Thursday, December 1, 2011
Tuning the 1.9 Liter Opel Engine Tech Tip
It seems that everyone who drives an Opel wants “More Power.” (You are not alone!) Having acceleration on demand, affects how driving an Opel feels, and in turn, how you feel about your Opel.
The “Engine Performance” section of the tech tip index to back issues of OMC Blitzes (available at www.opelclub.com) shows this subject has been repeatedly revisited all the way back to 1985. Cal H.’s 6-part 24-page engine rebuilding articles of 1989-1992, the “big valve head” build article of Sept. 1988, and the other engine upgrade articles of the 1990’s, are among the most popular back issues ordered from the OMC Treasurer. The years since then have no doubt resulted in greater wear and tear to the original 30+ years-old Opel 1.9 engines, so it seems like a good time to review options that will get you more power.There are many possible ways of machining the stock 1.9 liter Opel engine for more power. Many discussions mention upgrading the airflow capacity of the cylinder head with installation of non-Opel parts like Chevy Valves (big valve 1.72? or 1.84? intakes coupled with 1.50? exhausts from V8 engines). This is often combined with installing Chevy pistons (from the 265 or 305 engines), and others advocate stroking the engine by modifying the Opel crankshaft to achieve a 2.4 liter displacement. The lure is lower entry costs, but the obstacle is locating experienced professionals, who understand some of the more theoretical aspects of machining parts that were never intended for use together, to assure proper clearances and heat-expansion tolerances (that were never specified in any Opel service manual). Quality engine machinists who will work on an Opel are a rare breed (and their services are usually priced accordingly).
