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Autopapyrus · Lada 2107 1.5 (2007)
https://autopapyrus.com/guides/lada/2107/cylinder-head-resurfacing-machining-the-head-mating-surface/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Lada 2107 1.5 (2007): Cylinder Head Resurfacing (Machining the Head Mating Surface)

Resurfacing is done when the cylinder head has warped after overheating: the mating surface no longer seals against the block, the head gasket blows, and coolant leaks into the oil or into the cylinders. The resurfacing itself is performed on a surface grinder or milling machine. Your part of the job is to remove the head, assess the warpage correctly, then reassemble and set the ignition timing and valve clearances after the machining.

Difficulty: Hard Time: 1-2 days (removing and installing the head takes 5-7 hours; the resurfacing itself is done on a machine at a machine shop) Steps: 16

Parts

9
№Part
01 Upper engine gasket set (VAZ 2103)
02 Cylinder head gasket, VAZ 2103, 76 mm bore
03 Valve cover gasket
04 Intake and exhaust manifold gasket
05 Cylinder head boltsnew preferred
06 Coolant
07 Engine oilif changing
08 Oil filterif changing
09 Valve stem sealsif worn

Tools

9
  • Socket and wrench set (including 13, 17 and 19 mm)
  • torque wrench
  • precision straightedge
  • feeler gauge set
  • gasket scraper
  • bore gauge or caliper with a depth gauge
  • valve spring compressor (if valve work is needed)
  • coolant drain pan
  • no sealant needed

Step by step

16 steps
  1. Let the engine cool down and disconnect the negative battery terminal. Drain the coolant through the drain plug on the block and the lower radiator hose. If the oil has mixed with coolant, drain the oil as well.
  2. Remove the air filter with its housing, the carburetor (or disconnect the linkage and hoses), the fuel hoses, and the cooling system hoses from the head. Disconnect the spark plug wires and the temperature sensor wire, and remove the exhaust downpipe from the exhaust manifold.
  3. Remove the valve cover. Set the piston of cylinder 1 to TDC on the compression stroke using the marks on the pulley and the timing cover, and align the camshaft sprocket mark with the mark on the bearing housing. Remember these positions so you can set the valve timing correctly later.
  4. Release the chain tensioner and remove the camshaft sprocket together with the chain, taking care not to drop the chain into the crankcase. Secure the chain with wire. Remove the camshaft bearing housing with the camshaft, then the rocker arms if necessary.
  5. Loosen the cylinder head bolts. Loosen them gradually, working from the outside toward the center, in the reverse of the tightening sequence. Remove the head and the gasket. If the head does not come off, rock it carefully; do not pry along the mating surface with a screwdriver.
  6. Clean the head and block surfaces of gasket residue with a plastic or soft scraper, taking care not to scratch the aluminum. Cover the block's passages with a rag so carbon deposits do not fall in.
  7. Check flatness. Lay the precision straightedge on the head surface lengthwise and along the diagonals, and measure the gap with a feeler gauge. The allowable deviation is about 0.05 mm over the full length; if the gap is larger, resurfacing is justified. Cracks in the head, between the valve seats, and in the coolant passages cannot be fixed by resurfacing. The head must be replaced or repaired by argon welding.
  8. Determine the allowable material removal. Removal should be kept to a minimum: usually 0.1-0.3 mm (just enough to eliminate the warpage) is sufficient. Every 0.1 mm noticeably reduces the combustion chamber volume and raises the compression ratio, so with heavy removal, knocking is possible on 92-octane (RON) gasoline, and chain tension and valve timing can also be affected. Do not remove more than the manufacturer's specification allows for the head height.
  9. Take the head to the machine shop. Before that, remove the valves and disassemble the head so that the resurfacing and the later valve lapping can be done properly. After resurfacing, check the surface finish and check flatness again with the straightedge. If a significant amount was removed, check the valve protrusion relative to the surface and the condition of the valve seats, and lap the valves if necessary.
  10. Wash the head thoroughly and blow out the oil and coolant passages. Make sure the studs and the threaded holes in the block are clean and dry, with no oil or coolant in them.
  11. Install a new head gasket on clean, dry surfaces, without sealant. Align the holes using the dowel sleeves and set the head in place.
  12. Tighten the head bolts with a torque wrench in two or three stages, in a spiral from the center outward, in the order given in the service manual. First stage: about 33-41 N·m (24-30 lb-ft); final stage: about 96-118 N·m (71-87 lb-ft) (check the exact value in the service manual for your engine). Tighten with the engine cold.
  13. Install the camshaft bearing housing, sprocket and chain according to the marks, and adjust the chain tension. Check the marks on the pulley and sprocket again after turning the crankshaft two full revolutions.
  14. Adjust the valve clearances on a cold engine (usually 0.15 mm for this engine; check the service manual). Install the valve cover with a new gasket and tighten the fasteners evenly with moderate force.
  15. Install the manifolds with new gaskets, the carburetor, hoses, spark plugs and wires. Fill with coolant, bleed the air from the cooling system, and start the engine.
  16. Warm the engine up to operating temperature and check for leaks. After the first 500-1000 km, many mechanics re-torque the head and recheck the valve clearances; do this according to the service manual. Check the ignition timing and adjust it if necessary.

Common mistakes and warnings

  • Do not resurface the head by eye and do not remove more than necessary: excessive removal throws off the valve timing, raises the compression ratio and can lead to knocking
  • If the surface has cracks or the warpage is severe, it is safer to replace the whole head
  • If you do not have experience with engines, leave the job to a repair shop, and have the resurfacing done by a specialized machine shop with a surface grinder