Hi, I am going through a XUD7TE rebuild and have yet another particular question.
One exhaust valve sea looks like this:
I have tried hard, but pitting is too deep to remove by lapping. Also, looking at the pitted edge seat closest to head surface an edge can be noticed. This particular seat is slightly off-center towards camera.
How bad is this?
P.S. As this is not the first nor last question in this rebuild, maybe I should simply start a blog topic? Please advise.
Valve lapping and seat inspection
-
- Confirmed BX'er
- Posts: 87
- Joined: Thu Jan 05, 2012 2:21 pm
- Location: Arendal, Norway
- My Cars: 1991 Citroen BX TZD Turbo
1989 Citroen BX GTi 4x4 - x 2
- Contact:
Valve lapping and seat inspection
1992 TZD Turbo berline, aircon, ABS
1991 TZD Turbo berline
1989 GTi 4x4 berline, ABS
1991 TZD Turbo berline
1989 GTi 4x4 berline, ABS
Re: Valve lapping and seat inspection
You probably need the technical document for this engine. It will give the valve seat width and cutting angles. The normal cutting angles are 45 and 30 degrees, and then lapped to a perect fit.
Valve seat cutting gear is not cheap, last time I looked some years ago around 600 quid. So for this a specialist is probably cheaper. But try and find the data for the seat geometry first. It should also give max permitted wear.
Valve seat cutting gear is not cheap, last time I looked some years ago around 600 quid. So for this a specialist is probably cheaper. But try and find the data for the seat geometry first. It should also give max permitted wear.
- citsncycles
- Over 2k
- Posts: 3224
- Joined: Sun Aug 08, 2010 9:14 pm
- Location: Dursley, Gloucestershire
Re: Valve lapping and seat inspection
Off centre wear may mean issues with either the valve or guide. If you're just going for an engine that should run OK then so long as you end up with a smooth ring around the seat the valve shoud seal OK, otherwise as mentioned machining or even a replacement seat may be needed, which will require specialist machinery. Where are you based, as there are various companies round the country that members here have used.
Mike Sims
BX 19RD Estate Mk1 - Timex!
BX 4X4 Estate - Oh god, I've done it again!
BX 17RD MK1 - it called to me!
BX14 TGE, - SOLD
XM Turbo SD,GS Club Estate,Visa 17D Leader,HY Pickup,Dyane Nomad,Dyane 6,2CV AZL,Falcon S,Trabant P50,3x Land Rovers (88" series 1,109" series 2a FFR,series 2a Marshall ambulance),DKW F7, Lambretta LD150 x 1.5,Mobylette SP93,Ural Cossack,Ural M63,CZ 250 Sport,Honda Varadero 125,lots of bicycles & tricycles including (but not only) Sunbeams,Higgins & Bates!
BX 19RD Estate Mk1 - Timex!
BX 4X4 Estate - Oh god, I've done it again!
BX 17RD MK1 - it called to me!
BX14 TGE, - SOLD
XM Turbo SD,GS Club Estate,Visa 17D Leader,HY Pickup,Dyane Nomad,Dyane 6,2CV AZL,Falcon S,Trabant P50,3x Land Rovers (88" series 1,109" series 2a FFR,series 2a Marshall ambulance),DKW F7, Lambretta LD150 x 1.5,Mobylette SP93,Ural Cossack,Ural M63,CZ 250 Sport,Honda Varadero 125,lots of bicycles & tricycles including (but not only) Sunbeams,Higgins & Bates!
-
- Confirmed BX'er
- Posts: 87
- Joined: Thu Jan 05, 2012 2:21 pm
- Location: Arendal, Norway
- My Cars: 1991 Citroen BX TZD Turbo
1989 Citroen BX GTi 4x4 - x 2
- Contact:
Re: Valve lapping and seat inspection
Thank you for your input.
I'm from Lithuania... But there is a great company to go to for a job like this. I shall get exhaust seats done.
I'm from Lithuania... But there is a great company to go to for a job like this. I shall get exhaust seats done.
1992 TZD Turbo berline, aircon, ABS
1991 TZD Turbo berline
1989 GTi 4x4 berline, ABS
1991 TZD Turbo berline
1989 GTi 4x4 berline, ABS