Hi all this is now the third time it has happened.
There is a lot of people out there who like to belittle things which they know nothing about.
I started making my fanshroud in 2000 it happened after our clubs tour to the south coast in december 1999. one of the bugs that drove down that time was owned by a friend and had a 2.4 liter type four with an upright conversion built by another friend of ours Hermann Ortlepp (Herman was racing verskrik and had a type four turbo drag bug which had a top speed (measured at 230kmh)) his conversion took a early non doghouse shroud and had a kink in the middle to even the airflow. the oil cooler was positioned under the nose of the car and it ran quite well. we were sitting on the beach one night and were bench racing. i suddenly made up my mind and told everybody that the year 2000 will see me build a proper upright conversion. we decided that it needed to seal the engine compartment and as we also had issues with leaky high pressure hoses we decided that the cooler was to be left in the stock position. Another friend Daan Jacobs said that the first one was to be his and when we got home he dropped a 1700 sub assembly at my house. i cut open a late beetle fan housing and noted that vw had a very complicated path for the left bank of cylinders. Discussing this issue with one of the ventilation experts at the mine where I worked he pointed out that the direction of rotation of the cooling fan favoured the right bank of cylinders. I measured areas and found that considerably more space was used for the left bank of cylinders in order to balance flow. VW used this imbalance also in order to duct air to the cooler and this I copied directly.
VW also used no less than 9 directional fins to direct airflow and they are of a proper airfoil shape which I did not copy directly choosing for practicality's sake to mold them from one layer of fiberglass. the front and rear tins were made from modified beetle pieces as well and copied in fiberglass. The first prototype ran in late 2001 and is still running in Daans Beetle with over 80000 km done.
Some info as to who copied who.
I copied VW's late fanshroud layout almost to the letter except for the revisions neccesary to fit onto the type four block ( the buck for the molds is still in my possesion and is a relatively crude afair consisting of sheetmetal the remains of a late fanshroud and type four upper tins.
The centering of the fanshroud I copied from Hermann but also saw it in a small advert in a VW trends magazine during the late 80's early nineties this ad was about 50 by 50 mm and was by a company called Oregon performance. I did not agree with the lay out of the DTM setup as the left side was to small in my opinion. By this time I had very limited acces to the Shoptalk Forums and also saw Joe the originator of the DTM's posts. I realy was impressed by his knowledge and although I differed from him in some aspects was very sadddened by the reports of his death. A very old photo of a corvair experimental engine was shown to me by my uncle around this time, this engine was from the corvair Astro project being a flat six overhead cam engine built in the early sixties (1966). this engine was featured in early hot rodding mags in the US and showed three cooling fans running of a common shaft these corvairs had a horizontal fan setup as standard but this engine had what ammounted to an upright conversion, the 3 fans was situated in such a manner that each fan cooled two cylinders. looking at these fanshrouds they seem to be very similar to what I had in mind:
http://www.corvaircorsa.com/astro1_02a.html
Remembering that a corvair engine runs the opposite direction to a beetle the humped appearance sprung to mind as first being wrong and then being right. having one cylinder to cool these shrouds also had to be cranked to cool each cylinder fully. I am sure that Joe must have been aware of this design as it was widely publicised in those years.
So as to the fact of who actually copied who and whose actual bits of a design can be incorporated into whose work I really can not say and will leave it at that.
I will say this though I have never seen a DTM in the flesh,I have never owned one and to the best of my knowledge there is not one such a fanshroud within 200 km from my home.
I designed my fanshroud from scratch using ideas of others.
I built the buck
I built the moulds
I made the pattern for the generator/ alternator stand myself
I designed the pully and had it made.
I set out to build ten conversions when the project was started as the type 4 was really not a well known engine in South Africa.
The goal was reached with Eugene's engine And I am extremely happy that some one without having the resources of any of the big aftermarket companies can actually build something like this and having it work.
On his engine I built the shroud, the intake manifolds the alternator stand, the oil filler and the carb linkage. the throttle bodies are by Precision race built in South Africa the innards of the engine which was not assembled by me was also done with South African inginuity Yes we bought some imported parts: a set of EMPI Plug wires.
As for the name IMPI yes it is a play on the great EMPI the difference is that
I took this name in the early 80's before the company was resurrected. An Impi is a group of zulu warriors much like a battalion of soldiers but can also mean a very quarrelsome person and those people who know me well can attest to that.
I would like to request every body to please stop giving all those armchair experts the satisfaction of writing nasty comments. I am not about to sue any body or pick a fight with any body over who was first
In my book anyone that can actually build a fanshroud is welcome to copy any of the features that I have used. I am available to anyone for a discussion as to why I shaped this that way or this way and even critisism is more than welcome provided you know what you are talking about
In my mind VW comes first especially if it has an aircooled heart.
Regards
Armand
The air cooled scene is supposed to be about sharing knowledge and passion for all things air cooled. well at least in our country it is! Impi will always have my support and i WILL market his product here to everyone that i can!