What's in Snake's Head?
Head Inspection and NuFormz Blockguard Install.


Immediately after my B16 swap, the engine started to sound like a diesel engine. Putt putt putt putt.

I looked between the block and head at the exposed portion of the headgasket. Sure enough, there was oil leaking there. It was time for a new headgasket. I figured it would be a great opportunity to install a NuFormz blockguard with it.

The NuFormz blockguard is used mainly for high revving applications. It is a metal piece, which fits against the outside of the cylinder walls to provide support and decrease the chances of detonation under high RPM while boosting. Detonation occurs when there is a lean situation in the combustion chamber. It gets really hot and things can detonate before the valves close. You may have seen pictures of cracked pistons and cylinder walls. The block guard is supposed to strengthen the walls to aid in preventing detonation. However, there are other opinions. Three months after completing this project, I’m regretting the installation of the blockguard. It was indeed a waste of money. Please take the time to read what others have to say about the blockguard:

    The Old One on Endyne posted on 12/06/00:

    There's a common misconception among Honda enthusiasts regarding cylinder breakage, what causes it and where it begins.
    Truth be known, a properly tuned engine, running detonation limiting equipment will break the cylinders mid-way down the bore, where rod side thrust is the highest. This is a primary reason we advocate longer rods.
    Cylinder cracking will spread to the top of the cylinder, rather than starting at the top and traveling downward.
    Blockguards seal the top of the cylinders from direct water contact and the additional aluminum mass acts to hold a lot of heat in that upper cylinder area, which in-turn, contributes to detonation.
    We've only run sealed decks on engines that are drag racing only pieces...and most of those were combinations where we were extending the deck height to permit the installation of longer rods.
    I do not recommend the use of Blockguard "type" devices in steeet applications, due to the issues I've pointed out.
    If you want an engine to last and run properly with a more "correct" air fuel mixture, make sure you've taken necessary measures to limit detonation and don't do anything to compromise cooling.
    We do "post" cylinders in engines we build. We'll have a feature up shortly showing just how it's done...and it'll also be in some magazine articles coming up. "Posting" the cylinders gives them tremendous strength and it actually aids cylinder cooling, which is a pretty good deal in our book.

    .....The Old One....

In order to install the blockguard, you will need to remove your engine head. The following describes the procedures involved in switching out the headgasket and installing the blockguard. I decided to install my blockguard because my head gasket was already leaking, and I plan on going turbo in the future. Usually when the headgasket leaks it is a good idea to check both the block and head for warpage. Fortunately, I didn’t observe any of this. You may be wondering how I knew the headgasket was leaking. This is very easy. On the spot just below the distributor between the head and block and next to the tranny you will see a thin sheet of metal. This is your headgasket. If you see oil or water on it, then it means it is leaking.

ALWAYS use a new headgasket whenever you remove the head. Once a headgasket is ‘squished’ the natural imprints from the block and head remains permanent. The headgasket resolves the very minor and differences in the height of the metal between the block and head. It serves to separate the oil from the water. There are some people who remove one of the layers from the headgasket to increase compression. I discourage this because it

  1. increases the chances of blowing out under pressure and
  2. increases the chances of warpage.

A stock headgasket is always recommended. There are copper headgaskets available, but from what I hear they don’t last as long as the stock OEM headgasket. Perhaps using a copper spray might help.

Engine head removal:

Begin by draining the oil and coolant from your engine. While it is draining, begin disconnecting the hoses.

Remove the bolt on the intake manifold bracket from under the engine.

Pull the intake pipe off the throttle body.

The valve cover should also be removed.

Remove the throttle cable.

Remove the brake booster and fuel return hose.

Remove the timing belt cover.

Remove the upper radiator and heater hoses.

Remove the header.

Disconnect all electrical connectors going to the head (injector connectors, VTEC harness, etc.)

Remove the distributor.

Move the engine wire harness out of the way so you can lift the head out of the car without any trouble. At this time I would recommend setting the engine at TDC, this is not necessarily required but helps put things in perspective. Loosen the tensioning bolt on the side of the engine so that you can slide off the timing belt.

Remove the camshaft holders. You will want to do this in the correct order. During removal, you work your way from the outside of the block in towards the center. After you have removed the holders, pull of the camshafts. Make sure you know how everything goes. I used a newspaper and laid everything in place as it was in the engine. It helped a lot.

Now remove the headbolts. Be very careful when performing this step. You will want to untorque them a little at a time. Perhaps loosening every headbolt 1/3 of a full turn can prevent damage. Again, make sure you are removing all of this in the correct order as described in the Helms manual. When I removed my headbolts I took about 5 steps to fully untorque them.

Make sure everything holding the head onto the block is removed and put somewhere safe. It is important to keep everything covered. Make sure all the hoses are disconnected. Hint: Check behind the hoses behind the head going to the EACV and heater hose. Now, count to three and pull the head (with the still attached intake manifold) off the block.

A visual inspection can be made at this point to determine what needs to be done. Here is a picture of what I found under my head:

This is a view of the head if you were to look at it from behind the intake manifold. Cylinder number 1 is on your left. Notice how the exhaust valves on the cylinder #1 are black while the rest are white. This is how I was able to determine I had bad rings on piston 1. If you were to do a negative posterize of the picure of the block, you would see that piston #1 is oily. It is also somewhat apparent in the pictures.

You should also check for cylinder warpage. A precision straightedge should be laid across the block as follows:

If you decided to install the NuFormz blockguard, it should be done at this point. I must warn you, it is very hard to remove the blockguard from the engine once it is in place. Attempting to remove the blockguard will definitely cause instant damage to the soft aluminum block. Make sure the blockguard is facing UP and towards you. Gently tap on all the edges of the blockguard until it is in place:

Now the headgasket can be installed. Make sure it is facing UP and place it flat on the block. It is a good idea to hold this headgasket in place with the 2 dowel pins connecting between the block and the head.

Carefully place the head back onto the block and begin threading the 10 headbolts until they are snug. It is highly recommended that you replace these headbolts! After a period of time these things stretch and become weak. Honda can sell them to you at about $2 a bolt.

Once all bolts are snug, follow a 2 step torque procedure. You will be torquing these bolts from the inside outward. First set your torque wrench to 22 lbs. Ft. Make sure you are using an accurate torque wrench because it is important to torque the bolts properly. On the second round you will be setting the torque wrench to 61 lbs. Ft.

Follow the torquing in this order:

Once the head has been torqued into place, you can begin connecting all the hoses to the manifold. Make sure you have the coolant line going to the EACV connected as well. Fill the radiator back up with NEW antifreeze and continue by bolting the header back onto the head. The bolts on the header should be torqued to 23-lbs. ft. Once you've done this, continue with putting the head back together.

Using clean oil, drench the cams so that they remain lubricated during installation. Place the cams in the proper locations in the head with the arrows facing up (shown on cam gear) Next, put the camshaft holders into place. Be sure to apply gasket sealant as shown in the picture below:

You will now place the camshaft holder pipes and screw all the bolts into place. Do not toque the bolts until everything is in place. Again, make sure the cam gears are pointing "UP". Once you have all the bolts in, follow the torque procedure shown below. Pour a little bit of oil into these holes so that the bolts don't get hung up when you are hand tightening them. Be careful not to overtighten the 10mm bolts! The 12 mm bolts will be torqued to 16 lbs. Ft while the 10mm will be torquedd to 8 lbs. Ft:

After you've torqued these down, install the timing belt and adjust the tensioner by tightening it in place while at TDC, then turn the crank 90 degrees, loosen the adjusting bolt and torque to 33 lbs. Ft. Install the timing belt cover. A lot of people spend a good amount of time trying to get this to fit properly. My tip is to aling the screws on each of the holes and tightening them 1 thread at a time until it's in place.

You now have an option to adjust the valves, or you can proceed with the next step. It is recommended you adjust the valves whenever cams are replaced or during the replacement of the timing belt. Information on doing this is available in another article on this site.

The valve cover can now be placed over the engine and the distributor should be installed at this point. Connect all the wires into their orginal places. Don't forget the wires behind the intake manifold! Also remember to put the 2 bolts back under the intake manifold bracket. Slide the intake pipe onto the throttle body and you should be ready to go after making a few checks:

Make sure everything is connected and in place. Change the oil on your car and replace the filter. Connect the fuel lines. Connect the brake booster vacuum line. Connect all connections that go to the head. Put the throttle cable back where it's supposed to go.

You are almost done. Before starting the engine, MAKE SURE you haven't left anything out.

Turn the key to the ON position and let fuel pressure build. The fuel pump will stop making it's whirring noise. Start the car. If you've followed the directions, everything should be MUCH BETTER than before, but if you hear any abnormal noise, turn the engine off IMMEDIATELY and began searching for the mistake.

The replacement of the headgasket made a huge difference on my engine. The putt putt putt sound went away. Acceleration was smooth. I drove at least 1000 miles before going into high rpm, and I made sure the water temp was at least warming up before I drove during the break-in period.

The OEM replacement headgasket is superior in quality and switching out the headgaskets is relatively simple as long as you pay attention to what is going on. You will notice that the order in which I've done some of these things isn't exactly how it's described in other manuals. Everybody has different ways of doing things, and this seemed to work for me, not once--but thrice. Good tools are a mechanics best friend. This procedure will let you know whether you need new tools or not.

After about a week check to see if you are burning any oil, or if you are low on coolant. If you are, more than likely you head or block was warped. This can only be fixed by doing the headgasket again and getting the warped pieces machined. Good luck, and remember, torquing the bolts to the correct specs is VERY important. Be sure to use accurate measurements when doing this.

Anyone else realize that Snake has donated more articles than anyone else?