In detail: do-it-yourself repair of a prior 16 valve engine from a real master for the site my.housecope.com.
How long does the Priora engine run? One hundred or two hundred thousand? After all, she has a lightweight ShPG with thin rings and narrow connecting rod bushings, and the connecting rod is centered on the piston, which dangles in the cylinder like a piece of ice in an ice hole. no weight ”).
Another client for a major overhaul managed to surprise - the engine of his Priora ran 327 thousand kilometers! The engine is completely factory, hydraulic lifters have never been changed, the catalyst and the program are still factory. Only the pump and timing kit were updated. As it turned out later, the client often drives on the highway, the motor does not regret giving it revs, and the oil was poured first by Castrol, then by Zeke (change interval 10 thousand km). A typical repair indication for Priora is a significant oil consumption.
We begin to disassemble the engine. I was surprised by the state of the head under the valve cover - soot and sludge are not visible, only yellow varnish (a common picture for Zeke). There are abundant deposits of oil slag in the intake ducts, the crankcase ventilation is also partially clogged with slag, although it has not lost its throughput.
The metal-glazed gasket looks out of date - traces of antifreeze leaving are clearly visible at the edges of the cylinders. The piston in the fourth cylinder is literally washed out along the edges - the engine largely consumed oil on the 4th cylinder. But the problem is deeper than expected - the trained eye will see characteristic signs of wear on the cylinder from the water (antifreeze) entering the pot. Although the client did not complain about the antifreeze leaving, it would be useful to carefully check the plane of the block - it may need to be milled. The condition of the cylinders was surprising - for such a run, the factory honing is still visible, and the bump of the pistons at TDC is not very large.
Video (click to play).
The combustion chambers in the head and the valve heads themselves are abundantly covered with slag from the oil entering the cylinders. All this must be thoroughly cleaned.
Surprisingly, the head was in good condition. The valves were restored, removing carbon deposits, the valve bushings did not require replacement (due to the absence of wear). New hydraulic compensators were installed. The camshafts were replaced with tuning ones - Nuzhdin 8.7 mm with a phase of 263 degrees... Shafts (made by grinding from the factory, do not require thrust bearings) are exchanged for used factory shafts, installed on factory pulleys and do not require modifications to the cylinder head. The client pays for the exchange of shafts for tuning 4000 rbl - a sheer freebie, compared to the "arrival" of their installation. The plane of the head was milled to 0.05mm, removing traces of punching from the metal-glazed unit. The valve stem seals were replaced with new ones (a real "Reserve") and the head went to conquer the million mark.
The motor was assembled, in addition to the tuning shafts, the catalyst was replaced with Box 4-1 and installed increased to 52 mm throttle valve. On this "tuning" ended, tk. the client initially came for a simple overhaul, the budget, as always, is not rubber, but getting 120-125 forces for a very modest investment was a tempting offer for the client.
After starting the engine and running in a little, the fuel system was diagnosed and the tuning program was recorded. As the compression ratio of a plug-in piston engine decreases, higher firing angles are required (relative to a conventional 21126 engine). Becausethe client's budget did not allow the online unsubscription of the program; from the chip operator's arsenal, a more or less similar “plug-free” version was selected for the prior's connecting rod. Let me remind you that the chip maker uses only his own programs, and not handicrafts such as a shmaulus or a hole punch downloaded from the Internet.
It was interesting to shoot the VSX graph from this engine. So, what happened with plugless pistons:
peak power: 128 h.p. at 6100 rpm (Red line), peak torque: 17.6 kg at 5100 rpm (blue line).
The shape of the torque graph is uneven; if the program was rolling online, the chip maker would try to draw out the shape of the torque graph. But even without that, the results are impressive - compare with the graph of the 83-horsepower Priora, which was capitalized by colleagues on the same pistons! You can also see the schedule of the serial Priora.
But even more interesting is the comparison with another engine - Priora from Mendelevsk, with a similar engine (after overhaul), the same exhaust, the same 8.7 shafts, the same controller and the same throttle valve. The only and key difference between these motors is that on the Mendeleev Priora, flat repair pistons (plug-in)! The program on that car was also not written online (the engine is almost stock), but the ignition angles are different - lower, for a higher compression ratio. There was received 119 forces and 16.3 kg of moment... The shape of the torque graph is noticeably smoother there. Let's superimpose both graphs (with a flat piston “plug-in” and an STK with a “plug-in”) on top of each other. The graph of a motor with a "no-plug" is shown with a dotted line. A large increase in torque is seen in the zone 2-3 soob and an increase in power of 7.2 forces in the zone 5-6 soob. At 3500 rpm, it sagged a little, but briefly and insignificantly. Perhaps an online unsubscribe from the program would have pulled out this zone (although not a fact).
What happens ?! Is a plug-free piston better than a flat piston? Yes, it is better, but only if the program is changed taking into account the reduction in the compression ratio. It's simple - the compression ratio has decreased slightly and the engine runs better on our lousy fuel!
Finally, about finances. The entire overhaul of the engine cost the client 43 thousand rubles on a turnkey basis - including spare parts (incl. shafts, throttle and catalyst insert-replacement), work and program for the controller.
Posted on November 8, 2015 The author of the article, photo-video materials:
Overhaul of the Lada Priora engine includes the stages of disassembly, search and replacement of worn parts and subsequent assembly.
Usually, during the repair of the Priora engine, the pistons are replaced; in some cases, additional cylinder bore is required. Engine overheating is a common reason for overhaul.
The motor can overheat due to faulty cooling system, leaking gasket, thermostat malfunction, etc. In mild cases, it may be sufficient to simply replace the gasket. But sometimes overheating of the motor may require serious repairs, which you cannot cope with on your own.
In the process of disassembling and assembling the engine, you will need:
Mounting paddle
Screwdriver
A set of keys
Piston setting device
Soft hammer
Torque wrench
Sequencing
Dismantling the engine does not cause any difficulties, therefore we will omit its description and present here only the operations for the repair and subsequent assembly of the motor:
Get rid of the carbon build-up in the cylinder block. Remove carbon deposits from the oil grooves in the cylinder beds.
Insert the bearing shells, referring to the marks you made when disassembling the motor. Make sure that the stopper tendrils of the liners enter the bed poses.
Then lubricate the liners with oil.
Place the crankshaft in the cylinder block and lubricate the half rings with oil. Make sure the half rings are installed in such a way that their grooves are directed towards the cheeks of the crankshaft
Install a half-ring, made of an alloy of steel and aluminum (it is white), on the front side of the center bed.
On the other side of the bed, install a metal-ceramic half-ring (it has a yellowish color).
Rotate the installed half rings so that their ends are flush with the ends of the cylinder bed.
Install the bushings in the main bearing caps. Again, be guided by the marks made during the disassembly of the engine. Make sure the locking tabs fit into the groove and lubricate the earbuds.
Install the covers according to the cylinder numbers printed on them.
Lubricate the ends and threads of the bolts that will secure the covers with engine oil
Install the third cover bolts. Do the same with the bolts of the second, fourth, first and fifth covers (in this order).
After tightening the bolts, check the crankshaft for ease of movement. Rotate it several times.
Install and secure the oil pump as well as the rear oil seal holder
Install the connecting rod into the piston and insert the piston pin. Be sure to lubricate both pin and connecting rod with oil.
Install retaining rings on both sides of the pin. Make sure they fit in the grooves of the piston.
Then install the oil scraper ring and piston rings on the piston. To do this, it is better to use a special tool, which is called a "puller".
Make sure the rings rotate easily in the grooves.
Gently wipe the crankshaft connecting rod journals and cylinder bores.
Insert the bushing into the connecting rod, making sure that its antenna fits exactly into the groove of the connecting rod. Lubricate the piston and bushing. Install a ring compression mandrel on the piston and lower the connecting rod into the cylinder.
Overhaul of the Priora engine includes several stages. They are as follows: disassemble the motor, find worn parts, replace them, and then reassemble the unit. In general, the process is simple, but you need to determine what the malfunction is, and only then fix it.
During the operation of this vehicle, the owners discover malfunctions and weak points of the motor. These include the following:
Quite often, Priora drivers complain that oil leaks under the cover of the valve-type mechanism. To fix this problem, you just need to replace the gaskets.
As a rule, repair work consists in the fact that it is required to bore the cylinders or simply replace the pistons. Often the owners are forced to resort to repairs due to the fact that the unit has overheated. This is due to the following reasons: the cooling system does not work well or is completely broken, the gaskets are installed leaking, the thermostat is malfunctioning, etc. In simple cases, it will be possible to simply change the gasket. But if overheating is caused by more complex and serious problems, then it will not be possible to correct the situation on your own, so you will need the help of specialists.
The frequency of servicing the Priora motor is approximately 15 thousand km. This is what the plant that manufactures this unit does. Experts recommend carrying out the first check after 3 thousand km. Basically, at this stage, more attention should be paid to the places where the attachments for the equipment of the mounted type are located. In addition, during the first inspection and maintenance, it is imperative that the oil or filters for it are changed.
If the engine has an 8-valve design, then it is required to check the condition of the valve clearances during the first check. If the motor has a 16-valve design, then such actions will not be necessary, since such a unit has hydraulic compensators. Similar checks are also carried out after 15 thousand kilometers for Priora.
When the odometer is already more than 30 thousand km, it will be necessary not only to replace the oil filters, but also the oily liquid itself. Be sure to also change the spark plugs, and then the filters in the power system.
Often, at about such a run, the timing rollers begin to function poorly or completely break. If the Priora has an 8-valve engine, then the gasket in the valve mechanism cover should be additionally replaced.
When the mark on the odometer reaches 45 thousand km, the oil should be changed again. It is imperative to check the tension in the timing belts. Moreover, these actions are carried out for an engine with both 8 and 16 valves.
Then scheduled maintenance is carried out when the mileage reaches 60 thousand km. This time you need to pay attention to the spark plugs and alternator drive belts. Sometimes you need to flush the power system. This is especially true of the place where the throttle pipe is located. It is recommended at this time to change the sensors that are responsible for idling.
When the mileage reaches 75 thousand km, on a unit with 8 valves, it is required to change the timing belts. The same goes for the oxygen sensor. It is also better to replace the coolant, since by this time it has already partially or completely lost its functions.
Further maintenance will be repeated for Priora. As a result, the minimum risk for this engine is approximately 100 thousand km. Sometimes, subject to all the rules and proper maintenance, it turns out to stretch this time to 200 thousand km of run. Of course, if you change the design (tuning), then this increases the power of the unit. But even if you follow all the requirements, then sooner or later you will not be able to do without repairs. Of course, compliance with the rules delays this, but you will either have to replace the parts yourself, or contact a specialist.
Repair of the Priora engine begins with disassembly.
To do this, you need to have with you screwdrivers and wrenches, a blade for mounting purposes, torque wrenches, a soft hammer, as well as a device to install the pistons.
The algorithm of actions is as follows:
Overhaul of the Lada Priora engine is not a difficult process. You just need to first disassemble the unit, then look for broken or worn out elements, replace them, and then assemble the motor.
