Hey guys so I did a compression test today on my ls-v and I'm wondering if the numbers are good or if I should pull it and do a rebuild.

Specs on motor

Stock b18b1 bottom end
B16 head fully rebuilt with new springs and retainers, valves, and seals
(Haven't bought cams for it yet so I'm running stock gsr cams)
New head gasket, water pump, timing belt, and oil pump.

I've put about 1000 miles on it since I got the head rebuilt and after break in I did do a valve adjustment. But anytime I punch it I dump a ton of black smoke.

So here's pics of each cylinder when I did the test
Yes the car was at operating temp but I did not have WOT

 

Oh and I'm using a stock p28 ecu. No catalytic converter and I do have an o2 sensor. No check engine light and no codes

 

Head is new, are you sure it was put together correct? Rings may be bad (defective) or your cylinders are tempered. 150 is low, I had a 190k d16y8 with a valve lap job that had 210psi across on original rings. My rebuilt b18c with p73 pistons has 240 across. Pull that motor something isn't right.

 

Yea I figured it's the rings because it does burn oil and the block is pretty raced out.

 

Strip the block and take it to the machine shop. They will tell you if your block is tapered. Probably will need to be bored out .020 over (81.5mm) and new pistons, rings, and head gasket.

 

Yea now I just gotta save up money to do a rebuild on it haha. Thanks for the help

 

Save your money and get a gsr short block. If you want reliability your better off with the gsr block imo.

 

Do the test again, but make sure you are at WOT. That makes a HUGE difference in the readings. Dont do anything else until you redo the test, properly.

 

Ok I'll try again tomorrow after I get off work and I'll post the results.

 

I was just going to say not to be so hasty with the tear down. All the cylinders are within tolerance for compression variance. I would say it's ether your gauge or something with the procedure. As mentioned you will get a more accurate reading with the throttle fully open. Also ensure that the engine is warmed up this will also help give a more acurate pressure. You can do it cold though. ether way!

Then once you have done all 4 cylinders dry, try dropping a cap full of engine oil down into the cylinder through the spark plug hole. Then do the test again and post up the results.

 

Yea I talked to a buddy of mine who is a mechanic and he said my compression specs are still fine for now. And thanks for the help. quick question though, do I take all 4 spark plugs out at the same time and then start the test or just the plug from the cylinder I'm testing and then replace it and move on to the next one.

 

I pull all of them.

It reduces the load on the engine, starter and the battery while you are turning it over repeatedly.

 

ok thanks for the info. should be home in about 2 hours and i'll do the test then

 

Sorry guys I was really busy all week. Finally re-did the test and at WOT @ 4 cranks each cylinder tested 150 and @ 10 cranks each cylinder tested at 170

 

170 isnt terrible if your using stock ls pistons. my old ls tested 185 and ran good, hardly burned any oil

 

eh, those numbers aare even but low. that about what my vitara motor put out and its compression was around 8:1. does it consume fluids? can you get access to a different comp. tester and/or do a leakdown test?

 

Did you try adding a cap of oil into the cylinders to see if the compression numbers go up?

 

This doesnt make sense. 150psi with and without wide open throttle? I would say there is no problem considering they are all consistent to each other.

 

Very good for a 95 . A 95 integra came in the other day complained that his car is misfiring a frequently , did a compression test and found 120 , 126 , 40 , 90. At idle only 3 cyl are working .

 

In my humble opinion, Im quiet confident its not your rings, its your valve seal. Oil from the head drips to your pistons via valve stem.

 

Quick questions. Why did you do the head gasket? Did you buy a gasket kit? If you did did you change valve seals? Did you bring your head to the machine shop and had the valves replaced ?

 

Doesnt matter pull them all out or not

 

lets talk tune.

what are you running for an ecu in your lsvtec? do you have a wideband?

 

I agree. Black smoke is an indication of too much fuel.

 

there is no way in hell you got 210 on 190,000 full of **** my gsr brand new with 10.0:1 was 220 yeah right