Well, when I did my compression test about 5 months ago, it was around 270psi across the board. Now my compression reads as follows:

1 230
2 230
3 235
4 240

Now the odd thing is, I just ran my car at the track, and I just dyno'd. Check this out. I ran faster at the track (13.3 @ 99), AND I put down MORE power at the dyno than ever. I don't burn any oil like I used to, and my plugs look fine... Except for the small silver looking deposits on the porcelin) I have NEVER had detonation issues in the past, and I hear no detonation now.. my timing has always remained the same. Check out this thread with my current and old Dyno and specs:

https://honda-tech.com/zerothread?id=1425460

I'm confused, I'm putting out a lot less compression.. but I'm making better numbers and better passes at the track? It makes no sense. I tried a buddy's compression tester just to see if my gauge was off.. but they both read the same exact thing. I'm stumped. Help me out HT!




Modified by LSVT3K 91 C1V1C at 9:16 PM 11/7/2005

 

Silver things is not a good sign. Add a few(FEW) drops of oil in each cylinder and test again. A few is a little then spin without plugs.

 

I'll go ahead and give that a shot. This is the first time I've ever noticed the small silver dots.. and I do check my spark plugs quite often. The electrodes are a nice tan color.. so I have no idea why I would have little silver deposits. I'm going to buy a new set of plugs and see if they appear again.

 

If you haven't changed any hardware from then to now, you might want to check your valve lash and timing belt tension. If the timing belt has streched, it will retard the cam timing. If the valve lash is loose, it will affect valve lift and duration...

Either way; if it's running stronger now, you might want to reconsider your 'ideal' cam gear and valve lash settings.


Modified by B20C5 Turbo at 7:31 PM 11/7/2005

 

are you sure the car was up to operating teputure? or at least at the general temp as the last time you did the compression test.

 

I just adjusted my valve lash before my dyno pulls. Valve lash has always been the same. .008 on both intake and exhaust just as Web recommended.

Engine was up to operating temp, I always make sure that I run my compression tests the same.

Fresturated.. I have never seen compression numbers drop with power increasing.

 

Even the number of cranks during the compression test can change numbers.

5 cranks compared to 10 cranks, etc.

You can do a leakdown test to see if you have any leaks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DEMNTD1 &raquo;</TD></TR><TR><TD CLASS="quote">You can do a leakdown test to see if you have any leaks.</TD></TR></TABLE>

Yep, that's next. I'm curious to know if anybody has ever seen anything like this go on...

 

Bump for sleep.

 

Did you disable the fuel system in both tests and hold the throttle at WOT?

 

You valves probably don't seal as well as before but your rings seal better now for better power.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rocket &raquo;</TD></TR><TR><TD CLASS="quote">You valves probably don't seal as well as before but your rings seal better now for better power.</TD></TR></TABLE>

I don't get it... Would that be from the valve lash or the new oil, or what?

Explain, Rocket, please.

 

Just a guess, but your valve seats can get trash or erode over time. Ring seal usually gets better after initial break-in.

 

Gotcha'.

Thanks.

 

I just had new valve seals installed when I put my new valvetrain and cams in maybe 8 months ago...

When I do compression tests I always pull out the ECU fuse to cut fuel, but I have always left the throttle closed...

 

my car did the same was pretty much 270 then went down to 240s range. but i still lay down 200whp so i dunno haha

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hayabusa160 &raquo;</TD></TR><TR><TD CLASS="quote">my car did the same was pretty much 270 then went down to 240s range. but i still lay down 200whp so i dunno haha</TD></TR></TABLE>

Odd.. I'd still like to find out why.

As for the silver stuff on my plugs, I'm pretty sure it was just anti sieze getting on the plug when I pulled 'em out.

Bump!

 

bump0rz

 

ttt