Piston marking
Content
Piston marking allows you to judge not only their geometric dimensions, but also the material of manufacture, production technology, permissible mounting clearance, manufacturer's trademark, installation direction, and much more. Due to the fact that both domestic and imported pistons are on sale, car owners sometimes face the problem of deciphering certain designations. This material contains a maximum of information that allows you to get information about the markings on the piston and figure out what the numbers, letters and arrows mean.
1 - Trademark designation under which the piston is released. 2 - Serial number of the product. 3 - The diameter is increased by 0,5 mm, that is, in this case it is a repair piston. 4 - The value of the outer diameter of the piston, in mm. 5 - The value of the thermal gap. In this case, it is equal to 0,05 mm. 6 - An arrow indicating the direction of installation of the piston in the direction of vehicle movement. 7 - Manufacturer's technical information (required when processing internal combustion engines).
Information on the piston surface
Discussions about what the markings on pistons mean should start with what information the manufacturer puts on the product in general.
- Piston size. In some cases, in the markings on the bottom of the piston, you can find numbers indicating its size, expressed in hundredths of a millimeter. An example is 83.93. This information means that the diameter does not exceed the specified value, taking into account the tolerance (tolerance groups will be discussed below, they differ for different brands of machines). The measurement is made at a temperature of +20°С.
- Mounting gap. Its other name is temperature (since it can change along with a change in the temperature regime in the internal combustion engine). Has the designation - Sp. It is given in fractional numbers, meaning millimeters. For example, the designation of the marking on the piston SP0.03 indicates that the clearance in this case should be 0,03 mm, taking into account the tolerance field.
- Trademark. Or an emblem. Manufacturers not only identify themselves in this way, but also give information to the masters about whose documentation (product catalogs) should be used when selecting a new piston.
- Installation direction. This information answers the question - what does the arrow on the piston point to? She "speaks" how the piston should be mounted, namely, the arrow is drawn in the direction of the car moving forward. On machines in which the internal combustion engine is located at the rear, instead of an arrow, a symbolic crankshaft with a flywheel is often depicted.
- Casting number. These are numbers and letters that schematically indicate the geometric dimensions of the piston. Typically, such designations can be found on European machines for which piston group elements are manufactured by companies such as MAHLE, Kolbenschmidt, AE, Nural and others. In fairness, it should be noted that the casting is now used less and less. However, if you need to identify the piston from this information, then you need to use the paper or electronic catalog of a specific manufacturer.
In addition to these designations, there are also others, and they may differ from manufacturer to manufacturer.
Where is the piston mark located?
Many motorists are interested in the answer to the question of where the piston markings are located. It depends on two circumstances - the standards of a particular manufacturer and this or that information about the piston. So, the main information is printed on its lower part (“front” side), on the hub in the area of the hole for the piston pin, on the weight boss.
VAZ piston marking
According to statistics, the marking of repair pistons is most often interested in owners or masters in the repair of internal combustion engines of VAZ cars. further we will give information on various pistons.
WHA 2110
For example, let's take the internal combustion engine of a VAZ-2110 car. Most often, pistons marked 1004015 are used in this model. The product is manufactured precisely at AvtoVAZ OJSC. Brief technical information:
- nominal piston diameter - 82,0 mm;
- piston diameter after the first repair - 82,4 mm;
- piston diameter after the second repair - 82,8 mm;
- piston height - 65,9;
- compression height - 37,9 mm;
- the recommended clearance in the cylinder is 0,025 ... 0,045 mm.
it is on the piston body that additional information can be applied. For example:
- "21" and "10" in the area of the hole for the finger - the designation of the product model (other options - "213" indicates the internal combustion engine VAZ 21213, and for example, "23" - VAZ 2123);
- "VAZ" on the skirt on the inside - the manufacturer's designation;
- letters and numbers on the skirt on the inside - a specific designation of foundry equipment (it can be deciphered using the manufacturer's documentation, but in most cases this information is useless);
- "AL34" on the skirt on the inside - the designation of the casting alloy.
The main marking symbols applied to the piston crown:
- The arrow is an orientation marker that indicates the direction towards the camshaft drive. On the so-called "classic" VAZ models, sometimes instead of an arrow you can find the letter "P", which means "before". Similarly, the edge where the letter is depicted must be directed in the direction of the movement of the car.
- One of the following characters is A, B, C, D, E. These are diameter class markers that indicate the deviation in OD value. Below is a table with specific values.
- Piston mass group markers. "G" - normal weight, "+" - weight increased by 5 grams, "-" - weight reduced by 5 grams.
- One of the numbers is 1, 2, 3. This is the piston pin bore class marker and defines the deviation in the piston pin bore diameter. In addition to this, there is a color code for this parameter. So, the paint is applied to the inside of the bottom. Blue color - 1st class, green color - 2nd class, red color - 3rd class. further information is provided.
There are also two separate designations for VAZ repair pistons:
- triangle - the first repair (the diameter is increased by 0,4 mm from the nominal size);
- square - second repair (diameter increased by 0,8 mm from the nominal size).
Please note that for different brands of cars (including for different ICEs), the value of the difference in repair pistons must be viewed in the reference information.
WHA 21083
Another popular "VAZ" piston is 21083-1004015. It is also produced by AvtoVAZ. Its technical dimensions and parameters:
- nominal diameter — 82 mm;
- diameter after the first repair - 82,4 mm;
- diameter after the second repair - 82,8 mm;
- piston pin diameter - 22 mm.
It has the same designations as the VAZ 2110-1004015. Let us dwell a little more on the class of the piston according to the outer diameter and the class of the hole for the piston pin. The relevant information is summarized in tables.
Outside diameter:
| Piston class by outside diameter | A | B | C | D | E |
|---|---|---|---|---|---|
| Piston diameter 82,0 (mm) | 81,965-81,975 | 81,975-81,985 | 81,985-81,995 | 81,995-82,005 | 82,005-82,015 |
| Piston diameter 82,4 (mm) | 82,365-82,375 | 82,375-82,385 | 82,385-82,395 | 82,395-82,405 | 82,405-82,415 |
| Piston diameter 82,8 (mm) | 82,765-82,775 | 82,775-82,785 | 82,785-82,795 | 82,795-82,805 | 82,805-82,815 |
Interestingly, the piston models VAZ 11194 and VAZ 21126 are produced only in three classes - A, B and C. In this case, the step size corresponds to 0,01 mm.
Correspondence table of piston models and ICE models (brands) of VAZ cars.
| Model ICE VAZ | piston model | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2101 | 21011 | 2105 | 21213 | 2123 | 2108 | 21083 | 2110 | 2112 | 21124 | 21126 | 21128 | 11194 | |
| 2101 | |||||||||||||
| 21011 | |||||||||||||
| 2103 | |||||||||||||
| 2104 | |||||||||||||
| 2105 | |||||||||||||
| 2106 | |||||||||||||
| 21073 | |||||||||||||
| 2121 | |||||||||||||
| 21213 | |||||||||||||
| 21214 | |||||||||||||
| 2123 | |||||||||||||
| 2130 | |||||||||||||
| 2108 | |||||||||||||
| 21081 | |||||||||||||
| 21083 | |||||||||||||
| 2110 | |||||||||||||
| 2111 | |||||||||||||
| 21114 | |||||||||||||
| 11183 | |||||||||||||
| 2112 | |||||||||||||
| 21124 | |||||||||||||
| 21126 | |||||||||||||
| 21128 | |||||||||||||
| 11194 | |||||||||||||
Piston pin holes:
| Piston pin bore class | 1 | 2 | 3 |
|---|---|---|---|
| Piston pin hole diameter(mm) | 21,982-21,986 | 21,986-21,990 | 21,990-21,994 |
ZMZ piston marking
Another category of car owners interested in marking pistons has ZMZ brand motors at their disposal. They are installed on GAZ vehicles - Volga, Gazelle, Sobol and others. Consider the designations available on their cases.
The designation "406" means that the piston is intended for installation in the ZMZ-406 internal combustion engine. There are two designations stamped on the bottom of the piston. According to the letter applied with paint, on the new block, the piston approaches the cylinder. When repairing with cylinder boring, the required clearances are performed in the process of boring and honing for pre-purchased pistons with the desired size.
The Roman numeral on the piston indicates the desired piston pin group. The diameters of the holes in the piston bosses, the connecting rod head, as well as the outer diameters of the piston pin are divided into four groups marked with paint: I - white, II - green, III - yellow, IV - red. On the fingers, the group number is also indicated by paint on the inner surface or on the ends. It must match the group indicated on the piston.
it is on the connecting rod that the group number should similarly be marked with paint. In this case, the mentioned number must either coincide with or be next to the number of the finger group. This selection ensures that the lubricated pin moves with little effort in the connecting rod head, but does not fall out of it. Unlike VAZ pistons, where the direction is indicated by an arrow, on ZMZ pistons the manufacturer directly writes the word "FRONT" or simply puts the letter "P". When assembling, the protrusion on the lower head of the connecting rod must match this inscription (be on the same side).
There are five groups, with a step of 0,012 mm, which are indicated by the letters A, B, C, D, D. These size groups are selected according to the outer diameter of the skirt. They match:
- A - 91,988 ... 92,000 mm;
- B - 92,000 ... 92,012 mm;
- B — 92,012...92,024 mm;
- G — 92,024...92,036 mm;
- D - 92,036 ... 92,048 mm.
The value of the piston group is stamped on its bottom. So, there are four size groups that are marked with paint on the piston bosses:
- 1 - white (22,0000 ... 21,9975 mm);
- 2 - green (21,9975 ... 21,9950 mm);
- 3 - yellow (21,9950 ... 21,9925 mm);
- 4 - red (21,9925 ... 21,9900 mm).
Finger hole group marks can also be applied to the piston crown in Roman numerals, with each digit having a different color (I - white, II - green, III - yellow, IV - red). Size groups of selected pistons and piston pins must match.
The ZMZ-405 ICE is installed on the GAZ-3302 Gazelle Business and GAZ-2752 Sobol. The calculated clearance between the piston skirt and the cylinder (for new parts) should be 0,024 ... 0,048 mm. It is defined as the difference between the minimum cylinder diameter and the maximum piston skirt diameter. There are five groups, with a step of 0,012 mm, which are indicated by the letters A, B, C, D, D. These size groups are selected according to the outer diameter of the skirt. They match:
- A - 95,488 ... 95,500 mm;
- B - 95,500 ... 95,512 mm;
- B — 95,512...95,524 mm;
- G — 95,524...95,536 mm;
- D - 95,536 ... 95,548 mm.
The value of the piston group is stamped on its bottom. So, there are four size groups that are marked with paint on the piston bosses:
- 1 - white (22,0000 ... 21,9975 mm);
- 2 - green (21,9975 ... 21,9950 mm);
- 3 - yellow (21,9950 ... 21,9925 mm);
- 4 - red (21,9925 ... 21,9900 mm).
So, if the GAZ internal combustion engine piston has, for example, the letter B, then this means that the internal combustion engine has been overhauled twice.
In ZMZ 409, almost all dimensions are the same as in ZMZ 405, with the exception of a recess (puddle), it is deeper than in 405. This is done to compensate for the compression ratio, size h increases on pistons 409. Also, the compression height of 409 is 34 mm, and for 405 - 38 mm.
We give similar information for the internal combustion engine brand ZMZ 402.
- A - 91,988 ... 92,000 mm;
- B - 92,000 ... 92,012 mm;
- B — 92,012...92,024 mm;
- G — 92,024...92,036 mm;
- D - 92,036 ... 92,048 mm.
Size groups:
"Selective selection" lettering on pistons
- 1 - white; 25,0000…24,9975 mm;
- 2 - green; 24,9975…24,9950 mm;
- 3 - yellow; 24,9950…24,9925 mm;
- 4 - red; 24,9925…24,9900 mm.
Please note that since October 2005 on pistons 53, 523, 524 (installed, among other things, on many models of the ICE ZMZ), the stamp "Selective selection" is installed on their bottom. Such pistons are manufactured using a more advanced technology, which is separately described in the technical documentation for them.
| Piston brand ZMZ | Applied designation | Where is the mark | Lettering method |
|---|---|---|---|
| 53-1004015-22; "523.1004015"; "524.1004015"; "410.1004014". | Trademark ZMZ | On the hub near the piston pin hole | Casting |
| Piston model designation | On the hub near the piston pin hole | Casting | |
| "Before" | On the hub near the piston pin hole | Casting | |
| Piston diameter marking A, B, C, D, D. | On the bottom of the piston | Etching | |
| BTC stamp | On the bottom of the piston | Paint | |
| Finger diameter marking (white, green, yellow) | On the weight pad | Paint |
Similar information for piston 406.1004015:
| Piston brand ZMZ | Applied designation | Where is the mark | Lettering method |
|---|---|---|---|
| 4061004015; "405.1004015"; "4061.1004015"; "409.1004015". | Trademark ZMZ | On the hub near the piston pin hole | Casting |
| "Before" | |||
| Model "406, 405, 4061,409" (406-AP; 406-BR) | |||
| Piston diameter marking A, B, C, D, D | On the bottom of the piston | Shock | |
| Finger diameter marking (white, green, yellow, red) | On the weight pad | Paint | |
| Production material "AK12MMgN" | Around the piston pin hole | Casting | |
| BTC stamp | On the bottom of the piston | pickling |
Marking pistons "Toyota"
The pistons on the Toyota ICE also have their own designations and sizes. For example, on a popular Land Cruiser car, pistons are designated by the English letters A, B and C, as well as numbers from 1 to 3. Accordingly, the letters indicate the size of the hole for the piston pin, and the numbers indicate the size of the piston diameter in the “skirt” area. The repair piston has +0,5 mm compared to the standard diameter. That is, for repair, only the designations of the letters change.
Please note that when buying a used piston, you need to measure the thermal gap between the piston skirt and the cylinder wall. It should be in the range of 0,04 ... 0,06 mm. Otherwise, it is necessary to carry out additional diagnostics of the internal combustion engine and, if necessary, carry out repairs.
Pistons from the Motordetal plant
Many domestic and imported machines use repair pistons manufactured at the production facilities of the Kostroma piston group manufacturer Motordetal-Kostroma. This company produces pistons with a diameter of 76 to 150 mm. To date, the following types of pistons are produced:
- solid cast;
- with thermostatic insert;
- with an insert for the top compression ring;
- with oil cooling channel.
Pistons produced under the specified brand name have their own designations. In this case, information (marking) can be applied in two ways - laser and microimpact. To begin with, let's look at specific examples of marking made using laser engraving:
- EAL - compliance with the technical regulations of the customs union;
- Made in Russia - a direct indication of the country of origin;
- 1 - group by weight;
- H1 - group by diameter;
- 20-0305A-1 - product number;
- K1 (in a circle) - the sign of the technical control department (QCD);
- 15.05.2016/XNUMX/XNUMX - a direct indication of the date of production of the piston;
- Sp 0,2 - clearance between the piston and cylinder (temperature).
Now let's look at the designations applied with the help of the so-called micro-impact, using specific examples:
- 95,5 - overall size in diameter;
- B - group by diameter;
- III - group according to the diameter of the finger;
- K (in a circle) - OTK sign (quality control);
- 26.04.2017/XNUMX/XNUMX - a direct indication of the date of production of the piston.
It is also worth noting here that for the production of different pistons, various aluminum alloys with alloying additives are used. However, this information is not indicated directly on the piston body, but is recorded in its technical documentation.
