Isuzu Impulse 90-92 Engine Parts Catalogue
The M100 uses an Isuzu 4XE1 1.6l engine modified by Lotus. The Isuzu Impulse XS used the normally aspirated (N/A) version of the 4XE1. The Impulse RS used the turbocharged version of the 4XE1 which was designated 4EX1-WT (With Turbo). Lotus modified both engines: the M100 N/A was designated 4XE1-M and the M100 Turbo designated the 4XE1-MT. Doc Fizzix took apart an Isuzu Impulse 4XE1-WT engine and compared the parts to an M100 4EX1-MT engine in this LEC post. Some major differences are:
- 4XE1-M engines (M100) used hydraulic valve lifters
- The oil check valve and relief valves in the head are different to supply oil to the hydraulic lifters.
- The lower intake (injector housing) manifold is different
- The engine oil filter adapter (The Impulse used a remote filter) is different.
The Isuzu 90-92 Engine, Emissions, Engine Electrical Parts catalogue was found by Wayne HERE. This catalogue is not available in some parts of the world so Inkitin has converted it to a PDF file, given some helpful instructions on how to read the data and also ensured that the text information is fully searchable. Please read the first page carefully. The catalogue also includes pictures and part numbers for the 4XF1 1.8L engine which did use hydraulic lifters and there is some mention in Doc Fizzix' thread that the 92 Geo-Storm GSi 1.8l 4XF1 head is identical to that used in the M100 but this is unconfirmed.
Download: Isuzu Impulse 90-92 Engine, Emissions, Engine Electrical Parts Catalogue pdf format, 6.0Mb