Stringing for alignment with lasers

Laser String Alignment
This weekend I used lasers to “string” my wife’s Liberty CRD and adjust its alignment.

I was recently looking at tools to improve the accuracy and the amount of time I spend doing my own wheel alignments in my workshop.  Like many other things, I believe that I can use some intelligence, ingenuity, and basic tools to do a better job than I would pay somebody else for.  Yes, it will take time, but I will know that the job is done right.

While looking at tools I stumbled across a great article on that discusses how to align vehicles the “old fashioned” way using strings stretched between jackstands.  I thought this was an instructive read, but I’d certainly trip over one of those carefully-aligned strings while making adjustments and have to start over.  Toward the end of the article, the author (Jeff Honeycutt) said that they rarely use strings anymore, as inexpensive lasers are actually easier to use.  Immediately this got my attention!

I knew that I had a pair of laser levels I used for my previous alignment efforts, and realized that they could be used this way, by lowering the included diffraction grating over the laser’s lens to spread the light out across a plane.  If this process worked well, I could save a bunch of money while doing a better job aligning my vehicles.

My previous alignment process used these same laser levels to check toe-in by attaching them to appropriate lengths of aluminum angle, laying them across the rims, and measuring the distance between the dots on my garage door with fabric store stick-on rulers that I’ve installed for this purpose.  By doing this at two measured distances from the garage door, I can determine the toe-in with some trigonometry.  I’ve set up a spreadsheet in my shop’s linux machine to do the math for me.  The problem with this approach is that I have to move the vehicle back and forth, hanging the laser levels and removing them again several times.  After I get the toe-in just right, I then have to adjust to center the steering wheel by trial-and-error.  If I’m stringing the vehicle, I’ll know when my wheels are pointed straight ahead (+/- some toe angle) and I can center the steering wheel without moving the vehicle.

So, I used this method with my wife’s Liberty CRD (yeah, it’s another diesel in the family!).  Pardon the crud on the vehicle, as winter refuses to release its grasp as of this past weekend.

First, I already know that the floor in part of my workshop happens to be almost perfectly level.  If the floor is not level side-to-side, you should look at using sheets of thin plywood, plexiglass (yes, I’ve used it that way before), or whatever you have laying around to get the vehicle level.  You can use a long length of clear tubing with water in it as a type of level to compare the positions of the hubs or the bottom or the top of the rim on both sides of the vehicle.

Checking Camber
I used this simple, inexpensive camber measurement device to ensure the camber was OK. Caster doesn’t tend to change much on its own.

Knowing that the vehicle was level, I pulled out a camber gauge that I purchased years ago from a forgotten source.  Racer Parts Warehouse sells a very similar one for $40, but I’m still not absolutely sure this is where I got it.  On this simple device, the standoffs are adjusted for the rim diameter and placed directly against the rim.  The knob, marked in 1/8 turn increments, is turned in order to bring the level’s bubble to the center.  A full turn is one degree, so the markings each represent 1/8 of a degree.  I found out that the Liberty’s camber was within spec, but that there was a little bit of asymmetry that I removed.  I don’t buy the arguments for asymmetry to counter crowned roads today, because we drive on such a wide variety of surfaces.  The vehicle should be set to drive straight on a more common uncrowned road.

Squaring the Plane of the Laser
The laser’s diffracted plane was adjusted to be vertical using a carpenter’s square.

Before starting on adjusting toe-in, I also checked to ensure that the steering wheel was in the straight, level position.  I would correct the front wheels’ position relative to the steering wheel, so that I wouldn’t have to mess with centering the wheel later.

Next, I put the laser levels onto some inexpensive tripods I picked up.  I might opt for some larger, heavier, more stable tripods later, but these worked well enough for now.  I set one up on the vehicle’s left side and used a carpenter’s square to check that the laser’s plane was at a right angle to the ground (yeah, I know the photo shows me doing this on the vehicle’s right side, which comes later).  I then rotated the tripod left and right with repeated measurements taken on the left rear wheel to ensure the plane was parallel to the wheel.  This is done by holding a ruler up at a right angle to the rim and seeing where the laser marks it.  By comparing the front and the rear of the rim at hub level, I was able to get the laser positioned properly.

Then, I set up the laser on a tripod on the other side of the vehicle and used the same carpenter’s square to adjust it to be vertical.  I measured the distance between the lines on the ground at the rear of the vehicle and at the front to see if they were parallel.  With some time, I was able to get them exactly parallel to eachother.  I then double-checked them with the carpenter’s square and knew that I could take good measurements.

Two Lasers Used for Alignment
Two lasers with diffraction gratings installed were used to make a pair of parallel planes that were at a right angle to the rear axle. Measurements for alignment were made from these two planes.

The Jeep Liberty takes very near zero toe (0.10 degree total toe), and that was what I targeted, with just a hair of toe-in.  Measurements are taken at hub level from the front and rear of the rim to the laser plane on both sides.  When you know the total toe spec, the difference between these measurements will be:

Delta = (distance across rim)*sin[(total toe degrees)*pi/180]/2

The pi/180 bit is there for spreadsheets that default to radians for trig functions.  The /2 bit allows for the fact that each side should cover half of the toe-in.  My calculation shows that the difference should only be some 1/100th of an inch, and so zero toe is a good target.  For applications where measurable toe-in is required, remember that the longer measurement should be at the front of the rim.

When I tweaked the adjustments I took the Liberty for a drive.  It tracked perfectly straight and the wheel was straight.  It wasn’t quite right before, but I was quite pleased with the results.

–Do it yourself, if you want it done right!




Are these the glow plugs used in NASCAR?

NASCAR Glow Plugs
Are these the actual glow plugs used by NASCAR? (Yes, I know better.)

Well, temperatures dropped, again, I had some smoky, rough starts on the TDI.  Voltage through my homemade harness looked great, but two of my plugs failed a quick continuity check using my multimeter — meaning that they were burnt out.  Hadn’t I checked this before?

So, I had to replace them yesterday.  I’d prefer the NGK glow plugs, but these are what I could get shipped from a local warehouse in one day.  As long as they aren’t too expensive and they get hot when voltage is applied, I’m not too concerned about the brand name.

However, check out the NASCAR branding on these Autolite glow plugs.  Are these the actual glow plugs used in NASCAR? 

Yeah, I’m being sarcastic.  I know, they aren’t really saying that these specific components (or any glow plugs at all) are used in NASCAR, but it’s still funny!

–We’ll see if this makes my 90 hp TDI any faster!  ;-)

$80 Glow Plug Harness?! Not on My TDI!

VW Glow Plug Harness
This is the original, poorly-built, overpriced piece-o-crap that VW sells.

It’s been a bit since I’ve last posted on this blog.  I’ve got some things going on that I’ve been hoping to share, but things haven’t panned out, yet.  I hope to make an announcement about some changes I’m making in life soon.  Soon!  Meanwhile, I’ll just say I’ve been quite busy on a project.

Additionally, my kids and I have also been working on a quadcopter, now that building a 3-axis stabilized platform is really pretty simple and inexpensive.  When we get it flying I’ll post a video and blog on that project.

We’ve had an unusually harsh winter here in Indiana, so I’ve been driving the diesel-converted Suburban [aka the Zombie Apocalypse Command Center (ZACC)] quite a bit.  When road conditions allow it, though, I save fuel by driving my 2001 Jetta TDI (ALH).  Sure, the Suburban gets reliable economy in the 20s, even in four wheel drive, but the VW moves me around with economy in the 40s.  Paying half as much to commute is a good thing, even if its in a beat-up little car with 260,000 miles on the odometer.

Because temperatures have been low, glow plug function has been important, and I recently noticed some issues with cold starts.  Making a cloud in a parking lot with a rough-sounding engine is embarrassing!  I often cycle the key on-off-on in order to increase glow plug heating before cranking the engine.  Recently it didn’t help, so I pulled the VW glow plug harness off and checked continuity for all four plugs.  Last year one of them died (no continuity) and replacing it made a huge difference.  All four plugs checked out OK, this time, so I figured my problem was another bad glow plug harness.

The glow plug harness on these vehicles is a poorly made plastic molding with only two conductors inside.  One conductor feeds the positive side of glow plugs #1 and #2, while the other takes care of #3 and #4.  Engine grounding completes the circuit for these plugs.  I’ve been reading a number of complaints about them going bad repeatedly because the actual connections get corroded at the glow plug terminal.  Bad design!  I’ve already replaced this part once.

Being a bad design is one thing.  Paying $80 per copy is another!  I hunted down the part number and searched all over the Web for a better deal.  Prices varied a bit, but they never went south of $50, so I decided that they were all horribly overpriced for a simple component that I could build myself.

I measured the connection on the dead glow plug from last year (not sure why I kept it, but it came in handy).  It came in at exactly 4mm and my recent multicopter work got me thinking about 4mm female bullet connectors.  I went onto eBay and bought a dozen sets of gold-plated male and female connectors for $5 delivered.

My Homemade Glow Plug Harness
This harness was made from 4mm female bullet connectors soldered onto 12ga wire with heat shrink (and some electrical tape–needed some larger heat shrink).

When they came in, I pulled off my VW plug harness to judge the needed wire lengths, soldered the 4mm female connectors onto the business ends of some wires spliced into a pair of Ys, covered everything in heat shrink (OK, yeah, some of it is actually electrical tape…for now), and spliced these assemblies into my wiring harness.  The bullet connectors were just a bit loose on the plugs, but I solved that by squeezing them ever so slightly with a crimper.  Now they fit onto the plug electrodes more tightly than the original harness does.

And, of course, my homemade harness works beautifully!

–No more embarrassing smoky, rough startups!

Free Book Promotion: 1st and 2nd of March

The Art of Diesel CoverWe are having severe thunderstorms in Indiana, tonight, and it seems like spring is in the air.  I think it’s time for another book promotion!

Thanks for the reviews, everybody!  I just noticed that my Dad recently reviewed the book.  I know he’s not exactly an impartial observer, but his review was appreciated.

I had a free book promotion several weeks ago, but this time I’m providing some notice, so that you can tell your friends.

My e-book will be available for free for the first weekend in March.  That will be Saturday the 1st and Sunday the 2nd of March.

The US link to the book is here:, but of course it can be found worldwide on Amazon by searching for The Art of Diesel.

Please grab a copy for yourself and pass this along to everybody you know who might be interested!

If you’ve read the book (especially if you liked it), please be sure to make your way back to Amazon and review it.  Any feedback I receive is greatly appreciated.

At present, the book is only available in the Kindle format that Amazon uses, but please note that free Kindle apps are available for almost any platform.  Even the latest Android-based Nooks can load a Kindle app to read this book.


Diesel Suburban: New Leaf Springs

Leaf Spring Comparison
The new leaf spring assemblies (5+1) are much beefier than the ones they will replace (4+1).

The Diesel Suburban just got a new set of leaf springs.  I’ve been messing around with the suspension since the diesel was installed and running.  The vehicle has seriously handled like a pig — and it’s not just because of its size.  I’ve driven large vehicles that handled better than this one.

  • My first shot at improving handling was to replace all of my bushings with polyurethane.  It didn’t help.
  • I realized that because I’m using the Isuzu 4BD1T’s power steering pump, I no longer had speed-sensitive steering, so I increased caster to get more “feel.”  No improvement.  I may still consider a non-speed-sensitive steering box at another time.
  • I swapped torsion bars in the front end for a set that were a bit stiffer, and got some improvement.
  • I swapped tires, and got no improvement, except that the newer ones don’t follow grooves in concrete as much.
  • I put a larger rear sway bar in, but it didn’t help.
  • I put some air-pressurized shocks in the rear to stiffen things up, but I suspect that spring wrap was still occurring.
Spring Overlap
The new springs feature more overlap between the leaves, which will further stiffen the system.

As mentioned in the last item, I found out that some other large SUVs had problems from the factory, because they were shipped with light rear springs that allowed some rear steer which is caused by spring wrap.  These vehicles were fixed by adding radius arms, but they could have also been fixed with beefier springs.

Nobody complains about Suburban handling from the factory, except when they’ve run into issues with the speed-sensitive steering being out-of-whack.  Many bypass the feature to get predictable behavior.  A suburban with 170,000 miles and over 14 years on the road may have weak rear leaf springs and start behaving in a similar fashion.

I called around, and found Warner Spring in Indianapolis had the best deal on a pair of OEM-style leaf springs.  Some online locations might have saved me $20, after shipping costs were included, but the headaches of online returns when dealing with 200 lbs worth of springs helped me to go with a local shop.

Overload Leaf Comparison
The overload leaf on the new spring shown here is much beefier and longer than the other. This will allow more load-carrying capacity.

Though the springs from Warner were supposed to be a direct replacement, they are 5+1 springs, rather than the 4+1 springs my K1500 Suburban came with.  That’s OK, as I wanted them to be stiffer, and certainly feel that this Suburban was too lightly sprung from the factory.

When I got the springs home and removed the original springs from the Suburban, I set them down side-by-side and took a few photos.  The differences include:

  • A 5+1 setup, meaning that there are five primary leaves, plus a single overload leaf.  This overload leaf doesn’t engage until heavier-than-normal loads are placed in the rear of the vehicle.
  • Heavier leaf overlap.  The leaves on the original springs didn’t overlaps as much, meaning that there was a lot less spring at the ends.  The overlap on the new springs will add to the stiffness of the system.
  • Beefier overload spring.  The overload leaf on the new assemblies is much longer and thicker than on the originals.  This means that it will provide more load-carrying capacity for heavy loads.
New Leaf Springs Installed
The new leaf springs are installed. I still need to get the vehicle up to highway speeds to know if I’ve improved the handling.

I got everything installed on Saturday morning, but I haven’t had a chance to get the Suburban up to highway speeds.  I have some errands to run and a meeting to attend this evening, so I will report back on whether this finally fixes my handling problems.  I did notice that this lifted the rear end of the Suburban noticeably, and I may look at ways to counter that; including lowering shackles and cranking up the torsion bars a bit.

–Still learning things the hard way!

Monday the 13th: Free Book Promotion!

The Art of Diesel CoverI’ve just set up a promotion on where free copies of my e-book “The Art of Diesel: Building an Efficient Family Hauler” will be available for free for one day only on Monday the 13th of January 2014.

The book can be found here:

If you download and read the book, I encourage you to post a review in Amazon and any other social media outlets you use.

–Thanks, and Happy Reading!



Generator Fun: Follow-Up

Kill-A-Watt at 60Hz
The generator needed to be adjusted to provide a correct 60Hz output. Here I’m observing the frequency as the furnace cycles, and only small changes are seen in the a/c frequency.

Early in the week I mentioned that I had some issues running my natural gas-fired furnace using my generator — which has been converted to run on natural gas as well.  Experimentation proved that there was something wrong with the power being provided by the generator.  My family was lucky that the lights came back on on Sunday night, as we’ve heard stories of people without power for up to 48 hours.  This is horrible when temperatures are in the negative teens and windchills are in the neighborhood of -30F (windchill will increase how much heat is lost through the walls of the house–by the same convective mechanism that affects your body).  I also talked with a few people who had power, but were still having issues with frozen pipes.

I thought about my technical problem during the week and considered my actions to determine the exact problem and make a correction.  First of all, I knew we needed more extension cords, so I stopped at a hardware store and picked some up, along with some cheap cord-wrap organizers and some water-tight cord connector covers — which were what we should have used for weather-exposed connections used to power heat lamps for chickens and rabbits. I picked up a heavy-duty 12-gauge cord long enough to reach from the generator to the furnace.

The generator had been left out and plugged into the natural gas line, in case we needed it again. Note that the ball valve before the quick-release was disconnected to avoid any natural gas leakage.  With my sled/shelter protecting it, I wasn’t worried about blowing snow or rain getting into the control unit or the gas metering system.  Because I live on a dead-end street in the boonies, only one (trustworthy) neighbor sees the side of the house where it was parked, so I wasn’t worried about theft.

On Saturday, when I had some time for experimentation, I fired up the generator and plugged my Kill A Watt meter into it.  The voltage was right at 120V, so that was OK.  I looked at the frequency of the alternating current, which should ideally be at 60 Hz.  I found that the output was actually at just over 63 Hz.  On a common, inexpensive, non-inverting generator like mine, the frequency is actually set by the speed that the engine is turning the generator head.

Engine Governor Adjustment
To get the alternating current’s frequency to the ideal 60 Hz, I had to adjust the governor on the engine, as shown here.

To adjust the frequency, I checked the throttle mechanism on the engine and found the governor.  This was easily adjusted with a Phillips head screwdriver.  The tip is to make adjustments while the engine is running.  On my generator’s Honda engine, turning the adjuster clockwise increased engine speed and A/C frequency.  I would expect other brands to be similar.  I slowly turned the adjuster counter-clockwise until the Kill A Watt indicated 60.0 Hz.  Then I observed it for about a minute.  Even unloaded, the frequency will wander +/- 0.5 Hz, and the key is to ensure that that the range centers on 60.0 Hz.  After a little more tweaking, I was ready to try running the furnace on the generator.

After letting my family know what I was doing (and waiting for a load of laundry in the washer to finish its cycle), I shut off all the power to the house using the master switch.  I wasn’t sure that other energy sources weren’t used for the thermostat or any other systems, so I decided to simulate (create) a full blackout.  I ran the cord into the furnace room, unplugged the furnace from the wall, and plugged it into the Kill A Watt meter which was plugged into the cord.  I was in contact with my son via walkie talkie, and asked him to turn up the temperature on the thermostat so that the furnace would kick in.

The furnace started right up with no complaints.  I heard the exhaust motor spool up first, followed by the ignition sequence and the main blower motor.  As the generator was loaded up, the A/C frequency stayed in the 59.5 – 60.5 Hz range.  I expected more fluctuation, and was favorably impressed with the result.  Further cycling showed that voltage was constant.

I’m satisfied that I’m ready for the next winter power outage.  I’d say “bring it on!” except that many others in the area aren’t prepared in this aspect and I’d like to see human suffering minimized.  The lesson I’ve learned is that a system with any level of complexity should be fully ops-checked before it is needed.  That’s obvious, but I hadn’t tried this out, and I wasn’t as ready as I thought I was.  Now my Kill A Watt meter will be kept with my generator supplies, in case further adjustments are needed.

-Be smart: Try not to learn things the hard way!

Cold Weather in Indiana: Generator Fun

Negative Teens in Indiana
Here’s a quick shot of the house this morning. I didn’t stay out there for very long!

It was fairly warm, with temperatures in the mid-30s (Fahrenheit) yesterday.  We had heavy snow in Indiana yesterday, with perhaps ten inches of depth.  As the sun went down, the snow continued, but the gusty wind was added as the arctic front came through.  This morning temperatures dropped into the negative teens and we will see a high today of nine below zero.

Hoosiers, for the most part, aren’t equipped or prepared for this kind of weather.  This wouldn’t have been a big deal where I was raised in Minnesota.  Everything is closed today, including the place where I work.

The coming snow and cold was something that everybody in Indiana was well aware of for the past several days.  Grocery stores were good places to avoid for their crowds and cleared shelves.  It wasn’t a scene of panic, but people around here sure rush to the store when a storm is announced.  Milk and bread are the first things to disappear.

Yesterday morning, as a wet, heavy snow was falling, we started noticing that our lights were flickering.  The area I live in is notorious for power outages.  If there is a thunderstorm, we are the first ones to lose power and often the last ones to recover.  This happened quite a few times earlier this year.  My family and I are well-practiced at rolling out the generator and running extension cords to where power is truly needed.

Quick-Release Fitting for Generator
The rubber hose that drops into the snow, here, is connected to a quick-release fitting.  The other end is connected to the generator.

Considering the possibility of long-term blackouts, the relative reliability of the natural gas system used to heat our home and water, and the cost of natural gas versus gasoline on a per-BTU basis, I decided that the generator should run on natural gas.  I purchased a tri-fuel (natural gas, propane, and gasoline) conversion kit for my generator and the necessary plumbing and hose fittings to make it work.  I put a tee and a quick-disconnect just after the meter on my house’s natural gas supply.  Now, as long as I have natural gas I can run my generator.

With winter coming, I saw that I could use the generator to power the controller and blower on my furnace; keeping the house warm.  This meant that heating my house would only require one grid to be functional, rather than two.  My furnace was hard-wired into the house’s power with only a breaker to disconnect it.  This makes powering the furnace difficult without a transfer box (perhaps I’ll get one installed later).  So, I added an outlet and rewired the furnace so that it plugs into it.  Now I can simply unplug it from the wall and plug it into an extension cord from my generator.

Generator With Sled/Shelter
The sled I built for moving the generator into position through the snow was used as a shelter to keep the snow out of the generator.

We had a based snow from a few days ago on the ground, heavy snow was falling, and the lights were flickering.  I started wondering how I’d get the generator through a foot of mushy snow to the location where my generator’s hose can reach the natural gas supply.  I recalled a pallet that my wife had left leaning against the back side of the barn, and thought about fashioning a sled.  I added some 1x4s with a 45 degree angle, some planks, and covered all of the gaps with shower board that I had laying around.  Voila!  I had a generator sled.

In the past, I’ve thought that I should build a shelter for the generator, so that it can be run in heavy rainstorms.  As I was building the sled, I realized that it could be placed inverted on top of the generator, in order to provide some shelter from the snow.  I added some sheets of Solex (leftover from a greenhouse project) to the sides of the shelter which would be exposed to the prevailing wind.

As predicted, the power went out.  Dragging the generator to the back of the house was one heck of a workout, as the sled could use more surface area for flotation; the generator and sled kept sinking in.  At every time I stopped to rest, my first movement as I restarted would basically lift the entire system to get it back on top of the snow, using the ramp I’d built into the front end.  It was a slow process, but it was possible due to the sled.

After dragging it through the snow, I rolled the generator off the sled into position.  I plugged the generator into the natural gas system and fired it up with no issues.  I agree with those who say they actually run better on natural gas than they do on gasoline.  I put the inverted sled on top and held it down with bungies.  Amazingly, it stayed in place, even with last night’s howling winds.  The snow buildup on top probably helped.

We ran extension cords everywhere, and I found out that the furnace wouldn’t fire up.  I experimented with multiple potential causes:

  • Bad ground?  Generators aren’t often grounded.  I thought the furnace was being fussy, so I grounded the system to the house’s ground and it made no difference.
  • Was too much natural gas being used by the generator to fire the furnace?  I shut off the natural gas supply to the generator and switched it over to gasoline, to find that it made no difference.
  • Adequate power?  This generator is rated at 8 kW peak, so I have no doubt that this would power the furnace which pulls a maximum of 12A (1.44 kW).
  • Inadequate extension cord?  I think this is it!

The startup transient must suck a lot of current when the blower starts up.  With the panel removed to troubleshoot the situation, I could see and hear the controller trying to start the blower.  It would blip the motor and stop right away.  The controller must have seen a momentary drop in voltage and reset each time.  I monitored a/c voltage with my multimeter and didn’t see the voltage drop, but it may have been too quick for my multimeter.  I think I need a better gauge of cord for this application, and will certainly ops-check it before we need it next time.

Thankfully, the power came back on at around 8:00 pm, but I know that many Hoosiers are without power with -30F windchill today.  My neighbors and I are OK, but this could be a real emergency for some.  It would have been tough for us, but in the worst case we would have moved to a single room, closed the door, and huddled around a space heater with blankets.  I would have to keep checking pipe temperatures in the basement to ensure that they were OK.

Good: We were well-prepared with stored food, LED flashlights, and candles.  We used our gas stove (lit manually with a handheld lighter) to heat water and vegetables to go with the home-grown chicken that my wife had been cooking in the crock pot all day.  Everybody simply dug in on what needed to be done.

Bad: I had made preparations for a situation like this, but hadn’t ops-checked the power system to see if I could really power the furnace.

Corrections:  We identified several things we need to do:

  • Get a good extension cord for the generator.  Installing a grounding rod would be a good idea, too.  Ops check the whole system.  Drag out my Kill-A-Watt, too, in order to characterize what’s happening.
  • Get more inexpensive extension cords.  Because we were worried about rabbits and chickens in the cold weather, we ran some 150′ of cords back to the barn’s greenhouse and chicken coop to run heat lamps.
  • I need some ski pants or other lower body covering.  Cotton jeans are a terrible idea when slogging through the snow.
  • We need a lantern to light up one room.  (We ordered a Rayovac SE3DLN on Amazon today.)
  • Eventually, we should consider warm weather clothing using open-cell polyurethane foam, based on the Phillips Arctic Living System (PALS).

Stay Warm!


Diesel Tweaks: Performance and Fuel Economy

With a few inches of snow last night and crews that don’t seem too interested in actually cleaning road surfaces, the Suburban was in its element today.  It was very slippery early this morning, and it wasn’t much better when I came home late in the day.

I decided that if I’m going to be driving this machine, I should take some time to make a couple quick adjustments.  I decided to adjust the injection timing to tune for better fuel economy and to adjust the wastegate pushrod for more boost.

Injection Timing Markings
The marks show how the injection pump has been moved relative to the engine block.

When I bought this engine, the injection timing was set at approximately 8 degrees before top dead center.  To find this out, I disconnected the output connection for the #1 cylinder on the injection pump, primed the system, and slowly rotated the engine while looking for the point where the fuel would be released from the #1 port.  The 8 degree timing was an indication that this engine was originally retarded from the normal Isuzu specification of 13 degrees in order to meet California emissions standards.  Of course, I fixed that.  In the attached photo, you’ll see a row of three punch marks I made on the pump on the left side of the vertical joint shown.  On the right side, you’ll see a row of three marks which were in alignment with the three marks on the pump when it was still retarded.  When I set the timing to the normal Isuzu specification, I made a single new marking in that location.

In the photo, you’ll note that the pump has been rotated even further recently.  I thought I’d see if further advancement of the timing would help the engine’s fuel economy.  Given that that two marks on the right are about 5 degrees apart, I believe I advanced the timing another 4 degrees; taking the engine to approximately 17 degrees BTDC. It actually hurt the fuel economy by several miles per gallon, so I pulled all but about one degree of this additional advance out.  I’ll top off the tank, again, and watch my fuel economy for a few weeks, again, under a variety of conditions.

17mm Gear Wrench with Flex
This 17mm Gear Wrench with a flex joint near the end allows me to reach the top injection pump mounting bolt between the pump and the engine block.

When viewed from the front, rotating the pump counter-clockwise advances the timing, while moving it clockwise retards it.  The injection pump is mounted with four nuts on studs that have to be loosened to rotate the pump relative to the engine case.  These nuts aren’t easy to reach, especially the bolt at the top of the pump between the pump and the engine block.  To reach this, I use a 17mm Gear Wrench with a flex end.  When I get the flex angle just right I can use it to loosen and tighten that bolt.  I should find a ratcheting wrench with a smaller angle between clicks, because it’s so tight in this area that I can only get 1-2 clicks of ratchet between tightening or loosening movements.

I’ve been reading Dougal Hiscock’s thread on turbo sizing and performance predictions on the 4BTswaps website.  Dougal also provided performance predictions that made it into my newly-released e-book The Art of Diesel.  Looking at these, Dougal predicts that the maximum horsepower can be extracted from these engines by allowing the turbo to produce around 26 psi of boost.  Because I once experimented with disconnecting my wastegate, I know that

Threaded Wastegate Actuator Rod
The rod on the wastegate was cut and threaded. With this threaded coupler installed, I can now adjust the length to tweak my maximum boost setting.

my GT2259 will produces approximately 25 psi of boost measured at the manifold, after an intercooler that has about a 1 psi pressure drop (based on further experimentation).  When I previously tried increasing the boost above the wastegate’s 15 psi setting, I didn’t actually increase the performance, but I hadn’t backed out the fueling screw or removed the aneroid pushrod.  I have more fueling available, now, so perhaps the additional boost would be put to good use.  This shouldn’t hurt normal fuel economy, as 15 psi is rarely seen and the wastegate isn’t exercised that often.

I’ve threaded my wastegate’s arm and installed a sleeve nut to make the length adjustable.  Tonight I considerably shortened the length, and tomorrow I’ll see how much boost the turbo will provide.  Soon I should have some butt-dyno and mpg results to report.  I’ll get back on this soon!

Book Released!

The Art of Diesel CoverMy e-book The Art of Diesel: Building an Efficient Family Hauler was uploaded to Amazon’s Kindle Direct Publishing site last night.  After a couple iterations of tweaking the format to work better on the Kindle (or on Kindle apps available for Android, IOS, PCs, and Macs), I hit the “publish” button.  This morning, I received notification that my book was available online.

Here is the US link to the book:

This is the book on the Suburban’s diesel conversion.

-If you buy a copy and read it, please be sure to review it on Amazon!