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by Bob O’Neill. Updated 3/4/08.
In December 1985 I purchased a standard Daytona. But what I really wanted was the Turbo Z with T-tops and the C/S handling package. Twenty years later I found the perfect project car. On the way to the Chrysler National Car show at Carlisle in 2006 we stopped by Madison Heights, VA where Wayne had found the car for me. Wayne AKA Hogtownhustler on the Allpar.com Daytona forum, is a friend that I’ve chatted with over the years on the forums and have visited a few times. He found this car and thought it would be perfect for my project. When I saw the car I knew he was right.
This engine was apart when I purchased the car. So this article will concentrate on the proper assembly of the engine with some additional information about my goals for the car and what roles the engine plays.
The car has 121,000 miles on the clock. This is not a great deal of miles on one of these 2.2 Turbo engines. The problem was that the owner had blown the head gasket. Once it was discovered that the head itself had a crack between the combustion chamber and the water jacket, the head was left off the block and parked outside in the elements for most of a year. The car was not badly affected by this but the engine block was. In the first generation Daytona there is a hood ‘grill’ which allows air in through the hood. It is my guess that this was installed is to help cool the turbo. There was a modification to the induction of the first generation Daytona which was available from Direct Connection. It was an intercooler which was mounted just above the valve cover and intake manifold. This would position it just below the grill. The theory was that the air which flowed through the grill would cool the intake air as it passed through the intercooler.
In addition to air, the grill allows rain to fall through the hood and onto the engine when the car is left out in the elements. Because the head was off the car rain collected in the cylinders. Cylinders #2 and #3 were badly rusted. Had this not happened it may have been possible to simply hone the cylinders for the rebuild. Because of the rust the cylinders were bored to the minimum over size and replacement pistons will be used.
Before I can discuss the engine rebuild I think it is important to understand my goals for this car and therefore the engine. This project car will be a show car and as we know, show cars which are driven must have a bit more guts than stock. It is an unwritten rule that just sounds right to me.
In 1986, the Daytona Turbo Z was equipped with a 2.2 liter turbocharged engine. This is a non intercooled turbo 1 engine and uses a suck through throttle body. This engine delivers 141 hp and 170 lb-ft torque.
Then, in 1986, Dodge installed the 2.5 liter engine in the Daytona for the first time. This is the engine which is in my standard Daytona. In comparison with the 2.2 turbo, the 2.5 TBI produces 100 hp and 135 lb-ft torque. The difference in performance between the 2.5 and the 2.2 is not really huge so I felt it necessary to plan the rebuild of the 2.2 so it would produce more than the stock 141 hp. The goal for the 2.2 turbo engine is 200 hp with 230 lb-ft of torque.
To properly rebuild an engine it is very important to pay attention to the details. Details such as the clearances between the bearings and the crankshaft journals as well as the clearances between the pistons and cylinder walls and the rings both in the grooves of the pistons and the rings end gap in the cylinder. There are other clearances which are also important and I’ll mention these when I get to that part of the engine rebuild.
The block was bored to the minimum over size as this was all that was necessary to clean up the rust and straighten the bores. This increased the bore of the cylinders from 87.5mm (3.44 in) to 88mm (3.46 in) or .5mm (.020 in) over size. The pistons used for this rebuild are the turbo 2 cast pistons and were manufactured by Mahle. Mahle is the company who originally provided the pistons for these engines. There is a slight difference between the turbo 1 pistons and the turbo 2 pistons. While the wrist pin is the same diameter in both engines the turbo 2 pistons use a floating pin where the turbo 1 pistons were press fit to the rod. Also in the 1986 turbo 1 engine used a lighter weight rod and weighed 659 grams. Since my goal for this engine is to make 33% more power and torque I decided to use the turbo 2 rods. These rods are heavier but stronger in the area where they connect to the crank shaft. The turbo 2 rods weigh 699 grams each and have more material in areas which are under stress in higher horsepower applications. The rods used in this rebuild were fitted with new bushings which were matched to the wrist pin. They were also modified to permit an ‘extra’ oiling hole in the small end and permits more oil to be supplied to the pin. The turbo 2 pistons also have oiling holes on the underside of the boss which supplies oil to the pin where it connects to the piston. Because the turbo 2 pistons are not press fit they require a snap ring to keep the pin in place. In addition to the rework of the rods I weighed each one and machined them to insure they were each within one gram of each other. Once this was completed they were shot peened to insure strength especially where the machine work was done. It is my hope that this extra step will help with rotational balance. I know the crank was in balance and during the internal components preparation I weighed each piston. Each piston weighed exactly the same, so when they are attached to the rotating balance should be really close.
There is one more thing about the block which should be mentioned here. This would be the oil pump. I did replace the oil pump even though the unit which was originally installed didn’t appear to have excessive wear. I didn’t see any logic in not replacing it since the replacement is ‘new’ and should be good for the life of the new engine. There is however one issue which I felt I needed to address. This is the oil hole in the block. The hole in the block is round and angles away from the oil pump. The oil pump’s output is oval and appears to be slightly off center, so I adjusted the oil galley hole in the block to better match the mating hole in the pump. It has been mentioned that this can return otherwise ‘lost’ horsepower at higher RPM. It is only a few as in two to five but if this simple modification helps flow the oil better then it’s a no brainer.
Check out the picture and notice the oval hole. I took a grinder before the block went to the machine shop to be cleaned and ground out this hole to match the oil pump output. I can see how horsepower could have been lost here. The original hole was round like I said and it angles away from the pump. It’s not perpendicular to the output of the pump. So, the pump would make pressure and have to force it into the galley. With this modification there is far less force needed to put oil into the galley.
Before beginning the assembly, the block must be cleaned and the thread holes cleaned as well. The way to insure that the thread holes are cleaned is to use a thread chaser of the proper size. I didn’t have a thread ‘chaser’ for the head bolt threads so I made one. Let me explain why. The thread chaser doesn’t cut new threads it simply cleans them to remove junk which may be on the threads. This junk can prevent the proper tightening of the bolts. I couldn’t use a tap because it cuts threads. So I did the next best thing. I took an old used head bolt and using a Dremel tool with a cutting wheel I cut four grooves parallel to the bolt through the threads. Then I cut a bit more at the ‘bottom’ of the bolt.
Once I did this, I oiled up the hole/chaser and using my hand only I threaded it into each bolt hole all the way to the bottom to ‘chase’ the threads. The reason to chase the threads is to remove the grit, machining dust or anything else that may be in the bolt holes on the threads. Using oil on the threads helps to lump contaminates together so when the chaser is unthreaded the contaminates are removed from the threads. If I noticed any hole that seemed to be especially dirty I chased it till it was clean. This step helps to insure that when the head bolts are tightened they will be uniformly tightened to the proper torque specification.
Once the threads have been chased on each head bolt hole the flatness of the decks should be confirmed. The flatness of the block should actually be done prior to building short block in case it needs to be returned to the machine shop. But if the shop did their job right, they would have checked the flatness of the block’s deck would have been checked and the block decked if necessary. To check it, use a straight edge which you know to be straight. A good quality carpenter’s square will work fine. Using a feeler gauge to measure, put the straight edge across the decks at a diagonal and straight. Take your measurements between the cylinders between the straight edge and the deck. Any warping of the deck will be evident if the measurements exceed .020”. Mine was flat and there was no measurement more than .010”.
The clearances between the parts are critical if you want to make the power and reliability goals set for an engine. If the clearances are too tight things will bind and will wear out with a bang. If they are too loose the same thing can happen. To insure that the bearings have the right clearance measurements are taken before final assembly.
The following are the required clearances for a ‘new’ engine. This information was pulled from the Factory Service Manual (FSM). While I was researching this I discovered some discrepancies in the information. Some of these discrepancies can be explained as simple typographical errors. But upon careful examination of the specifications I did some further research. It appeared to me that some of these specifications were very tight. I noticed that even the Plastigage didn’t come in a size which would measure less than .001”. Some of the specifications in the FSM called for as little as .0004”. The following table compares information I pulled from the Factory Service Manual and from a popular Turbo Dodge web site.
The following table compares information I pulled from the Factory Service Manual and from a popular Turbo Dodge web site.
Notice the differences in the specifications. After getting some additional insight on these numbers from engine builders and documents provided by the bearing manufacturer, it seems that the FSM numbers are actually closer to reality. In a document published by the makers of Clevite 77 bearings (the bearings I’m using in the rebuild) the rule of thumb is .00075 to .0010 inch for each one inch in journal diameter. The 2.2 liter main crankshaft journal diameter is 2.3622”. This means that a nominal clearance of .00236 inch would be a good ‘starting point’. The Clevite 77 document goes on to say that for higher performance engines it is recommended to add .0005”. If we consider that my engine is a ‘higher performance’ engine then the starting point for clearance would be .00286” for the main journals. The rod journals for this engine are 1.968 inches in diameter. The rule of .00075” to .0010” still applies. So the clearance starting point for the rod journals would be .001968” or .002468” for the higher performance engine. So if the clearances I measure are within these specifications it will prove that the machine work was done properly.
There are actually two ways to measure these clearances. One way is to use an accurate dial caliper to measure the diameter of the journal and an inside micrometer to measure the inside diameter of the bearing. The bearing should be installed in the block and rods with the crankshaft NOT installed. Then the caps should be torque properly and the inside diameter can then be measured. Take these two measurements and compare them. The difference will be the installed clearance. But this doesn’t take into consideration the run out of the crank or any possible out of round condition of the journals.
This is best done with a product called Plastigage. This is a tiny plastic ‘hair’ or ‘wire’ which flattens between the surface of the bearing and the journal. The width of the flattened Plastigage is then measured with the chart supplied. The Plastigage plastic ‘rod’ which is cut to length and placed on the journal cap or rod cap 90° from the split line of the cap and about ¼” off center. This will represent the area which will be closest to the journal. Oil must not be used for this measurement step as it will smear the Plastigage.
Clean all oils from the crank journals and caps. Install a bearing in the journal and the cap. With the Plastigage applied to the bearing cap, position the journal cap on the block and tighten the cap to the block or rod with the crankshaft in place. Then torque the blots to their proper torque. The bolts should be oiled with engine oil for this step. The process of setting the bolts to their proper torque will squeeze the Plastigage flat as seen in this picture.
Using the measuring chart which comes with the Plastigage, measure the width of the Plastigage that has been flattened. This will tell you the clearance between the journal and the bearing.
I started the build by arranging all the parts necessary ready for easy access.
Notice in the upper right of this picture there is a brown box. There is a vernier caliper in that box it has a dial on it which reads parts of inches. The dial indicator to the left of it will be used to measure crank end play. In the bottom right of the picture on the table is the Factory Service Manual. I’ll reference this for clearances and torque specifications.
I started with the bare block. The block had already been machined and cleaned. The threads were chased and the exterior surfaces were painted. I checked to insure that the intermediate shaft bearings were properly installed and that their oil holes were open to the oiling galley. To insure that the rings properly seal, the bored cylinders were honed to final size. This cleans up the boring machine marks and provides a surface which the rings can use which provide a good sealing surface. Notice the crosshatch in the cylinders.
The next step is to measure the rings in the cylinders. This is done with the ring at .662 inches above the bottom of the bore. To insure that the ring is properly positioned, use a piston and slide the ring into the cylinder to the proper depth. The new part ‘top’ ring gap measurement is between 0.25 to 0.51 mm (.010 to .020in) with a wear limit of 0.98 mm (.039in). I measured .020” on my top rings with them positioned at the bottom of the cylinders as called for in the FSM. This isn’t too bad since the block was milled and is not a ‘new part’. Gary Donovan’s site recommendation for a high boost engine is .020” for the top ring. So, I guess I should be happy with this measurement.
The new part ‘second’ ring should measure between 0.23 to 0.48 mm (.009 to .019) with a wear limit of 0.95 mm (.038in). I measured .019” for all four of my second rings in the same location in the cylinder as the top ring. This was again wider than the smallest FSM requirement but within the range of ‘new parts’. The recommendation by Gary Donovan’s web site for a high boost engine is .016” for the second ring. Again I am happy with this measurement.
The oil rings measure wider. The FSM says they should measure 0.38 to 1.40 mm (.015 to .055in) for new parts with a wear limit of 1.88 mm (.074 in). I measured my oil rings at .033”. While this is again not on the low end of what the FSM states for new part measurements, the oil rings didn’t measure at the top of the minimum range either. They are closer to the middle of this range. I’m pleased with this measurement.
All in all, each of the oil ring end gaps measured within the ‘range’ of new part measurements and well below the wear limits. Just for grins I measured the piston at the top of the cylinder as they seemed to feel a bit sloppy when I used one to push the rings down into the cylinders. So I put a piston in one of the cylinders as it would later be installed with the top up. I then measured the piston to cylinder wall clearance on one side. I measured a .0025” gap between the cylinder wall and the piston. When I consult the FSM I discover there is a measurement for this. The FSM states the Turbocharged engine should have a new part piston to cylinder wall clearance of .0015 to .0025”. So once again this measurement is on the high side of new part measurements but nowhere near the wear limit which is .0037 in this case.
As I was getting ready to install the pistons to the rods I notice the paper which came with the pistons. It states that the measurement should be made at the bottom of the piston skirt 90° to the wrist pin and not the top. It also states that the skirt of the piston to the cylinder wall clearance should measure .0016” .5” up from the bottom of the cylinder. So I put one of the pistons in the cylinder and measured the skirt to cylinder wall at .0016”. Now I’m happy. This measurement confirms that cylinder walls are properly prepared for the pistons and the gaps in the rings are well within specification.
Before taking the measurements the main bearings to journals, I installed a repair sleeve on the crankshaft. The rear main seal ‘journal’ was worn and had a groove in it. The machine shop didn’t mill it to remove the groove and I didn’t want to install a seal over this groove as this would only result in premature failure of the seal. I slid the sleeve over the seal journal to start the installation. These ‘repair sleeves’ have an inside diameter which is nearly the same as the diameter of the journal. Because this provides a really tight fit these sleeves are very easily damaged. They must be installed ‘all at once’. This is really hard to do without the proper ‘tool’ that will apply equal pressure all the way around the circumference of the sleeve. I didn’t have one of these tools so to solve this problem I used the flywheel once I had the repair sleeve started and partially installed. Then I tightened down the flywheel toward the crank to fully set the repair sleeve on the rear main seal journal.
Once the crankshaft was prepared I proceed to measure the clearance between the crank journals and the bearings. I did the main journals first. To do this the bolts which hold the main caps in place must be tightened to their proper torque with the Plastigage material placed across the bearing on the cap. The FSM states that the bolts should be lightly oiled to achieve proper torque. The Plastigauge is placed about ¼” off center and the caps are torqued in place. This is done dry with no oil as the oil tends to ‘melt’ the Plastigage. This extra step is a time consuming one but if you want to insure that the clearances at your bearings are correct it’s a necessary step.
Comparing the crushed Plastigage with the provided guide.
As you can see in the picture, the measurement taken after the caps were removed shows .0020” clearance between the bearing and the crankshaft journal. All of the journals measured the same.
The FSM states that the new part main bearing clearance should be .011 to .054 mm (.0004 to .0023in) with a wear limit of .102 mm (.004in). Again, this measurement is not at the bottom of the scale it is within the limits and well within the wear limit. Gary Donovan’s website suggests a .0025 to .003” measurement for the main journals so I am happy with the result of the main journal clearance measurement.
Once the main journals were cleaned to remove the Plastigage, it was time to actually start assembling something. I applied a liberal amount of assembly lube to the journals of the crankshaft and the bearings. Assembly lube is different than regular oil as it is designed to stay in place during assembly and it offers better lubrication than oil for the first start up. Once the engine is running, the oil washes the assembly lube away and it mixes with the crankcase oil. Next, the block is fitted with the bearings. Each main crankshaft journal has a saddle in the block where the journal rides. The bearings have two halves. One half is installed on the block side of the saddle or journal and the other is installed in the caps. I installed the block side bearing half in the block and applied the assembly lube. Then I installed the crankshaft onto these bearings and insured it was not binding by turning it just a little. With the assembly lube in place and the crankshaft installed on the lubed bearings it was time to install the main bearing caps and torque the bolts again. Proper torque for the main bolts is 30ft lbs then ¼ turn.
Once the crankshaft bearing caps are torque and the crank spins freely, the last crankshaft measurement is the end play. End play is the amount of travel the crankshaft can take forward and back. There are two methods to take this measurement. One way is to use a feeler gauge and measure the distance between the thrust bearing and the mating surface of the crank. The thrust bearing is the center bearing on the #3 main journals on the 2.2 and 2.5 engines. First, use a screw driver and pry the crank all the way toward the rear of the block. Then on the front thrust bearing surface measure the distance between the bearing and the crank surface with a feeler gauge. The second way to measure this is to use a dial indicator. Using a clamp or a magnetic stand, mount the dial indicator so it is touching the end of the crankshaft. Then use a screw driver to force the crankshaft toward the back of the block. Adjust the dial indicator to zero. Then using the screw driver force the crank toward the front of the block. The distance it moves is the crank ‘end play’. The FSM states that the new part measurement should be 0.05 to 0.18 mm (.0.002 to 0.007in) with a wear limit of 0.35 mm (.014in). I measured .003” of end play.
With the crankshaft installed, the main cap bolts properly tightened and the end play measured it was time to install the pistons. Before I could install the pistons, each piston needed to have the rings installed on them and the pistons had to be installed on the rods. Installing the rings on the pistons was somewhat of a chore. There are three ring grooves in the piston. The top ring and the second rings seal the piston in the cylinder. The third groove is wider and is for the oil ring which is designed to scrape oil from the wall as the piston moved down the cylinder wall. The rings are installed from the bottom up so the third or oil groove is installed first. The oil ring is a three part ring assembly. The center separator piece is used to push the scrapers away from the piston and toward the cylinder wall. This is done to scrape excess oil from the cylinder walls. Once the separator is installed then the thin scraper rings are installed. Care must be taken to follow the instructions with the rings. In the case of the Sealed Power rings I installed, the center expander met and did not interlock. I looked at this and thought that this was going to provide too much diameter for the oil scrapers. But as I installed the lower scraper then the upper scraper I realized that this center separator would act to force the scrapers against the cylinder walls and that the diameter was not going to be too big. Once the oil rings are installed it is time for the second ring. These have and up and a down. In other words installing these rings upside down can result in an improper seal. There is a tiny dot on the ‘top’ side of the ring. This indicates that this side is up and should be installed on the second groove with the dot facing the top of the piston. Next is the installation of the top ring. The same dot appears on the top ring. Once all the rings are installed I installed the rods to the pistons.
The pistons and rods I’m using are from the later model Turbo 2 engine. These install on the piston with a floating wrist pin. These pins are kept in place on the piston with two snap rings. One ring fits at each end of the wrist pin once it’s installed in the piston. These can be a real problem to get in place especially with all the assembly lube making things really slippery. I installed one snap ring on each piston prior to using the assembly lube. This made the installation of half the snap rings easier. Next the connecting rods needed to be installed on the pistons. Consulting the FSM I noticed that the rods should be installed with the oiling hole facing the front (or timing belt side) of the engine. The notches on the pistons must face the manifold side of the engine or the back of the engine. Once the connecting rods were oriented properly on the pistons and the wrist pins are held in place with the snap rings, the piston rings gaps needed to be properly oriented. This is done by putting the oil ring scrapper gaps at 180° from one another and the second ring gap 180° from the top ring gap. And these gaps should be 90° from the oil ring gaps. So the resulting orientation of gaps would be a gap every 90°. With the gaps positioned correctly the rings are oiled up really well. Assembly lube is NOT used here because it’s too thick. Oil works best. At this point it is time to install the pistons. It is important to put something on the threads of the connecting rod bolts to protect the crankshaft journals during assembly from being nicked by the bolts. Some clear plastic or rubber tubing will work with this. Once the rings are nicely oiled up and the threads covered, a ring compressor is used to compress the rings on the pistons. Next use assembly lube to coat the bearing on the connecting rod. With the rings are compressed and the bearing lubed the piston is placed in the cylinder with the notches of the piston facing the manifold side of the engine. Gently tapping the piston through the ring compressor and into the cylinder will position them in the cylinders. Use care not to ‘tap’ too hard and never tap the center of the piston. Always tap around the edge of the piston where it is thickest.
Once the piston is installed in the cylinder the bearings halves are installed on the journals at the big end of the rods and these get a good amount of assembly lube. I then installed the matching bearing on the rod cap and used assembly lube to lube the connecting rod cap bearing. Then I installed the connecting rod cap on the studs which are pressed in the big end of the rod and torqued the nuts. These are torqued to 40 ft lbs and then ¼ turn. I then repeated this process for the other three pistons.
At this point the short block is assembled. The next step is to install the seals for the front and rear main or crank seals. These are installed in ‘housings’ which are then mounted to the block. Once they are installed in the housings using some sealer around the outer diameter of the seal the inner diameter or rubber part is lubricated really well. These are then slid over the seal journal on the crank. It’s a good idea to allow the seal to center allowing the seal housings to then be bolted to the block. There is either a thin gasket or some RTV which seals these housings to the block. The next step is to bolt these housings to the block using some thread lock on the threads of the housing bolts.
With the seal housings in place the oil pan can now be installed. Use RTV to seal it using the rubber end pieces but not the cork flat pieces. Use RTV on the flat pieces and at the corners where the rubber pieces meet the flat parts of the oil pan.
Now the bottom is buttoned up, the crank is sealed in the front and back and oil pan is on. Next step is to install the head. Check the head surface for flatness like you did the block.
To install the head be sure that all the surfaces are clean. Then be sure that there is a film of oil on the cylinder walls. Put the head on the block after you put the gasket on the block. There are some indexing pins at either end of the block to insure that the gasket lines up properly and doesn’t move once install. These same index pins help to locate the proper position of the head. Once the head is in place, thread the new head bolts with washers down snug and then torque the head bolts. I used the Mopar Performance head bolts. These require a little oil on the threads to insure proper tightening. These bolts are also ‘torque to yield’ bolts. The sequence to proper torque is to tighten each bolt in order to 45 ft-lb first. There is also an order to tighten these.
The last steps are to install the manifolds, turbo, sprockets; timing belt and engine mount brackets. Once the engine is fully assembled it’s time to add the flywheel, clutch and pressure plate and the transmission. With the assembly complete the engine can be installed in the engine compartment of the car.
I really look forward to testing the performance of this engine. I expect it will meet my expectations.
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