well i did a compression test on my motor today and i was like wtf.every cylinder maxed out my gauge at 300 psi! also i did a test right after my build and it was 210 psi all across.now its got 600 miles on it, should i be worried about this?

the set up is,
b16a
os ctr pistons
head milled .4 thous.
block decked .5 thous.
oem head gasket
ss valves not flat faced
thats every thing that should affect the cr.also i put about a half a cap of oil in each cylinder,and the throttle was open.The numbers seemed high to me,what do you guys think?

 

My friends b16..os ctr pistons stock valves, head gasket no milling or decking put out 255-260 with no oil. This was also a cold engine. With this, I see your numbers being accurate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sickerhatch &raquo;</TD></TR><TR><TD CLASS="quote">well i did a compression test on my motor today and i was like wtf.every cylinder maxed out my gauge at 300 psi! also i did a test right after my build and it was 210 psi all across.now its got 600 miles on it, should i be worried about this?

the set up is,
b16a
os ctr pistons
head milled .4 thous.
block decked .5 thous.
oem head gasket
ss valves not flat faced
thats every thing that should affect the cr.also i put about a half a cap of oil in each cylinder,and the throttle was open.The numbers seemed high to me,what do you guys think?</TD></TR></TABLE>

ur numbers r wrong im sure u mean .040 on the head
and .005 on the block

anyhow to the point i dout u can run a motor with ptc pistons and a .040 milled head

i did a search on this befor and because i couldn t get any good help
i had to do it myself

well i found a stock b16 milling the head .040 and the block .007 is the limit
i try milling the block about .010 and the piston hits the head this is with a stock headgasket

now if u run a thick headgasket
but u already listed a stock

 

no my numbers are not wrong the head was only milled .4 not .40. This is why i was so suprised.But the motor runs great so im not to worried.But still does any one else have any first hand experiance with a simalar set up?

 

im thinking right after the build,the piston rings werent sealed thus less compression. compared to 600miles afterward the initial buildup theres more compression after the rings have sealed?

or carbon buildup...&lt;- i highly doubt that you'd build that much carbon to raise your compression in 600miles anyway....

any other opinions? i know im probably wrong though..

 

how many times did the motor crank?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ceLtic &raquo;</TD></TR><TR><TD CLASS="quote">im thinking right after the build,the piston rings werent sealed thus less compression. compared to 600miles afterward the initial buildup theres more compression after the rings have sealed?

or carbon buildup...&lt;- i highly doubt that you'd build that much carbon to raise your compression in 600miles anyway....

any other opinions? i know im probably wrong though.. </TD></TR></TABLE>

you would be correct....the rings seal rather quickly...and carbon buildup will also slighty raise compression....

 

i cranked it over 7 times thats what my manual said to do.im thinkin the oil in the cylinder raised it some,plus the rings have now sealed. Thanks for the replys

 

 

the head was only milled .4 not .40

.4 is the same as .40 ..........................

 

try it again with out the oil in the cyl., you only do that to diagnose bad rings.
you got 210 with 0 miles on the car? now that the rings are seated...
thats pretty high compression you got there

 

.4 looks the same as .40 to me

now .004 and .040 are a BIG difference!! as is .4 to .040

to say .4 tho is extremly confusing to me....

is this .0004??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sickerhatch &raquo;</TD></TR><TR><TD CLASS="quote">no my numbers are not wrong the head was only milled .4 not .40. This is why i was so suprised.But the motor runs great so im not to worried.But still does any one else have any first hand experiance with a simalar set up?</TD></TR></TABLE>

you are confused. you DID NOT mill your head .4". don't tell me you took almost a half an inch off of your head. you would have almost no combustion chamber. your head was milled .004" which is 4 thousandths. .040 is 40 (forty) thousandths. thats a crap load and still is not right.

your head was milled .004". you've just got a properly sealed high compression motor. most likely over 12.5:1 or 12.6:1. that kind of compression will usually peg a 300 psi guage.