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From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Estimation of air velocity through inlet ports, with calculations for required air flows at various RPMs and valve lifts.

Identifier  ExFiles\Box 17\6\  Scan148
Date  24th August 1933 guessed
  
-5-

(2) Estimation of air velocity through inlet ports.

Set V = vol. of air/cyl/sec. taken.
Set n/N = ratio of period of effective valve lift/period of cycle.
Set e = valve lift.
Set l = mean valve lift.
" V2 = vol air/sec through port.

Assuming depression in cylinder on induction stroke to be approx. constant.

V2 = V x n/N x l/e

Tests to be carried out at flows corresponding approx. to 2750, 3000, 3250, 3500 R.P.M. and at 1/3, mean (.354") and full (.480") lift.

Calculated air flows required.

Phantom:- 2750 R.P.M. V2 = 64 cu.ft/min. - 1/3 lift.
" V2 = 141.5 cu.ft/min. mean lift.
" V2 = 192.0 cu.ft/min. Full lift.

3000 R.P.M. V2 = 68.0 cu.ft/min. 1/3 }
" = 150.0 cu.ft/min. mean } lift.
" = 203.5 cu.ft/min. Full }

3250 R.P.M. V2 = 70.7 cu.ft/min. 1/3 }
" = 156.5 " " mean } lift.
" = 212.0 " " Full }

3500 R.P.M. V2 = 72.2 " " 1/3 }
" = 160.0 " " mean } lift.
" = 216.5 " " Full }
  
  


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