this might be the worst moment of my life. i rebuilt my bottom end because there was a loss of compression and i thought it was the piston rings. i spent a ton of money rebuilding the bottom end, hoping that would fix the problem.

anyways i was putting the head back on tonight and i noticed this, can't believe i noticed it before:




on both ends of the head, there seems to be holes between where the cams would go. this isn't normal is it? what would cause that if it isn't normal? would those holes cause a loss of compression/running poorly?

to further clarify: here's where the holes are:


please help, does anyone know if those holes are supposed to be there or not? and was this why my B16 was running crappy?

 

that looks like the normal casting of the head.

did you have the head checked/machined/valve job/valve seals?

im sure its fine.

 

i haven't had the head checked out yet. i'm pretty sure i need to resurface it because there's some small scratches on the underside of the head.

i was just scared because that second picture especially doesn't look like there's supposed to be a hole there - it looks pretty ragged. you'd think if that was on purpose, it be a more perfect oval or something. but if that's how it's supposed to be, that's a huge relief

 

im 99.99999% sure those are casting impefections........the head is fine man!

 

ok thanks alot. that scared me for a second

 

I'll second the 99.999999999% sure those are casting imperfections because my head looks just like that!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by guedo148 &raquo;</TD></TR><TR><TD CLASS="quote">i rebuilt my bottom end because there was a loss of compression and i thought it was the piston rings. </TD></TR></TABLE>
In the future you should start doing leakdown tests. A leakdown test pressurizes the cylinders with air from a compressor, and you can more-easily identify compression loss sources. For example, if the air is shooting out of your PCV valve, you know it's probably the rings. If it's coming out of the intake manifold, there's probably an intake valve leaking. From the exhaust port, probably an exhaust valve leaking. Leakdown tests are great. Much more informative and quicker than a compression test (although it is not a total substitute). To further test your whole motor's blowby (precisely) use a blowby flow meter connected to the PCV valve.

Just trying to save you some time and money. DIAGNOSIS.

 

thanks, i did the oil trick where i put a tiny bit of oil in the cylinders and the compression went up so that led me to believe it was the rings but when i took apart the engine the rings looked fine. how do you tell if the rings are bad, or can you tell just by looking at them?

 

LOL i thought there was something wrong with my head when i saw the same thing like 2 years ago. But then i saw my friends head and it looked exactly the same.