Can anyone more technically astute on the eta engine go into >further detail on the low friction, but consequently quicker >wearing aspects of this motor?
Ben answers: >>As far as I’ve seen, the bottom end of the eta is really no >>less sturdy than the ‘i’ motors… >>The main area where the eta motor is ‘low friction’ is the >>valvetrain. The eta cam only has 4 bearings, as opposed to the >>7 on other small-6 motors, and the valve springs are considerably >>softer too. The Metric Mechanican (MM) Catalog (816)231-0604 agrees with Ben’s statements. The ETA engine has four bearings versus seven on the 325i head. However, the ETA engine still has the same basic head with seven bearing journals. MM uses the 325i (seven bearing) camshaft with stiffer valve springs, by drilling extra oiling holes in the three other cam journals. The head is ported for a 19% flow increase. MM uses 85mm (versus stock 84 mm) pistons with very deep valve reliefs, so a broken timing belt won’t cause bent valves (valves can’t hit the pistons). Stock rods and crankshaft are used. Redline is increased from 4,800 to 6,000 rpm. Horsepower increases from 121 stock to 185
Related Questions
- Can anyone more technically astute on the eta engine go into >further detail on the low friction, but consequently quicker >wearing aspects of this motor?
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