Can anyone tell me the normal direction of rotation of crankshaft?

I'm stripping timing belt on my way to head gasket land & need to know which way to turn the crankshaft to line up tdc.
Is it clockwise? It's jacked up at the mo otherwise I'd rock it in gear to see.

Thanks

Ah... Yes it is. I found in one of mr hj's pdfs. Thanks!

You can always tell on any engine by the timing belt tensioner, its not normally on the pulled/tight side.

Now I've had a feel of it, that makes sense. The belt's off & head cover. Tomorrow I'll tackle the head.

Cheers

I'm making progress with the head, just so I can understand more can anyone please point out tell tale signs that the head gasket was actually shot or not? Cheers:) 

Bit hard to tell from a pic but the arrowed points look a little iffy although the top one might just be the angle



and you should drop the coolant out first if you have left it like the first pic then you may have it in the oil and possibly rusty rings too.

Thanks for looking, ok so I'm looking for staining around the compression chamber from either block or head face. I'll have a closer look in the morning & take a better photo.

I drained the oil & coolant out at the start so I was surprised to see coolant pouring out of the head as I removed it. I spotted it in the pots when I took the photo & mopped it up with paper towel. But there's still some in the coolant void. Is there another drain plug or hose on the bottom of the block I've missed?

It's making me think this is where a blockage may be. I thought that before when I've drained the system to change the thermostat & the coolant is sitting there full up to the top of the Thermostat housing. Is that normal?

I'm guessing the plug sleeves need to be removed before skimming. I can't find anything in the manual about removal. Looks like they're bonded in? any idea how to get them out?

Cheers for the help

When I had the head skimmed on our three pot I took all the valve clearance adjusters out so all the valves were shut and so long as the rocker cover face can be clamped down flat also wash out all the oil and make sure there are no sticky bits for swarf to stick to then wash a couple of times through after the skim and run some compressed air through you don't want swaft in the enging it can block the oil way and cause a big failure. As for the plug bits if you need to make it flat it has to come off, the manual is for a trained workshop not like a Haynes or Klymer which are meant for know nothing commoners.

There was oil around the 3rd spark plug inside the plug jacket so I guess it needs taking out & resealing. I don't know the 3 pot, it sounds different to the 1.3

My thinking is the valves & the plug jackets have to come out otherwise you can't have it pressure tested. That's my plan, if I'm wrong maybe someone in the know will give me a heads up.

TBH I haven't a clue as to what you mean by plug jackets and the water jacket is tested by (air) pressure for leaks so valves in or out make no difference but it does depend on what they are using to seal the head for testing some may test the combustion chamber but they are then into sealing even more stuff off, I would ask how they want the head and let them have it how they want it.

Have you still got the old head gasket?

Take some really good photos in big resolution, if not just a photo of each compression ring.

You can see failure where it goes black - it should be silver.

Black is the carbon leaching though the gap in the exhaust fumes.

I think those plug tubes are an interference fit, but I'm not sure as I've never taken them out, if there is oil staining down the sides of the inside of the tubes, I would guess its the rocker cover oil seals that have gone.

Yep, I'll take some pics in the morning.

What do you mean by interference fit?

Struggling to take clear photos in this light, there's a storm brewing Batten down the hatches tonight!
Meanwhile I've come across a replacement head

http://www.gumtree.com/p/cars-vans-motorbikes/diahatsu-hi-jet-2004-13-16-v-cylinder-head-complete-with-camshaft-and-cam-gear/1036121623

Off to look at that before I go further with this one.

Won't be much more than getting it skimmed so long as it's flat, came from a collision damaged apparently.

Why do you want a replacement head?

What you do with a head is:-

Remove the cam and followers with the 14mm bolts.

Inspect all the journals for "picking up" marks/grooves.

Use a wire wheel brush to clean the combustion cups up - inspect for cracks between the valve seats.

If that is all OK,

Send it to a cylinder head place, where they will chemically clean it, skim it, vacuum test the valves/regrind if needed and pressure test it.

Then you get a nice head back.

If you want to be a tight arse, just get a skim and pressure test.

You could buy a second hand head which is in worse condition than the one you've got.

Have suspicions that my head has been skimmed before, so I'm taking them both to get checked, tested & skimmed if necessary. Will have the valves checked at the same time.
The journals look smooth & clean on both.
I'm hoping the newer head won't need a skim, it's done 40,000 opposed to 80,000 of my original.
Either way I'll pick the best one & pass on the other at some point.

I heard skimming (if a bit heavy) can alter the compression ratio to the point that it can create problems later on down the line.

Belts & gaskets & new radiator arrive on wednesday... she better appreciate all this pampering. Hoping she'll be ready for the weekend...  

Alloy heads are funny things.

They don't bannana like a typical old cast head.

While they are bolted down, after getting hot, they sit there in what I describe as "thermal tension distress".... When you remove them, they get chance to "let go" and release!

Only when you watch one being skimmed on the machine will you see what I mean.

They get low spots and high spots in places you wouldn't really expect.

And you couldn't measure for it in any way really....

Maybe if you cleaned the head face up, then put it on a true'd flat engineers table, with a coat of that engineers blue on it, then rubbed the head against the table, you would see the spots that are blue and those that are not!

As I watched one head get skimmed, the machine cut in some places and not in others on the first few passes - highlighting the high spots. And unusual spots they were too. It hadn't twisted or bent, it had lumps n bumps

While in situe on a car, I imagine the gasket will compress to take this up as it warps with the heat. But while you are fitting one, it won't "deform to suit" unfortunately.

Catch my drift?!

I'm getting it. The newer one's dressed & ready, I'll try the bench test, I'm curious.
What about the block face? if the head's been distorting would that not transfer through the the block, that's aluminium too isn't it?

The guy I bought the head from reeled off his mechanical pedigree & spoke with such authority about experience with hijets. As a novice I'm grateful to hear anyones opinion & experience. He pleaded with me not to skim it, it doesn't need it he said.

His angle was;
Avoid electrolysis at all costs as this is what knackers a lot of head gaskets,
Make sure the earth strap to the head is good.
Only use dionised water 50/50,
Drop in half a litre of lucas oil stabiliser when I fill up with oil.
Test the water with a voltage meter.
This should sort it... until there's a leak in a from pipe,rad, cap or fitting.

Makes sense... but my brain was aching as he explained it in great detail.

Block warping has crossed my mind too, quite a bit!

Speaking to the machining guy who does all my stuff, he claims that blocks don't tend to need decking/skimming because they don't warp like heads, due to the heat mostly gets transmitted through the exhaust ports in the head. The few that he has done for serious performance engine work have always been pretty true.

Also he claims due to the shape of the block, and how the water jacket sits, the outer aluminium never gets hot enough to warp, and because the liners and surrounding aluminium is a consistent/symmetrical long tube shape, with a large physical mass, it doesn't tend to mis-shape - unlike the thin walls of the cylinder head round the ports which get battered by exhaust gases.

I pick his brain alot, he doesn't know about "cars" but he does know about machining engines, and I make him cups of tea - and don't barter on the price. I have used a few engine machining places over the years, but have stuck with this guy for a while now.

Speaking of heat, the exhaust side of the head was where the warping was, and mostly at the end nearest the cam sensor. Which makes sense, because the log exhaust manifold design means that cylinder number 4 will be where the hot spot is. All the hot gases have to go through that end of the manifold. I bet the temperature difference is quite a bit from one end of the manifold to the other.

And from taking a few heads off hijets now (!) the gaskets are always the most fucked (black marking on the ring) on cylinder number 3 and 4, on the exhaust manifold side.

Over the years I have changed quite a few heads which have cracked, normally on turbo cars which have had the boost cranked up. And they always crack round the exhaust ports, and exhaust valves - right through to the water jacket.


I can only give you my opinion, which I have made up as I have gone along. What is right or wrong is one of those life long questions! And engine talk has lots of conflicting opinions. It is quite a subject of know it all bastards, big talk, wild theories and those who have worked in professional engine design/testing R&D keep their wisdom to themselves as its their key asset!

This is a really good read, cheers guys. By the way raydreadz, my cylinders (2 & 3) filled up with coolant after I cracked the cyl head gasket too. Couldn't find any obvious way to drain the coolant out of the block otherwise! Good luck with the head job

And I really appreciate your opinion & all your input HJ. I never would have taken on this head gasket without all the info I've picked on here. I haven't had the smell of petrol & oil on my clothes for over 10 years! & I'm lovin it.

I'm checking out your endeavours nc30 with interest too. I picked mine up for £250 & a prayer. The cooling jacket around the pots on yours look really clean, is that after cleaning with brake cleaner? mine is stained rusty orange.

Nope, not cleaned them. That's how they were. I think the main problem with mine was oil starvation to the head. Your coolant reminds me of Kenan & Kel... "Who loves Orange Soda?"

It's opposite for me it seems, I'm keeping my original head, the camshaft & journals are like new.
I stocked up on degreaser, brake cleaner a bottle brush & various wire brushes. Gonna give everything a scrub & wash tomorrow while the head's getting skimmed. Also will give all the coolant pipes a soak & spray with rubber protection & check over.

New radiator arrived today! Shiny bling:bounce:

Nice, sounds like your little van is having xmas early! Make sure you take a pic of the freshly skimmed head. I'm going to have a go getting the old gasket material off my block tomorrow. One thing I thought (and I am absolutely NOT an expert on this, feel free to correct me anybody) is be careful you don't score the face of the block that mates with the head (i.e. avoid using a really coarse wire brush). I'm not sure how I'm going to do mine, but I have wooden lolly-sticks here in abundance, and imagine they'll be fairly gentle at scraping the gasket off of the block. Again, I've never done this before, but aluminium is SO soft, it'd be a shame to have a lovely flat head and a rough block!

All the best, look forward to seeing your progress!

I use a gasket scraper (stanley blade holder type)...

http://www.ebay.co.uk/itm/STANLEY-028590-WINDOW-GLASS-BLADE-SCRAPER-PAINT-REMOVER-/310371502688?pt=UK_DIY_Material_Paint_Varnish_MJ&hash=item4843954a60