failed block warning signs
 

Not on my BRZ, I'm not boosting the little guy. No, I have another engine that has cracks and has been sleeved. The engine builder is confident it will hold, I know it won't and I'm fully stupid for trying to use it because I know it's going to fail, but here we are.


I am trying to figure out how the failure will present so I can catch it if it does. Obviously, there's the no doubt failure with oil and water all over the road, that's easy, but it's that slow, subtle failure I'm trying to watch out for. Regular checks of the radiator and the sump for the wrong fluid showing up will likely be a daily thing, but I'm thinking about plumbing a pressure sensor into the block to monitor the pressure of the coolant in the water jacket.


I probably won't have my new engine blocks in until next year at this rate so I just need this one to last that long while I wait for the new parts and work through the drivetrain so it can handle the next engine built on a solid foundation.

Monitoring crank case pressure might be the better way to go if you're thinking that route. I would expect if something is leaking that you'd see the most obvious pressure change there.

Though I would honestly think that the vibration signature and engine sound would be the first alert. If any cracks form, the resonant frequencies of the block will change as it becomes less stiff in certain areas. I would expect this to happen before any fluids start moving around.

Oh it's cracked up real nice already, even has a blob of JB weld on the outside, BONUS!This whole thing is so Ill-advised. It's like "hey, how hard can I pull on a grenade pin before it comes out and how will I know when it just released?"

I'm not seeing the point in the question. The block has already failed if you have a hole in the side of it.....Troll maybe?

WTF?

I won't dare to ask how that happen... but that doesn't look like a fa20.

As you or your mechanic use epoxy to fix it I assume I not a major structural damage; that been said it could last... for some indeterminate time.


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What was your biggest clue? The "NISSAN" stamps on the side? :lol:

RB or KA? lol I had a KA24DE once that had a Penny JB welded over a crack in the block. not sure how that happened but never had an issue until i blew it up on purpose before pulling it out

The iron and the Nissan did help lol


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It's an RB26 from a GT-R. The blocks are poorly cast in many cases and crack most of the time between the water jacket and bolt holes. I have all kinds of that and the cylinders were sleeved. The external patch is on a crack caused by the force of the front diff which is integrated into the oil pan shifting up under load and literally trying to break the block's back; again, a common failure. Unfortunately, the new blocks I ordered are on indefinite delay so I had to use what I had. What I had was absolute crap.

The engine builder swears it will hold. I know he's wrong. How long it will hold is something nobody can know. What I am trying to do is formulate the best warning system to alert me when it splits in case it doesn't immediately present with fluid all over the place. I was thinking a new leak would cause a shift in not just temperature, but also pressure in the cooling system. I can watch for that. I'm just not sure if the pressure will drop or rise, but if every day it's sitting at one point then suddenly swings I can shut it down and save the internals.

A friggin penny? That's so fail it's win! :lol:

I say try it out, if there is a huge issue make the engine builder take fault and do all the work to repair it since hes saying its safe..lol.

My girlfriends dad accidently installed a stud to far into the head of his engine and it pierced through a water jacket or something(when bolt is removed coolant pours out), so his fix was to send the bolt in with some type of gasket maker or something..small block chevy little s10 makes a buttload of power and is holding up.. lol

That's GM, though; that actually works. My buddy made head gaskets out of red RTV for his old low comp anemic Monte Carlo 350.

It's a long story, but we have different levels of acceptable. Part of my haste and thus my acceptance of a block that is a ticking time bomb is to get an engine running in it so they can get it put back together so I can get it away from them so I can have a more trustworthy builder build the replacement engine properly when the new blocks arrive.

I would assume it would push a freeze plug out before it would go thru the JB Weld.

agreed. unless you have way more than normal coolant pressure, that'll probably hold forever. if you have high coolant pressures, you have much larger problems lol

That's what I'm thinking. Since my new turbo is not water cooled I have a free threaded hole into the water jacket where I could stick a pressure sensor. I have plenty of extra gauges so I could use an oil or fuel pressure meter and relabel it OH SHIT!

I mean, you have a replacement block coming. I'd cross my fingers, keep it on stock psi and keep the AAA card handy

That could be a problem since I'm going to be bolting one of these on it. :iono:

http://www.full-race.com/store/image...64-5mm-1-0.jpg

Now we are talking things up my alley! Through the years I have had no less than 4 engines that had cracks or holes in them from various different causes and "repairs" that were just as varied (including JB Weld). Like you have said you have no clue how long it will last. My results went from a month or so to 15 years and counting (as of last year when I last saw the guy with my old car).

From my experience your "Oh shit" gauge may as well be labeled "too late anyway" since if the repair fails bad enough to register on a gauge there will be no going back.

You said a new block right now is not an option anyway so throw it in, drive it and wait for the cloud of steam and oil that may or may not show up.

I don't care about the block. I just want to catch it before the rotating assembly gets hurt. I can always reuse it in the new block.

Is that an area under lots of pressure? I can't tell.

Don't underestimate JB weld. In the welding industry, epoxies are supplying labor-cheap welds over conventional mig/arc/tig welds, and are actually stronger, last longer and have less of an error/fail rate.

It's part of a larger, um "scheme" if you will. There is epoxy smeared inside the water jacket and there are cracks running across the deck. It's really bad.

JB Weld is some amazing shit. Surface prep is key. If done right, I wouldn't be surprised if something else let go before that repair.