![]() There's a lengthy article on this web site about fuels and VW engines if you are interested. The main difference between the AD (outside the USA) and AE (mostly USA) series engines was the compression ratio. ![]() Dished pistons were used on the "smogged" engines like the AE series to reduce the compression ratio from 7.5:1 back to about 7.0 or 7.2:1. The displacement remains at 1600cc for both the AD and AE engines. In California, the AE series also originally had a throttle positioner and were jetted rather lean (they had a 34PICT/4 carburetor when everyone else was using a 34PICT/3). The throttle positioner slowed the closing of the throttle when you lifted off (it would not snap shut) to reduce low rpm emmissions. I don't know if they were "original equipment" in other parts of the US or just in California. Someone wrote - There's a part in the your cooling articles that can be misleading: There's a quote by a gentleman that says that lower compression ratios make for more inefficient engines. (A reliable source) of technical information doesn't think so. To make a car more reliable as a driver that's exactly what you do and you get your power by tweaking some other things. ![]() Rob responded - You have used the words "efficiency" and "reliability" as though they were the same thing. Technically, the higher the compression ratio, the higher the pressure build up inside the engine AFTER ignition, so you get a bigger push on the pistons, which means more power from that amount of fuel. BUT, the heat inside the cylinder increases with increased compression and then you run into detonation/pinging problems, unless you use a higher octane (and higher cost!) fuel. An efficient high compression engine CAN be as reliable as a low compression engine, so long as you use the correct octane fuel for the higher compression engine.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |