Thread: 2.25 motor questions.

Originally Posted by tucker

How do I tell if my motor is the 7.1 or 8.1 compression ratio?

If you look at the head. There should be a large "8" stamped on a raised (machined) section on the middle of the passenger side of the head.

However there is no guarantee someone hasn't had a 7:1 head machined.

What type of spark plugs should I use?

I used to run NGK BP5ES

Can't remember the timing, I originally had a 7:1 motor and later changed it to 8:1. I would set the timing to the manual figure, but then play around and see where it would run best either side of that.

Originally Posted by tucker

Just another question about the 2.25 petrol motor in my series 3.
I looked up the setting in my workshop manual for the ignition timing and I get 3 diffrent settings depending on the octane level in the fuel.
I also get two diffrent compression ratio motors that have different timing settings as well.
I also went into the auto shop to get some filters, oil, plugs and points and again needed to know the compression ratio as the spark plugs are diffrent. As for the points I was told that Bosh don't make them any more for the 2.25 motor.

Ok I guess my list of questions are,
How do I tell if my motor is the 7.1 or 8.1 compression ratio?
What ignition timing should I set?
What type of spark plugs should I use?
Where can I buy points from?
Geee".... so many questions.

Thanks again for all that have helped me out before.

Repco or any auto electrician should be able to help with the points the originals were lucas DSB 101 points but Bosch make the same type under the number GL19 for 4 cyl and GL19V for six cyl.

AJ