Ive been told that small scratches on cylinder walls wont show up on a compression test, now i have a b16 block that id like to turbo, but the previous owner ran without an intake for awhile and there are some light scratches on the walls. no smoke or anything but they are there. is this something to worry about, or if i get good compression results does that mean there is NO LEAKAGE WHATSOEVER. i guess what im asking is, if the compression numbers are close together, does that mean the block is healthy? even on turbo cars with all of that dense air in there?
__________________



Modified by Sport_Injected at 5:33 AM 11/11/2004

 

You will want to leak test the motor. This will tell you exactly if the scratches are affecting compression. Most scratches will induce blowby so I would get the block honed before adding any power adders.

 

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by msmotorsports &raquo;</TD></TR><TR><TD CLASS="quote">You will want to leak test the motor. This will tell you exactly if the scratches are affecting compression. Most scratches will induce blowby so I would get the block honed before adding any power adders.</TD></TR></TABLE>

how is the leakdown test more affective then the compression test? thanks for the reply

 

compression test tells you more or less how much peak pounds per square inch you are making, while the leakdown tells you what percentage is slipping by over what time period. take it a step further and you can sometimes detect what is leaking.. valves, valve guides, rings, headgasket, etc.