4g63's are famous for hosing crankshaft thrust bearings. This video illustrates the process of how to check the thrust bearing clearance whether the motor's in the car or not. Of course in my case the motor's on a stand for this video. Lucky for me!
In cases where the engine is still in the car, the same procedures can be used so long as the indicator is attached to the engine block. The plunger can be set up touching either the inside of the crank pulley or by removing the clutch cover plate and contacting the flywheel.
What the thrust bearing does, is prevent the crankshaft from having lateral movement in the main bearings. If a crankshaft develops excessive movement here, clutch engagement and hydraulic problems will begin showing up, followed shortly thereafter by catastrophic failure of main bearings, rod bearings, connecting rod failures, oil pressure problems, or even broken blocks, crankshafts and rods in extreme cases. It's important that every 4g63 turbo engine is within spec on this measurement.
When the crankshaft aggressively wears through the thrust bearing developing lateral play, this is called "crankwalk". On some block castings, replacing the bearings will NOT fix the problem. An engine block that is prone to crankwalking can not be fixed. The only option in these cases is to replace the shortblock and rotating assembly with new or used parts that are stronger than the one you've unfortunately encountered. For the 2g guys, the best option for repairing this problem is to remove the 7-bolt turbo shortblock your car came with and replace it with a 6-bolt from a 89-92.5 production date turbo DSM. Non-turbo blocks CAN be used; however, the block will not have oil squirters that aim towards the back of the pistons. That stream of oil aides lubrication to the wrist pins, cylinder bores, and somewhat cools the pistons. All good things on a turbo setup. Aside from that difference, there are no other differences between the non-turbo and turbo blocks. The pistons and thus the compression ratios are different, but that's it. Oil squirters can be machined into the main galleries of a non-turbo block, but it's more trouble than it's worth unless you can't find a turbo block.
There are tons of differing theories about what causes crankwalk. Nearly all of them are plausible and logical arguments. I will not get into those debates in this video in order to focus on procedures for testing and replacement. Please feel free to google "crankwalk 4g63" and read the volumes of information available already. The arguments and gathered data are older than the Eclipse itself and in abundant supply on the internets. Magnus, RRE, VFAQ, and many other parts vendors have lengthy write-ups on their own research and development. The bottom line is that the 6-bolt shortblocks are LESS likely to suffer from this.
Next time you see someone with a video that looks like it was shot with a potato asking "does this sound like crankwalk", you can send them this video. There's a reason for every noise, rather than focus on the sound, focus on eliminating the real problem. KNOW if it's out of spec.
Blueprint 103 - Connecting Rods
Connecting rods are the crux of the engine. They're responsible for
carrying the force of the explosions that occur in the combustion chamber
and using it to turn the crankshaft. Oil clearance specifications of the
"big end" and "small end" are crucial to maintaining consistent oil
In this video we take 3 measurements:
Rod Journal (also called Crank Pin) Diameters
"Big End" Bore diameter
Using the Journal diameters and the "Big End" Bores, you can calculate your
oil clearances of each bearing. The process is illustrated here. Anyone
rebuilding an engine who doesn't know its history should check all of these
clearances whether or not they're re-using the rods. If the crank,
bearings or connecting rods are going to be replaced, it's imperative that
you measure the new parts as well to ensure they're in spec.
Blueprint 105 - Main Bearing Oil Clearances
In this episode we measure the bores for the crankshaft and calculate the
oil clearances based off of information gathered in the previous video. If
you subtract the diameter of the crankshaft from the bore diameter, you end
up with your oil clearances.
If this were an assembly with new parts, I would have also paid close
attention to bearing measurements 45° off-centerline just to make sure the
bearings aren't pinched. I would also have double-checked the clearances
using Plastigage. But what I'm doing here is just getting baselines prior
If you're doing a dry assembly like this, DO NOT ROTATE THE CRANKSHAFT.
Without oil, there is nothing preventing it from being damaged.
Cylinder Head 204 - Porting & Polishing
This is a first-generation 1992 1.6L Hyundai Elantra
small-combustion-chamber head. Thats what it is. It's a J1 Elantra
cylinder head. Good luck finding another one like it. (read more)...
In Cylinder Head 106 I talked about the mainstream porting theories as they
are discussed. We looked at a cylinder head that I have thousands of
dollars of professional work performed on, and a bone-stock
second-generation head that I didn't port.
In this video I just might do something you haven't seen done before. For
some, that may be uncomfortable. The port and polish job I perform here is
what I think will work best for my current build. This is not an extreme
killer port job. What will be different here is where port textures are
concerned, I will be following the advice of a reputable source that will
remain un-named. You're free to port yours differently than I do in this
video, and I give you that out, around the 20 minute marker.
The Hyundai is far from being an ultimate-performance build. It's a $400
box of scraps with nothing but time invested. It's perfect for this video.
My finished product WILL be an improvement over what I had. I don't yet
have access to a flow bench. I still have an achievement to un-lock. As
far as you should be concerned with the techniques I employ... without flow
numbers there is no evidence of what this will do, but we will gather lots
of info from dynp sessions and drag strip time slips. If I could test it on
a flow bench, I would.
There are MANY, and when I say many, I mean thousands of flame war
mongering pirates floating around on rough seas with a hair trigger cannon
finger itching to fire if you port a head any differently than what the
herd mentality says to do while porting a cylinder head. I cover the herd
mentality because it has merit. It's been tested. Tried and true. But I
don't follow it to the letter of the law. I'm definitely not here to
de-bunk it. I would port a cylinder head differently for each build based
on how that engine was used. There's an extremely valid reason why
relating to air speed. It's not the texture of a port that maximizes the
effect of fuel atomization, but the velocity of the air running through an
x or y sized valve. The driving factor in this is the piston speed. I'm
not going to give you the technical information, but will refer you to
information about the Lovell factor. There's a better description of this
in the links below, and even a calculator to help you find your engine's
Why the Lovell factor is important:
Lovell gas factor calculator:
Only people who have flow testing equipment know for sure what really works
and have the capability to produce a perfectly-matched port job for the
ultimate performance build. Those guys know the definition of ultimate,
and THEY are floating below the water Aegis-class submarines ready to blow
your comment up if you don't know what you're talking about. They don't
care if you're an armchair mechanic or a herd of pirates. I will say,
they're zoomed in pretty close on me right now, and I'm expecting to take a
few hits. My work will be tested based on Dyno and drag strip performance,
and the results will be posted here. Fortunately, those kinds of videos
are a WHOLE LOT EASIER TO MAKE!!!
Blueprint 106 - Cylinder Bore Inspection
We're close to the end of the 100-level series. In this video I show you
how to measure the cylinder bores using 2 different tools. I compare the
results and illustrate what to look for to determine whether or not your
engine is in-spec.
The block I'm using is a 6-bolt turbo
4g63 from early '92. It has 150,000 miles and this video also serves as a
testimony for the durability of Mitsubishi's cast-iron solid-decked Sirius
I engines. This engine will be cut for a new set of pistons, so these
measurements are needed to determine what size pistons I need to get.
.030" is as far overbored as you should ever take a 4g63. Boring larger
than that will take too much off the side clearances between the cylinder
walls and result in compromised strength from hot spots. The only time
you'll ever need to cut a bigger hole is when an imperfection prevents you
from using the pistons you have, or if you're changing to a larger piston.
If you cut the block to its service limit, you have no room to fix an
imperfection should one develop... so it's best to cut as little as you can
get away with. Boring a cylinder .020" over does not significantly
increase its displacement.
Blueprint 104 - The Crankshaft
It's important to know what you've got even before dealing with the
machinist. If you want to inspect a crankshaft, this is how you do it. I
detail the process of removing the crank and what to measure. All
specifications in this video are illustrated with a 6-bolt 4g63 turbo block, but are all actually the same for
7-bolt engines with the exception of the rod widths.
Blueprint 101 - Using Micrometers, Calipers, & Bore Gauges
THESE MICROMETERS ARE PROPS. They're cheap, easy-to-read, and they were
defective straight out of the box. They couldn't be calibrated. The
graduated sleeve was seized up and rusted to the bodies of each one.
They're also not accurate enough to measure taper or runout on a bearing
journal which is necessary if you're rebuilding an engine. If you're going
to rebuild an engine and you're not already familiar with these kinds of
tools, this video is required material. None of your measurements mean
anything if they're not accurate. I illustrate the calibration and use of
3 major tools needed for taking measurements, and a brief demonstration of
how they work. These are by no means the ONLY ways to use or calibrate
these tools. This is simply the method I will employ to measure parts in
later videos so this instruction doesn't distract from their intended
messages. Even if you're familiar with these tools, you may find something
useful here, or even be able to correct me and my rusty skills.
When I can afford a $1200 set of Micrometers, I'll re-make this video.
4g63 Balance Shaft Elimination - bearing modification
This is the first part of a two part series about balance shaft elimination
on 4g series engines. This video details the bearings, the other video
will cover the front case modifications. I've already got a low-def video
of the front case mods, and I plan to re-shoot that one in HD when I'm in
the assembly phase. It's linked in the video.
The balance shafts are designed to cancel out harmonic vibrations caused by
combustion and the spinning rotating assembly. They may offer a greater
degree of comfort to the driver and passengers, but with that comfort comes
Often, when a 4g63 timing belt gives up, it's because the balance shaft
belt breaks or comes loose and takes the timing belt out with it. When
that happens, it can total your pistons, valves, damage the crankshaft,
wrist pins, timing belt tensioner and crank angle sensor. Basically, it
can total your motor. The balance shafts also have a combined weigh over
10 lbs and both are driven off the timing belt making them additional and
heavy rotating mass. If you've got a lightweight flywheel but still have
balance shafts, you have your priorities mixed up.
So here's what you do with the bearings. It's easy. You can do this at
home. You CAN do it with the motor in the car, BUT DON'T. You must enjoy
punishment to do this like that.
The end result will slightly increase your oil pressure, but usually not
enough to cause concern unless you have a full-circumference bearing turbo, ball bearing turbo--with your oil feed coming off the oil
filter housing. The head feed would be better in that case because it's
regulated at 15 PSI.
Blueprint 107 - piston-to-cylinder wall clearance
This video covers how easy it is to calculate piston-to-cylinder wall
clearance. It's too easy. This is important because too loose of a gap
and the rings won't seal properly. Too tight and the pistons will scuff
the cylinder walls, ruining the bores.
We've touched on thermal expansion several times now, and the reason it
keeps coming up is because turbo engines
achieve much higher cylinder pressures, and therefore generate more heat
than a normally aspirated combustion chamber experiences. This affects the
growth of the metal parts when they're at operating temperatures, so turbo pistons need more cylinder wall
clearance to account for this.
I will cover the ring grooves, compression and oil rings in a 200-series
video while assembling this engine with new pistons. For now, these will
just be saved for a rainy day. After all, I have a stock bore stock 4g63
engine in the Colt.
7-Bolt Shortblock Failure - Full Diagnosis
If you are your own mechanic, there is no more important character trait
worthy of development than the ability to own your mistakes. That's where
the line is drawn between good mechanics and bad mechanics. It's not the
failures but how they deal with them that measures their ability.
In short, it's not easy to admit you did something wrong or were negligent.
But if you don't own it and talk about it, it doesn't get fixed, and
nothing positive can come from it. It was my quest to overcome my clutch
issue that lead to the creation of a video. That video is the textbook
perfect guide for how to correctly install a DSM transmission.
Crankwalk as described is caused by a casting defect. This was not a
defect. This was preventable. A lot of people would find something like
this and not tell anyone out of embarrassment. I'm not ashamed. It's my
fault. I got good use out of this engine and it was tough enough to make
it 48K miles since the last rebuild despite my abuse. I'm here to tell you
if you bought a used car that's had its clutch replaced, or if you ever pay
someone else to do it... make sure it has this bolt. It's stashed away
between the starter and the transfer case, so it's hard to see. Make sure
all of your bell housing bolts are torqued properly because fastener
problems can destroy your shortblock, clutch and transmission. If your car
fails because of a mis-aligned transmission, you have no reason to blame
It wasn't until I bought my next AWD car that I discovered there was a
smaller bolt on the other side of the block. I destroyed 3 transmissions
in the GSX first. With the damage already done to my crankshaft, I then
lost a shortblock. It's an ounce of prevention that's worth metric tons on
your bank account.
Grade 10 M8x60 bell housing bolt = MD706012. It gets 22-25'lbs of torque.
Owning my mistake permits me to learn from it through con$equence$, and
never repeat it. What good would it have done anyone else for me to learn
this lesson and not share it? That's why I'm providing this video to all
of you. Sharing it can perhaps help someone else avoid this costly
mistake. This is the final chapter for my 7-bolt, and this book is going
back on the shelf.
Here are some valuable resources if you're trying to read bearing damage:
And of course, now that I've covered the complete oil system, transmission
and driveshaft series of videos, you now have all the tools necessary to
ensure your 4g63 lasts a very long time. Whether the casting defect
exists?... or it's all caused by a bolt, or the harmonics, or whatever...
Sure, crankwalk exists and it's horrible. But with the small amount of
movement required for your crankshaft before it contacts the block isn't
far enough to make your clutch drop to the floor when you turn. You'd be
hearing woodpeckers and jackhammers on the crank long before that clutch
pedal would fall to the floor. Some people are going to hate on me for
saying that. That's fine. I believe all of the people who experienced the
clutch pedal issues had fastener problems on their bell housing.
DSMs get a bad reputation for this but we can change that. Crankwalk is
never the cause of your engine failure. Crankwalk is always a symptom of
the real problem. It's your disease that makes you deny it's your fault.
You've got the 'itis. DSM-itis.
Whenever you dig deeper, you'll discover what applied all of those thrust
loads to your crankshaft to begin with, and it's not going to be a casting
defect that moves your crank .101". Mine only went .014", but all of the
same parts failed.
PLEASE tell me in the comments if you find this bolt is missing from your
Many of you have seen this one before. I apologize if bringing it back
Domestickilla gave me a crankshaft, and it's a nice one that I want to
clean up and use again. You'll be seeing a lot of it and because of this,
this video deserves to be here. I fixed what I broke, and this was my
In this video Ballos Precision Machine demonstrates magnetic dye penetrant
testing, crankshaft polishing and inspecting the balance of a "butchered"
4g63 6-bolt crankshaft.
Cylinder Head 105 - Valve Job Basics
Valves not sealing? Valves not bent? This is how you fix that problem.
In this video I outline the basic valve job procedure. Cleaning the
valves, cleaning the seats, cleaning the combustion chamber and lapping the
valves in to make a better seal.
Here I cover the process start-to-finish. It's the same exact process for
pretty much all non-rotary combustion engines. It takes patience and
perseverance to do this job, but anyone can do it. Reference your service
manual for measurements and service limits. Everything else that's not in
your service manual is in this video.
I apologize for not having broken busted crap to work with in this video.
It's more beneficial to all of you when bad fortune falls on me because it
gets well documented, and many people watching these videos are looking for
answers. If you have bent valves, you will discover it quickly once you
chuck one up in the drill. You'll see the face of the valve wobble around
while it spins. You'll see evidence of this damage on the valve seat. If
it's bad, you may see damage on the valve guides in the form of cracks or
missing pieces where the valve guides protrude through the head ports.
Give all that stuff a good visual inspection. ...and if you doubt yourself,
never hesitate to get a second opinion or consult a machine shop. They
will have access to expensive tools that you wont find in your average
Block Preparation Part 1
Preparation for powder coating and Glyptal application. Audio track is an
original performance by Rojo Del Chocolate.
My block is being powder coated rather than painted. It's just something I
do. The GSX had it on the last block so it's getting it again.
Since the tools are so similar and the mess is the same, I'm going ahead
and preparing it for the Glyptal application as well. These 2 coatings
will require being baked separately. The powder coating is baked on at a
hotter temperature than the Glyptal, so it's going first.
The surface preparation instructions for Glyptal is as follows:
Surface to be painted should be dry and free from dirt, wax, grease, rust
and oil. Remove all grease and oil by washing surface with mineral
spirits. Wipe or scrape off all loose dirt, rust or scale.
The last sentence is what's covered in this video. The 2nd sentence
happens next (although it's already degreased), and I'll get it back from
powder coat with it in the state described in sentence #1 completed. If
following these instructions to the letter of the law.
Second and third opinions in... the main journal is fine.
You'll notice that I didn't coat the main caps, or "suitcase handles". I'm
not going to. You bang around on these installing and removing them, and I
don't want to risk chipping them once they're coated. They're below the
windage area, and there will also be an un-coated main bearing girdle down
This video covered 25 hours of actual work. Yes, I kept changing into the
same filthy clothes every shoot because I wanted it to look consistent.
You have to take your time doing this kind of work, and be VERY VERY
CAREFUL! If for some reason you're crazy enough to attempt what I do in
this video, you do so at your own risk. This is an elective treatment that
I've never done, but I am by no means the first person to do it. I'm
learning about it just like the rest of you.
Turbo Elantra Bearing Failure Diagnosis
I had time to look at this thing up close. Go through the oil system, and
check out all the bearings. Looks like another good study for my oil
system series because it's the opposite problem that my GSX experienced.
High oil pressure can be remedied a number of ways, but left unchecked can
actually take a toll on your bearings. The way your engine bearings work,
the parts they suspend are supported only by an oil film layer, and flow
needs to be right in order for it to work as an actual bearing. If the oil
supply is insufficient, then it loses the ability to suspend the part
causing it to crash into the bearing surface. If oil flow is too great,
friction is increased, the flow becomes turbulent, and the oil film doesn't
form properly. High oil pressure can float and spin rod bearings, and
that's worst-case scenario.
I had several un-favorable conditions going on inside this engine and that
makes it a little bit difficult to link what my engine experienced to any
one singular thing. I think it's easier to look at it like some sort of
From sub-standard parts for how the engine components would be used, to oil
pressure, to part fatigue, to part history to abuse... this thing's got a
little bit of everything working against it and that's why it's such a
hilarious car. It was given to me with one condition. "See what this
thing will do, and see how long it goes before it breaks." My take on it
is, the parts are still less than ideal, and they've still got life left in
them. It's worth fixing. These parts are worthless as a race motor, and
normally I'd have junked 'em, but it's the Hyundai.
Calculate Your Compression Ratio
This is everything you need to do to calculate your compression ratio. No
foolin'. Every equation and process demonstrated. Find all your
variables. Know your exact compression ratio in every cylinder. This is
how you do it.
Just because your service manual says your car is 7.8:1 or 8.5:1
compression doesn't mean that it is. Whenever there are casting
irregularities, variations in piston height, parts that have been machined,
non-OE parts, or changes to your head gasket selection, your compression
ratio WILL change. It's highly probable that you're only CLOSE to spec if
you've never touched your engine at all since it was "born", and that it
doesn't MATCH spec. Even if it did, how would you know? This.
V1 Swept Volume
V2 Deck Volume
V3 Piston-to-deck clearance
V4 Piston dish cc's
V5 Head combustion chamber cc's
The ratio math:
V1+V2+V3+V4+V5 = volume of combustion chamber at BDC
V2+V3+V4+V5 = volume of combustion chamber at TDC
The ratio is...
(V1+V2+V3+V4+V5) ÷ (V2+V3+V4+V5) : (V2+V3+V4+V5) ÷ (V2+V3+V4+V5)
BDC ÷ TDC : TDC ÷ TDC
First you fill in the variables, then you calculate volumes, then you add
the volumes, then you reduce the ratio (fraction). It's that easy.
Here are your magic numbers:
0.7854 = Pi quartered to the ten thousandth
16.387 = number of cc's in a cubic inch.
If you divide any number in cc's by 16.387 it gives you inches. If you
multiply any number in cubic inches by 16.387 it gives you cc's.
Quartering pi lets you use the calculation:
BORE x BORE x STROKE x .7854 = volume of a cylinder
π x (BORE ÷ 2) x (BORE ÷ 2) x STROKE = volume of a cylinder
Either way is right. You get the same result if you calculate pi to the
ten thousandth. While I apologize for all the math, no I don't. I'm
really not sorry. You actually clicked here for it whether you realize it
or not. This is ALL the math, the tests, and the whole process to
calculate your cylinder volumes and compression individually even if you
don't know any of your variables yet. All of my numbers are present for
those who want to calculate out the last 3 cylinders out of curiosity just
to see how it affects cylinder volumes and compression ratios from one
cylinder to the next. Why would I do that for you? Why would I deprive
you of that practice?
Just assume that all 4 of my combustion chambers are 41.75 ml if you do
Clicking like share and subscribe helps a channel grow. It also motivates
me. Don't sweat the camera. It's enough to know that so many of you care
about what I'm doing here. From the bottom of my atmospheric dump, I thank
you all! This gift horse's teeth are all over the place, but he sometimes
poops gold nuggets.
PS: Use ATF for your piston dish volume tests, not alcohol. Of course
it's better just to use the spec sheet included with your pistons... but
not everyone gets that luxury. Water is just fine for head combustion
chamber tests. Dry and re-oil all parts that water touches.