Ok guys, my brother accidently went from 3rd to 2nd @8000 rpm while running with nasa at PIR last weekend. It was his first event and was doing well until the accident happened.

It drove home fine with a little noise happening.
Then yesterday he informed me that it was making like a popping bubbling noise.
I checked the compression and these were the results.
Cylinder 1: 170
Cylinder 2: 180
Cylinder 3: 175
Cylinder 4: 150

Now I know + or - 10 is still within good standings but the 150 has got me worried.
It makes the popping/bubbling noise often now while at idle.

I am going to be tearing the head apart to see what it could possible be. Any ideas on what I should be looking for? or if any what should I upgrade while I'm in there?

thanks for any information and advice you can give me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by f1nal zeros &raquo;</TD></TR><TR><TD CLASS="quote">Now I know + or - 10 is still within good standings but the 150 has got me worried.</TD></TR></TABLE>

Gotta love the money shift.

Is that compression tester known to read well? I would have expected higher all across, but some testers read different. It's possible everything is fine, but it's possible all the valves are bent. Leakdown test might show valves.

-Chris

 

same thing happened to me, hopefully i figure out whats wrong real soon and can shead some light on your situtation.
But I do reccomend doing a leakdown test
good luck!!

 

While the head is open any recommendations on what should be replaced or upgraded? This will be for a NA application.

The block has 84k miles on it so I am going to replace the oil pump, water pump, and timing belt.

Any other items I should consider replacing or upgrading?

 

add oil to #4 and do the test again

if the numbers go up, then its not the valves

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">

Gotta love the money shift.

Is that compression tester known to read well? I would have expected higher all across, but some testers read different. It's possible everything is fine, but it's possible all the valves are bent. Leakdown test might show valves.

-Chris
</TD></TR></TABLE>

umm...how can the engine still worK if the valves r bent? lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drifter_X &raquo;</TD></TR><TR><TD CLASS="quote">

umm...how can the engine still worK if the valves r bent? lol</TD></TR></TABLE>

If the head of the valve taps the top of the piston, they can bend just a little. They will tick louder, and not seat against the valve seat completely, and you'll get crappy compression and beat up the valve seats.