We are in the process of refurbishing another 1986 190E 2.3-16 with a warped head due to overheating. The unit is about 0.012" from being true or flat, and before I authorize the shop to take that much material off, I was hoping someone would be able to identify what the material removal limits are. The manual I have from MB only lists the differences between the 16 valve engine and the 8 valve version in the 2.3 liter four of the time. The Haynes manual I have is also similarly indirect about the 16 valve engine - it implies all is the same unless otherwise noted. In most cases this is not a concern, however, before I get the head cut I would like to confirm the allowable dimension for cylinder head height, after remachining. The Haynes manual lists the following:

"New" Cylinderhead height: 98.4mm to 98.5mm [3.877" to 3.881"]
Minimum Cylinderhead height after machining: 97.8mm [3.853"]

This would leave 0.022" of stock to remove, presuming the minimum condition of the cylinderhead height now, and presuming the head has never been off before (bought the car on eBay two years ago, solid vehicle, cosmetically a little stressed, but no rust and a solid engine at the time. Daughter drove it with the thermostat stuck closed, thus the problem). The Haynes manual also notes there are some allowable deviations from perfectly flat, and suggests a longitudinal distortion of 0.006" is allowable as is a transverse distortion of 0.002". If anyone can confirm these values apply to a 190E 2.3-16 with the Cosworth head, I would be very grateful. Thanks, Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)