NIVAS FROM OZ AND AROUND THE WORLD
Project Yuri (Part 2) - When Oil and Water Collide
"Water in the engine oil sump is never a good sign..."
It has been a while since i had a 4x4 to call my own. Having moved to Sydney, the need for 4x4 was no longer there and finding parking for a large 4x4 in the city was about a joyous as visitng the dentist. So i had gone the way of the city car and while it was better for the daily commute and parking, it wasnt long before i was missing the weekends exploring and getting out on the trail. They say you dont miss something until it is gone and I admit in my case there was more than a little bit of truth. So i decided it was time to get another 4x4, but which one. For me the whole concept of the vehicle was to become a new project or hobby. This opens up the options, condition is less of an issue because it will be worked over anyway so when I started looking for the new project car I admit i wasnt too worried about the condition of the car. It would be fun sorting out any mechanical or bodywork issues along the way.
My first car was a Lada Niva and the memories of the good old days, rallying that car to an inch of its life, or the endless mud runs after a downpour. I knew how capable these little wagons were and at least here in australia they had a great reputation of getting the job done offroad to those who knew them. Thanks to a deal with the then USSR, the australian Govt swapped wheat for a batch of lada nivas, they were cheap and in good supply back then. This started to sound like an ideal lada niva project?
The memory wasnt so bad as to forget the undocumented little "features" of build quality that would never be far away. Things like snapping front diff bolts, randomly operating electrics, falling windows the list goes on. It had some courtesy features too like auto leaking gearbox and transfer cases that let you keep check on the oil levels, if they stopped dripping it meant there was not enough oil so top them up.
Ok so it wasnt quite that bad, but it did get me wondering what would it be like if we were to go all out and heavily modify the niva with only offroad performance in mind. most of the Niva's i had ever seen were only ever lightly modified. Maybe a 2" lift and some suzuki rims with slightly bigger wheels, all manner of odd looking nudge/bull bars seemed to complete the look. So what would it be like to go all in, pull out the stops and fit a serious lift of 4-6", Flex out the suspension, add some traction enhancment with front and rear lockers, slow things down in the rough with some crawl gears and top it off with some chunky large diameter mud tyres. They were good from the factory offroad but with a these strategic mods they should be unstoppable.
So the plan was hatched, I just had to find one and that ladies and gentlemen is the first problem of modern Niva ownership in Australia. See the ever tightening exhaust emmission laws made it unprofitable for lada's to be imported in australia and in the late 90's there were no more new ladas in australia. At first only a few really missed them, but i started asking around my friends "When is the last time you have seen a niva on the road?". The answer almost always was "Oh yeah, i havent seen one in years, they were everywhere once, but they must be around right?". So the search began and one fateful day a niva came up for sale on gumtree,com. It was a bit rough in the body, 20 yrs of exposure to the elements had open a few holes here and there. Mechanically it was not too bad, brakes were shot and the engine didnt run, but for less than $500 you could hardly complain.
I spoke with the gentleman who was selling the niva to me and he was an enthusiastic weekend dabbler. The car had clearly given him years of faithful service and he was a little sad to see it go. one thing he mentioned though is he was a little perplexed as to how he could put water in the radiator and it would almost instantly appear in the sump. Anyway I knew there would trouble lurking in the engine, but a 4x4 for a price that was measured in hundreds not thousands of dollars, it was a deal and Project "Yuri" was born.
We have all heard the saying "Oil and water dont mix". Engine oil and coolant (Water) are not the best of friends, engine designers take great care with seals and gaskets to ensure the two never come together. One of the more important gaskets in that respect is the head gasket. Finding itself sandwiched between the engine block and the engine head one of its key jobs is to seal the coolant galleries and the oil return galleries from the hot combustion gas and each other. It is not too uncommon for older engines, especially engines that are perhaps suffering from extreme wear, poor servicing or given hot ignition settings by owners trying to extract every last HP from their ever slower car. In an older model car a leaking or "Blown" headgasket is ta likely suspect in allowing coolant to find its way into oil sump. More modern or higher performance cars may have a Coolant to Oil heat exchanger or Oil Cooler, and you can from time to time find a problem there where corrosion sets in and a small perforation can develop inside the fins of the oil cooler, but a niva is a simple beast and there are none of these devices to be found.
So the question then becomes where is the leak?
Well the starting point was to remove the Head from the engine. From there we could see if the head gasket was leaking or examine the head and block for cracks or other issues. When I removed the head on Yuri's engine I found a few surprising things. Firstly, the head was in immaculate condition. It was pristinely clean, even in the combustion chambers, the machined face was clearly very fresh. Which told me one thing,It meant that the head was very likely to have been recently cleaned, and possibly overhauled. True enough it had new valve stem seals fitted and had been decked. I checked the head for any warping using an engineers straight edge and feeler guages on the cross and it came up nice and flat. A welcome bonus indeed. The head gasket though, was new as well and very clearly appeared like it was not leaking at all.
So where was the coolant leaking through from?
my 5 yr old "apprentice" mechanic helping to remove the head
Unfortunately the possiblities are never going to be nice once its established its not a head gasket failure. I set about carefully examining the head and block for cracks or porosity. Sometimes cracks can develop in the head or block castings from heat cycling or over heating or sometimes in very high performance engines they can simply exceed the material strength of the block, but that last one definately isnt going to happen on any normal niva.
I have had the "pleasure" of working with some serious porosity in a couple of engine blocks over the years, porosity is basically where there are voids or flaws cast into the metal, they can be relatively small less than a millimetre in size but can link up through cracking over time to allow gas or fluids to pass through. Well the truth is it wasn't porosity either and after about 20mins of dedicated searching with a flashlight I found what I was looking for, a hole. Quite a decent hole and in a location that was not all that obvious.
How did the hole get there?
The answer is even more interesting than the fact of the holes existence. What had happen was that a main bearing cap bolt, one of the main bolts that keeps the crankshaft in position had snapped off. Upon falling out of the main bearing cap housing it was picked up by the counter weight of the crankshaft and driven up into the block, such was the force of the impact that it smashed a fragment out of the block, opening a convenient but very undesired link between the coolant gallery and the sump area imediately below. the secondary result of having coolant flash off inside the engine is that practically every bearing surface inside the engine, including the distributor drive gears are compromised with corrosion. The end result is a terminal diagnosis for "Yuris" engine. Time to find another replacement engine.