2.2 head gasket replacement tips

Hi, I read storys on the net about people trying to replace head gasket on their 2.2 engine without success. Well here,s some tips
Before removing the bolts be sure the engine is totally cold, and give a little unsrew on each bolt to prevent head stress.
I did a lot of head gasket, and the most problem of people is that they dont clean enough the surface on both side (head and block) I use light brass wire drill brush to clean surface, after, I check for porosity if the,re is; I use JB weld to fix, after it's dry I take a staight piece of 3/4 plywood and glue on a 320 wet sand paper (black one) I spray small amount of water on it and put the head on it. By moving the head on the wood plate you get a nice clean straight polish surface. (re-check with a ruler) If the head is too bent dont do it replace the head or try a shop. Be sure to get all the dust out with compressor. If you want to reuse your bolts it's possible but make sure the threads are in good condition and clean them with the brass brush. Oil them with 5w30 before installing. Tight by hand your bolts and torque them in circle long bolts 46lbs and small 43lbs dont go direct to 46 I start slowly 25 and them I go up . When this is done you have to torque an extra 90 degrees? what is that...this is very important I use a big 1/2 inch normal bar then I position the bar at 3 o'clock and them I go down to 5 o'clock not 6 it's enough if you use old bolts, gasket wont leak be sure!

The loosening the bolts gradually is a great tip, unloading the torque evenly is as important as torqueing them evenly.

Sorry to do this to your tips again, but...

The additional 90 degrees is what is called "torque to yield" which means that you tighten them to where they begin to stretch. That means that they should NEVER be reused because the torque won't be correct on a second additional 90 degrees. If you actually did the 90 degrees instead of 3 o'clock to 5 o'clock, I would bet money that at least one would snap. The reason they give a measurement in degrees is that the torque begins to fall after it peaks (that's why you can't use a torque wrench to get them there), which makes the bolt a bit like a spring, it keeps force on the gasket all the time, even when differences in thermal expansion would cause a non torque to yield bolt to reduce the amount of clamping force significantly. The bolts should also not be oiled or lubricated in any way. The oil can fill the bottom of the hole and make the torque wrench click before the bolt is fully tight, then the oil gradually seeps out past the threads and you're left with a loose bolt. Oil also makes it easier for the bolt to come loose. To get accurate and even torque, clean the block holes out with a thread chaser, then penetrating oil, then brake cleaner, then compressed air. The engineers give the torque specs for dry holes, or if specified, thread sealer/locker.

I'm not going to say anything about the JB Weld and not perfectly flat plywood...

The loosening the bolts gradually is a great tip, unloading the torque evenly is as important as torqueing them evenly.

Sorry to do this to your tips again, but...

The additional 90 degrees is what is called "torque to yield" which means that you tighten them to where they begin to stretch. That means that they should NEVER be reused because the torque won't be correct on a second additional 90 degrees. If you actually did the 90 degrees instead of 3 o'clock to 5 o'clock, I would bet money that at least one would snap. The reason they give a measurement in degrees is that the torque begins to fall after it peaks (that's why you can't use a torque wrench to get them there), which makes the bolt a bit like a spring, it keeps force on the gasket all the time, even when differences in thermal expansion would cause a non torque to yield bolt to reduce the amount of clamping force significantly. The bolts should also not be oiled or lubricated in any way. The oil can fill the bottom of the hole and make the torque wrench click before the bolt is fully tight, then the oil gradually seeps out past the threads and you're left with a loose bolt. Oil also makes it easier for the bolt to come loose. To get accurate and even torque, clean the block holes out with a thread chaser, then penetrating oil, then brake cleaner, then compressed air. The engineers give the torque specs for dry holes, or if specified, thread sealer/locker.

I'm not going to say anything about the JB Weld and not perfectly flat plywood...

Well, this is your opinion and I respect it, this is my third head on 2.2 and as far as I remember it last before the rust eats the car. When I say oiling the bolts, I mean very little, So you probaly right in some ways, but some people eat pizza with the cheese under the pepperoni and some over it...that doesn't mean the pizza isn't good, just another way, I'll be honest with you if something going wrong with the way I work on engine It will be a pleasure to tell you the truth and I'll apologize.



best Regards

Denis

Nope, peperoni has to go on top of the cheese :)

http://www.enginebuildermag.com/Article/2343/threaded_fasteners_torquetoyield_and_torquetoangle .aspx
http://www.enginebuildermag.com/Article/1126/perfect_engine_sealing_starts_with_proper_head_bol t_use.aspx

Just a couple I found on Google. Those recommend oiling the threads, while I learned to use thread adhesive (I use blue Loctite brand thread adhesive), which acts as a lubricant until it dries. So, I was wrong when I said "the threads should not be oiled or lubricated in any way". We all keep learning, I was taught that, but apparently I was taught wrong. Right method but for the wrong reason. Down south, with far less road salt, we'll get 200-300K miles on a car before it falls apart. You may never have a problem doing it that way, but read the sections about performance/diesel engines in those links. Too much compression force and not enough clamping force and the head lifts off the block a bit. If I tried that with my 14+ PSI boost, I'd have problems.