Sickly engine - any ideas please?
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Dominic
- Minor Addict
- Posts: 640
- Joined: Tue Dec 27, 2005 4:50 pm
- Location: North West
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Hi again folks
I've just stripped down the cylinder head, having bought a new exhaust valve. I thought that it would be a good opportunity to re-grind all the valves, as the head is now 10,000 miles and 15 months old. The inlets of the 3 unaffected cylinders are all as new still, but the exhaust valves were showing a fair amount of pitting, so took a fair bit of bedding in. Is this sort of pitting normal after such a short time?
All 4 hardened seats look to be in fine condition though. I have however discovered another problem, namely that the inlet valve stem looks as if it has partially seized, as it is very scored, with tiny "blobs" that have have left small trails behind, and become polished off on the high points. The valve guide also looks to be rather rough and scored. The exhaust guide however looks reasonably ok.
My main question is: Is it a feasible job to replace the guides myself, or should this be left to an engineering shop that specialises in engines? The aim is to replace the inlet and exhaust guides, and both valves.
I have a feeling that the engine was running a little lean, as the deposits in some of the cylinders were a little on the white side of biscuit colour. This particular cylinder also had the "advantage" of rather a lot of oil burning from previously scored bore.
Needless to say, I have opened up the jet by 1/4 turn!
All the best
Dom
I've just stripped down the cylinder head, having bought a new exhaust valve. I thought that it would be a good opportunity to re-grind all the valves, as the head is now 10,000 miles and 15 months old. The inlets of the 3 unaffected cylinders are all as new still, but the exhaust valves were showing a fair amount of pitting, so took a fair bit of bedding in. Is this sort of pitting normal after such a short time?
All 4 hardened seats look to be in fine condition though. I have however discovered another problem, namely that the inlet valve stem looks as if it has partially seized, as it is very scored, with tiny "blobs" that have have left small trails behind, and become polished off on the high points. The valve guide also looks to be rather rough and scored. The exhaust guide however looks reasonably ok.
My main question is: Is it a feasible job to replace the guides myself, or should this be left to an engineering shop that specialises in engines? The aim is to replace the inlet and exhaust guides, and both valves.
I have a feeling that the engine was running a little lean, as the deposits in some of the cylinders were a little on the white side of biscuit colour. This particular cylinder also had the "advantage" of rather a lot of oil burning from previously scored bore.
Needless to say, I have opened up the jet by 1/4 turn!
All the best
Dom
Owns: Skoda Citigo
1968 Morris Minor Convertible[sig]3739[/sig]
1968 Morris Minor Convertible[sig]3739[/sig]
Yes - the guides can be driven out and new ones fitted - do one at a time with a straight edge across the others to tell you when it's in far enough. Good solid smack with a heavy hammer does the job. However - you do need a good stepped drift to do this - fits down inside the guide with an outer diameter that's just a small amout less than the guide O/D. This is a worthwhile tool to have in the tool box for the future anyway!
