Opel GT Forum banner
1 - 1 of 1 Posts

· Currently in Opel Detox.
75 Posts
Discussion Starter · #1 ·
Let me preface this by saying to all that I do not plan to do this conversion at this time.

For all the die hard engine conversionists, I wanted to expound or impart some little knowledge I've gained. I have a mazda Protege short block in my garage. This is the same block as the Miata 1.8 DOHC motor.

Here is what makes this intrigueing, there is very minimal work to be done on this motor to mount.

I just test fit this for verification. The Opel motor mount cradle and even the block mounts ALMOST fit. With modification to the rear bolt hole on the mount that attatches to the block, you can bolt it on the 1.8 mazda block. You don't have the centering hole at the top of the triangle, but you know one sheet of metal and a drill and tap, and you're there, as you have the room for such mods. The only part that doesn't fit well is the oil cooler that is mounted on the passenger side right in line with the motor mount. Again, an easy fix as you only lack about 1/4 inch to clear.

The motor sits only 11 1/2 inches forward of the cradle's centerpoint and only 9 1/2 to the rear. The 1.9 Opel sits almost a full 13 to the front and 11 1/4 to the rear. The problem is the length of the miata tranny as I know it is longer (I think by 6 inches if I remember) to the shifter than the GT's. Here you only gain 2 and you'd still have to mod the shifter.

The only other reason that this is interesting is that the accessory and fuel injection set up will let you run full accesories (i.e. AC compressor, fuel injection and alt) in the stock mazda positions without conflict to the GT engine bay. Also by saving a couple of inches in the front, the rear of head ignitor setup should clear as the motor is also a slight bit shorter than the GT.

the other positive for the miata's is that they are plentiful used with under 75k miles because the owners rarely drive them as an every day car, and there is a plethera of aftermarket performance mods.

All that said, I still think If I attempt a conversion I'll go rotary just for stock power.
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.