identifying motor and heads Options

[914fun]

This number is on the side off a motor I have: SI 12 004.101.102A 10 0 22H. Can I tell what motor it is with this number? I need to know if it is a 1.7 or a 1.8. also this number is on one head: 171158.

[Dave_Darling]

The punched numbers you have in the photos above appear to be done by a shop, probably meant to keep all of the parts together during a rebuild. The numbers sticking out are casting numbers.

Neither have anything to do with the displacement of the engine.

You can find out the original displacement if you find the engine serial number on top of the engine. Many are on some of the webbing on top of the right case half (914 orientation) near the flywheel end. Some are in front of the oil filler tower. Serial numbers that start with "W", "EA", or "EB" are 1.7 engines. "EC" are 1.8 engines. "GA", "GB", and "GC" are 2.0 engines. All other codes were not originally installed in 914s.

The cylinders for the 1.7s were 90mm across. The 1.8s were 93mm, and the 2.0s were 94mm.

The register in the head where the top of the cylinder goes is 100mm across on the 1.7 heads. That same feature is 105mm across on the 1.8 and 2.0 heads. The 2.0s have spark plugs that tilt toward the outside of the engine, while the 1.7s and 1.8s (and all non-Porsche applications) have plugs that stand straight up. The 2.0 heads also have three studs holding the intake runner pipes onto the heads, the others all have four studs.

I do not believe that any of the engines had "step studs" (different sizes on each end) installed on the exhaust ports from the factory. They are a popular modification to make when a stud gets stripped or broken, and are available from many engine supply places.

--DD