Steep learning curve

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Think I’d rather be anal with this as this is my second engine build. My first was checked and pressure tested and I believe that was a great move and was worth it’s weight in gold. That’s was a different beast though and revved to 9k.
However, machining costs have shot up?! Looking at 200ish all in for pressure test and re-face/flatness test. I obviously don’t want a full on skim. More just a propper check.
 
dieseldog69 said:
I would go hole hog an get it skimmed, valves and seats ground and sealed up tight.
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Bit tricky right now. Only shop was a high quote, I think it’s been skimmed before due to 0 hole so wouldn’t want to skim again and if paying that much labour I’d get a fresh one from turners I think! How you getting on?
 
resto_d1 said:
Think I’d rather be anal with this as this is my second engine build. My first was checked and pressure tested and I believe that was a great move and was worth it’s weight in gold. That’s was a different beast though and revved to 9k.
However, machining costs have shot up?! Looking at 200ish all in for pressure test and re-face/flatness test. I obviously don’t want a full on skim. More just a propper check.
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used to do them but i never bother with a pressure test,money for nothing generally if it looks ok it is
 
dieseldog69 said:
I'm dying to get back to work properly.

At this rate I will be looking up casual farm labouring to just get out the god damned house.
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I know what you mean!! I work from home half the week anyway but I like the social side of going out and seeing people as I’m a hermit here. Going a bit loopy with no interaction. Shame the dog can’t talk. Wonder if he’d have a German accent?
 
jamesmartin said:
used to do them but i never bother with a pressure test,money for nothing generally if it looks ok it is
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this is my thoughts James. I don’t like that corrosion on the head but I obviously asked you and when the gasket is up against it it doesn’t encroach on the cylinder edge rings of gasket. Tis close though!
It was coming in at 200 odd for the checks etc and the tolerances aren’t exactly fine on tdi. Going to get a decent din edge and go with that. I’ve cleaned the surface up as well as I can without being ham fisted. I used a brass brush and brake cleaner then 1200 wet n dry on a block. I don’t know if this is bad practice to be honest but have done before with no problem.
I’ve painted the lot black. Not everyone’s cup but I think it looks pretty clean!
EA2863EF-5F46-4570-A34C-A5FF3525CB55.jpeg
 
your pitted area is no issue ,flatness within 2 thou is as you wouldnt want it skimmed again, a skim shouldnt be more than 60 quid unless you have the valves done which has a cost supposed other work is unnecessary such as pressure test or a flatness test which takes a few seconds with a straight edge,and is part of a skim ie so you know how much to take off and whether its worth it as its too bent
 
Cheers. Yes, it looks like it’s had a skim but I assumed so by the no hole gasket. Incorrect assumption as this doesn’t actually relate to the head, more the tolerances on the block. Either way I don’t really want it skimmed so I’m ordering a straight edge (meant to order today) and it it’s out it’s bin. I’m half tempted to lift the block too but don’t want to spend on a crane. I’ve got to do the cambelt anyway and I have to do a weld repair around the pedal box. Would be nice to do the repairs and seal up from the other side, paint the lot.
I think steering box will need to come out too due to big leak. I could always make an a frame lift but not so keen on that
 
jamesmartin said:
your pitted area is no issue ,flatness within 2 thou is as you wouldnt want it skimmed again, a skim shouldnt be more than 60 quid unless you have the valves done which has a cost supposed other work is unnecessary such as pressure test or a flatness test which takes a few seconds with a straight edge,and is part of a skim ie so you know how much to take off and whether its worth it as its too bent
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I have heard of people pocketing piston heads to get around the need to skim a head beyond what is normally OK. And I mean Landy diesels not just talking generally. Have you ever heard of it, positively or negatively? Alternatively are there various thinkness gaskets around in case OP needs to skim beyond the 2 thou you mention? I am aware that the more you skim the more a head is likely to warp. Dolly Sprints needed skimming for a pastime and they did produce extra thick gaskets to compensate.
Just wondering.
 
As above the gasket doesn’t denote your head skim. If you skim the head you cut the valves back down to spec. But yes, I think there is a max. I wouldn’t be keen on taking much off one. It gets quite thin around injector seats and I’d bet they’d crack. I’m not experienced in landy or 300tdi though!
 
I think what your referring to is known as a head saver shim? I don’t see the point to be honest unless you get good rates! I’d rather get a fresh turners one and not f about.
 
Stanleysteamer said:
I have heard of people pocketing piston heads to get around the need to skim a head beyond what is normally OK. And I mean Landy diesels not just talking generally. Have you ever heard of it, positively or negatively? Alternatively are there various thinkness gaskets around in case OP needs to skim beyond the 2 thou you mention? I am aware that the more you skim the more a head is likely to warp. Dolly Sprints needed skimming for a pastime and they did produce extra thick gaskets to compensate.
Just wondering.
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pocketing is std practice if rebuilding an engine you put back everything to book tolerances, thicker head gaskets are for garage repairs
2 thou is a basis from when skim is necessary not the amount to skim off that would need to be about 5 to 10 thou at least,below 2 its not necessary as it will tighten down with no ill effect
once a head has reached a certain temp its likely to bend again without been boiled like what caused it to bend in the first place,with a 300 tdi if egr temp sender on top of head wiring connector showed signs of melting which many have done skimming was pointless as head would move with just normal good cooling system max engine temps
 
jamesmartin said:
pocketing is std practice if rebuilding an engine you put back everything to book tolerances, thicker head gaskets are for garage repairs
2 thou is a basis from when skim is necessary not the amount to skim off that would need to be about 5 to 10 thou at least,below 2 its not necessary as it will tighten down with no ill effect
once a head has reached a certain temp its likely to bend again without been boiled like what caused it to bend in the first place,with a 300 tdi if egr temp sender on top of head wiring connector showed signs of melting which many have done skimming was pointless as head would move with just normal good cooling system max engine temps
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Sorry James you kinda lost me there.
So pocketing piston tops is standard practice? Never knew that.
"thicker head gaskets are for garage repairs" by that do you mean that if a car has a head gasket problem and is taken to a garage, if they decide not to put it out for machining that they would "cure " the problem with a thicker head gasket?
Under 2 thou not worth it, it would tighten down, ......I get that.
But you lost me with the rest of it.
Do you mean that if a head has been cooked it is basically shot and needs replacing with one that hasn't? And do you also mean that if the problem was down to a cooling problem and the cooling problem was rectified then just putting it back together again as normal would be OK?
Sorry to be so thick. My only experience of machining heads has been with petrol engines and there it was usually with cast heads, which seem to be a lot more tolerant of quite deep skims. The Dolly Sprint obviously was not like that as it was a/ like a swiss cheese and b/ ally although I did get it sorted in the end in that department.
Pinto heads could be skimmed lots and responded well provided decent gaskets were used and only needed more special treatment if you went a bit more potty with it, then you had to do special stuff around the cylinder bores, can't remember the technical term for the moment, "wiring" "Ringing"? something like that! Ditto A series and B series.
So much I don't know!
 
Stanleysteamer said:
Sorry James you kinda lost me there.
So pocketing piston tops is standard practice? Never knew that.
"thicker head gaskets are for garage repairs" by that do you mean that if a car has a head gasket problem and is taken to a garage, if they decide not to put it out for machining that they would "cure " the problem with a thicker head gasket?
Under 2 thou not worth it, it would tighten down, ......I get that.
But you lost me with the rest of it.
Do you mean that if a head has been cooked it is basically shot and needs replacing with one that hasn't? And do you also mean that if the problem was down to a cooling problem and the cooling problem was rectified then just putting it back together again as normal would be OK?
Sorry to be so thick. My only experience of machining heads has been with petrol engines and there it was usually with cast heads, which seem to be a lot more tolerant of quite deep skims. The Dolly Sprint obviously was not like that as it was a/ like a swiss cheese and b/ ally although I did get it sorted in the end in that department.
Pinto heads could be skimmed lots and responded well provided decent gaskets were used and only needed more special treatment if you went a bit more potty with it, then you had to do special stuff around the cylinder bores, can't remember the technical term for the moment, "wiring" "Ringing"? something like that! Ditto A series and B series.
So much I don't know!
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i was going by your first post and thought you meant pocketing valves is cutting their seats so they sit deeper in the head,though it is also done in the piston crown but youd be doing that for different reasons than skimming a head,the alternative is to use a thicker head gasket as when you skim the head you effectively put the valve nearer the piston ,and on a modern diesel the valve would likely hit the piston without a thicker gasket ,obviously the better fix is adjusting the valves by cutting their seat so the sit deeper,10 thou skim 10 thou cut on the seats,this costs and a thicker head gasket is cheap
once a head has reached a critical temp its knackered and will move under normal head temps not as a new head which will only move when over heated,over heating is because of a cooling system failure, fixing that and the head is usually a cure but not if head has been over cooked
 
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You would also have the factor of affecting compression should you fit a thicker HG to compensate for the head skim. This is probably fine on a old hat tractor engine like these and you'd just lose a few HP?
I am same as you @Stanleysteamer - my last and only build was a 1.6 vvti 20v on trumpets. That revved to 9k and tolerances were so much finer. That did go to the shop but don't think it was skimmed....
It drank oil through stem seals.
 
I also used plastigauge on pretty much everything to measure my tolerences - cam shells, crank shells. Amazing stuff. you put a little line of what looks like 1mm thick playdough on the shells, torque down the crank them remove. The crank squashes the line and you measure the squashing against a little hand chart. It worked brilliantly!!
 
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