Head Gasket replacement - Who has done it themselves?

[VinnyRusso]

I have begun to remove the heads to replace the head gaskets and, likely the drivers side head.

Who has done this before... I had some questions...

Is there a write up somewhere? The factory manuals are kind of a joke on some topics...

 

[SEASNAKE]

Still need advice? I did this a long time ago when swapping heads out.

 

[Jack B]

Why don't you list the questions. One thing you do not want to do is rotate the engine with the heads off, these cars have liners. Personally, i would use a thread chaser to clean the head bolt threads in the block, that is not tap, a thread chaser is far different. Make sure you clean the head bolts (if not new) and do not use any lubricant for reassembly.

You will also want to replace the exhaust gaskets and intake gaskets. If you have not already bought the head gaskets you may want to use the thin gaskets to increase the compression ratio. Check with Viper Specialties for the gaskets.I would also get an organizer to make the all the hardware goes back in the original location.

 

[VinnyRusso]

Why shouldn't I rotate the engine with the head off? I lubricated the cylinders by wiping them down with oil before I did... How else are you supposed to clean off the piston tops?

I was able to secure a set of ARP head studs to reassemble... overkill I know, but they were free...

I have all new OEM gaskets to use for reassembly.. I replaced the thermostat and gasket also.

As for the thread chaser, I have a tap, I assume the thread chaser is just a dull version of the tap... I did buy the ARP assembly lube... Should I get the thread chaser and not use the tap carefully...

 

[VinnyRusso]

Here's what the pistons looked like, I had to clean them off...

 

[AZTVR]

Why shouldn't I rotate the engine with the head off? I lubricated the cylinders by wiping them down with oil before I did... How else are you supposed to clean off the piston tops?

I was able to secure a set of ARP head studs to reassemble... overkill I know, but they were free...

I have all new OEM gaskets to use for reassembly.. I replaced the thermostat and gasket also.

As for the thread chaser, I have a tap, I assume the thread chaser is just a dull version of the tap... I did buy the ARP assembly lube... Should I get the thread chaser and not use the tap carefully...

Jack B's cautions are excellent advice. They are based on best practice as a result of things getting screwed up.

If there is sufficient friction between the rings and the liners, and the liner has less friction with the block, you could move the liner out of position. What percentage of the time does that happen? I don't know. I haven't worked on a Viper engine but, have worked on a Triumph engine with wet sleeves. I used a homemade fixture to hold the liners in place using the head bolts. I don't know what they do with the Viper configuration.

Taps are metal cutting devices. Chasers are designed only to re-form the threads. A tap would cut away the metal if threads were damaged. If they were not damaged, then MAYBE there would not be an issue. I wouldn't take the chance on such an expensive engine, especially with an aluminum block. You need all the thread material you can get to hold the tension of the head bolt. This is just my 2 cents as a cautious shadetree mechanic with not a lot of experience. I usually work on the theory that whatever can go wrong will go wrong, so, I try to do it as "right" as practical. (I do own a set of thread chasers.)

 

[VinnyRusso]

Jack B's cautions are excellent advice. They are based on best practice as a result of things getting screwed up.

If there is sufficient friction between the rings and the liners, and the liner has less friction with the block, you could move the liner out of position. What percentage of the time does that happen? I don't know. I haven't worked on a Viper engine but, have worked on a Triumph engine with wet sleeves. I used a homemade fixture to hold the liners in place using the head bolts. I don't know what they do with the Viper configuration.

Taps are metal cutting devices. Chasers are designed only to re-form the threads. A tap would cut away the metal if threads were damaged. If they were not damaged, then MAYBE there would not be an issue. I wouldn't take the chance on such an expensive engine, especially with an aluminum block. You need all the thread material you can get to hold the tension of the head bolt. This is just my 2 cents as a cautious shadetree mechanic with not a lot of experience. I usually work on the theory that whatever can go wrong will go wrong, so, I try to do it as "right" as practical. (I do own a set of thread chasers.)

Well, fingers crossed because I already moved the engine a few times to rotate the pistons to the top of the block... so I hope nothing moved! I would assume I could see it if they did.

I ordered the ARP thread cleaner through my local speed shop... It will arrive tomorrow...

I don't suspect the threads to be bad, as I did replace the bolts in the head (just a few threads) before cleaning the deck to keep the bolt holes clean. It was PITA to clean around, but better than compromising the threads.

What else Should I be cautious about when reassembling?

 

[Jack B]

We are on the same page, measure twice and cut once. The first time i tried to bolt down a set of viper heads, I noticed the torque readings were not consistent as I tightened down the heads, it was the less than perfect threads in the block, since then, I always use the thread chaser. You can use some thread lubricants, however, depending on the lubricant, you will have to reduce the torque. In some cases, it is a dramatic reduction.

As far as rotating the engine, you can buy dog bones for the viper, They are a set of ten straps that you bolt to the top of the block, they keep the lkiners in place.

Jack B's cautions are excellent advice. They are based on best practice as a result of things getting screwed up.

If there is sufficient friction between the rings and the liners, and the liner has less friction with the block, you could move the liner out of position. What percentage of the time does that happen? I don't know. I haven't worked on a Viper engine but, have worked on a Triumph engine with wet sleeves. I used a homemade fixture to hold the liners in place using the head bolts. I don't know what they do with the Viper configuration.

Taps are metal cutting devices. Chasers are designed only to re-form the threads. A tap would cut away the metal if threads were damaged. If they were not damaged, then MAYBE there would not be an issue. I wouldn't take the chance on such an expensive engine, especially with an aluminum block. You need all the thread material you can get to hold the tension of the head bolt. This is just my 2 cents as a cautious shadetree mechanic with not a lot of experience. I usually work on the theory that whatever can go wrong will go wrong, so, I try to do it as "right" as practical. (I do own a set of thread chasers.)

 

[Jack B]

1. The ARP assembly lube will give you the percent of torque reduction, it is dramatic. If you use the assembly lube and use full torque, you will probably damage the threads.

2. Make sure all the liners are not raised above the plane of the block.

3. While you are in there, you might want to put in a 180 degree thermostat. That also needs a new gasket.

4. Personally, while you have access to the intake manifold I would match the throttle bodies with intake manifold. The best tool is a dremel with an abrasive drum.

5. The G2's have a bad habit of **** oil off the drivers side valve cover. In many cases you will find the inside of the manifold caked with oil, this is also a good time to clean the manifold. It is not easy.

6. Search on the burping topic. The best way to fill with anti-freeze is from the hose at the heater box under the hood on the passenger side. You will probably have to burp anyway. Sometimes it is extremely difficult to remove all the air. For sure, do not take an immediate ride, let it idle to confirm it is cooling properly.

Why shouldn't I rotate the engine with the head off? I lubricated the cylinders by wiping them down with oil before I did... How else are you supposed to clean off the piston tops?

I was able to secure a set of ARP head studs to reassemble... overkill I know, but they were free...

I have all new OEM gaskets to use for reassembly.. I replaced the thermostat and gasket also.

As for the thread chaser, I have a tap, I assume the thread chaser is just a dull version of the tap... I did buy the ARP assembly lube... Should I get the thread chaser and not use the tap carefully...

 

[VinnyRusso]

1. The ARP assembly lube will give you the percent of torque reduction, it is dramatic. If you use the assembly lube and use full torque, you will probably damage the threads.

2. Make sure all the liners are not raised above the plane of the block.

3. While you are in there, you might want to put in a 180 degree thermostat. That also needs a new gasket.

4. Personally, while you have access to the intake manifold I would match the throttle bodies with intake manifold. The best tool is a dremel with an abrasive drum.

5. The G2's have a bad habit of **** oil off the drivers side valve cover. In many cases you will find the inside of the manifold caked with oil, this is also a good time to clean the manifold. It is not easy.

6. Search on the burping topic. The best way to fill with anti-freeze is from the hose at the heater box under the hood on the passenger side. You will probably have to burp anyway. Sometimes it is extremely difficult to remove all the air. For sure, do not take an immediate ride, let it idle to confirm it is cooling properly.

Thank you!!!

1. the ARP Paperwork says to use 120 ft lbs when tightening. Sound right?

2. I will double check this when installing the heads.

3. I did add a new Thermostat and Gasket, but before I put it all together, I hear I should drill holes in the thermostat to aid in air bubble removal? Is this true? Are there tips on this mod?

4. Another good tip, easy enough.

5. I will check this today and see how bad it is, if at all.

6. There must be 100 different "tips" on burping the system... Again, does this "drill the thermostat" modification help at all?


thanks again for everything, hoping to have it back together this weekend.

 

[Jack B]

Burping is an art, however, since I started filling at the heater, there has not a problem. You do have to install a tee. They are available in any auto parts store, even Walmart has them.

Thank you!!!

1. the ARP Paperwork says to use 120 ft lbs when tightening. Sound right?

2. I will double check this when installing the heads.

3. I did add a new Thermostat and Gasket, but before I put it all together, I hear I should drill holes in the thermostat to aid in air bubble removal? Is this true? Are there tips on this mod?

4. Another good tip, easy enough.

5. I will check this today and see how bad it is, if at all.

6. There must be 100 different "tips" on burping the system... Again, does this "drill the thermostat" modification help at all?


thanks again for everything, hoping to have it back together this weekend.