Just stripped my cossie head down to fit new valve stem oil seals and noticed that about 4-5 exhaust valves have not been seating propperly and are thick of carbon.

What affects would i have got off this as i thought the car was running mint before i stripped it.....?

 

errrrr, they're supposed to be like that?

as the exhuast valves open the exhaust gasses go around the valve over the back of the valve into the port and into the mannifold leaving carbon deposits as it goes.

 

no i mean balls of carbon you can see they not shutting fully..

 

a wise man once said "if it aint broke, dont fix it"

 

lol the head gasket went at croft.......so decided to rebuild it as oil perssure was a bit low anyhow. so now had reground crank, new mains, bigends, thrust's, rings, honed bore, stud n nut kit, cometic head gasket, oil pump, everygasket new,

and now i starting on head....

 

low performance!!!

So grind (lap) the valves back in and change the stem seals will your at it

 

a good possibility that if left,the valves would burn out!!!

the valve seat conducts a lot of the heat from the valve..

a basic no frills head rebuild at NMS is pretty damn cheap IMO,worth having done properly

 

funny thing was it seemed to run ok but when it came on boost it never felt like it had the kick it used to .......

i going to lap the valves in tomorrow and i got the valve seals to go in...

 

by the look of it the guide's have not long been done and it looks like it has had new valve seats....

 

good man!

Its worth spending time on and really doing a top job - the exh valves will probably be very pitted and require lots of work!

Alex

 

ahhhhhhh i'm with you now!

 

yip that the bit i dreading.....