i recently bought a 1990 miata. the previous owner claims that a motor swap was done. what are some markings or ways to tell exactly wat i have. this way when i go to buy an aftermarket ECU i dont buy one for the wrong year

 

check the vin

 

back trace it.

But srsly check the vin. Then research what the differences are (there are plenty of visual things) between 1.6 and 1.8 motors.

 

Luckily you buy an ECU for the engine harness, not the engine. Unless they swapped the harness, an ECU for a '90 will work in your car.

 

I just so happen to be my block and cylinder head with a tape measure in hand. I have the 1.8. I measured the 'humps' on my valve cover and they are 16" long. That measurement does not include the cam sprocket cover. Mine is cut off.

The block deck and the cylinder head surface measures about 15.5" long.

Also, a little forum tip. From now on, do not post in the Meet and Greet section of the forum. You have already done so. You want your subject matter to be appropriate for the section you are posting in. I would have posted this in General Miata Chat.

 

A: What is your location - put it in your sig
B: Where is a picture of said engine?

 

If we're being technical, the section this belongs in is located here: forum.miata.net

I would have just looked up intake or exhaust port spacing and measured that.

 

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