This week's find...

 

Left abandoned in the junk yard... one man's junk is another man's treasure!!!

 

Damn, nice find! Someone must have thought, "oh this block is too dirty to ever run again!"

 

More like, it's locked up, rusty in the cylinders , never changed the oil and there is water in the crank case... no way this was taken care off and it's not suitable to rebuild...

The bearings actually look almost perfect. If it wasn't a long crank, I would use it... maybe I should machine the rear flange down...

 

Oh and someone left 1/2 quart of Trans fluid and some used sand paper in the junkyard so I could clean the cylinder up just enough to make sure there was no hole in the cylinder...

 

Oh we arn't going there- cleaning during assembly is a whole other issue which I recommend people avoid all together by using a stock, unopened engine. My recommendations are towards novices with daily drivers. In case you are wondering where I am coming from. People that want 200k from their engines.

Ok, same here. I never said don't do it. I said only that "if the motor is not unique or rare it would be a better idea to find one in good running shape than to use one with quesitonable past" or something to that effect, which still applies/stands and makes perfect sense, and is good advice for those seeking reliable 200k daily drivers.


So this is where we are. What does it take to ruin a block. I said if you run an engine with 30k with no air filter, it will be ruined. Alot of machine shops will agree. Some will not. Some would never say never, and choose to try and clean and fix a block no matter what. I mean they are made of metal, and we have welders and sanders and ****, so why not? My words of advice again: directed towards people with daily drivers that want 200k. You dont want a machine shop doing "Extra cleaning work" to get your engine cleaned up for 100 different reasons that range from: they might not do it right (read where you wrote: proper machine shop) all the way to: they cleaned it fine at first but then left a mess after their 'proper' machine work. The less a machine shop needs to do to prep a block the better, thus finding additional non-rare, good running OEM engines to rebuild over trashed/seized/junk is still a good idea regardless of what you think of the 17 year old interns ability to clean a block at the local machine shop.


This is a whole other issue. Lack of proper cleanliness... not necessarily cleaning procedure, is a very common problem associated with building engines. This problem is understated in the V8 crowd presumably because we are in America and have many more machine shops dedicated to this platform. In the 4 and 6 cylinder/Japanese engine world, the problem is much worse. Nearly every rebuilt 4-cylinder sr20det for example has a problem before it reaches 20k miles. The level of attention to detail and cleanliness required is off the charts. And typically the same machine shops that handle the V8 engines will try this particular 4-cylinder and have all of these problems/issues with the build, using the same exact procedure and cleanliness they use for their V8 counterparts. Which tells me that perhaps V8 engines are being assembled in sub-par conditions, they are just able to tolerate it longer for whatever reason (larger clearances?)


If you run an engine without an air filter (I like this example) it will ingest many compounds that are both NON metallic and very INERT. Such as pollen and fungus spores. These compounds, some of which science still doesn't know what they are consisting of, being so inert, will stick to parts and cause clogs, leading to metallic debris/failure as passages dry up, and are VERY difficult to clean, you can scrub and torch them without much result other than a black sticky mess lump left behind on the metal surface. There is also the issue of sand/grit/silica, which will pit aluminum parts and impregnate itself all through the airpath, making every components of the engine (head, deck, piston, valve) into useless trash. You cannot "clean" through a pitted, ruined deck. Cleaning has limitations. There are good answers for alot of the un-cleanable areas (shave the deck/head, change the pistons/valves) but there is still the issue of what these un-cleanable particulate have done inside the oiling orifices of the engine. You cant "shave" the space between the first and second rod bearings where non-metallic inert compounds have decided to live. The machine shop, even the best one, isnt going to scope every oil galley looking for bits of grit that are hanging around. High temperature might even make the problem worse by facilitating side reactions with other available biological compounds, some of which bond to metal easily.

I appreciate this, its very important to clean thoroughly, but the problem is understated and the solution is over-stated. All I am really saying is, you can't be too careful, and, the less you leave in the hands of others (i.e. machine shop cleaning details) the better.

 

kingtal0n I call BS on almost 100% of your posts lol, Core motors are used all the time and hold up just fine. You do realize how the blocks are made in the first place and what they are made out of don't you? Then they are machined and come on contact with many different types of material. Many people prefer seasoned blocks over new. Even a brand new block has to be cleaned and machined before it's used unless you trust something that is mass produced is going to be up to spec when you get it, Most are not. Brand new does not mean better in many cases.

 

none of this has anything to do with a block thats been trashed by abuse, like the no air filter situation. I never said used blocks are bad- that is the only kind of block I've ever used. I only pretend that we should be going for GOOD RUNNING blocks, engines which are CURRENTLY in USE, they have 50k or 100k on the clock, the oil looks clean, smells clean, engine isn't making any noise, run fine, PERFECT candidate for a high performance rebuild or to use as it sits.

If you find an engine in the scrap yard, I give it a 50/50 general chance of success regardless of how careful you are. If you collect data and compare salvage yard blocks vs good running blocks rebuilt you will see a higher rate of failure in the blocks with questionable backgrounds. It is simply statistics at work here. Much higher percentage of current running, high mileage engines will survive the rebuild because generally these engines cleaner and more well maintained. It is basically a cleanliness problem, where an engine spends its entire life headed towards disgusting muck and carbon fragments embedding and conglomerating in every conceivable space whether burnt or breathed, carbon from fungus is just like carbon from gasoline, fungus spores contain a myriad of other compounds that also facilitate their own reactions and contain many different kinds of atoms ranging from Nitrogen to metal.

Call BS all you want thats what the internet is for. Plenty of "crazy people" Over the years (Look through my telescope! Look through my microscope!) almost got lynched/stoned to death for their outrageous ideas which turned out to be scary or relevant uniquely


an edit to apply this also:
Imagine we actually tested a series of JY blocks and found that it was more like 70/30, 70% of the time you get a good block. The test could be repeated in another state and those stats could reverse. The availability and location of your personal existence is a factor when deciding whether to go JY for a block or attempt something with what you already have. That is why I specifically chose 50% as a general number because truly there is no good way to express percentage of good JY blocks to a forum which includes the entire world.

 

It does if your the one collecting the money and making the profit...

Your spot on though. Look at how they assemble theses engine's new on an assembly line. They literally slap them together with parts from bins. No measureing, no cleaning casting flash, no clean room. Just lube it up and assemble it. Every thing is within a spec and it is slapped together.

 

every expensive engine for ultra-high performance OEM vehicles like the GT-R and ferrari is always built in a clean room. If the cost of assembly < failure rate cost there are always some limitation to the steps taken to ensure reliability (if the cost of some % additional failures is less than the cost to protect better from those failures then I think you know what happens). Also, Nissan and Toyota engines, even in the 80's, were built to very strict high tolerance standards, the rod bearing is 0.0008"-0.0013" for example using 5W-30 and they have OEM grades for bearings that range in the 0.000X place for rebuilding available.

lol at "slapped together" I am sure even FORD has taken measures to improve the cleanliness of their facility where engines are assembled. I'd be surprised if someone from ford doesn't jump out of the bushes with a video of such a place (looks around)'

And I am not sure about Ferrari, but I assumed they had the intention of giving their real performance engines the cleanest startest bill. It was just a wild guess though. The GT-R I am sure is built clean room style, I've seen that video. Anything you really care about, even your own body, should be kept in a 'cleanest possible' room. Don't let mold take over your houses walls and just live with it, because you won't be living with it for long.

 

99% of all of kingtalons post warrant a "TL;DR". He's one of those people who try to analyze every little thing to make himself appear smarter than everyone else in the room. Must be an engineer. lmfao

 

 

Clearly!!!

First he talks about regular production engines going 100k miles then he brings Ferrari's into it which are not even capable of going that many miles without a major overhaul. Why would anyone tear down a perfectly good running and well maintained 50K-100K mile motor and rebuild it? That's a waste of a perfectly good donner engine.

Trolls are like rodents. Once they find a little bit of food, they keep coming back and shitting all over the place. Eventually they move on and find somewhere else to ****...

blk00ss, You know what they say; "You Can't Fix Stupid No Matter How Hard You Try"

 

He's no engineer. Yes, over thinking things is a trademark but it also requires fundamental understanding of certain principles which he is clearly lacking. Engine can't be cleaned or are forever junk if they get metal shavings in the oil passages? Wtf? That means every engine block that has ever been manufactured is junk based on the processes required to create them in the first place! How does he think oil passages were created in a sand cast block? SMH.

 

Oh, and now that this thread is back from the dead, a spun or displaced cam bearing doesn't instantly make the block junk, but it could be too expensive to fix than its worth. On my lq4, the number 3 cam bearing walked out. No obvious signs of spinning and the cam journal took the brunt of the damage. I had the shop measure and then install new bearings with loctite to insure clamp up before moving on to machining. I lucked out and it's perfect. However, if it was a no-go, I would have just sourced a different used block because the cost to machine the bearing journals oversize is more that a good used LQ block! None of this BS about not being able to clean the block...

 

This must be kingtal0ns idea of a clean room, For someone worried about contaminants his pictures certainly don't show it.

 

You read my mind! I saw that and wanted to post it but I'm on mobile right now and couldnt. Thank you, lol.

 

He is talking about pollen and fungus spores? Should the engine be assembled at a CDC facility with the engine builder wearing a Hazmat suit?

 

Ah very good I am glad you brought this up. In this picture I am 15 years old. I did not understand how to build an engine yet. That was my first camshaft swap ever. I would still to this day wash my camshaft, although I would be using gloves of course to avoid touching it. Its a great illustration of what differences in assembly/cleanliness can mean for an engines life span, is really relevant if we only have one single car. Preventing an issue is why I am preaching to noobs to use stock engines adjust the atmosphere.

How does one become an engineer BTW? I worked hard for the degree with a similar title but I am no engineer. I like math for fun, but never have needed to rely on it for safety.

 

Ive been preaching NOT to rebuild engines, NOT to open engines. Where does it say I am telling anyone to rebuild their engine unnecessarily? Thanks for pulling up all my posts and bolding them also cheers. sorry if i was short with anything I posted.

You may not have much experience with small displacement engines, but I do. A tiny grain of sand will clog an oil passage in a nissan 2.0L engine and cause a meltdown, trash the block. The same goes for a bit sludge buildup or any other obstruction. It is very common, huge problem in the sr20det community for example. These are lessons people learn the hard way, assemble and then failure shortly after using the same procedure they would use to build a V8 which often has less trouble with debris for whatever reason (clearances?). That doesn't mean throw caution to the wind just because you are using a larger engine; it means that **** HAPPENS and you should do everything you can to prevent it.

My post emphasis is on using a clean engine to start with if it is available; a good, solid piece of advice that nobody can argue with. Mileage isnt a factor; it is cleanliness. I'd rather rebuild an engine with 248k that still runs than one with 50k and has a questionable background.