I have a B16 thats having a probleming bogging @ WOT. So after replacing pretty much everything I can think of. I did a leakdown test.

Results:
1-25%
2-45%
3-27%
4-35%

My freind that did the test said it isn't that bad of results. Shouldn't be the reason for bogging. We could feel the air leaking out from the VC breather,and the cams where still installed, when test was done.

My Q? is whats normal, if this isn't "that bad".

 

Either you did the test wrong, or your motor is pretty worn out! Leakdowns should be below 10%, worst case. Generally, a fresh motor will leak down around 2%.
If you did the test correctly (with each cylinder at TDC on the compression stroke), you can listen at the air cleaner, exhaust pipe and dipstick to hear where the leaks lead.
If you hear air at the intake, intake valves are worn and not sealing.
If you hear air at the exhaust, ex valves are worn and not sealing.
If you hear air at the dipstick, your rings are shot.

In any case, those numbers are very high! Good luck.

 

well, the block has about 1200miles on it since the rebuild.

We had the dip stick out, and could hear air comming out of the dip stick hole.
What about when air comes out of the VC breather tube?

 

the breather tube and dipstick are both connected to the crankcase...which means rings...are you sure you did the test right? cause your buddy doesn't know what the hell he is doing if he thinks those numbers are normal. Whats the compression at?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WERA689 &raquo;</TD></TR><TR><TD CLASS="quote">Either you did the test wrong, or your motor is pretty worn out! Leakdowns should be below 10%, worst case. Generally, a fresh motor will leak down around 2%.
In any case, those numbers are very high! Good luck.</TD></TR></TABLE>


ive never had a motor with 2% and they have all made hundreds of horsepower and ran fine. even on my leakdown gauge up to 20% is low and something i wouldnt worry about, especially if your compression is good.

if the compression is low and you are pulling over 20% leakdown then id be worried.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WERA689 &raquo;</TD></TR><TR><TD CLASS="quote">If you hear air at the intake, intake valves are worn and not sealing.
If you hear air at the exhaust, ex valves are worn and not sealing.
If you hear air at the dipstick, your rings are shot.
</TD></TR></TABLE>

take the valvecover off when you do it, that way you can put your hand/ear over the crank vents from the head to the block and see if its rings better

 

havn't had achance to do the c/r test. I'll do it this weekend. I'll have my buddy try the leakdown again, or I'll just pay a shop. See what they come up with.

As for the block. It has about 1200 miles since the rebuild. Maybe the rings didn't seat right.

I still don't understand why it bogs under WOT thow.

 

Did you get a chance to remedy the problem?

Inquiring mind wants to know

 

Yeah, we do! Shirley he's diagnosed it by now?

 

sorry guys. I never got a chance to find out what it was. Insted I pulled the motor out lastnight. I'm shipping the head off this week to get a little PnP, and the block is getting rebuilt as well.

I did put in a SOHC into the car, and will fire it up later this week.
I never understood why my B16 was bogging @ WOT. If it is the wireing, i'm shure it will happen with this SOHC.

I'll update as I find out more info.

All comments weclomed.

 

u did good because those leakdown # are crap.

 

I'll took the head of the block lastnight. I'll post pics up later today.