It is the first time I've ever attempted anything like this, and I have learnt a hell of a lot.
Thought I'd share with you 10 of the things I have learnt about rebuilding an engine, mainly resulting from my own failings.
Have the right tools.
Can't stress this enough.
This means having a good quality set of tools to work with.
Some of the things I bought and really appreciated were spline sockets to prevent bolts and nuts from "camming out", and a breaker bar.
Now if you've done things on your car already you might have these, but if not go out and get a set.
This also means having the right tools for the job.
Engine rebuilding takes a few specialist tools, and while you might be able to get away with substitutes, you might run into problems (as I did).
Do your research.
When you rebuild, work out if you are going for a stock replacement of broken/worn parts, or a full rebuild using forged internals.
Work out your budget and try to stick to it.
If possible, get the factory workshop manual for your engine, or a Haynes/Chilton's manual.
Review it before you pick up a wrench and figure out what you are going to do and how you're going to do it.
Surprises are good at Christmas, but not when when you're trying to take apart a motor.
If you can't find information in there, try to find a respected source on the internet.
And make sure you get the CORRECT manual (i.
if you have a 7-bolt 4G63 engine don't use a 6-bolt 4G63 engine guide and think that everything will be the same.
Prepare for the unexpected.
Regardless of how well you plan and research, something at some point will go wrong.
A bolt will break off, a part you thought was strong will just fall apart as it comes off, or things won't line up when you're putting everything back together.
When it happens try to keep calm and think logically about what has happened.
That can be hard, and I've got hugely annoyed at myself, the car, things going wrong and my relatively lack of mechanical know-how over the past few weeks.
But one of the best things you can do is go back inside, have a cup of tea and think about your problem and what you can do to solve it.
Expect things to be worse than you imagine.
This goes hand-in-hand with number 3.
If you think you have damaged a piston, expect that when you drop everything out there will be more than 1 piston damaged.
That way, if the damage is bad it doesn't come as a big shock to you, and if it's not all as bad as you thought then it's a nice little motivator and confidence booster.
Bag 'em and tag 'em.
Vital if you want to save a lot of frustration when putting things back together.
Every nut and bolt you take off, put in a bag and label it well.
Have as many bags as you want (I currently have different bags for certain pulley bolts, fuel injector clips, for conrod bolts...
It makes things so much easier when you can just look through your bags and instantly find the parts you need for the big of the car you're working on.
This one depends on where you live, but has been such a bind for me.
I don't have any car friends who live too close by, and the nearest town & decent hardware store is at least 40-50 minutes away (only 15km or so but buses are so slow) and which requires 2 buses to get to.
Case in point: I'm working on the car, and realise I need a box-end wrench, but my toolkit hasn't got one.
Cue around 30 minutes waiting for the next bus, about 50 mins in bus journey, 30 minutes walking from the bus stop to the store, buying tool and back again, 30 mins again waiting and 50 mins travelling.
So for one wrench I've had to take over 3 hours out of my day to get.
With a car it would have been about 40-50 mins maximum.
Of course, this goes well with number 1, and you'll notice many of these are related.
Parts cleaner and WD40 are your friends.
When you get into the engine, cleanliness is definitely next to godliness.
Cylinder walls must be as close to spotless as you can manage, with any specs of dirt & grit removed.
To make things seal you're going to need clean surfaces, so parts/brake cleaner, some Scotchbrite and a wire brush are vital.
If something's dirty, clean it well.
If it's clean, give it another clean to make sure it's spotless.
Similarly, once you get the head off the block, the clean surfaces you've got might want to rust pretty quickly depending on the humidity (my block developed a thin layer of rust in hours).
Coat everything in WD40 and put a towel over the block to keep moisture out as much as possible.
It will keep things lubricated and keep the rust away.
Have some good friends.
Whether they are car enthusiasts or not, friends can make your rebuild project so much easier.
I was very lucky in this regard, and have had people all over the world offer me encouragement online through internet forums and emails, and also here in Okinawa people have been helpful and...
well, what god friends and good people should be.
Check, double-check, triple-check.
The last thing you want when you start your engine for the first time after a rebuild is for your pistons to go smashing into your valves or the timing belt slipping.
When you are putting everything back together, make sure everything is right.
Nuts and bolts need to be torqued to the right amount, connectors re-attached, and vacuum hoses fitted back up.
Double-check everything is right to minimize the chance of something going wrong when you finally turn the key.
This can be so hard to do, especially if the car is your only form of transport and you really need it to be on the road again.
But rebuilding an engine for the first or 2nd time can teach you a hell of a lot.
I know more about the car's internals than I ever thought I would (still not too much!) and am actually looking forward to having the chance to rebuild another 4G63 engine I've got without the pressure of needing it to be on the road ASAP.
Hope that has given you some things to think about.
Let me know if you have any other ideas.