Zero compression in cyl#1

[eric91gst]

ok, after putting a different head on the car and using a stock hg with arp head studs i did a compression test. At first from 1 to 4 it was about 150 200 something then 180 then 160. How can the compression on number 2 be so high over 200! Could compression being this high have caused the hg to pop. After primeing the motor i started the car and it ran for abou 30 seconds then died. I did a comp test and from 1-4 it was 0 90 155 155. I dont understand how the comp was over 200 since the stock compresison isnt even that much. I looked into cyl 1 with the spark plugs out and could see that there was liquid on top of the piston. I put a screwdriver down there and it looked brown with green on it. This has to be a blown hg righ, and this wold have caused my 0 compression? Could putting assembly lube or anything on the cyl walls casue the comp to raise that much. Whats going on here?
-thanks

 

[beccari56]

Sorry to say this but that is probably a blown head gasket, unless the head you installed is warped or cracked. Green is coolant, which is bad in the cylinder. You have to have a pretty big hole to get 0 for compression, like a valve stuck open. Don't use assembly lube on the cylinder walls during installation. You have to use regular motor oil on the piston skirts during piston install. The assembly lube is too thick and will fill the space in the combustion chamber and could cause your compression to get very high since nothing will get past the rings. You will have to pull the head and look at what happened to the gasket first. If it's ok (doubtful) then look at the head real close. Good luck with this.

 

[JayRolla]

Wow these blown HG have been coming up a lot. When you did the head install did you make sure you cleaned our the bolt holes on the block before torquing down the head?

You need to used compressed air to clean the holes out or you will get false readings on your torque wrench. Bam blown head gasket. Seen it happen a lot. Those holes can get filled with a lot of crap.

 

[eric91gst]

well i bet the kead might be warped now. IM going to take it to a shop and have them check it out and machine it if necessary. Should i go with a mitsu MLS hg this time. Also what is the proper torque sequence for the arp head studs because it is different from what someone told me on here then what the haynes manual states. Also i did use assembly lube on the walls before i put it together. After that i did a comp test before i started it and #2 cylinder was over 200. Do u htink this popped the hg a little before i started it, and then after i started it, it just went completely. This is plausible, right?
-thanks

 

[JayRolla]

Yes go with a mls hg. What kind did you use before?

 

[eric91gst]

I had a stock felpro hg before. Also, can i reuse the arp head studs since the comp in number 2 cylinder was over 200? Would this be enough to make the studs stretch. I mean i only drove the car for about 5 miles and only at 9 pounds of boost. thanks

 

[romeen]

I had a stock felpro hg before. Also, can i reuse the arp head studs since the comp in number 2 cylinder was over 200? Would this be enough to make the studs stretch. I mean i only drove the car for about 5 miles and only at 9 pounds of boost. thanks

I doubt that would be enough to stretch the ARP's. But the only way to be certain is to use a micrometer to measure the length of the stud to see if it is still within specs. I don't know the exact numbers off the top of my head but can dig them up for you if you need them.

 

[eric91gst]

I doubt that would be enough to stretch the ARP's. But the only way to be certain is to use a micrometer to measure the length of the stud to see if it is still within specs. I don't know the exact numbers off the top of my head but can dig them up for you if you need them.

-yeah if u could look that up for me that would be great because idk where to find the specs fo them. Try and get back soon, thanks a lot.

 

[romeen]

eric91gst, I was unable to find the information that I earlier referred to. So I called ARP this morning to ask them about it. I spoke with Cody in technical support and was told that (unlike the rod bolts) they don't use measurement of length to determine if the head studs are reusable. He said it's important to follow ARP's torque specifications and install instructions, as I'm sure you know. If you adhere to their torque specs then you should be able to tell by "feel" (yes, that's the word he used) when attempting to reuse them. They should feel nice and tight when the proper torque is reached. If they feel "soft" when the recommended torque is reached then they should be replaced. He also said this is quite rare and generally they can be reused over and over as long as their recommended torque specs are not exceeded.

Sorry for the unintentional misinformation I gave you earlier (I was thinking rod bolts). Hope this helps.

 

[eric91gst]

thanks a lot, One last question. Do you think i will be okay using a mitsu mls gasket and just having the head resurfaced and not having the block decked. I am worried about it not sealing but the block should be fine shouldnt it?
thanks a lot for your help

 

[romeen]

thanks a lot, One last question. Do you think i will be okay using a mitsu mls gasket and just having the head resurfaced and not having the block decked. I am worried about it not sealing but the block should be fine shouldnt it?
thanks a lot for your help

Usually the block is fine. If you have any doubts I have heard of guys using a straight edge and feeler guage to check it. Just make sure to clean the block well.

 

[eric91gst]

O, ive also heard about people using copper spray when they use metal head gaskets. Is this even needed since my head is not warped and perfectly straight?

 

[JayRolla]

O, ive also heard about people using copper spray when they use metal head gaskets. Is this even needed since my head is not warped and perfectly straight?

Ummm yes you use copper spray everytime. And the felpro is crap, it is not stock unit at all, never use felpro anything. I usually spray it once, let it get tacky, spray it again and install.

 

[eric91gst]

where can you get the copper spray from and what is it actually called in stores? And just spray both sides of the head gasket right, nothing else? Also jay rolla, I have seen some of your posts in other threads about the arp install. You stress the fact to clean the bolt holes in the block and blow them out with compressed air. Arp says screw them in hand tight only, but on some of the holes i cant twist them all the way down with my hands. Should I retap these threads in the block to clean the threads up, Thanks alot

 

[romeen]

You should be able to find the spray in any auto parts store.
http://www.permatex.com/products/au...r_Spray-A-Gasket_Hi-Temp_Adhesive_Sealant.htm

If you try to clean the threads with a tap be very careful not to damage them. If you decide to do that put some of the molylube in the channels on the tap for any metal shavings/flakes to stick to. But the compressed air should be sufficient.

 

[eric91gst]

Alright thanks guys