Tools - Refacing Cylinder Heads Using Tool (9526)
9219porsche01
Model
911 C2/C4
Part Identifier
1570
Group
1
Number
9202
April 28, 1992
Subject:
Refacing Cylinder Heads with Use of Tool 9526
ATTENTION:
Service Manager/Service Technician
This bulletin replaces Technical Bulletin Group 1, 9202, dated 3-13-92.
Models Affected:
911 Carrera 2/4, Model Years '89 (K) '90 (L) and'91 (M) up to engine number:
62 M 06836, M64.01 - Manual Transmission
62 M 52757, M64.02 - Tiptronic
Concern:
Oil leakage between cylinder and cylinder head. Oil "leakage" in the case of 911 Carrera 2/4 engines means oil leaking (drops forming) from the cylinder to cylinder head mating area, resulting in oil wetness on the lower area of the cylinder head or on the exhaust heat exchangers. Due to higher operational temperatures of the Carrera 2/4 engines, some blackening (carbonizing) of oil at the lower sealing area is possible. If there is only a small discolored area on the bottom of the cylinder head without wetness, this can be considered normal and no repairs are necessary.
General Information:
When repairing oil leaks from the cylinder to cylinder head sealing area on engines prior to the above engine numbers, all cylinders and pistons should be replaced and all cylinder head sealing surfaces refaced. Cylinder head nuts are reusable.
The cylinder heads must be refaced to accommodate the dimension of the new cylinders. Refacing can be done without cylinder head disassembly. Refacing of the sealing surface requires a lathe and use of special tool 9526. Tool 9526 can be rented free of charge from Porsche Cars N.A. Technical Support Department at phone number (702) 348-3253.
If no reputable machine shop is available to the dealer, cylinder heads may be sent for resurfacing to:
Porsche Cars North America, Inc.
Technical Service Center
4775 Air Center Circle
Reno, NV 89502
When sending cylinder heads to the above address, be certain to provide proper shipping protection. Packing cylinder heads correctly will reduce the risk of heads being damaged in shipment. Do not send cylinder heads with cam housing and gears, only send complete cylinder heads. Also enclose a clear copy of the work order with the heads.
Parts Information:
When ordering parts (piston /cylinder and gaskets) use part numbers for engines from '91 (91-) or from engine numbers:
M62 M 06837, M64.01 - Manual Transmission
M62 M 52758, M64.02 - Tiptronic
Parts Information (cont.):
Piston and cylinder sets are sold individually due to different height and weight groups. A quantity of six per engine is required. Different cylinder height groups can be used in one engine as long as the same height group is used per cylinder bank.
Any one of the four different piston /cylinder set part numbers can be ordered:
964 103 915 22 - Piston /cylinder set
964 103 915 23 - Piston /cylinder set
964 103 915 24 - Piston /cylinder set
964 103 915 25 - Piston /cylinder set
Any of the above part numbers can be used; check parts availability of each number before ordering. The following parts are also required:
964 104 115 00 - Head gasket (Qty. 6)
964 100 902 00 - Gasket set (Qty. 1)
Repair Information:
Refacing Cylinder Heads with Use of Special Tool 9526
1. Clean cylinder heads (do not sandblast assembled cylinder heads).
2. Install special tool 9526 on the short 8 mm cylinder head studs. Tool cut out faces intake valve (Figure 1).
3. Mount special tool 9526 with assembled cylinder head in lathe.
Repair Information (cont.):
4. Check lateral and radial cylinder head run-out with dial gauge (Figure 2). If necessary, lateral run-out must be adjusted on lathe. Radial run-out can be adjusted by loosening special tool 9526 mounting nuts and positioning cylinder head as required.
5. Machine 0.10 +/- 0.02 mm from inner surface (arrow 2 in Figure 3). The diameter of the machined surface must be 145 mm (Figure 3). A surface quality standard of 32 micro-inches must be maintained. Machining should be done with a cutting tool at right angle to the work. The cylinder head surface may only be machined a maximum of 0.20 mm.
6. Mark cylinder head with -10 or -20 appropriately on intake flange (arrow in Figure 3).
For additional information on refacing cylinder heads refer to 911 Carrera 2/4 Workshop Manual, Volume 1, page 15-10e.
Warranty Claim Information:
Damage Code: 1570500002
Sublet labor for machine shop as needed. (Consult District Service Manager for authorization above $100.)
Warranty Claim Information:
(cont.):
Labor Operations: Time Units
C2 C4
1001 1901 R & R Engine 640 810
1570 2076 R & R Cylinder Heads 1250 1250
1310 2050 R & R all Pistons 100 100
3435 2750 Detach and Re-attach Trans. 70 70
at Flange (Manual Trans.)
3735 2750 Detach and Re-attach Trans. 130
at Flange (Tiptronic)