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Engine Rebuild

This page details the performance rebuild of a Chrysler 420A engine. The procedure is similar to the rebuild of any engine, but its always nice to see examples with a car like yours. This page is by no means comprehensive, but it does cover all the major aspects of a teardown and rebuild.

First things first. You need to obtain a good core block and head. Blown engines are cheap, but it can be a dangerous bet. Once you obtain an engine, you'll want to examine it for damage. While dissassembing the engine, be sure to put bolts and small parts into labeled bags. This will come into handy when you reinstall everything.

It's probably easiest to start by removing the valve cover and cam caps. The valve cover uses an 8 mm socket and the cam caps use 8 mm and 10 mm. If any of the cam caps look like the picture above, the head is garbage. The bearing surface is machined right into the cap and head. If it is badly scored, there is no good repair. A good shop could probably add material to the damaged surface and re-machine it. It's probably cheaper to just locate another head.

Put all of the cam caps in little bags to keep them from getting scratched. If you plan to reuse the cams, you had better examine them. All machined surfaces should be free from any scoring or pitting. Any wear should be even from left to right. If they pass inspection, you better wrap them up in some plastic.

Use a 15 mm socket to remove the head bolts and separate the head from the block. Unless you want to reuse them, throw away all of the adjusters (lifters) and followers (rockers).

Examine the head sealing surface for damage. It should be flat and free of scratches. Take a look at the valves too. They should not have any dents or obvious damage to them. Wrap the head in plastic and set it aside with the other parts.

Now its time to tackle the bottom end. A 10 mm socket will take off the oil pan bolts. You can smack the oil pan along the side to break it free. Use a 13mm socket to remove the oil pick-up tube. Unbolt each rod at the crankshaft using an 11 mm socket. You can pound each piston out the top with a rubber mallet. Notice how tight the clearance is between the piston and cylinder. Your forged pistons won't fit this tight.

Take a look at each piston. You won't reuse them, but you want to look for damage. If the ring lands are broken like the picture above, then you had better look extra hard for damage on other parts of the block.

Take a good look at the picture above. Thats what you are working towards. However, a little crankshaft sprocket is standing in your way. You'll want good access to this part, so put the block on an engine stand. You'll want grade 10.9 M12 x 1.75 bolts. Thats two in the 80 mm length and 2 in the 100 mm length with matching nuts and washers. Bolt the arms of the engine stand bracket to the 4 accessible points on the rear of the block. Now its time to get to work. You will need WD-40, an air impact gun, a small harmonic damper puller, several M6 x 80 mm bolts, and assorted washers. This sprocket doesn't give up easily, but it will go. The bolts thread into the sprocket. The washers keep the bolt heads from escaping the arms of the puller. The impact gun is a necessity. It helps break the sprocket loose from its home. You'll probably want goggles as the tiny bolts can break and go flying. Once the sprocket is off, you can remove the oil pump. Once you remove the oil pump bolts (maybe 12 mm), you should tap the pump with a rubber mallet to break it free. Then you can slide the pump forward off of the crankshaft snout. Now, you can use a 15/16" deep well socket to remove the oil filter adapter. With that out of the way, you can remove the inner and outer bedplate bolts. You'll need a 10 mm and 13 mm socket here. Then, you have to break the bedplate free from the block. One of the engine stand arms is attached to the bedplate. Remove that bolt and leave the engine supported by 3 arms. Start by beating the bedplate at various points and directions with a rubber mallet. If you don't get anywhere, you can carefully tap various places on the bedplate with a 3 lb hammer. Don't mess us any sealing surfaces and don't crack off any parts. There are dowell pins in the block, so don't hit too hard parallel to the sealing surface. Eventually, the bedplate will break free from the block. Lift the bedplate straight upwards and set it aside. Examine the bedplate bearings for wear. There should be no deep gouges or uneven wear from side to side. Now pull the crankshaft straight upwards to remove it and set it aside. Examine the block bearings for wear like you did above. Now bolt the bedplate back into place and re-attach the engine stand arm. Rotate the engine so that you have a good view of the cylinders. You need to measure the bore (diameter of cylinder). A snap gauge and micrometer is the right way to do this. You can do an ok job with a vernier caliper. Measure each bore several times to get a feel for the real reading. The standard bore should be 3.4446-3.4452 inches. If it is within the standard spec, you should get them bored out to the next size (0.020 over). This ensures that you will have a smooth, round cylinder wall. If it is larger than this, you'd better figure out how much larger. You'll need to decide whether to buy 0.020, 0.030, or 0.040 overbore pistons. If your measurement is smaller, then try again.

Take a good look at the crankshaft. You'll want to examine all of the smooth bearing surfaces for damage like you did on the other parts. You'll need a micrometer to measure the main journals and connecting rod journals. This will tell you what bearings to buy. The standard main journal diameter is 2.0469-2.0475 inches. If your main journal is smaller than this, get the crankshaft cut down to the next size bearing and buy the appropriate main bearings (0.010, 0.020 under). If the main journal is larger than this, buy a new micrometer. The standard connecting rod journal diameter is 1.8894-1.8900 inches. Same rules apply to this measurement. Be sure to check every journal at 2 points that are 90 degrees apart. This checks for out-of-round (oval diameter).

Now its time to buy some parts. You know what size bearings to buy and what size pistons to buy. You'll want to determine your piston compression ratio of course. This depends on your goals, so I won't get into that area. You'll also need to determine if you want a standard or long rod engine. I won't tell you which one to choose. Next up is head work. The sky is the limit here. As a minimum, I suggest you replace the lifters, replace the rockers, replace the valve seals, get a standard valve job, and have the sealing surface checked for flatness. One better is mild cams, matching springs, and a performance valve job. You can go much further with aggressive cams, big valves, and porting. I went with a 2.0l long rod engine with forged components and an 8.8:1 compression ratio. The rotating assembly was balanced and the blocked decked to ensure flatness. The head work is pretty mild with a 3 angle valve job and moderate cams. The head was also decked to ensure flatness.

You will have to give your pistons to the shop with the block. You will also have to determine what clearance to use between the pistons and cylinder wall. Forged pistons require more clearance than the stock pieces. I recommend that you follow the piston manufacturer's instructions. I used a 0.040" clearance per JE's specs. The shop will bore the cylinders to match the pistons and clearance that you give them. If you want the crankshaft polished or machined, they will need that too. I would certainly get them to polish the crank. If you want them to balance the rotating assembly, they will need the pistons, rods, and crank. As soon as you receive the block back from the machine shop, coat every bare surface in WD-40 to prevent corrosion. It can happen very quickly.

If the shop didn't do it for you, you should remove all of the oil and coolant plugs. The goal is to knock one side of the plug in, so that the other end flips out. You can then grab the end that is sticking out with a pair of pliers. A flat ended punch is good for knocking the plugs in. The small oil plugs may also be removed by punching a hole in them and prying them out. A sharp centerpunch works here. Just don't damage the sealing surface of the plug. You should lightly sand the sealing surface with 400 grit paper. Once all the plugs are out, you should flush all of the holes out with water. Compressed air is good for blowing the water out. You might as well hit the painted surfaces with degreaser too. You want to remove any grit or trash left from the machining process. You don't want that in your oil pump or coolant system. You can install the plugs with a light coat of RTV (oil and water safe). Evenly tap the plug in using a small hammer. A socket that is just slightly smaller than the plug can be used to help you tap the plug in. Only tap the plugs in as far as the stock ones were. Too far and they will fall in. It is a serious pain to remove a plug that has fallen in. If the machine shop removed the alignment dowels on the head gasket sealing surface of the block, you can pound them in now. There should be two in the upper surface of the block. You can pound them in squarely with a light hammer. You just need 1/4" or so sticking up.

Since the block is clean now, you can paint it. Put the block on the engine stand and cover all important sealing surfaces and holes with tape. Put a couple of even coats of engine enamel on the block. Once it is fully dry, you should remove the tape and coat all bare metal surfaces with WD-40 to prevent corrosion. You may choose to wrap the block in plastic for storage.

If you are having any valve work done, you should supply new valve seals and keepers. They won't need the adjusters, followers, or cams. Once you get the head back from the shop, you should remove the oil and coolant plugs just like the block. Clean it out and replace the plugs like you did on the block. You should probably wrap the head up and store it.

Now it's almost time to build. Open up your lower gasket kit and inspect all the little gaskets. Some of the gaskets probably won't be used as most kits are for several cars. You'll need some RTV silicone sealant if your kit didn't include any. The black, grey, or copper tend to work well. You will need to buy anaerobic sealant. Loc-tite 518 or Permatex 51813 are appropriate. Most parts guys won't have a clue what anaerobic sealant is, so you are on your own. The Permatex stuff is in a blue tube and costs about $13. You'll also want to buy some moly assembly lube. Pick up several oil filters and two cases of store brand 10W-30 oil too. You may want to pick up a couple specialty tools too. Feeler gauges are necessary to measure ring gap. You will need something to file rings with. You can buy extremely fine files or a proper ring filer. Two strips of Plastigage should be needed (you'll be measuring values from 0.0008-0.0024"). You will want a ring compressor (band types work well). Buy or borrow torque wrenches in inch-pound and foot-pound sizes. The rest of the required tools and supplies should be pretty standard.

Lets start by checking the fit of the crankshaft. Clean the main bearing journals in the block and bedplate with laquer thinner (or alcohol). Install the main bearing shells in both the bedplate and block. Grooved shells go in the block. Make certain that the oil holes line up with those in the block and the tabs fit into place. The bearing shell with thrust faces obviously goes in the center position. Clean the crankshaft bearing surfaces with WD-40. Now cut strips of plasti-gage that match the width of each bearing shell. Lay one strip in the bottom of each bearing journal in the block. Now, carefully lower the crankshaft onto the bearing shells in the block. Don't rotate the crankshaft once its layed down; that might smear the plasti-gage. Carefully lower the bedplate onto the crankshaft.

You can now drop the bedplate bolts into the holes. Use the old bolts from the engine (not the new ones you bought). Install bolts 1-10 finger tight, then torque to 55 ft-lbs in sequence per the picture (13mm socket). Then install bolts A-K finger tight, then torque to 20 ft-lbs in sequence per the picture (10mm socket). This will crush the plasti-gage. Carefully remove the bolts in the reverse sequence. Tap the bedplate upwards with a rubber mallet to free it from the block. Carefully lift the bedplate and set it aside. Do the same to the crankshaft being careful not to smear the plasti-gage. Compare each crushed peice of plasti-gage on the block with the measurements on the package. It should have stuck to the block, but it might stick to the crankshaft. The standard value is 0.001-0.0023 inches with a limit of 0.0003 inches. If you chose the right bearings and the shop did good work on the crankshaft, the clearance will be within spec. Write these values down so you know which bearing has what. Clean all of the plasti-gage off with WD-40 and strips of newspaper. The bearings and crankshaft must be spotless. Clearances should always be checked at two crankshaft positions, 90 degrees apart. So, lay down more strips of plasti-gage in the bearings on the block. Hold the crankshaft in the position that you used on the last test. Rotate the crankshaft 90 degrees (quarter turn) and lower it onto the bearings in the block. Lower the bedplate into place and tighten the bolts like before. Pull everything apart and read the clearances shown by the plasti-gage again. If a bearing has a different clearance on the first test than it does on the second test, the crankshaft is "out of round". The values for one bearing can be up to 0.0001 inches different before it is considered "out of round". If anything is suspect, do the test again. If the values show that the clearances are too tight, you can get the crank polished down a little. If they are too loose, then you'll have to get the crank ground down to the next size and buy undersized bearings (hopefully this will never happen). If the crankshaft is "out of round", you will have to get it ground down and buy undersized bearings (this should not happen either). If the values for one bearing vary more than 0.0001 inches from the left edge to the right edge, you have a taper problem. You have to machine the crank to solve this. As a final check, you can push the crankshaft all the way to one end of the block and insert a feeler gauge in between the thrust bearing and crankshaft bearing surface. This should be 0.0035-0.0094 inches with a limit of 0.015 inches. This measures the crankshaft end play. If that is too large, you may have to get special bearings. If the crankshaft passes the tests, you can move on.

If the rods are not installed on the pistons, do it now. If the rod has to go on in a certain direction, make sure you do it. Some rods have oil squirters, so they must be installed a certain way. Anyway, lubricate the small end of the rod with assembly lube. Do the same to the pin and slide it into the piston and through the small end of the rod. You can use the supplied cir-clip to keep the pin in place. You can usually install the cir-clip with your fingers and a tiny screwdriver. You should mark your rods to match up with a certain cylinder. The cylinder closest to the crankshaft pulley is the #1 cylinder. You can lightly dremel a number in a non-critical location on the rod. I really wouldn't use metal punch letters. You don't want to affect the structural integrity of the rod. Now, its time to plasti-gage the rod bearings. Clean the big end of the rod bore with laquer thinner and install the bearing shells. Clean the bearing shells with WD-40 and newspaper. With the crankshaft temporarily installed in the block, rotate the block right side up. The crankshaft should be at bottom dead center for the first cylinder to be tested. Drop the first piston and rod into the bore. The rod cap should obviously be removed at this point. Nest the rod end onto the crankshaft bearing surface. Now place a stip of plasti-gage onto the bearing in the rod cap. It should lay right in the bottom of the bearing shell just like when you tested the main bearings. Carefully push the rod cap into place on the piston rod. Lubricate the rod bolts per the instructions (usually with assembly lube). Evenly torque the rod bolts to the recommended spec. Loosen the rod bolts and tap on them to separate the rod cap from the piston rod. A tiny jewelers hammer can be used to tap things loose. You need to separate the rod cap without messing up the plasti-gage. Measure the plasti-gage and record the number. Clean the bearing shells and crankshaft with WD-40 again. You can measure the remaining rods in the same manner without rotating the crankshaft. Some pistons will be a bottom dead center and some will be at top dead center, but it doesn't matter. Record the numbers and clean the bearing shells. Now, you have to rotate the crankshaft 90 degrees. Don't move it anymore than you have to as it has limited lubrication. Plasti-gage each rod again with the crankshaft in the new position. Record the values and clean the bearing shells. Just like on the main bearings, you need to measure in two places. The same tolerances apply here too. You can also check connecting rod side clearance. Push the rod to one side and insert a feeler gauge in the gap. The value should be 0.005-0.015 inches. If it is too large, you are probably screwed.

The seal between the block and bedplate is extrememly important. Screw this up and you may have to pull the engine again. Use a razor blade to clean off all of the old sealer residue from the block and bedplate. Follow this by cleaning the sealing surfaces with rubbing alcohol and paper towels. Clean them until the paper towels come back spotless. I think I cleaned this area for 30 minutes before I was satisfied. Now, spread anaerobic sealer onto the block as shown. You need a continuous seal around the perimeter of the block. The sealer will curve around external bolt holes and only be broken by the front main seal, real main seal, and crankshaft sensor. Those three breaks are critical, so bring the sealer all the way to the edge. Then lay the "bedplate" o-ring down it its groove (bottom left of picture). Forget that and you'll have leaks for sure. If you got any crap on the bearings, clean them with WD-40. Clean the crankshaft bearing surfaces with WD-40 one last time. Then wipe assembly lube onto the block bearing shells, bedplate bearing shells, and crankshaft bearing surfaces. Be generous, this is what keeps your engine from destroying itself on the initial start. Now carefully lay the crankshaft down onto the block bearings. If you don't have your new bedplate bolts out, make sure they are laid out and ready. Then, carefully lay the bedplate down onto the crankshaft. Make sure that the alignment dowels in the block nest into the bedplate. You can then tap the bedplate into place with a rubber mallet. Be sure that it drops down evenly.

The anaerobic sealant will start to cure now, so keep moving. Grab each new bedplate bolt, dip it in clean oil, and shake off the excess. Drop each bolt into its corresponding hole. Install bolts 1-10 finger tight, then torque to 55 ft-lbs in sequence per the picture (13mm socket). Then install bolts A-K finger tight, then torque to 20 ft-lbs in sequence per the picture (10mm socket). You should be able to grab the crankshaft and turn it. It should turn smoothly. If it feels tight or like its catching, you must have screwed something up. In that case, you had better put the bedplate back off and investigate. Wipe up and excess anaerobic sealer that squeezed out between the block and bedplate. You don't need that swimming around in the oil. While you are down there, re-install the oil filter adapter. Put a new o-ring in the adapter and drop it into place, locating the alignment dowel in its hole. Tighten the adapter down with a 15/16" deep well socket.

So, now its time to flip the engine over and fit the piston rings. This part of the build is very tedious and can't be rushed. Set up a clean work surface and lay the rings out in groups. Put all the top rings, secondary rings, expanders, and oil rail rings together. Pick up a top ring, compress it slightly with your fingers, and push it into the bore of the #1 cylinder. You can write #1 on a piece of tape and stick it on the block next to that cylinder, if you want. Now, use a new piston to push the ring evenly down into the cylinder about 1 inch. It must be perfectly square or your measurement will be wrong. Now, use the feeler gauge to measure the ring gap. Hold the feeler gauges lightly with two fingers and make sure they are parallel to the depth of the cylinder and perpendicular to the cylinder wall. Select the strip on the feeler gauge that can be slid up and down through the ring gap and offers just a slight amount of resistance. You'll notice how important it is the hold the gauge perfectly to match the ring gap opening. If you catch the gauge on the ring and disturb it, use the piston to re-seat it in the cylinder. Once you get an idea of the ring gap, compare it to the gap listed in the ring instructions. You may also find that other owners have preferred ring gaps. Follow whatever you are comfortable with. Now, your measured ring gap should be smaller than the recommended gap. If its not, then you probably have the wrong set of rings. Also, if the ring ends overlap each other in the cylinder, you have the wrong rings. You can use a ring filer, fine flat files, or dremel with flat stone to open up the ring gap. Most ring instructions will tell you to file one end of the ring squarely and towards the inside of the ring. You can check how square your cut is by compressing the ring down so that the ends almost touch. Then you can see if the gap is even. If its not, then make it even. Once you think you have it right, use the piston to set the ring squarely back into the cylinder. Measure again with the feeler gauges. Keep doing this crap until you finally get the ring gap exactly right. Remember that you can always take more material off, but can't put it back on. When the gap is right, lightly file the edges of the ring to take off any burrs. Again, file towards the inside. When it is 100% perfect, label it with tape for the #1 cylinder. Fit the top rings for the #2, #3, and #4 cylinder like this and label them. Fit the secondary rings and oil rail rings just like this. Don't touch the expanders. If you haven't already, you should probably grab a beer and punch an inanimate object now. Take a break and come back to install the pistons

Now this part of the build isn't too bad. First you have to figure out the piston orentation. Your pistons may have to be installed with a certain side facing the intake or exhaust of the engine. Once you figure that out, write notes on the piston top. Most rings install relative to the front of the engine, so make sure you note that. You need something to hold the piston and rod while you install the rings. I put a sandwich bag over the big end of the rod and held it lightly with a small vise. If you have a special "long rod" bottom end kit, you will likely have to install spacer rings at the bottom of the oil control ring land. You can open the ring up with your fingertips and carefully guide it over the piston top. Be careful not to let it scratch the sides of the piston. It is spring steel, so it won't break. If it has a stamped dimple, that will likely fall into the cut-out of the lower ring land. Push this spacer ring down tightly against the lower ring land. Now you can get on to the normal rings. Start with the piston used in the first cylinder. Remember that you labeled each ring with a cylinder number. Reference your piston ring instructions and install the rings in the recommended order and orientation. They will likely have you install the oil ring expander first. That can just be stretched open and dropped into the lowest ring groove. The bottom oil rail ring goes on next. It is spring steel, so you can just stretch it open. Make sure it nests into the expander. The upper oil rail ring is next. Make sure the gaps fall in the right directions and that the three rings nest tightly together. Next is the secondary ring. It may have a real top and bottom, so read the instructions and install it the right way. This ring may be iron, so it is brittle. Only stretch it enough to get it on. Once installed, it should fit tightly into its groove, but move freely. If it catches, you may have to file a burr off. Align its gap and move onto the top ring. It may have a top side, so pay attention again.

Now, its about time to install the piston. Follow the ring manufacturer and piston manufacturer's instructions for oiling. You will likely have to apply clean oil to the piston skirt. You will want to soak the piston ring compressor with WD-40. Check the ring gap orientations one last time and carefully tighten the ring compressor down onto the rings. Alot of ring compressors have a rib that keeps the compressor from slipping down into the cylinder. Make sure you put it on the right way. Clean the cylinder one last time and wet it with WD-40. Remove the rod cap and apply assembly lube to the upper bearing shell. Make sure the crankshaft is in the bottom dead center position for the first cylinder. Drop the first piston and rod into the first cylinder. Make sure you orient it in the right direction. Hold the ring compressor tightly to the block. You can tap the piston down with the wooden handle of a mallet. You should be able to feel each ring pass from the compressor into the cylinder. Every couple of taps, check to make sure the rod end is clearing the crankshaft. Tap the piston all the way into the cylinder, until the compressor is free. If the piston ever binds up during this, pull it back out and re-install the compressor. A ring may have slipped out and caught on the block. Whatever you do, don't force it. Once the piston is fully in the cylinder, you can push it down and guide the rod end onto the crankshaft journal. Do it slowly; you don't want to damage a bearing or anything. When the rod end is fully nested onto the journal, prepare the rod cap bearing shell with assembly lube. Apply the appropriate lubricant to the rod bolts. Screw the rod cap into place with the bolts finger tight. Torque the rod bolts evenly down to the proper torque. Turn the crankshaft so that the next cylinder is in the bottom dead center position. Install the rings and piston in the same way. As you install each piston, the crankshaft should get harder to turn. It should still turn smoothly and not catch at any point. If it catches or takes excessive force to turn, you had better figure out what is wrong. Better now than on the first road trip.

Now you can turn your attention to the oil pump. Grab the anaerobic sealant and the oil pump o-ring from the kit. You won't need the oil bypass gasket because the bypass bolt should already be installed in the new pump. If it isn't, you can put it in under the bolt head and torque to 39 ft-lbs. Clean the oil pump sealing surface and block sealing surface with alcohol. This is just as important as the bedplate to block seal. Run a bead of anaerobic sealant around the perimeter of the pump and around the counterbore for the oil pump o-ring. The sealant should run all the way to the edge of the lower part of the pump. You can drop the oil pump o-ring into place now.

You shouldn't need the front main seal from the kit, because it is installed in the pump already. If you actually have to install the front main seal, then go back in time before you covered the backside of the pump with the sticky sealant. With the pump laid down on a wood surface, evenly pound the seal into place with a large socket and mallet. Stop when the seal is flush with the outer surface of the oil pump. Lube the inside lip of the front main seal with clean oil. Now, slide the oil pump onto the crankshaft and push it towards the block. You may have to rotate the pump a little to get the pump rotor to engage onto the crankshaft. Tighten the oil pump bolts to 17 ft-lbs (pretty sure its a 12 mm socket). Clean up any excess sealant that squeezed out. You can install the new water pump now too. Either use the water pump o-ring from the gasket kit or the one that came with the pump. If one is contoured to match the outline of the pump, use that one. Slip the water pump o-ring into the groove in the pump. If it won't stay in place, use a little RTV sealant to hold it. Wet the o-ring with water or coolant and bolt it to the block. Torque the bolts to 8.7 ft-lbs with an 8 mm socket.

Its about time to drop the head down onto the block. First, you have to prep the headgasket sealing surfaces. Even if you had the block and/or head decked, you should check it for flatness. Lay a metal straight-edge on the head gasket sealing surfaces. Get right down at block level and look for gaps in between the straight-edge and sealing surface. Pay special attention to areas around the cylinders. You should also check the surface finish. It should be smooth, even finish without any obvious tool marks or gouges. Obviously, it should not have any remaining carbon, dried coolant, or gasket residue. Gasket remover and a plastic scraper will take that off. If both surfaces pass inspection, then you should clean them both with alcohol. It doesn't have to be spotless. You just need to clean off the dirt and oil. If any of the pistons is at top dead center, rotate the crankshaft, so they drop down some. Its best to give yourself some room, because you will be installing the head and then cams later. Pull the head gasket out of its packaging. At the time of this build, the Chrysler MLS (multi layer steel) head gasket was the best available, so I'll discuss that one. Clean any dust off of the gasket with alcohol and hang it up by a wire from one of its corners. Lightly coat both sides of the gasket with copper gasket sealant spray. Just apply a light, even coat. Let it tack up for a few minutes before touching it. Carefully remove it from the wire and carry it over to the block. If you drop it, you'll have to clean it and re-apply the sealant. Hold the gasket over the block and figure out the right orientation. Lay the gasket onto the block sealing surface and push the gasket down onto the alignment dowels. Make sure that the oil and coolant passages line up with the gasket. If they don't, you had better pull the gasket off and flip it around. When the gasket is on right and seated properly, get the head. Carefully lower the head down onto the block. Make sure that the head seats onto the alignment dowels. When the head is squarely situated on the block, you can get the head bolts. Take them out of the packaging and clean off any dust. Lay them out in two groups (long and short). Dip each bolt into clean oil and drop it into it's corresponding hole. The four short bolts go in the corner holes and the six long bolts go in the center holes. Use a 15 mm socket to tighten the bolts down in the following sequence. Torque bolts 1-6 to 25 ft-lbs in sequence per the picture. Then torque bolts 7-10 to 20 ft-lbs in sequence per the picture. Torque bolts 1-6 to 50 ft-lbs in sequence and then torque bolts 7-10 to 35 ft-lbs in sequence. Again, torque bolts 1-6 to 50 ft-lbs in sequence and then torque bolts 7-10 to 35 ft-lbs in sequence. Finally, use a breaker bar to turn bolts 1-10 an additional 90 degrees in sequence.

Since the head is bolted down, you can concentrate on the cams. Remember that you can't fully remove or install head bolts with cams in place. Remove the cam caps with 8 mm and 10 mm sockets. Since you cleaned the head previously, there isn't much prep work. Locate the machined bores that the adjusters ride in. Wipe each bore clean. Get a cup of clean oil ready. Dip each new adjuster in oil and drop it into its bore in the head. Next, you should dip each follower in oil and lay it over the adjuster and valve stem. It will have to balance there until you put the cams in. Speaking of that, unwrap your cams. Whether they are new or old, you should clean them with WD-40 and wipe them dry. If you are installing new cams, remove the cam magnet from the old cam and screw it into the new cam. An allen wrench is needed here. Just line up the pegs on the magnet with the holes in the cam and tighten the bolt down snug. Lube all of the machined surfaces with assembly lube. You can also lube the bearing surface in the head. Carefully lower each cam into its corresponding place in the head. The cam with the magnet goes on the exhaust side, if you're keeping track. You really shouldn't be able to mix them up. You may have to wiggle the cam some to get it to side right. Don't expect it to sit perfectly with the valves closed.

Now apply assembly lube to each of the smaller cam caps and drop it into place over the cam. Don't worry about the two larger cam caps right now. Each cap must go back in the correct location and orientation. Each cap will be marked with a number 1-6, letter L or R, and an arrow indicating the front of the engine. There are matching marks on the head to keep you in line. When all of the caps are in place, drop the cam cap bolts into place. Since the cam is likely not sitting evenly in the head, tighten each cap bolt in the sequence above just to get a little resistance. Keep tightening them a little bit at a time in that sequence until you have each cap down flush against the head. Now break out the torque wrench and tighten each cap bolt to 9 ft-lbs in sequence. That should be an 8 mm socket.

Now clean any oil from the flat machined surfaces of the two remaining cam caps (the larger cam caps you set aside earlier). You can now apply anaerobic sealant to the caps per the diagram above. Put a little assembly lube on the surface that touches the cam and drop it into place. Torque the six larger bolts to 21 ft-lbs from the inside out. That is a 10 mm socket. Tighten the single small bolt to 9 ft-lbs with a 10 mm socket.

Now, apply some clean engine oil to the inside lip of the camshaft seals. They go on the end of each cam and under the long cam cap that covers both cams. Evenly tap the seal into place with a hammer. Be sure that the inside lip does not bend backwards and that the internal spring does not pop out. You can try to use a socket to help you do it evenly. Stop when the seal is flush to the side of the head and cam cap.

Grab those camshaft sprockets. If you bought adjustable ones, make sure they are zeroed out and have the lock-bolts tightened down. If you are cheap like me, you'll just paint your stockers. Notice that the stockers say "2.0l Front" on them. This side should face outward on the engine. Slide each sprocket into place and rotate the intake cam so that its alignment dowel faces down. Rotate the exhaust cam so that its alignment dowel faces up. If you feel any resistance, back off and figure out what the problem is. The crankshaft should be rotated so that the pistons are sitting halfway down the bore. If not, they may be getting in the way. Rotate the crankshaft if you need to move them out of the way. The arrows on the sprockets should exactly face each other now. Thread the camshaft sprocket retaining bolts into the cams. You will need a tool to hold the sprocket still while you torque the bolt down. Either build a tool with fingers to grab the sprocket between the spokes or jam something between the sprockets. Either way, you need to torque those bolts to 73 ft-lbs with an 18 mm socket.

You might as well put the valve cover on now. I chose to shave the letters off a stock cover and put a new logo on there. Whatever you do, now is a good time to clean and paint your old valve cover. Engine enamel works well and can be heat treated in a household oven. Put the valve cover gasket and spark plug well gaskets into the grooves on the backside of the valve cover. If they won't stick, put a little RTV in to hold them. Run a bead of RTV along the edges of the two large cam caps where they meet the head. The valve cover gasket can't get down in the crack, so you need a little RTV. Run a bead of RTV along the top of the half-moon shaped plug at the rear of the intake cam. If you need further clarification on the valve cover stuff, read the Valve_Cover_Gasket_Replacement guide. Now, flip the valve cover over and drop it down onto the head. Make sure no gaskets slipped out and got jammed between the cover and head. Pop the rubber grommets into the valve cover bolt holes if you removed them earlier. Put the washers on top of the grommets and push the valve cover bolts into place. Lightly snug them up to seat the valve cover on the head. Then, torque all bolts to 3.3 ft-lbs in the sequence shown on the diagram above. Tighten all bolts to 6.5 ft-lbs in the same sequence. Finish with a torque to 9 ft-lbs. A deep well 8 mm socket is needed.

It almost looks like an engine now. You might want to take a break now, because this next part is going to suck.

Push the half-moon shaped key into the groove in the crankshaft snout. This locks the crank sprocket in place. Put some WD-40 on the crank snout and inside the crank sprocket. Push the sprocket onto the crank snout and engage the key. You should start to feel some resistance as the sprocket gets tight on the crank snout. You will have to pound the sprocket on with a deep well socket and 3 lb sledge hammer. You can also try to thread a long bolt in the crankshaft hole and use it to pull the socket down against the sprocket. An impact gun will likely help as the crankshaft will try to rotate. Either way, stop when the sprocket is just a hair away from the oil pump. Under no circumstances should the sprocket touch the oil pump housing. Next, you can bolt the lower timing belt cover into place on the block. I suggest you cut the cover right at the joint between the head and block. That will make the head easier to pull later. The timing belt cover bolts just need to be snug. 9 ft-lbs and an 8 mm socket will do it. Bolt the tensioner pulley bracket and pulley onto the block. I don't think there is a specified torque for them. How about 25 ft-lbs? YOu can loosely bolt the hydraulic tensioner in place. Keep the pin installed for now. The tensioner should slide freely on its bolts from left and right freely. You'll need some space to work the timing belt around.

Rotate the crankshaft to make the TDC mark on the crank sprocket 1/2 tooth before the TDC mark on the oil pump. This gives you a little slack to run the timing belt around the pulleys. Align the marks on the camshaft sprockets. Take a look back at the previous picture. You will want to install the timing belt like that. Engage the timing belt in the teeth of the crankshaft sprocket. While holding the belt on the crank sprocket, engage the belt onto the water pump sprocket, run it behind the idler pulley, engage it onto camshaft sprockets, and finish by running the belt in front of the tensioner pulley. Hold the tensioner pulley to keep the timing belt tight. All of the marks should be exactly where you left them. If you turn the crank sprocket to align the TDC marks, all belt slack should be taken up between the crank and exhaust cam. If you still have some slack, you better try again. When you think you have it right, apply 20 ft-lbs to the bolt on the tensioner pulley. This will hold the belt tight while you slide the hydraulic tensioner up against the tensioner pulley. While still holding the torque on the pulley and holding the tensioner up against the pulley, tighten the tensioner bolts. This is best done with two people, but you can manage by yourself if you are creative. When the tensioner bolts are tight, you can let go of everything. If you got the tension just right, the hydraulic tensioner pin will slide right out with no resistance. If you get this on the first try, go play the lottery. You can look at the pin to see if you need more or less torque on the tensioner pulley to get it right. Try it again, but put more or less torque on the tensioner pulley before tightening the hydraulic tensioner bolts. It will probably take a few tries to get it just right. When you finally get it, rotate the engine over two times using the crankshaft. All of your marks should still line up. If they don't, remove the belt and try again.

Bolt the outer timing belt cover into place. Cut it to match the inner cover you installed earlier. Now, the timing belt will be protected from rocks and flying debris, but you can pull the head or change the timing belt a lot easier. Plus, you can show off your cam sprockets.

Just a few more things to finish up. Slip a new o-ring on the oil pick-up tube. Bolt this down with a 13mm socket. Lay down a bead of RTV sealant at the crack between the oil pump and block. Then, lay the oil pan gasket down over the bead of RTV. Drop the oil pan down over the gasket and loosely install its bolts. Use a 10mm socket to torque them to 9 ft-lbs. Start in the middle of the pan and evenly work your way out. Now, you can safely remove the engine from the stand and lay it on the ground (sitting on its oil pan). Unbolt the engine stand bracket from the engine. You have to gain access to the rear of the block to install the rear main seal. Make sure the opening in the block for the seal is clean. You can clean any burrs with fine sandpaper. Clean this surface with alcohol. Also, make sure the edge of the crankshaft is smooth. You don't want it to grab the inner lip of the seal. Check to make sure the seal has a spring in its interior. That is a necessary component. Run a light film of RTV sealant around the edge of the rear main seal. Run a light film of clean oil around the end of the crankshaft and inner lip of the seal. Now, the goal here is to pound the seal into the block evenly. It will fight you every step of the way. There is a special tool to do this, but you will probably have to use a mallet and patience. Hold the seal and start tapping in several different places. Like starting in the 12 O'clock position and moving to 6 O'clock, 9 O'clock, and then 3 O'clock. You want to knock the seal in a little at a time, without pushing one side in further than the other. Stop when you have the seal flush with the block. You can bolt up that sheetmetal spacer plate to the rear face of the block now too. That should take a 10mm socket.

You can put some of the little stuff back on. Like the oil cap, passenger side motor mount bracket (14mm socket), cam sensor (10mm socket), crank sensor (10mm socket), and crank pulley. Temporarily install the stock lifting brackets onto the block. Wrap any lifting chain with tape to keep it from scratching your nice new engine. Now all you have to do is remove the old engine.

Keep working until you can pose in the empty engine bay like a dumb-ass (see example above). Take a break and have some lunch. Now, toss that new engine into the car.

Keep working until your car looks like the one above. If your car isn't green, this might take a while. Double check every bolt and connection. Fill up all of the fluids. Keep the car on engine stands. Now, fire the engine up. It might cough a little, but let it run. If you have an oil pressure gauge, look at it. You will likely see the oil pressure start at 75 psi and drop down to 25 psi as the engine warms up. While this is happening, look everywhere for leaks. You are looking for coolant, oil, exhaust, anything. If you have a really major leak, shut the engine off too fix it. If it is minor, you should probably just let it go for now. It might seal up as the engine warms up. You should keep running back to the cockpit to check out the gauges. If you have a boost gauge, check the vaccum. It will likely be in the 16-20 in-Hg range. If you have an air/fuel gauge, make sure the O2 sensor starts to cycle after a minute or so. After the engine has fully warmed up and run for 15 to 20 minutes, shut it off. Drain the oil and change the filter. This should remove any loose debris that might have made its way into the system during the build. If you have a turbo with an internal wastegate, you may choose to remove the actuator before driving the car. This will keep you from building any boost. Start the engine again and let it fully warm up. Find an empty stretch of road and do a 30 to 50 mph run and compression brake back down to 30 mph. Keep the car in the lowest gear that will keep you below 4k RPM max. Keep the car in the low gear during the compression braking to pull a lot of vacuum. Do this repeatedly for the next 20 miles. Now, drive in stop and go traffic for the next 200 miles. Stay off the interstate. Use your gears and vary the engine RPM when cruising, still keeping under 4k RPM. Compression brake when possible. Don't lug the engine in a high gear. When you hit 220 miles, change the oil and filter again. Use cheap dino oil again. Do the same stop and go traffic crap until you hit 620 total miles. Just change the oil this time (cheap dino oil). Do the stop and go traffic thing again, but mix in some highway cruising if you have to. When you hit 1,020 miles, change your plugs and do a compression test. If everything looks good, you can put the wastegate actuator back on (but keep the boost low). Change the oil and filter again with cheap dino oil. Drive in mixed stop and go traffic and interstate cruising until you hit 1,520 total miles. Now, you can change the oil and filter with full synthetic or whatever you would normally use. If everything seems to be running well, you are free to drive the car how you want now. Full boost, rev limit, whatever it was built to handle. Have fun and keep it between the lines!

Contributed by Corbin

Cars Modifications Power Engine Rebuild

Cars Maintenance Powertrain_Maintenance Engine Rebuild

Document statistics: Last modified on 2008-12-14 13:02:35 by Corbin

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