1.7 piston/cylinders with a 1.8 engine

[LCOX]

I just bought a 74 1.8 longblock that needs new pistons and cylinders.

I've got a nice set of earlier 1.7 pistons/cylinders.

Can these be used with 1.8 heads and 1.8 case/crank and rods? Thanx L

[Dave at Pelican Parts]

They can be used with the 1.8 case, crank, and rods. Not with the heads. You'll need adaptor rings made to fit the cylinders into the registers on the head because the OD of the 1.8 cylinders (at the top) is larger than that of the 1.7 cylinders.

You'll have to work out what the compression will be. If it's under ~7.5:1, the motor will be pretty gutless. If it's over ~9:1, you may have problems with pinging even on premium gas. IIRC, most of the 1.7s ran 8.2:1 or thereabouts.

--DD