Hello fellow Diesels,
Thank you for all the responses. My plane is BD-4 experimental, already built ready up to the fire wall, waiting for a suitable Diesel engine. I’ve broad margins regarding weight and power. The plane can be equipped with engines between 118-350 HP. First, as we are in Sweden, I've been intending to fit it with the Volvo D5 common rail, all of aluminium, even the block, 183 kg by 163 HP, a marvellous engine. However 5 cylinders plus the high pressure pump on the front, make the engine very long, resulting in that the PSRU (propeller speed reduction unit, weighing approximately 25-30 kg) is coming to a place far too much in the front. This fact can be compensated only by placing lead (dead weight) at the back of the plane as counterbalance to retrieve the essential Centrum of Gravity. That’s why I consider that a VW engine is more suitable. I’ve already made some sketches which show that the whole driving unit (engine and PSRU) can be placed under the original cowling made for a Lycoming engine. The penalties are: A relatively heavy engine, although it is lighter than the Volvo (the VW block is of cast iron, not of aluminium) and some less power, 130 HP versus 163. Hence I think the advantages are more. Presumably, the power of the VW can be screw up for a of couple of minutes to 150 HP for take off. As well the VW is much more shorter than the Volvo the balance weight in the back can be diminished or in best case completely eliminated and finally, the VW PD is representing the latest generation in Diesel technology contra Volvo which is a Common Rail. If you think of the fact that a Lycoming or a Continental engine of today doesn’t differ much compared to their 50 years old ancestors (except their selling price) you probably understand my endeavours. Gremlin has recommended the Thielert engine: They have of course possibilities and resources beyond all measures compared to myself. Thielert dismounts completely the brand new original (Mercedes) engine and with many modifications, rebuild it to a flight engine. The ready built and certified flight engine, called Centurion 1,7 rated to 135 HP, suitable for the private and commercial market. Their selling price is extremely high matching to the air market. As I personally am belonging to the group of home builders with moderate resources but with much enthusiasm Thielert is not the solution for me. My present plane with the VW Diesel is my third machine to build. Among us home builders there is very essential to keep down the costs. Therefore my policy is adopted to the experimental category: take a mass produced car engine and in doing so, utilise the latest technology and the acceptable purchase price. Gremlin proposes even to use the VW with distributor pump by 90 HP. As a matter of fact these older types of Diesels are not running as smooth as the ones with electronic injection resulting in serious torsional vibrations hardly disturbing in a car while most hazardous in flight. Regarding a car, the whole body, say about 1000 kg is acting as a linear flywheel damping resonances while in the air the same is replaced with the inertia of the propeller of some kgs and of the inpact of the air. On the other hand I’ve already bought a VW PD which has run just a couple of thousands km in a Passat. I’m not even intending to open the engine but the Steering Box can not be utilised just as it is. It would not have been strange to me to build another box containing the elementary functions only. However, Jan, alias “Jan6K” computer expert, is advising me to keep an original box and to block all the connections
(for instance ABS, EGR, immobiliser and so on) which are not needed in the air. Matthias, alias “MatthiasTDI96” agrees with him totally. Jan recommends for:
“adapting the original box to your needs by just removing sensors (and replacing their inputs by appropriate signals) and interconnections to other systems (such as immobilizer)”
As I do not have any box at present the one which I will purchase later, that has to be reprogrammed concerning the immobiliser functions as well. I’m going to be used more and more to apply an original box. The idea as such seems to be very practical and realistic and I would need some info concerning the same. Is there anyone of you who
can offer some assistance in this matter?
Regards
Tom
tomflyer7@hotmail.com