Compression test

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(Dynamic compression ratio: fix link)
 
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==To check compression:==
 
==To check compression:==
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'''Disable spark and fuel'''
 
'''Disable spark and fuel'''
  
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Ideally, warm up the engine first. Piston and rings are designed to provide optimum sealing at operating temperature.
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On a vehicle with a electric fuel pump pull the  fuel pump relay, let engine idle until it stalls out.  For mechanical fuel pump, I think using a vise grip and 2 thin blocks of wood (to avoid crimping the soft line) on the rubber fuel line will work.  This prevents fire hazard.
 
On a vehicle with a electric fuel pump pull the  fuel pump relay, let engine idle until it stalls out.  For mechanical fuel pump, I think using a vise grip and 2 thin blocks of wood (to avoid crimping the soft line) on the rubber fuel line will work.  This prevents fire hazard.
  
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*[http://www.uempistons.com/calc.php?action=comp2 KB/Silvolite DCR calculator]
 
*[http://www.uempistons.com/calc.php?action=comp2 KB/Silvolite DCR calculator]
 
*[http://www.rbracing-rsr.com/comprAdvHD.htm RSR DCR calculator]
 
*[http://www.rbracing-rsr.com/comprAdvHD.htm RSR DCR calculator]
{{Note1}} Some dynamic compression rtatio calculators (like KBs) ask for an additional 15 degrees of duration be added to the IVC @ 0.050" lift point figure. This works OK on older, slower ramped cam lobes, but the faster lobe profiles may need to have 25 degrees or more added to be accurate.
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Some dynamic compression rtatio calculators (like KBs) ask for an additional 15 degrees of duration be added to the IVC @ 0.050" lift point figure. This works OK on older, slower ramped cam lobes, but the faster lobe profiles may need to have 25 degrees or more added to be accurate.
  
{{Note1}}If the intake valve closing (IVC) point isn't known, it can be calculated:
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If the intake valve closing (IVC) point isn't known, it can be calculated:
 
# Divide the intake duration by 2
 
# Divide the intake duration by 2
 
# Add the results to the lobe separation angle (LSA)
 
# Add the results to the lobe separation angle (LSA)

Latest revision as of 10:14, 24 August 2023

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