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5 valve vs 4 valve airflow

5 valve vs 4 valve airflow

5 valve vs 4 valve airflow

(OP)
I'm currently designing a relatively unorthodox diesel (and ethanol) 4 (short)stroke engine and I can't seem to get conclusive information on wether it is or not beneficial to use 5 valves per cylinder.

Sure there is a gain in the lower inertial values per valve-unit and greater flow area but my main doubt lies in the possiblity of flux interference between valves.

Additionally, I can't seem to find any mentionings of the benefits of variable valve lift and timing on diesel cycle machines. It should at the very least provide a power saving at lower operation speeds/loads by permiting less force to be applied on the valves when less intake is necessary, right?

In case this is of any influence in the matter, the engine is (theorectically) highly boosted in a quite linear fashion (rpm-wise) and possibly chemically intercooled previously to chamber entry. Bore=92mm; Stroke=75mm; 12 combustion chambers

I hope I wasn't to confusing. Thanks.

RE: 5 valve vs 4 valve airflow

You might also consider the structural question of how you're going to support the chamber roof between the valves.

Less valve opening at low loads or speeds amounts to throttling, and I don't think Diesels like that much at all.

Mike Halloran
Pembroke Pines, FL, USA

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