Supercharging components Holden 6

Aussiespeed has been working on the components including manifolds for superchargers, drives pulleys and tensioner kits Holden 6 cylinder red, blue and black motors. We are going to start at the front of the engine to show what can be supplied by Aussiespeed and some of the additional things that will be required or that you can make or source your own.


Pictured is a Holden 6 cylinder red motor harmonic balancer on the right and a black/blue balancer on the left. The balancers have all the same dimentions except that the rear section of the outer ring on the black / blue is thicker. The timing mark on the balancer on both models are different. You can use a blue/ black balancer on a red but remember the timing mark is in a different position.

When it comes to what brand what material and what type of balancer we could spend hours discussing it. The balancer we are using and supply with street engines is a standard cast factory harmonic balancer that is stripped the seal area is easy sleeved and the outer ring is chemically bonded to the centre hub.


It is a bit difficult to see but you can see small dimples in the the area where the rubber bonds the inner and outer of the balancer. The balancer is placed in a jig to locate every thing perfect then A 2 part rubber compound is injected into the two halves  then the balancer is cooked in an oven for a length of time to enable the rubber to cure. We know there are other companies with other methods of manufacturing and modifying balancers and we have tried most. We dont run our own supercharged or modified engines without a chemically bonded balancer regardless of brand unless we are assured the product is chemically bonded.


This is a powerbond balancer that was supplied by a customer that has had the centre machined to accept the Aussiespeed bolt on lower supercharger pulley and has also been chemically bonded as the rubber had failed.


The step machined in the balancer locates the drive hub and the better the fit the less problems you will have with belt alignment and the crank hub and pulley being mounted centrally on the crank. Simply relying on 3 bolts for aligment would be a bad decision, the bolts hold the hub in place and are not the thing that does the alignment. Sure you can run additional woodroof keys and wider keys that require additional machine work to the crank but we are only looking at supercharging for street engines running mild boost.


This hub is of a Holden 6 cylinder engine and is similar to what is supplied by Aussiespeed without the larger lightning holes. Note the small spiggot in the centre hub it is what does the location of the hub to the crankshaft and balancer. The outer ring of the crank hub extends past the outer ring of the balancer for an added bit of insurance similar to the balancer guard fitted to the xu1 Torana.


With the crank hub fitted to the balancer note the outer ring covers the bonded rubber joint incase of balance failure. The supercharger drive pulley locates to the hub and has 4 bolts to secure it to the hub.


This picture shows a Romac balancer that was purchased new and was chemically bonded before fitting. The blower crank hub differs from the standard Holden balancer and has the location on the backside of the crank hub. The bottom pulley can be switched to be used on any Aussiespeed supercharger drive snout with the 4 bolt quick fit hub.


The drive snout pictured has been converted to accept Aussiespeed quick fit 4 bolt supercharger pulleys, Location of the supercharger needs to be considered when fitting a bolt on style hub.


This is the Aussiespeed supercharger pulley quick fit hub available in various lengths. The hub has a 3/16 key way slot and is supplied with extended center bolt and 4 pulley bolts.

A supercharger installed on a Holden 6 cylinder complete with the belt tensioner, This tensioner allows the use of standard radiator hoses and thermo housing.


We will be adding more info regarding our Aussiespeed Street Supercharging kits and components.





Mounting a Holley Carb sideways

For many different reasons people need or want to mount a Squarebore Holley or Quick Fuel carburetor sideways. If the intake manifold is not drilled for it and you have not got a full machine shop at your finger tips Aussiespeed have an option that requires basic tools to do the job.


The Aussiespeed AS0110 can be purchased on its own or as a kit.


fitted to an Aussiespeed Holden 6 manifold the AS0110 is only 12mm thick and when an AS0201 heat insulator is used only adds another 6mm.


Due to different plenum shapes some additional grinding may be required around the edges. The adapter was made under size as it is much easier to remove material than to add it. You will see there are only 3 studs fitted to the adapter and 3 counter sunk screws that fit to the original threaded holes in the manifold. One bolt 5/16 unc “not supplied” goes through the carburetor, adapter and manifold into an original tapped hole.


The adapter has been designed so the carburetor can be placed closer or further away from the cylinder head. This has been done so if there is shocker tower clearance problems in the engine bay or the carb touches the rocker cover it can be mounted either way.


As engines do not sit flat in a car the angle of the carb pad to get the carb to sit flat does not change.


The 5/16 unc bolt that goes through the carb, adapter plate and into the manifold.


This AS011o is being fitted to an Aussiespeed AS0016 Ford 6 cylinder crossflow engine, with the adapter plate fitted and the plate blended with a die grinder the 3 counter sunk bolts and 3 studs have been fitted.


The Aussiespeed heat insulator is CNC machined from Australian made phenolic material. Its purpose is to keep your carby cooler as it slows heat from the manifold heating the carb and fuel in the fuel bowls.


The Ford 6 crossflow that this is set up on is highly modified and performs better with the carb spacer fitted. A longer bolt with a lock nut was installed to keep the gasket between the manifold, adapter and carb spacer.


Done fitted and up and running and every thing reconnected this engine responded very well with repositioning of the carburetor. Not all engines will see gains from moving the carb sideway, it will depend on cam and cylinder head modifications.


Thanks to Tony from angry X performance for the Falcon conversion pics.



Exhaust Header Wraps

We have been asked about the use of exhaust tapes and wraps  on our Automotive and Go kart header pipes. There are good and bad points about the product but i must say with mild steel pipes and when fully wrapping the pipes “I Would Not Recommend it”.  Exhaust wraps are designed to keep heat in the pipes to improve scavenging of the cylinders. Exhaust wraps reduces the radiant heat of the exhaust in the engine bays and can stop burns on the arms of drivers with open engines like go karts. We do not know of any header or exhaust manufacturers that will warranty their headers if any header wrap is installed. Header wraps damage headers and exhausts beyond repair due to excessive heat held within the exhaust. On go kart engines the extra heat that is inside the pipe can damage cylinder head when operated for long periods.
With the tape removed after this pipe had a blow out you can see that the pipe is to badly damaged to repair.

Nearly all NASCAR and other racing engine builders used header wrap tapes for the added power gains and to reduce heat from hot pipes in engine bays. Due to the operating temps and the damage done to the pipes and headers they had to be replaced after each race. Now days with the advance in thermal coating technologies there are materials that can be applied to give a hard wearing outer finish and when the pipes are coated both inside and out you can get gains in performance and your pipes will live much longer. Thermal wraps and blankets are good to protect under bonnet items from heat, and when applied correctly on hot exposed exhausts on motor bikes , off road buggies and go karts to reduce the risk of burns to the driver. There are companies who produce products and materials that can be used to reduce the heat of your headers heating your starter motor,  fuel and brake lines as well as suspension and inner body panels and covers. On exposed exhausts for long pipe life  cool air needs to be around the exhaust header and pipe to stop temperatures getting that high that can lead to exhaust failure and a simple way we have found to cover a pipe to lessen the change of a driver being burned is by running a thermal barrier along the length of the pipe as shown below.


By adding a piece of thermal tape running along the top of the pipe it still allows air to cool the pipe but does reduce the risk of burns to your body.


A short piece of thermal tape with a hose clamped tightened is a way of securing the ends of the tape.


with the clamp positioned it can be tightened to hold the tape on the flange end of the exhaust.


Stainless steel zip ties can be used to hold the tape secure to the exhaust, remember to place them so it holds the tape and you wont burn your arm on the clamps. So depending on your club rules will depend if you are allowed to run the tape in the class you race in.

Holden 6 supercharger kit Aussiespeed

The Aussiespeed Holden 6 cylinder supercharger kit fits both 9 port red motor and 12 port black/blue motor cylinder heads. The kit is supplied with most components for you to bolt it on with some common sense and basic tools. In the kit we have tried to supply just about every thing you need and apart from the harmonic balancer there should not be any additional machining required.


With our testing we used a chemically bonded Holden 6 cylinder harmonic balancer that was a standard neutral balance  rebuilt factory balancer fitted with an Aussiespeed AS0520 steel balancer hub that extends over the outer ring to stop the “pulley ” “outer ring” from flying forward. The balancer will available from our online store .


We recommend that you use at least a chemically bonded harmonic balancer when fitting a supercharger to your engine. Aussiespeed offer crank and snout hubs for use with aftermarket balancers like powerbond and Romac.


The simple step that is required to be machined into your Holden 6 balancer.


Note the centre with the raised boss, this locates into the machined step on the harmonic balancer to ensure the crank hub and pulley are located on the crankshaft centreline. The lower supercharger pulley also locates on a boss and 4 bolts to hold the pulley to the crank hub. We can supply chemically bonded harmonic balancers with the additional machining required done for not only  Holden but also Falcon 250 2V, Crossflow Ford, SOHC 3.9, 4.0, Hemi 6, Slant 6, Chevy V6, inline Chevy sixes, 240, 300 Ford big 6 and Holden V8 engines. After market steel performance harmonic balancers can also be used but may require a bevel to be machined on the centre to locate the bottom hub or pulley.


We have tried to get the blower belt tensioner to fit with factory hoses and thermo housings and to look neat and use components apart from the arm that can be purchased any where in the world. A drive snout support can be fitted and is recommended when fitting your supercharger, the support mounts back onto the engine block.


The Aussiespeed AS0521  bolt bottom crank pulleys are available with both male or female  stub on the pulley, where room is limited between the balancer and radiator or if you have a wide after market harmonic balancer like Romac, Power Bond, Ross, B&M or another brand the hub may not be required as the balancer can be drilled for the crank drive pulley to be fitted directly to the balancer.

We get many enquiries from people wanting to lay buy there supercharger kit, we know that building a car isnt cheap and rather than killing the credit card or getting a bank loan our payment plan can help you to plan without costing any extra unless there is a big shift in the US dollar that can raise the cost of the Weiand superchargers. Our lay buy system is simple we ask that you make regular repayments, if for some reason you fall on tough times just let us know. We have had customers pay of larger purchases over a 12 month period so dont be scared we will work with you.

The first kit we will explain is the Holden 6 cylinder 9 and 12 port basic kit, many upgrades and add ons are available but lets start with the basics. These kits are designed for street strip type application using most off the shelf parts. If you want a supercharger for an all out race engine or fuel injection and computer controlled ignition systems, or other exotic parts there are lots of companies out there that handle those extra bits you need.

Intake manifold will accept 142 or 144 Weiand superchargers, the manifold is supplied to suit a small block Chevy long water pump drive and a standard size harmonic balancer. The manifold is fitted with a backfire valve kit is machined on the head face and supercharger mounting face. Due to many different flange width and sizes with after market extractors additional triming of the manifold flanges may be required. Another new product available from Aussiespeed are our tubular headers in 1 5/8 for both red and blue motor Holden 6 cylinder engines.

Belt Tensioner bracket and spring loaded mechanical tensioner. The belt adjusting bracket is a sand cast aluminum clamp on style that fits to the machined section on the Weiand super charger drive and replaces the complete Weiand belt tensioner / adjuster including the large spring. The 2 piece conrod style tensioner bolts over the drive snout and the mechanical tensioner bolts to this and rotates to tighten the belt. The mechanical spring loaded adjuster is supplied with a flat idler pulley as it runs on the back side of the supercharger belt.


Crankshaft Hub and the bottom drive 6 rib pulley are supplied to suit a standard harmonic dampner that needs to have a small simple step machined in the centre where it fits on the crankshaft. We can supply a new balancer with the modification or you can send yours to us and we can do the machining process for you. The hubs are also available for larger aftermarket harmonic balancers but do require a hub to be fitted onto the supercharger drive snout also.

A supercharger 6 rib drive belt and socket head bolts for the pulleys and other bolts are supplied for the components supplied to suit the components supplied by Aussiespeed. A snout support that runs from the drive snout to the engine block is highly recommended and available from Aussiespeed, this is something that you may wish to fabricate your self as well as a support bracket from the manifold to the engine block.

So what you get for your money you can add extras but for the guys who want to workout bonnet height, radiator clearance or fabricate extra parts them self this kit includes the basics.

Machined satin finish Holden six Blower manifold.
Sand cast tensioner arm and mechanical tensioner assembly.
Steel wide face crank hub and 6 rib steel pulley 70mm .
Supercharger6 rib belt and required bolts.

Extras we can supply as additional components are Drive snout supports, manifold to engine block supports, Aussiespeed Big Tube Headers, ignition systems, Quick Fuel carburetors, Weiand Superchargers and spare parts as well as a range of different crankshaft adapters, many sizes of both 8 & 6 rib pulleys, bolts, fasteners and many other of the shelf components to complete your project

For Current Pricing on 12 Port Kit Click Here

For Current Pricing on 9 Port Kits Click Here


Superchargers importing or buying used

With the release of many of the manifolds and components related to the Aussiespeed street supercharging range, we thought we would let potential customers some of the superchargers that can be fitted to the Aussiespeed manifolds.


Aussiespeed manifold with the blower pad to mount the 142/144 can be purchased undrilled if you are wanting to build your own kit.


Supercharger base plate allows the fitment of an M90 Eaton to Aussiespeed manifolds and can be purchased not machined for your own custom install.


This allows fitment of the Weiand 177 supercharger to a 142 or 144  manifold


This makes fitting the M112 Eaton supercharger to a 142 or 144 manifold a lot easier

The Aussiespeed manifolds based on the 142/144 Weiand, Holley and B&M bolt pattern all use the drive from the small block Chevrolet V8 long water pump this is the correct length and on some models a top pulley coupler is supplied to get the correct alignment. The part number of the drive is WE-6070 in a satin finish and WE-6071 in a polished finish.


Weiand Supercharger drives are available in polished and satin finish.

On some engines the factory Weiand / B&M / Holley spring loaded belt tensioner is used and on some engines this is replaced by the Aussiespeed unit. The information below is simply to warn potential customers of some of the down falls related to purchasing supercharger kits online from sellers online, auction sites, forums and social media sites. Before you make your purchase remember that when it comes to purchasing over seas it all looks good until you get loaded up with the following fees, charges and unfortunately the conman who troll the internet. We are not trying to scare you into buying from us but just wanted to relay an experiences from a customer recently..


The customer purchased a supercharger from an online auction site in the USA and though great i have found a supercharger for $1200.00 USD buy it now that was listed as a low mileage 142 with all components to fit to a small block chevy.. When the kit arrived in Australia the buyer found.


GST was charged, plus a fee from customs for processing the import, proof of payment { needed a commercial invoice } and nearly got charged storage as the seller didnt not want to forward a receipt and it took around 2 weeks to get a copy of his credit card statement linked to his paypal account. This was allowed for payment proof that attracted a { fee of $53.00 international transaction fee} . The figures below are some rough figures he told us..

Purchase $1200.00 USD = $1411.16

Shipping $295.00 USD = $340.00

GST $175.12 AUD.

Customs Inventory fee $92.00 AUD

Credit Card Fee $53.00

Total. $2071.28 Then a new drive had to be purchased that was around $900.00 so at just under $3000.00 for a used supercharger i hope for the buyers sake the housing isnt warped or the rotors dont have big scours or damage.



Someone advestised a used Weiand supercharger on a race engine parts for sale site, the listing said every thing you would want to see its brand new never used, going a different way with the build, can ship anywhere and all the pictures straight from google. Bargain $900 USD can supply ignition system, carburetor, fuel pump and a bunch of other stuff. The guy though great he can get all this stuff for $1500.00 USD plus shipping the guy said he had a buddy who should be able to get it shipped to Australia for $175.00 USD. The seller said send me $300.00 deposit with an international money sending firm then he would get it boxed up and workout the shipping. The guy in Australia sent the $300.00 USD and has never heard from the guy again. Cash was sent and guess what it couldnt be traced and cooperation from the other end was non existent.. So if he can scam 3 people for $300.00 each its $900.00 if he gets 10 its $3000.00. We are not trying to scare you into buying your supercharger from us all we want to do is to make people aware of some of the things that can go wrong,  Please be careful if it sounds to good to be true it normally is.. We hope this info might save a few people from being separated from there hard earned cash.

In 2015 Aussiespeed will be adding over 60 new products to our supercharging range, this will make supercharging 4,6 & 8 cylinder engine easier than ever before.

Weiand-super-charger-kit new-weiand-supercharger-kit



Ford Pre crossflow Krogdahl engine

This is the engine we hope to slot into the Aussiespeed Slingshot dragster, it is the first Ford 6 cylinder that was fitted with the cylinder head. The engine has done over 250,00000 KM

Checkout our range of Ford 6 cylinder parts manufactured by Aussiespeed by visiting out online store..

as0170r slant 6 aussiespeed valve cover

Slant 6 Valiant alloy Rocker covers available in a range of surface finishes.


Wrinkle black cast alloy slant 6 rocker covers


Bright red Slant 6 valve covers are just a few in the Aussiespeed range.



Holden Krogdahl Head

One of the earliest pictures that we know of of a 6 cylinder Holden fitted with a Krogdahl head and triple DCOE webers was back when Bob was in Townsville


The pipes used on the exhaust were 2 inch and the camshafts had around 650 thou lift, With the way the cylinder head was designed then an engine that would hold together at 10,000 to 12,000 RPM took a lot of refinement, Many of the parts used in the engines were Krogdahl designed, there were some of the shelf parts used but some exotic parts made from exotic materials had to be used on the real big horsepower engines.


The early Holden red motor on a go-power dyno, this engine once sorted did make some impressive numbers horse power wise. Many speculate about the power output but as we have nothing that is cold hard facts we are going to stay well clear of the horsepower numbers game.


The Torana before it had a tidy up and fitting of a cylinder head to a highly modified engine.


From what we have been told the Torana with one of Bobs engines fitted outside his workshop many years before he retired. The Torana is still around with a now fuel injected DOHC  Krogdahl engine.


After all the hard work the boys got to let of a bit of steam, the Torana was ran for many years in the upper parts of QLD.


Another Torana that ran a Krogdahl cylinder head on a Holden 6 was one that came from down in Victoria.

A very short video of a triple weber Holden 202 fitted with a Krogdahl cylinder head, be sure to turn up the volume they sound different.


A prepped Holden 6 cylinder engine That was fitted with a DOHC cylinder head, extensive work is carried out on the oil galleries to keep the bottom end oil flow up.


Early engines used a modified stock Holden timing cover, yes the standard cam is still fitted to the block, lets just say the cam under goes some modification.


A crank trigger is used to fire the ignition system, note the fuel pump drive in the distributor hole.


Engine and belt covers were manufactured to give the factory look, the great thing with the head design was it could be used on a mild street engine right up to an all out racing engine with a reduction in valve size and camshaft lift.


Notice the adapter on the front of the crank, some of the Krogdahl engines were run without harmonic balancers or flywheels. A crank hub with an alloy drive pulley and an automatic flexplate with the rotating assembly balanced and a reduction of the bobweights on the crank.


Check out the Aussiespeed range of Holden 6 cylinder speed equipment by clicking here


Krogdahl head more info.

When we got to actually see our first Krogdahl cylinder head in the flesh we were kinda blown away that something we here at Aussiespeed had discussed had been done before many years ago. We were not going to go the exact way that the Krogdahl was developed. We were and still are looking at an over head valve cylinder head that could be used on a mild street engine through to a competition engine.


The cylinder head has 2 spark plugs per cylinder, an engine with twin plugs is what is used in the aviation industry. Bob told us that the engine can idle as low as 600 rpm and was much smoother when run with a twin ignition system. A distributor is fitted in the valley of each of the camshafts and is timed to fire on the compression stroke. Later model Krogdahl cylinder heads went to computer controlled ignition.


The port design was very much the same as later model cylinder heads the shape of the port and runner was being used back when we were still  young boys. The head is symmetrical and  either side can be used for intake or exhaust manifolds.


The raw casting could have been machined with cylinder head bolts and water passages to suit either Holden or Ford 6 cylinder. The early pre crossflow mustang and falcon engine was a candidate for the cylinder head. The internal core box to make the water passages has gone missing and unfortunately is a major part in casting the cylinder heads.


One of the proto type engines. The fuel injection manifold has twin electronic injectors and with 6 throttle bodies and 2 injectors per port the engines fuel requirements could be handled better at high rpm and when used with a quality computer the fuel curve could be adjusted to deliver optimum performance.


The camshaft drive belt as used on the Krogdahl engine incorporated its own belt tensioner. A timing cover was also cast to suit the Ford 6 engine that made up part of the cam drive.


Different styles of valve covers were cast for the Krogdahl engines, these ceramic coated headers were also designed and built to suit the Krogdahl head to fit Falcon and Mustang body styles. As you can see the picture was taken in 2008.


An old picture of Bob with the Ford EA to AU style SOHC engine fitted with a DOHC head fitted to a Falcon engine a few years before he retired , Bob had traveled over 250,000 KM with the engine in one of his own cars.



Krogdahl Cylinder Heads

Ever since i was a kid i was interested in cars and engines, i think i brought my first car magazine at around 7 years old i borrowed books from the library and found myself reading car magazines, Street Machine & Van Wheels, Performance Street Car, Custom Rodder, Vans Utes & Trucks, Street Rodding just to name a few. As well as technical books related to cylinder heads, engine performance, cams and valves, superchargers the list went on.

One issue that i do remember was about a guy in Townsville who had designed, refined and built his own DOHC, hemispherical, crossflow design twin spark plug cylinder head that could be used on a few different inline 6 cylinder engines. That guy was Bob Krogdahl, It was in 2014 after trying to track Bob down for a few years that we first made contact and after many phone calls regarding the tooling, patterns, core boxes and specialised machining tools some of which have been destroyed or gone missing a meeting was arranged. Bob is in his 70s and has been retired a few years and has many other interests now outside of automotive. Bob flew down to Adelaide and after some idle chit chat a large packaged was put up on the bench and there it was, an early casting that had many imperfections and was not able to be used on an engine. I had finally got to see a Krogdahl cylinder head in the flesh and to meet the man that made it all happen.


Page one from street Machine Magazine. Click on the picture to enlarge.


Page two of the street machine magazine, click on the image to enlarge.

It took Bob 20 years from when he first started the cylinder head to getting the first engine running, As Bob said the first head was fitted to a Holden red 6 cylinder engine fitted to a 6 cylinder sprint car. To start with they laughed and mocked Bobs idea but it wasnt long until people started to change there mind as more development and refinement was done and the sprint car be come a front runner.


On Sunday the 21st of October at 5.15pm in 1990 the first Krogdahl cylinder head took its first breath, Bob tried to get it published in the birth notices in the local paper but wasnt allowed so it was put in the general notices. So it was 20 years in the development, untold amounts of money and no one kept a record of the hours spent over the 20 years.

The Video is of a later Holden 6 cylinder fitted with motec fuel injection and a Krogdahl cylinder head. This engine was one of the later engines built after many of the refinements had been done on earlier engine fitted with the Krogdahl twin cam cylinder head.

The knowledge, experience and theories of somethings that i was lucky enough to talk about in the time i spent with Bob was one of the highlights  of my time in the performance industry. Bob retired around 2004 and with only around 12 completed engines built the engines are some thing i would classify as rare.


We have over 2000 photos and a few videos of the development and processes related to the Krogdahl head that we will be adding to these pages.


aussiespeed manifolds rocker covers carb scoops performance speed equipment


Aussiespeed Blower to manifold adapters

With so many different superchargers available and so many different engines that customers want to fit a blower that wont blow the bank the basic bolt pattern on most of the Aussiespeed supercharger manifolds are based on the Weiand 142 or slightly larger Teflon rotored Weiand 144 .


Ford 6 cylinder EA to AU sohc manifold with the base plate mounting for the Weiand 142 and Weiand 144. From this standard bolt pad Aussiespeed have a range of adapter plates to fit other superchargers.


This is the casting to fit the larger Eaton M112 to the Aussiespeed range of manifolds that will accept the 142/144 Weiand supercharger, the scooped area allows the bypass valve that is built into the supercharger to be fully operational.


The Eaton M112 supercharger can be fitted with the Aussiespeed AS0512 adapter, For fitment of the M90 GM style supercharger Aussiespeed AS0510 is the part number.


The rear top entry was designed for fuel injection, we have a few intake systems also under development.


The M112 dummy fitted up to an AS0038 Chevy inline supercharger manifold, We hope soon to have the proto type supercharger drive snout finished that will be available in various lengths and will be made right here in Australia.

Aussiespeed High Performance and Racing Engine Products