selectcase Posted January 22, 2007 Share Posted January 22, 2007 I am rebuilding the cylinder head on my 200tdi & I have noticed while grinding them in that the new valves have a very - very small contact area on the valve seat probobly about 1mm. I have checked the part number and its correct at err1157 but measuring the head diameter the old one measures 39.5mm and the new is 38.92. the new valves were supplied by a reputable supplier btw Quote Link to comment Share on other sites More sharing options...
Les Henson Posted January 22, 2007 Share Posted January 22, 2007 New valves have to be re-ground into old seats I'm afraid. Les. Quote Link to comment Share on other sites More sharing options...
selectcase Posted January 22, 2007 Author Share Posted January 22, 2007 yes it was while grinding the new ones in I notices that they are nearly 0.6 mm smaller than the old ones as the contact area is thinner Quote Link to comment Share on other sites More sharing options...
Les Henson Posted January 22, 2007 Share Posted January 22, 2007 I didn't read your post properly, sorry. The new valve heads should be the same diameter as the old ones. A smaller valve head diameter would increase the chances of a step forming in the seat, and also valve recession. A correctly ground valve would have a contact band of 2.5 - 3mm. Les. Quote Link to comment Share on other sites More sharing options...
selectcase Posted January 22, 2007 Author Share Posted January 22, 2007 Its my fault really for not specifing o.e. manufacturer parts - i think these are "allmakes" they came in a blue/white box with pcitures of 3 interlocking cogs and cost about £5 each all in. It just shows how poory pattern parts are manufactured - i will have to source some o.e.ones - brit-car do them for about £8 quid eash the genuine ones are closer to 18 + vat I will check the exhaust ones as well they looked ok but its better to check I noticed that the pattern ones are closer in size to the 300tdi specs so maybe they are boxed incorrectly, there are no part numbers on them. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.