Category Archives: 2.4L Ecotec

Ecotec Timing Chain Guide Bolt

2 Replies

Timing chain guide bolt cover (circled in red)

The other day, I found an article about the poor design of the Ecotec timing chain guide bolt.  Specifically, how prone the bolt is to backing out.  In extreme cases, the bolt can get tangled in the timing chain and shear off.  Needless to say, having bolt fragments fall into the timing chain of a contact engine, could potentially cause rather expensive damage.

If I am not mistaken, the 2.4L Ecotec powering bowtie6 is the same engine currently installed in the Polaris Slingshot – so if you happen to own a Slingshot, then you might want to read on…

The Fix

Amazon has the replacement bolt made by Dorman – about $20.  Here is what the label on the box looks like:

Dorman Timing Chain Guide Bolt replacement part number 917-954

The factory bolt is tiny and you get to it by removing a “plug” on the front of the engine.  You can see that cover plug in the top photo on this post (i have added a red circle around it).  Once you remove this plug you can insert a long 10mm socket and take the bolt out; be careful though because you don’t want to drop it!  This is what the pair looks like once they come out:

Bolt on the left, cover on the right…

Here is the front of the engine with the bolt cover removed:

Removed the plug…

And this is what the new bolt looks like:

and replaced it with this…

Finally, this is what the new bolt looks like installed:

Replacement bolt securely in place…

Moral of the Story:

When my original bolt came out, it was not exactly “tight”.  I am afraid had I ran it longer it would have eventually backed out.  And this would not have been a happy time.  Some things I have learned from this:

  • Replace the Ecotec timing chain guide bolt – it is cheap and it is easy.
  • If you own a Polaris Slingshot, do yourself a favor and read up about this.  For a mere $20 you will save yourself a lot of grief.
  • I wanted to show more pictures of the new bolt but I am afraid of copyright issues.  Please, if you have read this far check out the Dorman Ecotec timing guide chain bolt page.  There is a wealth of information there; even a video.
  • NOTE:  I don’t get a penny from Dorman about this  I also very seldom endorse folks.  But, I have read enough (and watched a few videos) about this kind of failure and figured it be best to do a PSA about the damage potential running the original bolt.

As always, be safe and hope all is well with you.  If you have any questions, let me know…

Ecotec Intake Manifold Upgrade

4 Replies

Been a long time since I’ve done any work on bowtie6.  This little car is just like a trusted Timex watch – it takes a beating and keeps on ticking.  This weekend I installed an upgrade:  the other day, I came across a vendor that offered a phenolic intake spacer for the Ecotec.  The advantage of a phenolic spacer is to help reduce heat transfer from the head into the intake manifold.

The intake manifold my cousin Jim made when we installed the Ecotec in bowtie6 is all aluminum (in case you want to know more about it, here is the link to a previous article with details about the custom intake).  We did this because the original composite intake from the Solstice was just too large and would not fit because the steering shaft lives where the factory intake is attached to the head.

You can see the intake in today’s featured image above, and as you can imagine it gets a bit warm.  I suppose the amount of time air hangs around the intake manifold is minimal, but any improvement would be helpful.  So, I sent the $99 plus shipping for the phenolic spacer and a couple of days later, one of the brown trucks delivered this:

The phenolic spacer matches perfectly the GM intake manifold plate Jim used to build the custom intake and is exactly 1/4 inch wide.  The “kit” comes with new gaskets and several replacement bolts.  Sadly the bolts did not fit the head of the LE5.  When I trial fitted all this, I noticed the factory bolts were about 1/4 inch too short (duh!), so I had to go find replacements.  Fortunately the local NAPA store not far from home had them in stainless, no less.  Torque settings on these bolts is not high, so the NAPA bolts worked just fine.  Not bad for $8 and change.

Taking the bolts out was a job!  There is just no room.  But, with a little patience and a few curse words, the manifold finally came out.  I remember I had used RTV on the original metal gasket and was left with quite a bit to clean up.  This is the intake manifold minutes after I had removed it.

And here we have the other side.  I had to remove the valve cover breather hose and the coolant hose.  You can also see the alternator is still bolted to the block (more on this later).After a little elbow grease, the head and the intake came clean.  From the mess in the the photos above, we have this:

Remember I mentioned the alternator being mounted?  Well, after trial fitting the whole affair, I found there was no way in hell the bottom bolts could be reached without dropping the alternator.  Here is what the phenolic spacer looks like in its new residence…

And here is a closeup…

I had to mark the spacer with “block side” and “intake side” so I could line up the new gaskets in the right direction.  Yes, they have a “side” – you can see that in the first picture above.

Then, the fun part:  getting it all back together.  As I mentioned the new bolts are about 1/4 longer, so it took some fiddling to get them lined up just right.  I had to pay close attention to the gasket orientation and used a bit of gasket adhesive on the gasket face next to the block and intake.  I left the faces that come in contact with the phenolic spacer dry because I did not want to risk damaging the phenolic material with the gasket adhesive material.

All that hard work, and you can’t even see the spacer!  So much of bowtie6 is like this too.

And so, it is time to start the engine and go for a ride.  But, we can’t have a good automotive project without the proverbial “oh shit” moment…

  • gaskets lined up – check –
  • bolts all accounted for – check –
  • no extra parts (yeah!) – check –
  • wiring connectors plugged up – check –
  • alternator properly bolted – check –
  • serpentine belt on – check –
  • engine coolant hose – check –
  • valve breather hose – check –

Get the keys, jump in and hit the ignition button.  Nothing.  Engine turned and turned, no fire.  Strong smell of fuel.

Damn!

I retrace steps.  Had to be something simple.  Turns out the plug for the injector harness is the exact same size as the one for the electronic throttle body.  I had them switched.  No wonder.  After swapping the electrical connectors, I tried to start the engine again.  This time, a cloud of smoke came out the exhaust – she was pretty flooded so I decided to let the engine idle for a few minutes.

Finally, backed the car up and went for a short drive.  I noticed no seat-of-the-pants improvement, but I did touch the intake when I returned and it felt much cooler.  I have no idea if all this is going to make a difference but there is no big investment here.  And yes, I would agree if you say that heat will still make it into the intake just by heat transferring through the bolts.

We shall see how this little experiment goes…

 

SuperTrapp Performance Tunable Exhaust

5 Replies

IMG_1485

Going through some bins in the garage this weekend, I found several spare discs for the Supertrapp performance tunable exhaust as mounted on bowtie6.  You can see the two discs in the picture above, towards the left.

I’ve written about the exhaust in a prior post (Click HERE) so I won’t repeat myself.  However, the idea behind the SuperTrapp tips is to control backpressure and noise.  This is accomplished by adding or removing those discs to the end tip of the exhaust.  The more discs, the less backpressure and the higher the decibels; consequently the less discs, the quieter it gets but the more backpressure accumulates.

So back to the two discs.  I got the notion to move things around as well as adding the two spare discs.  Here is what the two exhaust pipes really look like:

IMG_1486

So I decided to remove a disc from the right side pipe and add the others to the left side pipe.  As you can see, the left side comes out at a 90 degree angle from the main 3″ pipe.  So, I figured what the hell!  The worse thing that could happen is that it sounds like crap.

Well, much to my surprise the experiment has worked quite well.  Backpressure has been reduced, noise went up (but only during WOT) and overall acceleration feels better.  I know, this is all measured by what is transmitted via the seat to my arse.  Good enough for me.  I like it!

IMG_1484

Fuel Regulator Fittings

2 Replies

The Ecotec engine uses a similar fuel delivery system as fitted in the LSx engines in that the fuel rail is “returnless”.  This means there is only one line feeding the fuel rail on the engine.  In order to make this work, a special fuel regulator with built in filter has to be plumbed not far from the fuel pump.  There are several fuel regulator fittings available and in today’s installment I’ll document my experiences.

In an earlier post, I wrote about bowtie6‘s Ecotec fuel system (click here) where I described the separate staging tank holding the fuel pump.  About two weeks ago, I noticed the insulation post around the fuel pump’s B+ terminal my cousin Jim had fabricated had deteriorated due to coming in contact with fuel from the tank.  In order to solve this problem, I had to take the small tank out which required disconnecting the fuel regulator fittings.  After putting all the bits back together I found the fuel regulator fittings were not exactly “clicking” correctly.  They held in place but I was not pleased with the fitment so I safety wired them in place as shown in the following picture:

We can all agree this is not exactly the most elegant way to do things.  So why the safety wire?  Well, turns out on the little plastic tabs that “click” the blue fitting in place are not exactly the best design in the world.  Sure, car manufacturers use them all the time and they work flawlessly.  However these are aftermarket units made by Russell (a division of Edelbrock) and they are not exactly OEM quality.  I found out this by experience and by reading the latest issue of Car & Craft’s engine swaps magazine.  So where is the problem?

The following photo shows one of the two pump-side lines going into the regulator.  I’ve removed the fitting so you can see the small ring around the metal tube (more on that later)…

The next photo shows the fitting and the small plastic clip that holds all this together:

The small white plastic clip is very cleverly made.  There are two sets of barbs on it.  The inner pair locks in place around the ring on the metal tube from the picture above this one.  That keeps the plastic piece from sliding out.  Then the barbs also lock in place on a shoulder inside the fitting.  However in order to make this work, the plastic spring loaded affair must be crisp and not in the least deformed.  Taking this apart deforms the plastic clip and this prevents a positive lock.

The last two pictures show the white plastic affair locked in place.  As mentioned previously, this assembly is then pushed on the tube in the regulator and if all goes well the two barbs on the plastic clip snap on the ring molded on the tube.  All this looks good on paper, but I noticed the plastic “clip” had lost some of its “spring” and this all did not really lock in place so well.  The kicker is that these fuel lines are holding 50+ psi pump pressure and if they decide to part ways, well… you end up having a real bad day.

Remember that magazine I mentioned above?  There was a very good article in that issue about fuel systems and they cautioned on using these fittings.  And, they also suggested an alternative.  Unfortunately, the alternative is also made by Russell.

I did call the Russell tech line and talked to a rather abrasive dude on the phone about my experiences.  Right of the bat, he was not very interested in my findings nor on making things right.  Basically he told me to buy the new fittings and took no ownership to the fact this was a bit on the “unsafe” side.  I even told him about the article in the magazine, but he dismissed that too.  At any rate why argue with someone unwilling to stand by their product so I ordered new fittings.  While not exactly “cheap” (they are about $16 each) quite frankly I rather spend the money and have the peace of mind this is not going to come apart and sling fuel all over the place.

The solution is to use these fittings:

These fittings have a much safer design.  Instead of the spring-loaded plastic affair, they have a threaded cap that holds the fitting in place.  The threaded cap has a “U” shape that slides over the tube on the regulator and when tightened grips the ring (look at the very first picture on this post) keeping everything securely in place.  With this together, there is no slippage and no danger of this ever coming apart.

This is what it looks like all completed:

As you can see, these fuel regulator fittings are much nicer and better designed.  If you are considering this for an engine swap, don’t waste your money on the fittings with the plastic spring-loaded clip.  Get the ones with the threaded cap.  You will be much happier and most important of all, safer.

 

ECOTEC ECM Tuning – Changes So Far

Leave a reply

I mentioned in the last post I’d go into more details about HPTuners.  This time I want to talk about the Ecotec ECM tuning changes done so far.  I’m far from being an expert however one needs to start somewhere…

Vehicle Anti Theft System (VATS)

The first and most important task is disabling VATS.  This is a prerequisite when doing an engine swap such as what we did here.  Failing to disable VATS renders the engine inoperable.  On earlier ECM’s GM devised a system by which the ignition key had a special resistor that would match a receiver in the ignition key tumbler.  This “match” would enable the ECM to fire the engine.  With those early ECM’s it was possible to wire an inline module and basically fake out the key resistor.  With modern ECM’s such as the one controlling the Ecotec, the VATS became more advanced.  With the aid of HPTuners though, this is a simple change in the flash file burned into the ECM.

Mass Airflow Recalibration

In bowtie6, we replaced the stock plastic intake with a smaller, more direct intake manifold.  The reason was not for performance but because the stock intake was too big and got in the way of the steering shaft.  The air filter housing was also replaced with a cone-shaped K&N air filter.  There is simply no room under the hood of the TR6 for the large box that holds the stock air filter.  These changes forced relocation of the Mass Airflow (MAF) sensor.  As expected, the stock settings for the MAF did not match the new configuration.  This manifested itself in a rather rough idle and poor performance.

Tuning the MAF took some doing.  I won’t go into all the details but suffice to say it took a few hours worth of driving down the road and logging data with the VCM Scanner.  Using the VCM Editor I was able to dial in the low and high MAF tables to more desirable values.  This resulted in smoother idle and better performance.

Seeking Professional Advice

This is where the tuning process gets a bit pricey.  After going through several  books and reading many long hours’ worth of posts I decided to find a local expert.  Sure enough I found a person with a great knowledge and familiarity with HPTuners and tuning GM engines. However this came at a price.  The results though, made a huge difference.

As expected, fuel efficiency is the ahead of pure performance in the  stock ECM.  This shows up the way the commanded air fuel ratios are pre-set across the RPM range, spark tables and the way that power enrichment activates proportional to throttle angle – among other things.  After quite a few alterations the ECM is delivering more performance at the expense of fuel efficiency.  The results are astounding:  throttle response is much more livelier resulting in more power being delivered and overall the engine is much smoother across the entire rev range.  It is now very easy to make the Ecotec reach its 7000 RPM redline.

What next?

The next step will be to take bowtie6 to a dyno.  Been there, done that before but this time we will be tweaking the ECM  This will allow even more accurate dialing in for extracting that last bit of power.  Also, something that is yet to be modified are the VVT tables.  The 2.4 Ecotec has variable valve timing and this first tuning did not touch VVT.  Who knows what we can do with this?

Another avenue left for exploration is E85 Ethanol.  I’ve been intrigued for a long time about this source of fuel.  FlexFuel vehicles have a special metering device that allows the ECM to calibrate itself on the fly.  I don’t have that metering device but I have HPTuners and this will allow a special E85 calibration flashed into the ECM.  Where I live E85 is very easy to find – there is a very large fuel station just down the street from my house – so this will be a fun experiment.  Granted, flashing the ECM to run E85 without a metering device means E85 has to be burned exclusively.  However, changing back to straight fuel is easy to do, simply by reflashing the ECM.

In Summary

I realize to each his own and this is not for everybody.  However, having all this technology at your fingertips (literally) is remarkable.  Why would anyone want to waste time on those relics of fuel metering called carburetors is beyond me.

Stay tuned…  Soon bowtie6 will be the first E85 Ethanol powered TR6…  🙂