fantastic internal condition. The cylinders appear new and the ring gap is at 0.012 inches, well within new spec. What I was so impressed with was the bearing condition. They are perfect and can be re-used. I find this interesting because the rod bearings do not seem to hold up well in Miata turbo applications. Also, there are no deposits internally. The bottoms of the pistons have no carbon or discoloration (another problem with turbo miata's).
With the exception of a slightly bent rod, the engine is perfect and everything could be re-used. I don't even need to have the block cleaned as it is perfectly clean inside.
I also spoke with the folks at Flyin' Miata today and they confirmed an engine teardown at 154,000 with similar results on Mobil 1.
Contrast this with those who do not maintain Miata turbo's as well. They have continual rod bearing failures, along with rapid ring and cylinder wear and often get less than 25K out of the engines.
Very impressed I am!
Chris
Anyway I am in the process of a full overhaul. I used Mobil 1 10-30 early on in the car's life and switched to 15-50 after installation of the turbo. The engine is in fantastic internal condition. The cylinders appear new and the ring gap is at 0.012 inches, well within new spec. What I was so impressed with was the bearing condition. They are perfect and can be re-used. I find this interesting because the rod bearings do not seem to hold up well in Miata turbo applications. Also, there are no deposits internally. The bottoms of the pistons have no carbon or discoloration (another problem with turbo miata's).
With the exception of a slightly bent rod, the engine is perfect and everything could be re-used. I don't even need to have the block cleaned as it is perfectly clean inside.
I also spoke with the folks at Flyin' Miata today and they confirmed an engine teardown at 154,000 with similar results on Mobil 1.
Contrast this with those who do not maintain Miata turbo's as well. They have continual rod bearing failures, along with rapid ring and cylinder wear and often get less than 25K out of the engines.
Very impressed I am!
Chris
) and would like to know if it did lower your fuel economy? I really cant afford to lower my fuel economy any further as its at 21 city and 26 highway (wife has a lead foot-hmmmmmm.....if i just cut her foo.....uhh....nevermind!). just curious!
