headgasket or rings ???

[Whitetalonb16g]

here is whats going on. I bought the car over a year ago, blew the headgasket replaced that and it ran fine besides the misfiring problem. Shortly afterwards I melted a #1 piston which in turn destroyed the block. So I found used 6 bolt shortblock installed new OEM gaskets and Timing best as recommended. We started the car which sounded great then I decided to drive it a few miles with occassional WOT to see how it held and I heard a pop then I see smoke behind me. We get it back to the garage and its still running ok, besides the smoke when I really rev it. Its hard to tell the color of the smoke but it looks white but sometimes grey. It has no smell to it either. I'm wondering since I am running straight water (inital testing purposes) that it wouldn't smell like a blown headgasket. I've checked the oil and it has no white or milky look to it. Then we did a compression test of the motor :

COMPRESSSION LEFT TO RIGHT

#4: 130psi
#3: 143psi
#2: 110psi ----- 129 w/ oil
#1: 140psi


i didn't test the others with oil just the low cylinder. I've already purchased a new OEM headgasket and thinking about getting replacement rings.

mods: 16g, K&N, ARP Head Studs, Walbro 255lph, ACT2600, 3" Exhaust, 2g manifold & 2g o2 housing.

any idea's would help.

 

[timloomis]

im betting its the rings because of what happened when you put the oil in.also,id replace the rings.theres such a pressure difference between them that you should just go ahead and do it.youll have the head off anyways.

 

[ZUUHLSGSX]

here is whats going on. I bought the car over a year ago, blew the headgasket replaced that and it ran fine besides the misfiring problem. Shortly afterwards I melted a #1 piston which in turn destroyed the block. So I found used 6 bolt shortblock installed new OEM gaskets and Timing best as recommended. We started the car which sounded great then I decided to drive it a few miles with occassional WOT to see how it held and I heard a pop then I see smoke behind me. We get it back to the garage and its still running ok, besides the smoke when I really rev it. Its hard to tell the color of the smoke but it looks white but sometimes grey. It has no smell to it either. I'm wondering since I am running straight water (inital testing purposes) that it wouldn't smell like a blown headgasket. I've checked the oil and it has no white or milky look to it. Then we did a compression test of the motor :

COMPRESSSION LEFT TO RIGHT

#4: 130psi
#3: 143psi
#2: 110psi ----- 129 w/ oil
#1: 140psi


i didn't test the others with oil just the low cylinder. I've already purchased a new OEM headgasket and thinking about getting replacement rings.

mods: 16g, K&N, ARP Head Studs, Walbro 255lph, ACT2600, 3" Exhaust, 2g manifold & 2g o2 housing.

any idea's would help.

its definately the rings. you should have anywhere from 175 to 215psi per cylinder. your numbers are low. 120psi is the service limit. cylinder # 2 sounds bad.