cylinder head help

[Tom]

I mentioned this too my boss who is a bit of a diesel engine expert and he replied: (unedited e-mail)

Hi Tom

Provided the head hasn't been overheated then the rainbow patterns
are just caused by normal heating of the
inlet valves.

He's cleaned off all the deposits that might have told us whether it
has run too hot!

The two highlighted marks are difficult to see - he needs to take
better pictures. I get into trouble if I submit
that kind of out-of-focus pic in a report.

Provided the highlighted marks aren't impact marks, they are on
non-critical areas of the head and shouldn't
matter.

If he's taken the head off, have the surface checked or simply skim
the surface as a matter of course.
CHeck the head for visible cracks - even some of these can be ignored.

If it's Peugeot/Citroen 1.9 engine - skim it.

Check ignition timing.
Check condition of injectors.

Ask:

Why was the head removed in the first place?
Did he undo the bolts in the correct procedure?
Did the engine have any symptoms - like funny noise, knocking,
overheating or poor starting?

sorry if it sounds at all derogitory but thats the way he is.

[Venom]

Thanks mate.

The reason I took the head off is because I bought a car with needs of replaced engine, so I bought ANOTHER engine and decided to recondition it even though I never heard it run.

I undid the bolts in "X" format, starting from the middle going outwards.

As said, didn't know the condition of engine, but it did have compression in each cylinder. These engines never have problems with piston rings and should not ever have with big-end bearing (knocking) unless some idiot previosly never changed oil and towed a lorry with it.

[manchild]

One tip that is checked 1.000.000 times. To remove rust from all parts instead of WD buy several liters of diesel and dip all rusty parts in it. Leave them like that as long as possible (days or weeks if possible).

[mep]

Tom wrote:
Those are exhaust valves, they are bigger than the inlets

Sorry one question why do you think that this are the
exhaust valves?
As far as I know are the inlet valves bigger because at
the exhaust valves you have a bigger pressure difference and
so you don't need such a big area where air is passing through.

Toms boss wrote:
the rainbow patterns are just caused by normal heating of the
inlet valves.

[Venom]

One tip that is checked 1.000.000 times. To remove rust from all parts instead of WD buy several liters of diesel and dip all rusty parts in it. Leave them like that as long as possible (days or weeks if possible).

No need. The metal itself didn't rust, I just remove it with fingers. The rust just gets on the dirt outside. However I did put some parts in diesel, and used it to clean the lower engine block.

cheers

[Ciro Pabón]

T... what's the English term for this... sand being blown on object that is being cleaned?

Sandblasting.

[manchild]

Damn, I knew it can't be difficult

[manchild]

Tom wrote:
Those are exhaust valves, they are bigger than the inlets

Sorry one question why do you think that this are the
exhaust valves?
As far as I know are the inlet valves bigger because at
the exhaust valves you have a bigger pressure difference and
so you don't need such a big area where air is passing through.

Indeed, normally aspirated engines have bigger inlet valves and smaller exhaust valves because it is harder for them to suck than to blow.

Turbo engines as one in question here has no problems with sucking because turbo blows in its cylinders but because of that engine has problem to blow out exhaust gasses so exhaust valves are bigger.

(too much sucking and blowing for one post )

[Tom]

Sorry, Of course inlets are bigger. I was really tired when I wrote that (day after the prom)

[manchild]

umm... why would exhaust channels be on above inlet channels? Must admit I've never seen engine with such configuration (exhaust manifold above than inlet manifold). That is why I wrote that on that pic Venom posted exhaust valves are bigger having in mind that engine is turbo.

BTW, what is the channel marked with yellow No1 for, cooling?

[mep]

manchild I don't realy understand what you mean.

I thing the yellow hole is for cooling because there are two screw holes
at the sides.

[manchild]

If that engine has exhaust and inlet manifold od same side than it would be normal for it to have inlet channels slightly above exhaust channels. On this pic channels linked with bigger valves are lower so using previous logic those valves should be exhaust valves.

Perhaps I got it wrong because I had in mind that pic shows valves of two cylinders in the middle. If that is however truth, what I previously wrote was based on typical 2 valves SOHC design

valves
OO OO OO OO

side view
--O-O-----O-O--
O-----O-O-----O

outlet - inlet - inlet - outlet - outlet -inlet - inlet - outlet