What can go wrong if an engine isnt built properly?
 

Im currently deciding what to do with my car, I seem to get used to power very quickly, and as you only live once, Im considering having my engine forged.

I was wondering though, what are the usual problems that arise if an engine is not built properly, and what are the things look out for?

I don't understand the question, if an engine isn't built correctly it breaks. So many small tallenances and settings in a correctly running engine. If you don't know what your doing then I would suggest letting a well know engine builder create a decent spec. If you had time and some decent tools you could do a self build but it' won't be cheap. Do you have a a power figure or budget you are working towards, what spec do you have currently?

I'm just asking what can go wrong, yes I know it breaks but there must be a cause?

Im not asking how to build an engine, I dont have the skill or tools :)

The list of what can go wrong is potentially massive as to how badly the engine has not been built properly.

For example not torquing things up correctly is massively simple but if not done correctly can lead to big end failure or heads lifting etc....

Or say for example the rings are not gapped correctly, then you could have smoke, poor compression, scoring of the cylinders.

There are so many things that could go wrong, so basically it wont last long if its a ****ter.

Have you got to the bottom of your 'lost' map problem? In answer to your question, a lot of things can go wrong with a poorly built engine!

and it can be very expensive to put right as well, if you do go for a rebuild don't let Joe from the local garage round the corner do it, make sure its a Subaru specialist.

Worst case scenario rod through block, hot oil across the engine, whole car goes up on fire, you cant get out in time and you are toasted, or you might be lucky and loose all power and drive thus ending up crashing into other motorists killing yourself & others plus those who loose control on your spilt oil.

So not much...............worst case lol

:lol1: not yet, emailed AndyF to book a time with him, but not heard back yet.

yes ive heard of rods going through the block, was the first thing that came to mind, but wasnt sure if thats down to too much power?

Everything else, surely the block wont catch fire;)

I suppose head gaskets not fitted correctly could be another problem.

The worst thing that can go wrong is you spend 5k on a high spec build & it blows up while you are running it in. The builder blames you or your mapper & it needs doing again so costs another 5K. Or as above you die, but at least you wouldn't have to bother with another rebuild LOL.

Possible one of the most stupid question I have ever seen asked on Scoobynet.

:brickwall

what a stupid question.

lots can go wrong and all will destroy the engine and cost lots to rectify.

engine building is a specialist job and if you have no idea what could go wrong you have no chance of ever building one yourself that will actually run

you read it and thought the same thing as me at the same time by the looks of it:lol1:

Just think, a rod goes through the block, that leaves a big hole.

Oil pump's still pumping oil, oil goes through hole into engine bay.

Oil lands of Exhaust manifold which is extremly hot, and now you have yourself something you can barbeque sausages on.. it's not all that uncommon either, I've heard of a few cars this has happened too.

To be fair, the guy said he has little mechanical knowledge. :thumb:

To us, yes, it sounds stupid. He will never learn though if you shoot him down on his first question.

To the OP, as already stated, lot's can go wrong. But a good engine builder will know how to rebuild it properly.

Buy cheap -Buy Twice! That is the most important thing to remember when having a rebuild.

:thumb:

Always worth keeping an emergency pack in the car just incase - probably more useful than an extinguisher :thumb: - least you can tuck into a snack while awaiting on recovery truck :Whatever_

Why is it stupid? I want to know what Im paying for, this is a public forum and is the forum not for gaining knowledge/ having discussions regarding all things Subaru??

I want to choose an engine builder wisely, and I would like to know all the facts in regards to potential causes of failure/things that can go wrong.

I also dont want to get ripped off, regardless of who the tuner is, I would still like to know what can go wrong, if I know then atleast I know what Im letting myself in for.

You probably have alot more knowledge than me, for all I know you maybe really good mechanically, Im not, but atleast Im trying to learn about the cars we drive.

If you dont have anything to contribute thats fine, but I dont understand why you then see fit to criticise?

Think its about time you went and changed your tampax.

What are you? His boyfreind or something? Troll that hides behind the internet, another one that criticises every one else but too afraid to do anything original with his own car.

You've got an STI right ???

Stop worrying about forged builds and bolt a proper turbo on your car as it is now.

http://lateralperformance.co.uk/prod...450bhp__billet

:luxhello:

You ain't gonna last long on here fella :lol1:

I'd get to the bottom of the lost power/map issue before I started thinking about rebuilds if I was him.

If I'd have seen this earlier before the thread developed I'd have said - everything !

But in view of other comments I'll expand a bit.

There are many possible failings to properly do one of the many tasks involved in rebuilding an engine, and each of those failings will result in a different type of failure of the engine.

Some will 'just' be annoying (eg. something not tightened enough, resulting in a small leak) but in an engine with this level of power the chances are that it will malfunction and the combustive power will be enough to blow something internal apart.

If we started a thread asking for just one thing that could go wrong as the result of a faulty rebuild - with no repeats - we would quite literally still be at it after 500 posts I'd say.

Can I ask the op (hi btw !) did you perhaps mean to ask what you should look out for after a rebuild, in order to get as early a warning as possible that things weren't right?

what "original" mods are you going to do then as uprating the power is a very common mod on an impreza.

Not at all Tyler. Pop along to the South Wales Scooby Stand at Rally Day for a chat :D.

Or The Jap Show on the 29 Sept at the Pod :D.

He's been on SN for a smidge over 3 years!

It's a stupid question in how you phrased it, considering how long you've been on SN. What would you expect to happen if an engine wasn't built properly? ;) There's only going to be one result, and that will end up in a big dent in your wallet, again after paying for a rebuild.

Engine builder is different to a tuner! Some places, SC, API, ET do everything in house, but, there is a big difference.

You need to get out more mate. Slim's actually quite a nice chap, bit of a pisstaker at times, but, he's alright in the flesh.

We find that engine failures are usually caused by "the nut behind the wheel ......"

Seriously, any complex piece of machinery, where highly stressed components interact with other highly stressed components, has every possibility of going wrong at any time.

Misuse is usually never far away.
Lack of maintenance is close up too.
Cheap replacement parts confuse.

Poor assembly will kill even the most expensive parts,. As many proud 'amateur engine builders ' on here have found over the years. Companies like us and RCM, Clinic, Engine Tuner turn out high performance engines time after time. That is our profession and it involves many years of training and understanding and attention to detail.

Just because so & so can put an engine together [ note: not BUILD it ] and it makes serious power for a short while until something fails through poor part selection. Or lack of talent with the spanners, doesn't qualify them as unlucky, it just goes to show that the process is more complicated than he or she thought.

Us professionals can never be as cheap as an enthusiastic amateur working from his home garage. But what we do provide is results at a known cost time after time. If you balance doing it once [ apparently expensively ] against doing it cheaply 2 or 3 times. I think you'll see the logic. We all offer a warranty, where, if we f*ck up or a quality part is faulty, we will stand by our service and products.

Advert over David APi

^ good advice

David's absolutely correct, I'd only add that it's perfectly possible to build the best engine in the land only to see it destroyed by poor quality injectors, duff fuel pumps, bad mapping, inadequate intercooling, faulty hoses and wiring, and surprisingly often by running around a track with not enough fuel in the tank!