300 Tdi Rebuild

Al2O3 said:

Do you mean on the engine build? Haven't spent that yet, but I'm not going to be able to avoid it. I could do it cheaper with Britpart stuff.

I haven't totalled the new chassis and body rebuild. Too scared

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I would have just chucked another engine in

jamesmartin said:

buy the 2 sets they contain every thing

i wouldnt do the valve guides or swap valve seats unless they are truly worn out, which i doubt yours are ,are turners refurbing your head

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Cheers, James. I'll buy the sets, but I'm thinking I'll go for the Payen ones from Paddocks they are still OEM. Top Set Elring £42.00 Payen £36.40 Bottom Set Elring £50.54 Payen £29.90

I can only detect a tiny amount of movement on the valves. I was thinking it would be false economy not to change the valve guides and valves? That's based on no experience though!

No, Turners are not doing the head. I was thinking of sending it to a place near Newcastle to have new guides pressed in and the valve faces dressed. Might not be now

Marmaduke said:

I would have just chucked another engine in

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A few people said that. I just thought you don't really know what you are getting and having spent nearly two and a half years rebuilding the body I might as well have a refurbed engine that I know. And, I fancied doing it

Al2O3 said:

And, I fancied doing it

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Are you sure you did not plan this???..........................

Cheers

Al2O3 said:

Cheers, James. I'll buy the sets, but I'm thinking I'll go for the Payen ones from Paddocks they are still OEM. Top Set Elring £42.00 Payen £36.40 Bottom Set Elring £50.54 Payen £29.90

I can only detect a tiny amount of movement on the valves. I was thinking it would be false economy not to change the valve guides and valves? That's based on no experience though!

No, Turners are not doing the head. I was thinking of sending it to a place near Newcastle to have new guides pressed in and the valve faces dressed. Might not be now

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just have the seats cut and new valves lapped into them, unless your forced theres no point in stressing the head which is what will happen changing the guides if you needed to redo guides its better to fit bronze liners and broach to valve stem size, the payen sets are fine its what i commonly use with a quality head gasket as its the gasket were it really matters

Al2O3 said:

A few people said that. I just thought you don't really know what you are getting and having spent nearly two and a half years rebuilding the body I might as well have a refurbed engine that I know. And, I fancied doing it

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you will have a lot of satisfaction building it and using it

neilly said:

Are you sure you did not plan this???..........................

Cheers

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Definitely not Not now anyway! After finishing the chassis and body I thought I'd do the engine in 3 or 4 years time. Not in 9 months
I will enjoy doing it though

jamesmartin said:

just have the seats cut and new valves lapped into them, unless your forced theres no point in stressing the head which is what will happen changing the guides if you needed to redo guides its better to fit bronze liners and broach to valve stem size, the payen sets are fine its what i commonly use with a quality head gasket as its the gasket were it really matters

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Hmmm, never thought about it stressing the head!
I'll take the other valves out this afternoon (should I keep the springs matched to the cylinders or will it not matter) To be honest, I think it will just be the exhaust of cylinder No4 that will need dressing. I suppose I could do it by hand?

jamesmartin said:

you will have a lot of satisfaction building it and using it

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I must admit, it'll be good to think I've rebuilt the lot. It's certainly a keeper.

EDIT
Except the gearbox. Fingers crossed that lasts a long time!
Oh, and the diffs!

springs etc dont need to be kept in order just valves once lapped or cut to a seat

This is a higher definition picture of the head face.

No cleaning done yet.
Molten alloy deposits, from the piston, are just flaking off the face of the head. You can still see the remainder as the greyish area against the black circle.
Here's a close up of No4

There was deposits between the two valve ports, but I scraped it away with my finger nail.

First clean (and possibly the last) of the head face.

Very pleased with the result.
A close up of No4

I've studied it with a magnifying glass and can't see any cracks.

EDIT
@jamesmartin if I do get the valve seats faced by this company, will they want the valves (new or old) to lap in, or will they expect me to do that?

new valves if you get seats cut,its the exhausts generally that pit the worst obviously,you can try lapping a new valve in the worst exhaust seat and see what they look like

Can you see the picture of the whole cylinder head with cleaned face? It's not showing up on my lappy, just a red cross.

jamesmartin said:

new valves if you get seats cut,its the exhausts generally that pit the worst obviously,you can try lapping a new valve in the worst exhaust seat and see what they look like

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I haven't taken the other valves out yet, but I'd expect No4 to be the worst as that is the cylinder where the piston was melting. The exhaust valve face had a good deposit of alloy on it, but the seat looks pretty good in that close up.
If I get the faces of the valve seats dressed slightly and new valves, will the new valves not need lapping in?

Al2O3 said:

Can you see the picture of the whole cylinder head with cleaned face? It's not showing up on my lappy, just a red cross.



I haven't taken the other valves out yet, but I'd expect No4 to be the worst as that is the cylinder where the piston was melting. The exhaust valve face had a good deposit of alloy on it, but the seat looks pretty good in that close up.
If I get the faces of the valve seats dressed slightly and new valves, will the new valves not need lapping in?

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yes though some machines cut the seat so accurately none is needed but its a way of checking where contact is made on valve and seat and its continuous around the seat/valve

jamesmartin said:

yes though some machines cut the seat so accurately none is needed but its a way of checking where contact is made on valve and seat and its continuous around the seat/valve

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That'll be where you use the engineers blue to see where it rubs.
Well, I could always ask them what they recommend. I might as well get the seats faced and new valves. I'll buy the valves before I take it in and then I can leave them too if they want them.

yes they need the new valves if possible, you set the cut angle 1 degree different that the valve so that contact is near the top of the seat, i dont use engineers blue i rub them dry a couple of times and look for the shiny ring a been continuous and b near the top and outer edge of valve

jamesmartin said:

yes they need the new valves if possible, you set the cut angle 1 degree different that the valve so that contact is near the top of the seat, i dont use engineers blue i rub them dry a couple of times and look for the shiny ring a been continuous and b near the top and outer edge of valve

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Do you use a special paste and one of those dowels with a rubber sucker on the end?

Al2O3 said:

Do you use a special paste and one of those dowels with a rubber sucker on the end?

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i do if they need lappinng in ,i find you need a drop of paraffing or similar added to the paste helps as its often too thick a consisteny nowadays, but generally if i send head to have work done they do it,i miss not having access to a machine shop that was part of the job of engine building i really enjoyed

the best compounds have coarse at one end fine at the other you allways finish with fine

jamesmartin said:

i do if they need lappinng in ,i find you need a drop of paraffing or similar added to the paste helps as its often too thick a consisteny nowadays, but generally if i send head to have work done they do it,i miss not having access to a machine shop that was part of the job of engine building i really enjoyed

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I'm tempted, but I think I'll let the machine shop do it. Thanks for your advice, James.

I've another technical question.
How do the gudgeon pins work on these pistons?
I can see on the picture on the Turners web site that there are circlips. Presumably to go in the sides of the piston. Are the gudgeon pins an interference fit on the con rods? ie, does one or the other need to be heated or cooled.