homeprofilethe carbuild planstage 1stage 2stage 3stage 4feedbacklinks








Engine & Drive line:

I strongly feel that the Ecotec V6 is basically a performance orientated engine at factory specification. If you study the upgrades and compare to the VN,VP & VR engine specifications, it is soon apparent that while these engines may look similar that is where the similarities end. This engine was a massive upgrade including revised cylinder head porting, lighter pistons, cross bolted main bearing caps, ungraded engine management and the list goes on. I believe with some basic and sensible upgrades that this compact baby will respond with serious results.

The engine will remain naturally aspirated with the rebuild not intended to be super extensive. The primary objective will be to keep it simple yet very effective and most importantly, affordable.

Initially I will start by bringing the engine back to as new mechanical condition. I am not going to waste time fitting expensive high performance parts to an engine that will not hold compression. Primarily the focus will be on engine breathing. Careful consideration to be given to camshaft selection. I am going to talk to all prominent suppliers of camshafts & components and hopefully select the right combination for this engine. Cylinders heads will be reconditioned with possible porting and valve upgrading. Cold air induction is a must. Extractors will definitely go on and I want to set up the exhaust just right as I want a great sound also. This is a very basic plan to begin with and I am sure that as I progress through this journey that several other modification will be included.

back to top

The game is on

Now, time to transform our factory specification VS into a credible My Street Car.

Before I start tearing the engine down its time for a dyno run to see just what our standard V6 Ecotec is capable of This aspect of the build is considered vital for the purpose of establishing our benchmark and starting point for all future modification comparisons. This is a results driven project with the success of this build being determined on genuine performance gains achieved. Guess work will not suffice.



Our stock Ecotec won't know what hit it after spending all of its previous life at no more than part throttle so some pre dyno tests, checking and tuning will be time well spent in our workshop. I will set the standard existing engine up to a satisfactory state of tune and service eg, no breaking down spark plug leads, filters in good order and just basic preparation to ensure we are mechanically sound. Dyno runs do not come cheap, so ensuring our tune status is to a high standard will hopefully give a clean power run on the first attempt.        



Our pre Dyno preparation has included a run on the tune scope, scanner hook up and general mechanical condition assessment. Fortunately no real problems discovered. Spark plug maximum KV's were a little on the high side with an inspection of the spark plugs revealing units that appear to have done a minimum 40 000k or more. With new spark plugs fitted, KV's are back to normal, the coils are happy and the ignition is ready. Air filter & fuel filters: OK. The transmission oil was more a greater shade of varnish so just for good maintenance, I carried out a transmission service as there are some hard days ahead. With that done we are all good and ready to rock & roll.


In conjunction with the dyno run, I will also have a temperature sender fitted in the air filter box. Air temperature & density have a major influence on power output so I feel logging induction temperature will be worth while for later reference.

back to top

On the dyno:

Having had no previous association with any of the dyno shops in our area, the challenge was now on to find a quality dyno equipped workshop to power run the My Street Car.

Having spent several years working with both engine and chassis dynamometers earlier in my career, I have a better than average understanding of dyno operating fundamentals. I have seen the good and the bad. Engines bouncing off rev limiters, under bonnet parts melting, stuff like that...!!! So I really wanted someone who knew what they were doing to ensure the car would be looked after and more importantly the information was 100% accurate.

The word had been out for some time that Nathan at The Throttle Shop in West Gosford was the man to see for dyno work as they sport a Dyno Dynamics 2WD unit that prints off the now well known power run graph which also incorporates air fuel ratio logging and air induction temperature correction. Well, it doesn't get much better than that and Nathan certainly didn't let us down. Very professional and all this done for a very reasonable fee.



Nathan was kind enough to let us watch the dyno run and and take some photos. Man, I just gotta get myself one of these, the memories returned, this is the best toy a mechanic could have. Even brought Kim over for the chance to check out what it was all about. Whilst I did get the Yeah, Wow... factor from her, the mood soon changed when I suggested we sell the house so as we can buy a chassis dyno for our workshop.

Nathan gave the My Street Car a series of brief power runs to establish a mean average. Once the power started to fall away the show was over and time to back off. Nathan certainly had a real feel for his work and all went very smoothly.



Well, check out that graph...!!! The stock Ecotec handled this like a trooper, was consistent and produced some damn fine numbers. 102.60kw with as little as 2kw between runs is a good result. Conditions for the dyno run were cool with ambient temperature approx 15c and air box temp approx 20c due to air box proximity to the radiator and general heat soak from the engine bay. The engine sounded great and run clean with only a puff of grey smoke from the exhaust towards the end. Not bad for an 11 year old engine.

With the dyno run now complete, we now have a starting point from which to work from. Where we will peak, only time will now tell. I am really excited now with the thought of unlocking the potential of this engine.

Well, that concludes the introduction and initial web site presentation for this project. Time to now soon get dirty...!!!

Just for a few weeks though, I am going to stall the build while I commence correspondence with camshaft and engine parts suppliers etc. I feel a little homework now will be time well spent to ensure we get it all just right before we take to the tools. I would love to receive some feed back, perhaps even some helpful hints or recommendations.

Hope to be back real soon,



Personal Note:

Whilst preparing the final dyno results, I overhead some breaking news on the radio that has floored me fair and square in my tracks. Concentration is lost, I am in shock..!!! Today is the 8th September, 2006. Peter Brock has been killed as a result of a car accident whist competing in a Targa event in Western Australia. This is something that I just cannot comprehend at the moment and is certainly news that is hard believe or accept.

Throughout my life has been inspired so much by this man. His motor racing ability, Holdens and just the character of Peter Brock gives you energy and drive to believe in yourself and achieve your goals. That is the power of Peter Brock to people like us.

Yeah, it's a bit sad hey...!!!

Peter Brock is a legend, larger than life and forever "King Of The Mountain"


back to top

The Journey Continues

Welcome back to the journey of My Street Car and perhaps the most interesting section of this project: The engine rebuild phase. There was never any question that the rebuilding of the V6 Ecotec engine was going to be the most challenging aspect of this project requiring patience, careful planning, research and quality workmanship that would ensure the V6 delivered the goods upon start up.

I strongly believed from the start that this engine had the potential for surprise...!!! However, I also I knew there was a risk of failure. A poor result on the dyno would have been devastating. Aside from the money spent, it would have been very embarrassing. There certainly were a few anxious days on the lead up to dyno day (D-Day....)

The conclusion...??? Just over a 30% genuine power increase. No fixing or fudging of numbers. The standard engine was even serviced and tuned before the initial dyno run to ensure net gains made with the modified engine were actual in every aspect. A Dyno Dynamics Chassis Dynomometer was used to once again ensure there was going to be no mistakes and variables such as air intake temperature would be calculated and corrected into the final power output result.

My Street Car is just wonderful drive. The engine really does sound magnificent, clean and crisp. On start up, you really know there is something going on under the bonnet. The exhaust gives a deep note and the engine really lopes at idle (which I don't mind at all). Whilst the engine does lope, it has never stalled. Once off idle, the engine is smooth and upon mild acceleration the engine feels like any other V6. It feels strong right from the word go and there is certainly no loss of performance whilst driving at suburban speeds. Where you really feel the difference is when you accelerate hard from 3000 rpm. This is where the engine really bites and within seconds you’re at redline. Freeway performance is fantastic...!!! I took the vehicle for a run up to Taree (a round trip of approx 500km). At 100-110k and in overdrive, the engine was just happy to sing away all day at 2000-2200rpm, no hesitation, faltering with the camshaft, just perfect. However, peg the throttle with the need for passing and the engine explodes into life displaying an unbelievable transformation of performance.

It is difficult for me to explain just how tractable and user friendly this engine feels and when needed, provides great performance. Its certainly now a good all rounder and at the moment I feel I am just out of the starting blocks, so to speak, with learning and discovering ways to further develop this motor.

I hope you find the following build report enjoyable and informative and perhaps in some way help interested persons who may be contemplating a similar rebuild. Whilst I have endeavoured to cover most details of this build, it is simply not possible to address every small detail. So I am
sorry if you find something I have left out. However, all the good bits that count are in...!!!

If you ever had any hesitation about modifying your own V6.... Don't... You won't be disappointed...!!!

Photo 1: The game is on...


Engine removed and ready for teardown. These are my beautiful 2 1⁄2 year old twins and they are in training early for the Commodore of the Year Award in the year 2025.



Photo 2: Engine tear down...


I took my time during the tear down phase cleaning and documenting all parts to ensure I had everything organised and I knew where everything had to go back upon engine assembly. This was also a time for checking, measurements, assessing overall engine wear and preparing a parts list and build plan. Fortunately, the engine was in good order so no real problems at this stage.


Photo 3: Short motor preparation and assembly...


The engine was taken apart leaving the crankshaft in-situ only. No major faults or wear noted with this motor having travelled an easy 175 000km with a good service record.



The basic short block preparation including the following:

  1. Honing cylinder bores. An essential aspect of the block preparation. Bore honing and finishing with the correct cross hatch and surface finish is critical to ensure proper piston ring bed end and gas sealing. I elected to keep the honing to a light surface finish with a shallow cross hatch as the piston rings of the V6 Ecotec are of a low tension, reduced friction, very narrow design.
  2. Piston cleaning: This is one area that was time consuming. Unfortunately, the piston ring grooves displayed heavy carbon fouling and really did require some attention. The method I used for cleaning was by means of snapping the old piston rings in half and using the sharp edge of the piston ring to scrape out the carbon by pushing the old ring in and around the ring groove. Soaking the pistons in parts washer solvent helps to soften the carbon.
  3. Cleaning: I cannot emphasise strongly enough the need for meticulous cleaning of all engine components before assembly. Time spent cleaning and preparing is critical for professional engine assembly and will eliminate premature failures upon start up etc. Clean and prepare bores by means of washing with hot soapy water. Immediately after cleaning, ensure all cylinder bores and bearing surfaces are lubricated to prevent surface rust. I fitted new welsh plugs and painted the engine block prior to assembly.

Short block assembly:

  1. Check all ring gaps: Quick and easy operation to ensure ring gaps are to specification. Also eliminates the rare possibility of obtaining an incorrect ring from a mistake in packaging. Simply push each piston ring squarely down the cylinder bore to a depth 5-15mm and measure ring gap using feeler gauges. (An inverted piston is ideal for pushing down and squaring ring)
  2. Installing pistons and fitting new big end bearings: Liberally lubricate pistons, rings, small and big end bearings. I fitted new big end bearings. To ensure bearing clearances were to specification, I performed a quick clearance check using flexi gauge.
  3. Rear main oil seal: The early V6 Ecotec's suffered from terrible rear main engine oil seal related oil leaks. To ensure this engine was going to be oil leak free, I replaced the rear main oil seal and alloy seal housing as a complete unit. GM Part No: GM-12585248 is the most up to date part number that supersedes every thing from VS through to VY and now comes complete with a revised rear main oil seal.

Photo 4: Short motor assembly complete...


Beautiful isn't it...



Photo 5: This photo displays the new Performance Camshaft and Multi Keyway Timing Chain and Sprocket set...


The decision for camshaft selection certainly made for some serious debate. Without question, an engine camshaft is the most influential component for determining an engines performance and overall design intent. The build up of this engine certinly proved this point...!!! My research and consequent final decision on camshaft selection sent the stress needle well into the redline.

Initially it was my intension to select a combination camshaft and fixed software package (Computer chip or Memcal) as this seemed the quick and easy way to go.
Whilst I have absolutely no doubt that camshaft/fixed software packages provide very credible performance gains and there is certainly no argument that they will work very well and perhaps are good value for money, I was simply failing to be convinced they would give me the performance edge I was looking for from this build up.

After discussing this issue with many people and taking several aspects into consideration, I just couldn’t get my head around the simple fact that “every engine is different” and who is to say that what may work in one engine may not work well in mine. For example: Exhaust design and configuration, variations in compression ratios, induction system design and modification, overall engine condition characteristics and even variations in climate will all have an affect on an engines performance and specific tuning requirements.

What if this engine did not make power or meet my expectations? Having no further capacity to make adjustments to the engines tune state would mean I have reached the end of the road with a poor outcome.

To overcome these concerns I decided to select a camshaft, from my research, that I felt would deliver the level of performance I was trying to achieve and install a programmable ECU (refer to photo 16)

The camshaft chosen was a Crow Cams Stage 3 grind. Part No: 8531563. This camshaft is about as big as you can go using a naturally aspirated engine and running a standard torque converter. To allow precise camshaft degreeing, I also fitted a Crow 9 Key Way Timing Set. Part No: CS6VS

Special thanks to Ron Spencer from Crow Cams for assistance, technical and product information provided during my camshaft research.

Photo 6: Camshaft degreeing...


From my experience of rebuilding engines, I have learnt and cannot place strong enough emphasis on the importance of camshaft degreeing or timing. Checking camshaft timing takes a little time however, establishing and setting camshaft position as per the camshaft grinders specifications can pay enormous dividends in performance.

With camshaft replacements, the chances of the camshaft timing being to specification using standard camshaft timing components in the straight up and down position (aligning factory dots) is very rare due to the many variations between engines and associated components.

For the My Street Car V6, I used the intake lope lift @ TDC method. The camshaft degreeing operation certainly resulted in a surprising outcome. To safe money, I thought I would reuse the original timing chain and sprockets, pending camshaft timing, as these parts were still in very good condition. However, upon installation, it was noted that the camshaft was 6-8 degrees retarded which to say the least, is considerable. To verify this result, I then installed the Crow Multi Keyway Timing Chain Sprocket Set at 0 degrees (Timing marks straight up & down) and the results were exactly the same. There was now no question that this camshaft was retarded at factory specification and installation and assembly at this setting would probably have left me wondering why the engine made poor power gains. Our camshaft degreeing operations concluded with the timing sprockets set at the 6 degree advanced marks to achieve the camshaft card specifications. Whilst this setting did concern me due to the variation from factory specification, I did recheck my work several times with the result from each check being exact every time.

Do not under estimate the power of cam timing...!!!

Photo 7 & 8: Cylinder head preparation...




As the design intent of My Street Car is to be a “budget streeter” my primary objective with the cylinder heads was to recondition them to as new condition with some basic modifications that would allow a marginal increase in gas flow.

The modifications incorporated into these cylinder heads include:

  1. 3 angle valve seat cut: A 3 angle valve seat cut consists of a 2nd & 3rd angle cut above and below the valve seat angle. These extra angles open up the valve seat area allowing increased gas flow past the valve head
  2. Back cut on valves: This shallow cut removes sharp angles allowing a smooth gas flow past the valve head.

These are low cost yet proven modifications that would be a standard requirement in all performance cylinder heads.

Special thanks to Ben at Central Coast Clutch & Brake (Coast HEADMASTER Division) for the high quality of workmanship crafted into these cylinder heads.

Photo 9: Engine long motor...


Nearing completion and awaiting external bolt on sub assemblies and components.


Photo 10: Fuel injector service...


This photo displays the engines fuel injectors installed back into the fuel rail and ready for fitment back on to the engine.

A definite mandatory minimum requirement when upgrading an engine is to ensure the fuel injectors are serviced and cleaned. Over looking this aspect of the fuel delivery system will be your undoing as an engine will not run efficiently, let alone make any power gain, with blocked fuel injectors.

All fuel injectors in service will over time slowly become dirty and carbon fouled reducing fuel flow rates and spray pattern quality. Quite often this gradual deterioration of the fuel injector goes unnoticed as the driver of a vehicle becomes accustomed to the slow rate of change. However, eventually fuel poor fuel economy, significant loss of power, poor idle quality and in severe cases an engine miss fire will occur as a result of excessively blocked fuel injectors. In many modern lean running fuel injected engines, we have found that a fuel flow reduction of as little as 3% is enough to cause a noticeable deterioration in vehicle idle quality and drivability. It’s amazing to see just how an engine comes back to life after only having a fuel injector service.

Using a quality in tank fuel injector cleaner at regular intervals and /or the use of Premium Unleaded Petrol will help maintain a fuel system to a high standard.

Special thanks to Phil Timmins / Woy Woy for servicing our fuel injectors.

Photo 11: This photo displays the serviced throttle body, new fuel filter and fuel pump installed into its mounting bracket ready for fitment back into the fuel tank...


As we are now chasing more power from of our engine, a bare minimum requirement was to ensure the fuel system is running at least to manufactures specifications. A new fuel pump and fuel filter was fitted to ensure this requirement was achieved. The fuel pump in a Multi Point Fuel Injected engine is a high pressure unit (240-260 kPa) that is designed to deliver a rate of fuel well beyond an engines normal operating requirements.

The standard fuel system in this configuration has so far delivered the fuel system performance required for the new engine.

Servicing the throttle body is a simple operation involving the cleaning and removal of carbon and dirt deposits that build up in and around throttle plate area and idle control valve and ports. A clean throttle body will ensure optimum idle quality and air flow.

Photo 12: Engine assembly complete...


This photograph displays the engine assembly now complete with most external accessories bolted up and ready for installation back into the vehicle. Check out the Pacemaker Headers. There is something about a quality set of headers that demands your attention. This engine is ready for business...!!!


Photo's 13 & 14: Engine installation complete including the fitment of a Cold Air Intake system...





All systems are go, we are ready to hit the road...!!! This photo also displays the fitment of the Cold Air Intake (CAI).

A key element in the quest for engine efficiency and increased power output is improving an engines ability to breath. A low cost yet highly affective means of achieving this is with the fitment of a Cold Air Intake system. The CAI is where the air induction track begins. The primary function of the CAI is to allow the maximum possible entry of clean cool air into the engine. It should be noted that cool air contains more oxygen increasing the density of the air being consumed by the engine. Cool air with increased density (high oxygen content) will result in a more complete combustion process increasing engine efficiency and power output.

Have you ever noticed that your engine sounds better and has more power when driving on a cold day or even early in the morning or late in the evening when ambient temperatures have dropped. This is because the inlet air being drawn into your motor has more oxygen (high density air charge)

A high quality, professionally developed CAI also creates a ram air effect as vehicle speed increases. You can liken this principle to the effects of holding your hand out the window of a vehicle travelling at speed or perhaps even the resistance of air you feel when you are riding a bicycle etc. By harnessing the force of this air flow, by means of a CAI system, a ram air effect will be created (air now being pushed). Directing this ram air into the engine via the engine induction system will significantly increase the engines breathing capacity.

For My Street Car, I used the CAI system that is factory fitted to the V6 Super Charged model. These are Holden Original Equipment components and are a direct fit to the standard naturally aspirated V6 model. Installation takes only 15-20 minutes. To compliment the increased breathing capacity of the CAI and modified motor, I also installed a K&N high flow air filter.

Listed are the Holden parts numbers:

Ducting assembly (Intake): PN: GM 92053314
Inlet assembly (Intermediate): PN: GM 92053315
Body assembly (lower air filter housing): PN: GM 92053006

These parts are available from any Holden Dealership and are very reasonably priced.

Photo 15: This photo displays the front section of the exhaust system fitted to My Street Car...


The exhaust is one area of the engine build up phase where I received a good response from various Exhaust Specialists and Manufactures that I made contact with when conducting some product research prior to commencing engine teardown. I feel this fact alone just goes to prove there is strong confidence by after market Performance Exhaust Manufactures that no matter what level of modifications are being carried out, that there is significant power gains to be made with exhaust modification. It has always been generally accepted that worthwhile and noticeable gains in engine performance are possible when upgrading an exhaust as a single modification, even on standard motors.

It should be noted that there is more to exhausts than most of us realise. In fact, exhaust tuning itself is a real science. There are so many factors that should be taken into consideration when designing or selecting an exhaust for a particular application. Engine displacement, level of modifications and intended usage are just some serious factors to be considered. An interesting point is that bigger is not always better. Power can actually be lost by over exhausting an engine (piping diameter to large) that does not have a level of modification to match. The vacuum effect (scavenging) of the header and exhaust will be reduced with large diameter pipes dissipating heat at an increased rate which creates a denser/heavier gas that requires more effort to push due to the cooler gas's increased resistance to flow.

The following is the exhaust specification chosen for My Street Car:

  1. Pacemaker Headers. Part Number: PH 5039: Whilst I honestly believe there are several quality headers in the market place, I was particuly impressed with the Pacemaker overall design and pipe configuration. The Pacemaker Headers are of a fully tuned design incorparating equal length piping. The quality and design of the Pacemaker product is exceptional and I felt strongly that this product has been researched and designed for actual performance gains not just as a standard replacement part.
  2. 2 1⁄2 inch Hi flow catalytic converter: Factory fitted Y Pipe retained and modified to allow connection to headers and high flow catalytic converter.
  3. 2 1⁄2 inch single system: Locally fabricated and incorporates both a main muffler and rear resonator that are of a straight through design. (No power robbing reverse flowing baffles)

Making a decision on the configuration of exhaust that I should use wasn't an easy choice. As the level of modifications for my engine were becoming more considerable than initially planned, it could be argued that a twin catalytic exhaust would have been more suited and possibly resulted in a slightly higher power output. As this is a budget type build, I decided to trial the single system to keep costs down. Having said that, I am on a learning curve and a lot of what I am doing will be learnt simply from trial and error. As it turns out, the engine is performing well and making very credible power. Would a twin cat exhaust have provided more power...??? I'd love to find out one day...!!!

Whilst I received great feedback from several persons, I would like to make a special thanks to Mike Richter who represents Pacemaker Headers as a Partner and is involved with Product Research and Design. The level of information received from Mike included a 3 page product information bulletin and technical guide that was loaded with interesting and informative information. This information was a great read and of great assistance with several aspects of this build up including engine design theory, modification considerations and consequent component selection.

Thanks also to David Creman from Carline Mufflers in Gosford for assisting with the exhaust design and for the workmanship crafted into the exhaust fabrication.

Photo 16 & 17: Photo 16 displays the Haltech Interceptor Piggy Back ECU and wiring loom. Photo 17 displays the Haltech front page tuning screen that is used to make adjustments and monitor performance change.






As mentioned with notes for Photo 5, it initially was my intension to install a combination camshaft/fixed software package. As per this information, I was reluctant to deviate from this plan. Fortunately, I feel I am able look back and believe I made the right decision.

Tuning this engine with the Haltech ECU has been the most fun I have ever had tuning an engine. No drilling out jets or making manual timing adjustments etc. All tuning is conducted from the driver’s seat, via a laptop computer.

For this application, I decided to use the Haltech Interceptor Factory Piggy Back ECU. This Haltech unit is fitted in parallel with the vehicles factory ECU. The great advantage of this set up is that by retaining the factory ECU, all factory engine settings are retained with the capacity now to make fine adjustments as required. It should be appreciated that the factory tuned ECU has been the result of literally hundreds of hours of development by expert personal from the vehicle manufacture. The final validated settings are no mistake and are locked in to provide optimum performance and economy for a particular load setting and application. Retaining the factory ECU means you also retain the vehicles valuable factory settings that provide good drivability and economy at light loads etc.

However, whilst the factory ECU will compensate for some change, there is a point where tuning intervention is required to optimise the performance modifications carried and mechanical deviation from factory design.

This is where the Haltech is brilliant. You really are in command with your tuning, having the scope to make unlimited changes. The software package is fantastic and the front screen a work of art. I am blown away with this product, its operation and tuning power.

Upon start up with factory settings, the car actually ran quite well. It wasn't until I started making on road adjustments that I realised that there was now so much more potential. On the dyno, the first run resulted in approx 125kw. After just 2 x adjustments we were into the 130kw zone. Having the capacity to make changes gives you full control of your tuning options. The outcome is now in your hands...!!!

I would like to make special thanks to Scott Hilzinger and Paul Davis from Haltech Engine Management Systems for the product information, recommendations, technical information and general assistance provided whilst I was searching this option.

Well, its time now to rest the engine for while and concentrate on the Chassis Dynamics development.


back to top




Stage 1
Engine & drive line

The Game is on

On the Dyno

The journey continues

Stage 2

Stage 3
Steering & suspension

Stage 4
Wheels, body & accessories