valve_calculator.rb

file.rb

require 'json'
require 'pry'

class ValveLifterPositionCalculator
  LIFTER_MEASUREMENT_FOR_GAP_MEASURE = 0.2090
  LIFTERS = [
    { id: 29, inches: 0.2090, mm: 5.30680 },
    { id: 32, inches: 0.2106, mm: 5.34924 },
    { id: 32, inches: 0.2103, mm: 5.34162 },
    { id: 34, inches: 0.2107, mm: 5.35178 },
    { id: 34, inches: 0.2113, mm: 5.36702 },
    { id: 35, inches: 0.2113, mm: 5.36702 },
    { id: 36, inches: 0.2144, mm: 5.44576 },
    { id: 36, inches: 0.2120, mm: 5.38480 },
    { id: 39, inches: 0.2146, mm: 5.45084 },
    { id: 39, inches: 0.2143, mm: 5.44322 },
    { id: 39, inches: 0.2138, mm: 5.43052 },
    { id: 39, inches: 0.2139, mm: 5.43306 },
    { id: 41, inches: 0.2150, mm: 5.46100 },
    { id: 41, inches: 0.2151, mm: 5.46354 },
    { id: 42, inches: 0.2157, mm: 5.47878 },
    { id: 43, inches: 0.2152, mm: 5.46608 }
  ]

  GAP_MEASURESMENTS = [
    { location: :intake,  position: '2A', mm: 0.18, inches: 0.008 },
    { location: :intake,  position: '2B', mm: 0.18, inches: 0.007 },
    { location: :intake,  position: '3B', mm: 0.20, inches: 0.008 },
    { location: :intake,  position: '4B', mm: 0.20, inches: 0.009 },
    { location: :intake,  position: '4A', mm: 0.23, inches: 0.013 },
    { location: :intake,  position: '1B', mm: 0.25, inches: 0.011 },
    { location: :intake,  position: '3A', mm: 0.28, inches: 0.013 },
    { location: :exhaust, position: '5B', mm: 0.30, inches: 0.012 },
    { location: :exhaust, position: '7B', mm: 0.30, inches: 0.014 },
    { location: :intake,  position: '1A', mm: 0.33, inches: 0.013 },
    { location: :exhaust, position: '6A', mm: 0.33, inches: 0.013 },
    { location: :exhaust, position: '8A', mm: 0.35, inches: 0.016 },
    { location: :exhaust, position: '5A', mm: 0.35, inches: 0.013 },
    { location: :exhaust, position: '8B', mm: 0.38, inches: 0.016 },
    { location: :exhaust, position: '7A', mm: 0.40, inches: 0.017 },
    { location: :exhaust, position: '6B', mm: 0.40, inches: 0.017 }
  ]

  INTAKE_GAP_ALLOWANCE_MIN = 0.008 # inches
  INTAKE_GAP_ALLOWANCE_MAX = 0.011 # inches
  EXHAUST_GAP_ALLOWANCE_MIN = 0.012 # inches
  EXHAUST_GAP_ALLOWANCE_MAX = 0.016 # inches

  def calculate
    calculations = {}

    GAP_MEASURESMENTS.each do |gap_measurement|
      position = gap_measurement[:position]
      calculations[position] = matches_in_spec(gap_measurement)
    end

    calculations.each { |position, matches| puts "#{position}: #{matches.join(',')}" }
  end

  def matches_in_spec(gap_measurement)
    LIFTERS.map do |lifter|
      total_gap = gap_measurement[:inches] + LIFTER_MEASUREMENT_FOR_GAP_MEASURE
      gap_after_lifter_used = total_gap - lifter[:inches]

      lifter[:id] if in_spec?(gap_measurement, gap_after_lifter_used)
    end.compact
  end

  def in_spec?(gap_measurement, gap_after_lifter_used)
    if gap_measurement[:location] == :exhaust
      gap_after_lifter_used >= EXHAUST_GAP_ALLOWANCE_MIN &&
      gap_after_lifter_used <= EXHAUST_GAP_ALLOWANCE_MAX
    elsif gap_measurement[:location] == :intake
      gap_after_lifter_used >= INTAKE_GAP_ALLOWANCE_MIN &&
      gap_after_lifter_used <= INTAKE_GAP_ALLOWANCE_MAX
    end
  end
end

ValveLifterPositionCalculator.new.calculate

# 2A: 29
# 2B:
# 3B: 29
# 4B: 29
# 4A: 34,35,36,39,39
# 1B: 32,32,34,34,35,36
# 3A: 34,35,36,39,39
# 5B: 29
# 7B: 29,32,32,34
# 1A: 34,35,36,39,39
# 6A: 29
# 8A: 29,32,32,34,34,35,36
# 5A: 29
# 8B: 29,32,32,34,34,35,36
# 7A: 32,32,34,34,35,36,39,39
# 6B: 32,32,34,34,35,36,39,39