Panoply

Car is a 93si. New motor setup using my old head from a b16 (went to machince shop to get refreshed) and bought a used b17a bottom end (was told had good compression, but can't verify that to be true). Results from the compression test were:

1. 120
2. 95
3. 0
4. 0

I was told a valve adjustment was done to the head after receiving it from the machine shop (can't verify that to be true, either). Was wondering if it is possible that a bad valve adjustment could cause the low compression I'm seeing on all four cylinders? Motor has sat for several months to a year. I know the first thing I need to do is a leak down, but I'd figure I'd start here on the question about the valves. Thanks.

Dc4LsTeG

iTrader: (7)

Are you doing the test correctly? What was done to the head at the machine shop? Are you sure mechanical timing is perfect?

Panoply

I am fairly positive that the mechanical timing is correct. Before doing the comp test I thought it was certainly the timing, but after removing the belt and reseting the timing just to be safe, I still could not get it to start, prompting me to do the compression test. As far as I know I am performing the comp test correctly. Holding throttle wide open and cranking 5-6 times. The head was cleaned, new seals, milled the head, and the old valves were reused.

grumblemarc

iTrader: (4)

Leakdown. Test.

Frase_civic

Did you put a fresh head gasket on?

Panoply

yes

Dc4LsTeG

iTrader: (7)

24TEN

iTrader: (2)

It's possible that the adjusting nuts on the valves are overtightened. This would cause the valve(s) to never close leading to 0 compression. One of my buddies did this once, was freaking out because of it. Easy enough to verify and shouldn't cost you anything as long as you have the tools to check it.

jbpnoman

And a leakdown test will tell the OP exactly where the compression is leaking from, confirming or ruling out the valves.

Panoply

Thanks for all the input fellas! 24TEN, I'm really glad to hear of an experience of 0 compression without it leading to a complete catastrophe. Although, I'm not sure that will be my case. I plan on renting a leakdown tester today from autozone. And I just got a coupon from Harbor Freight for 50% off their 3 gallon air compressor, which I believe is rated to 100 psi. I figure the compressor would be adequate for a job like this? Anyone disagree?

kyden

was the valve adjustment done after the head was installed?

Panoply

Kyden, I'm unsure on that one. A "friend" did most of this work, which is the reason to much of my uncertainty. My best guess would be that he installed the head and then did the valve adjustment, but it well could have been before. I just picked the motor up and he told me everything was good. Obviously not, though. Had he done the valve adjustment before installing the head, would that lead to problems like I am seeing? Thanks.

Panoply

Alright, I finally got myself a compressor, leak down tester and some time. I bought the tester from harbor freight, and noticed that the tester may be bad. Like the instructions told, I made sure before applying any compressed air that the **** of the regulator on the LD tester was turned completely counter clockwise. At this point the gauge reads 0 psi and the needle of the cylinder leakage gauge rests at 100%. As I open the regulator, I notice not much psi is building, but that the cylinder leakage gauge decreases from 100% to 0 (or Set), and usually the pressure gauge was in between 18 and 24 psi in order to reach 0 on the cylinder leakage gauge. To me this seems somewhat backwards, shouldn't my cylinder leakage gauge start at 0 and climb to 100% leakage? This is my first time doing a leak down, so excuse my noobness.

On cylinder 1 to reach 0 on cylinder leakage it took 24psi. I heard air escaping from the intake and exhaust
Cylinder 2 it took 18psi to reach 0, and again air escaping out of intake and exhaust
Cylinder 3 took 18 psi to reach 0, air escaping from exhaust
Cylinder 4 took 22psi to reach 0, air escaping from intake and exhaust

I know that either my LD tester is either bad, or I don't fully understand how to use it. However, the air escaping from the intake and exhaust seem to be pointing that the valves may be stuck open. I don't have any valve adjustment tools (anyone rent them on h-t?). Any insight would be extremely helpful. Thanks.

94EG8

All you need to adjust valves is a set of feeler gauges, a 12mm wrench, and a flat screwdriver.

Panoply

nice looking out 94EG8. suppose i was thinking of the tool they use to install valves/springs. thanks for the input!