Teardown and inspection of another DSM machine shop short block build

[BogusSVO]

Short block teardown and inspection
7bolt 4g63T

I had this short block dropped off at my shop about 8 months ago as a core turn in. The story I was told was it had less than 2000 miles on it. It was shipped in from another machine shop that specializes in the 4g engine.



First thing I noticed is the block head gasket surface was belt surfaced.


A closer view.


Next I checked crank end play.
By hand I could move the crank appox .050
I mount the indicator and zero it.


Next with a pry bar I pull the crank forward and get .063 of crank movement.


Also the oil galley balls were not removed so the crank can be cleaned.


After removing the rod caps, I noticed that the bearings are showing copper in an odd wear pattern, this leads me to believe that the crank rod throw, or the rod housing bore is finished on a taper.

Also it looks like a fair amount of grit was in the oil.


The crank was ground .25mm on the mains and .50mm on the rods. The etching on the crank shows this.


The bearings were marked and the correct sized bearings installed.


The wear on the rear thrust can be seen easily.




The crank is junk due to wear in the thrust face.


The 4th main got chewed into also from excessive crank end play.


So now the block is in the scrap pile.
The block had been bored .020 (.50mm) over and had evo pistons installed.
I measured the bores, and found 1 cyl .0005 tight, 2 of them were spot on, and the last was .0005 loose.
Next I measured one of the pistons and found it collapsed. The others were not measured at this time.
Not all the damage to this short block can be aimed at the machinist or the assembly of the engine. But the trash in the bearings, the taper to the rods or crank and the belt surfaced block can be, along with the inconsistent cylinder bores
The crank end play could be from an improper install of the girdle, or a heavy clutch.

There was a chunk of the oil pan gasket still on the block.


Once I removed the chunk of gasket, I found the machinist/assembler of this short block had signed his work.

 

[G]

Stage one lol! /ubbthreads/images/graemlins/rofl.gif Oil pan gasket? Wth?

 

[citymunky]

so glad I didn't buy a DSM graveyard Frankenstein block.

 

[strokin4dr]

That's sad...

 

[matt92vr4]

My galant is currently sitting in the side yard with rod knock. I was able to get 3000 miles out of the DSM GY 1g rod/ 2g piston combo. I guess I did well.

 

[GSNT]

I can't say I would ever buy anything from a company with "Graveyard" or similar words in the name. Also if it seems too cheap to be true, you can guaran-damn-tee it is.

 

[Woody]

Wow. It's hard to trust most shops now a days.

 

[manikbastrd]

Holy crap. I am soooooooo glad to have seen this. I was thinking about buying one from them and now there is no doubt that I will not touch that company.

 

[prove_it]

Funny thing is I had a block with only 30k original miles. I pulled the pistons and replaced with a eagle/wiseco combo. I pulled a cheap ass move of not machining a single thing. Just swapped everything in, new bearings and plastigauged it. Everything was close enough. Put it together and to this day it runs, even after 30k miles. In that time I've had serious knock from experimenting with tuning, oil starved it and put new bearings in it, just bearings, have rev'd it to 9k lots of times. Daily driven on e85, driven in temps from -40(yes) to 110. Everyday I go WOT pretty often. She gets beat on. It sees 5k+ rpms more often than 2k.

I'm making 325whp with it at 22psi (s16g). I did everything "wrong" for the most part.

And it still got more mileage than what most dsm gy blocks ever get, haha

 

[VR_IV_MR]

Quote:
Funny thing is I had a block with only 30k original miles. I pulled the pistons and replaced with a eagle/wiseco combo. I pulled a cheap ass move of not machining a single thing. Just swapped everything in, new bearings and plastigauged it. Everything was close enough. Put it together and to this day it runs, even after 30k miles. In that time I've had serious knock from experimenting with tuning, oil starved it and put new bearings in it, just bearings, have rev'd it to 9k lots of times. Daily driven on e85, driven in temps from -40(yes) to 110. Everyday I go WOT pretty often. She gets beat on. It sees 5k+ rpms more often than 2k.

I'm making 325whp with it at 22psi (s16g). I did everything "wrong" for the most part.

And it still got more mileage than what most dsm gy blocks ever get, haha



f*** off.

 

[jnava]

lol

 

[GSX_TC]

Interesting. Glad you caught that and thanks for letting us all know as well.

 

[toybreaker]

I hate to see sh*t like this. /ubbthreads/images/graemlins/frown.gif

... but if all the years in the business only taught me one thing, it's that there's always three sides to the story.


The customers version,

the shops version,

and the truth (as *mostly* told by the teardown)



In this case, it looks like the thrust got wiped out, and there can be many reasons for that.

... starting with the basic design (that has kicked many a good man's ass)

... moving thru high thrust loading from silly clutches and piss poor adjustment procedures

... and ending with driving style (dumbasses that sit at a red light with the clutch in)

It goes without saying that lots of things can wipe out the thrust.



Seen 'em all, (in various combinations) over the years


Good designs can handle some abuse, but some engines are just "touchy"


As far as the "taper" evidenced on the rod bearings, in most cases, the rod bearings will show the effects of the crank moving laterally.

It's quite possible that it was not taper on the crank pins that did that to the rod bearings, it's much more likely that happened from the crank walking back and forth.

When the clutch loading shoves the crank forward, the rods will get side loaded,

... sure as the sun will rise tomorrow.

Your looking at the result, (more than likely.)



As far as the bores being five tenths + / -

... well, in a production enviroment, that's not too terrible

You and I both know it can be done better, (even drunk, I could hold a tenth /ubbthreads/images/graemlins/devil.gif )

... but for all intents and purposes, anybody that would hack and dash the deck job with a tool meant for resurfacing the wooden deck at your house, well those hacks usually don;t even get within a thou or two of optimal / blueprint clearance.

You get what you pay (and settle for)


These guys are well known for f***ing up basic rebuilds, it's true

... but if you research almost anybody, you'll find they have had an issue or two.


If you'd like a little unsolicited advice, only a fool throws rocks when he's in the business.

... lest somebody post up a trashed engine they worked on.

Some asshats could break a steel anvil with a rubber mallet.

... and giving a well spec'd block to someone who doesn;t "get" certain laws of physics will result in just as trashed a unit as the most slovenly assembled brick.

High revs / hard loading a cold motor will f*** up almost as much sh*t as machining (or tuning) issues when it comes to knocking skirts around.


Myself, I reserve judgement, and *generally* keep my opinions to myself unless I know all the facts.

The way the engine was assembled is only partly told during a teardown.

... the rest is in the customers hands,

... and who knows how many hard launches this package saw beofre it landed on your shop floor.

(I once killed a cherry motor due to starvation when I got the chassis to "hook") /ubbthreads/images/graemlins/devil.gif


... Those "knocked skirts" tells me there's more to this story that meets the eye


Do you know for a fact the pan has never been off?

(I only trust customers at their word so far anymore!)



Not defending these asshats, (or arguing any facts)

... just balancing the equation, since they are not here to defend themselves. /ubbthreads/images/graemlins/wink.gif

[edit]
If you;d really like to get to the bottom of what happened in this case, be fair and send them a link to this thread and lets get their side of the story


I'd like to see them respond to their bad guy thread as well.

 

[BogusSVO]

toybreaker, I agree with you with how many reasons the thrust can fail.

I am not trying to throw rocks at all, just show what I found.

The 2 big fail points I have with this build is the belt surfaced deck and not removing the crank balls. The third is the one tight bore, granted .0005 is not much at all, but I would rather find .0005 loose.

Also, this same post is on 2 other fourms, one I know of has an employee of them on it, and he replied to the thread. All he had to say was the engine was built before he worked there.

Ill grab up the crank and rods and check them for taper, some time in the future and see if my taper theory holds true or not.

 

[prove_it]

Improper break in could kill it fast too. I've known guys that will put in a 4k built engine, start it up and go beat the crap out of it and drive all day long and not even change oil til 3k no matter what.

My opinion: All are at fault. It is a known fact that graveyard engines are hit and miss.

If there are two different rods in the engine though, that sounds like to me a poor assembly job. Who knows if the bolts were properly torqued, and RECHECKED. Issues can arise when you get two or more people working on one thing. That could be the case, or hell maybe the customer was running a 2600 lb or even a 2900lb clutch with the wrong step on the flywheel...

No one knows, but as a business it's a tough call to help out. If you help one guy in a case like this, your expected to help everyone or you'll get a bad name. Don't help and you get a bad name. It's not easy running a business like graveyard, especially with customers that beat the sh*t out of a car that was have-assed together.

 

[thecman02]

They did better work when they had "less equipment". They just bought parts. Shipped everything to a real machine shop then bolted the sh*t together after it was machined. Some of the people working/worked there I wouldn't even trust to take measurements.

 

[Redwood]

^^ im pretty glad i took my car to tyler and john for this reason right here. gy has a bunch of jokers working there. hope people catch this in time to check there motor if it has gy parts in it.