Update - we've been very remiss on the reporting of the progress - more coming soon. One very interesting thing that transpired recently was the discovery of what engine was used in this car. Here's a little background. There are basically three different types of engines used in the 956/962 over it's career:
- An air-water type first developed / used with "Moby Dick" in the late 1970s.
- A more developed version of the air-water engine that used no air cooling at all (water-water)
- A fully air-cooled engine that was used in the IMSA racing series over here in America.
As I mentioned above, the air-water engine started out life as a development for the "Moby Dick" 935:
Running a displacement of a little more than two and a half liters, it had the traditional Metzer-style engine bottom end with new water-cooled heads. I believe the reasoning behind going to the four-valve heads (as opposed to the two-valve heads on the air-air motors) was to allow for more air intake and better efficiency during each intake cycle. Doing so then facilitated the need for water (antifreeze, etc.) to be used to cool, as I don't think there was a way to design a four-valve head that would cool adequately, etc.
On a side note, the IMSA air-air engines were really nothing more than a 935 engine that was transplanted into a 962. I generally call these 935 engines, and the 962 engines name I leave for the air-water engines. As most everyone knows, these air-air engines were highly successful in America too (we have the 1987 and 1988 Sebring winner which has one of these engines).
Back to the car featured in this post - 106b. So, in 1987, Porsche introduced the "new" water-water motor, and installed it in their factory cars (which gave the factory teams an edge). (
Side note - they also used the first PDK automatic transmission that year which performed very well on the track, but was not yet reliable enough for endurance racing.). So, back in 1987, you could only get one of those water-water motors if you were a factory team. Or so we thought.
Trevor Crisp of Katana LTD in the UK (the chap restoring 106b for us), found this very entertaining photo from the 1987 season:
So, if you look carefully, you will see that this is a water-water engine, being raced by the RLR LiquiMoly team in 1987! Not sure how or where they got the "newer" engine, but someone must have known someone at Porsche. Photo-documented evidence, otherwise, I would not have believed it. You can also tell from the coil mounted at the rear of the engine, the air-water engine coils are mounted on the fan housing (no fan on this one).
So, a very rare breed indeed. Back in March of last year, I bought a *ton* of extra engines and 962 parts left over from Dahmen racing. As part of the deal, we were having two air-water engines assembled. But, we decided mid-stream to change course and have the 2nd engine rebuilt as a water-water engine. This would make it very unusual and also now historically correct. Here are photos of the engine, almost complete (this photo has the wrong fuel rails on it, as we are going to be using the older-style fuel injection, which is what they ran in the car in 1987 - newer long block, with the older-style 1.2 BOSCH Motorsports Motronic system). I think the factory ran one or two cars in this configuration, but no one else:
So, there you have the update on the engines. I saw our email newsletter went out with a nice fancy picture of the old engine, and I thought I would update with the new info!
-Wayne