More Powerplant Ponderings

I wish I knew enough about this stuff to make sense of it.

Thanks to TuuSaR in comments, I have some sort of confirmation that Saab still have some ongoing interest in the SVC engine. The confirmation comes by way of a European patent that was applied for earlier this year. As I said, my technical knowledge is very limited, but the patent application does state that:

An object of the invention is to provide a reciprocating engine having a variable compression ratio and having a compact design.

The patent application gives all sort of details about it and some diagrams that were waaaay over my head. You can view the application here.

The important thing, for you and I as average punters, is that this technology isn’t dead. Hopefully there’s some light at the end of the tunnel. It’s innovation like this that, if successful, could extend the life of the gasoline engine. And the life of Saab Automobile AB.

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  1. That’s really weird. The SVC engine was unveiled in prototype form in 2000. Nothing was heard of about it again until we started discussing it here and at SAABCentral, as well as a comment I made at the GM blog. Then lo and behold a few weeks ago they apply for a patent? Weird timing.

  2. Gripen,

    They actually filed the application in February 2005, but the timing of the publication (31 August) is quite a remarkable coincidence.

    It’d be interesting to see if any comment comes forth from Saab about it, or if any could be drawn from them.

  3. I had been posting quite a bit about it over at SAABNet around that period and before, before being banned and having all of my posts removed by SAABNet’s owner. I know that there have been SAAB employees reading the boards over there. Maybe someone saw one of the posts! Or maybe it’s just coincidence.

  4. Thanks for pointing this out. I missed this on the U.S. PTO site (Appl. 20050183680) because SAAB isn’t listed as the assignee, but is listed as applicant on the EU site. This is completely different than their previous patent (U.S. 5,562,069) applied for in 1993. The one previously discussed tilted the whole head assembly, including the cylinder liners. This looks much more promising because it only moves the crankshaft, and should elimiminate the leakage/noise problems associated with the bellows. Since the crank flange must not be moved vertically because it transmits power to the transmission, there is a coupling between the crank end and the flange (sort of a rod with pins arrangement) to which the flywheel is mounted. Hopefully, it’s reliable. If they can quiet the supercharger, this looks great. I’m only a little concerned that their claims were drafted a little on the narrow side, too detailed. I would hate to see a competitor design around the patent without paying licensing fees. Now I’m excited about SAAB again!

  5. Ted, thanks for translating some of it for me. From my limited understanding, it did look diferent to the previous system, but I wouldn’t have had the confidence to say so.

    It IS exciting, isn’t it. Let’s hope GM has the cohunas to back it in.

    Gripen, you were banned too? Chalk up another one for Scott’s shitlist.

  6. Someone is going to have variable compression engines sooner or later. I never realized how much work is being done in that area. A quick search of the US PTO published applications revealed this:
    Ford is working on a variable length connecting rod (20050150471),
    Someone else has a barrel engine mentioning the problems with Saab’s tilting head, which also says SAAB has the best solution offered so far (20050145207)
    Someone else has a subsidiary arm which seems to shift big end of connecting rod (20050061270)
    Honda has an inner/outer piston arrangement (20050056239)
    Toyota has movable cylinder block similar to SAAB’s tilting head (20050028760)
    Check them and more out here:

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