Quote:
Originally Posted by Casper
Very few people realise the differences between a two valve motor and the 4 valve motor because it is rarely spoken about. Down low the two valve motor will stomp on any 4 valve of the same capacity (NA) but if the upper rpm limit is too low then the 4 valve loses out because it performs better at higher RPM. That MB and Nissan motors never worked properly in SC is not surprising given they were handicapped from day one by the 4 valve configuration.
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Yep, plus the benefit of only one camshaft mounted low in the engine for the pushrod engines, whereas the 4 valve DOHC engines have 4 camshafts, so four times the weight, mounted up high - so heavier and a higher centre of gravity.
Pushrod engines may well be considered "old" (although overhead cam engines aren't much younger) but there are ARE some benefits, particular when there is a set of regulations containing rev limits to manage costs.