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 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 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!!!
How to Assemble a Chevy Engine Part 1
This video will show you how to assemble a Chevy engine (or any engine)
starting from the basic block. It goes through installing the crankshaft,
checking for the right clearences using plastic gage, installing the rings
on the pistons, installling the piston in the block, checking the rod
bearing clearence, torquing all the bolts to the collect specifications,
installing the rear main seal, and demonstrating how the motor works from
the bottom view and top view.
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.
Blueprint 101 - Using Micrometers, Calipers, & Bore Gauges
If you're going to rebuild an engine, 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.
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.
6-bolt 4g63 Crankshaft Chamfer & Oil Clearances
These are some things you need to think about during your build. Some
engines don't have any chamfer on oiled journals whatsoever. All equipment
like that can benefit from at least a light chamfer like the one that's on
a stock Mitsubishi crank shown in this video.
When you Chamfer an oil passage, you create a low-pressure zone where the
edges of the oil passage lift away from the bearing as it passes over it.
The principles of fluid dynamics dictate that if there wasn't an available
substance to displace that low pressure zone (in this scenario, there is an
oil supply), cavitation might occur. If we were talking about
aerodynamics, the effect would be lift.
An extremely-advanced or leading chamfer is actually capable of sucking oil
off of a flat bearing, whereas a trailing chamfer vacuums oil out of a
gallery and does a better job of spreading it around.
The modification that was performed here is intended to increase oil flow
to the mains and the rods. It's mentioned in the video that I'm setting up
my rod oil clearances on the looser side of spec. This will decrease block
oil pressure because more oil will be able to leak past the fillets of the
crankshaft and back to the pan.
But there's another modification being performed. A balance shaft
elimination. There will be lots of debate about this in the coming videos
as that transpires, but one of the side-affects of doing a BSE is increased
oil pressure. With several internal oil holes plugged off inside the
block, I will have a spike in oil pressure. I had my chamfers cut straight
in order to offer the largest practical surface area to apply oil to the
mains and rods. My intention is to relieve some of this oil flow that
doesn't have anywhere else to go. With the added flow, the straight
chamfer is actually beneficial to the mains, allowing them to intake more
oil as well as to spread more of it on the flats below the grooved upper
The animations illustrate this completely. They were created by
yours-truly. I know the oil hole on the mains is on the wrong side. It
was too much work to fix, but they get the point across. Don't laugh at
them any harder than I did.
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.
Cylinder Head 203 - Valve & Spring Installation
There are 2 critical values in getting your valvetrain geometry correct.
Valve install height and spring install height. On some models of cylinder
heads, getting these values is easier than it is on a 4g63 cylinder head.
On the first Glyptal video, you heard me complain about the complexity of
the casting and how hard it was to reach all the nooks and crannies while
applying that coating. The casting is very complex on a 4g63 head. There
are hydraulic galleries for the lifters elevated above the valvetrain
surface which make accessing each valve bore with precision measurement
tools very difficult. It's because of this that you need to do some math
to get these values correct.
Stuart is going to show you the process for obtaining the stem height and
spring height values on a 4g63 head. Using these numbers you can determine
other work necessary to correct the spring height value to correct seat
pressure, and ensure you have adequate valve travel for your springs to
It looks like rocket surgery, but really it's pretty simple. The ultimate
goal is to get every valve spring in as close proximity to one another as
you can, while doing your best to nail the recommended specification
PROVIDED BY THE VALVE SPRING MANUFACTURER.
Loose valve springs can result in leaky valve seats, valve bounce and
deflection that will drastically shorten the life of the valvetrain. If
valve bounce is severe, it can cause engine-killing interference with the
Tight valve springs can cause excessive valvetrain vibration generated by
the force necessary for the camshafts to push them open. On the narrow
side of the spectrum this can increase friction on the cams which can wipe
lobes and shorten their lifespan, and on the severe end in not only
increases the likelihood of wiping a cam lobe, it can lead to binding valve
springs and crashing the valvetrain.
You have to hit the sweet spot.
Valve springs specifications include several variables that help you
achieve these goals. The manufacturer rates their springs for their
installed pressure and height. They have a compression limit referred to
as valve spring bind which tells you how far you can compress them from
their installed height before the coils begin to bind and the spring stops
The valve springs used in this video are rated at 97lbs @ 1.440" installed,
and .500" lift. This means they should bind at .940", but my cams will
only generate .433" lift, giving me plenty of head room at the top (.067")
to prevent binding if they are installed correctly. One thing we found
which I wasn't expecting is they're a little on the stiff side of spec. We
measured 100lbs at 1.452", so rather than risk setting them up too tight,
that's where we set our tight specification. This decision was made
because if the rated pressure is lower than our actual measurements, this
would in theory decrease the lift specification and increase the
possibility of binding. Our install pressure ended up still higher than
spec with a barely-larger-than-spec spring installed height.
I don't consider this a defect. It is close enough within the margin of
error that it shouldn't cause any problems, and anyone doing this job right
will measure and check all of these specifications to ensure these parts
are what they say they are. That's what you watched us do. I'm confident
that this will work because the 4g63 utilizes a hydraulic self-adjusting
If the stem height is too high, it can be reduced by grinding the ends of
the valve stems to shorten them. This will have no affect on spring
installed height when the parts are assembled, however; it will change the
amount on paper that you'd need to subtract from the stem height in order
to accurately calculate spring installed height. If any of the valves have
been ground to shorten their stem height, all of the valves should be
measured separately with their retainers and keepers assembled, and that
new value subtracted from stem height individually to obtain each spring
installed height. You can't reduce this value any other way short of
replacing the valve seat.
If the valve stem height is too low, you can modify the valve seat or
machine the valve spring perches (seat or retainer) to increase the size of
the spring installed height. Another method would be to cut the valve seat
deeper to recess the valve.
In my video, we show this whole process on a brand new set of Supertech
valves. All of them are identical, and all of the retainers are new and
identical. Because of this (and yes we checked it), and because no valves
required any grinding, we only needed to use one value in our math for all
Hopefully this video clears up the process and covers the options available
for making changes if they're necessary. If you land within 3% of spec,
you've done your diligence in achieving correct valvetrain geometry.
How to polish a crank ( crankshaft )
Engine-Guru.com Presents a video on how to polish your crank shaft. Any
questions call 616-430-3114 ask for KYLE.
We are located out of Grand Rapids, Michigan.
Cylinder Head 101 - Remove Cams Rockers & Lifters
Going through a 4g63 Cylinder Head? You're on the right channel. I don't
know how many parts there will be to this series, I suppose it could go on
forever... We all have different ways of doing it, and I'm going to show
This video won't put a dent in most people's grey matter outside of
entertainment value... but I tried to keep it fun. I'd like to leave at
least a small dent. But no music in these because they're going to cover a
lot of ground and fast. I'm not doing anything difficult. This part of
this job really isn't. Most everybody pays someone else to do the
complicated stuff for them, and those people do it every day so it's still
easy unless you earn your money to pay for it from difficult and degrading
But this video's about getting started. There's some safety and
organization tips to be aware of before diving in. Stuff that could help
people whether or not they even own a Mitsubishi. Everything else is in