Announcement

Collapse
No announcement yet.

Kermit Weeks Napier Sabre hot-rod?.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    Re: Kermit Weeks Napier Sabre hot-rod?.

    Advances in metallurgy/heat transfer knowledge, high-silicon low-expansion piston alloys
    & low-friction plasma/nikasil-type coatings over the past 7 decades have come a long way..

    The Napier Sabre was right up there specific output-wise for big `40s recip' aero-mills,
    but there is no reason why the current techniques used in building reliable ~440hp/ltr 2-stroke G.P.
    bikes could not be investigated too..

    Comment


    • #47
      Re: Kermit Weeks Napier Sabre hot-rod?.

      Originally posted by J.A.W. View Post
      If you want to see another [very interesting] way of firing 2 at once..

      Check out the Napier Deltic mill..



      - As used by the USN in the `Nam - to power its 'Nasty' class fast patrol boats..
      Ah, it doesn't really fire "two" at once. One cylinder at a time, the fact that the cylinder happens to be occupied by two pistons is immaterial.

      By the way, if you look closely at the animation of a Deltic, you can see that (like the American Fairbanks-Morse opposed-piston diesels) the two pistons don't really meet in the middle simultaneously. The exhaust-side piston arrives first and has already started back down on its power stroke by the time the intake-side piston arrives at TDC. In the F-M engines, all the exhaust pistons are on the lower crank and all the intakes are on the upper crank, so the timing is achieved with "lower-crank lead" of a few degrees over the upper crank. This allows the exhaust ports to close first and open first improving scavenging and for the blower to over-fill the cylinder while the intakes remain open, as well as delivering a bigger percentage of power to the lower crank, leaving less to be tranferred from the upper crank through the vertical quill shaft, especially since a big chunk of the upper crank's output goes to spinning the blower even before factoring in lower-crank lead. The Deltic is... as I said.. balls-out weird and its not that simple. But the exhaust pistons do all still lead their intake counterparts for the same improvement in scavenging and allowing the blower to over-fill the cylinders for effective boost. Getting all that to work requires spinning one of the cranks the opposite direction to the other two- which was the "ah-ha!" moment that made the deltic workable.

      Comment


      • #48
        Re: Kermit Weeks Napier Sabre hot-rod?.

        Ah, I think you'll find that 2-cycle mills fire every time they reach the combustion chamber..
        & since in the case of the Deltic, 2 pistons form that together..

        Comment


        • #49
          Re: Kermit Weeks Napier Sabre hot-rod?.

          And for some strange reason, this is the second time today I've found myself talking about Napier Deltic diesels. So I just happen to have some Youtube video (and mainly audio!) cued up already. Nothing, except maybe a flying saucer, sounds quite like a Deltic. Crazy Brits... but I love it:



          and

          The first start of the engine after the coolant system has been modified to work with a Serck hydrostatic system. Answers on a postard to the follwing quest...


          On 20th September 2003, at Barrow Hill, Class 55 Deltic no. 55019 'Royal Highland Fusilier' erupts as she takes a small train + sister loco D9009 'Alycidon' ...




          4th November load bank run. 1200rpm approximately 450hp. The oil on the side of the loco is caused by a) a larger than usual amount of oil passing the pisto...

          Comment


          • #50
            Re: Kermit Weeks Napier Sabre hot-rod?.

            Originally posted by J.A.W. View Post
            Ah, I think you'll find that 2-cycle mills fire every time they reach the combustion chamber..
            & since in the case of the Deltic, 2 pistons form that together..
            But that's still just one cylinder at a time.... Its all about how you count when there are more pistons than there are cylinders.

            It really never makes much sense to fire two cylinders simultaneously in an engine unless its essential for primary balance. Smoothing the power delivery usually trumps higher-order imbalance, which is why none of the myriad configurations of, for example, the 71-series 2-stroke Detroit Diesels fire simultaneous cylinders, even though it makes for some funny crank layouts and firing orders compared to 4-stroke v-types of the same number of cylinders (and bank angles) as the 8-v-71, 6-v-71, 12-v-71, etc.

            Comment


            • #51
              Re: Kermit Weeks Napier Sabre hot-rod?.

              Yeah, that's some internal combustion intensity...
              Sir Stanley Hooker, who made the Rolls-Royce supercharger program work so well,

              [even though they wouldn't share it with Napier, wartime or no..]

              "described 4-stroke engines as having 'one stroke to produce power
              & three to wear the engine out'."

              For really wild Brit stuff, check out the Ricardo/R-R Crecy..
              2-cycle, spark ignition, sleeve valve,
              massive out puts of heat/power/drama..

              Comment


              • #52
                Re: Kermit Weeks Napier Sabre hot-rod?.

                With regard to the Deltic pistons 'sharing' the same cylinder, they don't really..
                except for the fluid dynamics, mechanically they run discretely-other than firing together..

                Comment


                • #53
                  Re: Kermit Weeks Napier Sabre hot-rod?.

                  In the case of the TZ 750 Yamaha mentioned earlier,

                  .. although geared together, each cylinder of the 2-cycle inline 4 operates discretely..

                  [carb/pipe for each, - no shared manifolding] but being a doubled 180`twin..

                  It had to fire 2 simultaneously..

                  Of course, it could have been configured with 90`crank throws..

                  As is the current Yamaha G.P. racing inline 4..
                  Last edited by J.A.W.; 05-01-2013, 05:27 PM.

                  Comment


                  • #54
                    Re: Kermit Weeks Napier Sabre hot-rod?.

                    Isn't the main problem that there are no complete and potentially airworthy engines in Kermit's stock and the other engines belong to the British government, installed in the Typhoon, Tempest, and in the racks at the Science Museum in London?
                    I really like the idea of a flying Sabre, but there aren't enough engines in existence to fly Kermit's single Tempest MkVI airplane.

                    And for that matter, Kermit doesn't race, ever. It won't happen, ever. Kermit bought a famous racing plane flown to victory by a very famous three-time Bendix victor racing pilot and un-restored it to military configuration and painted it to represent a very small faction of the USAAF, that's how much he thinks of air racing and it's history.

                    Maybe I missed the part in this thread where;
                    a) Kermit now races.
                    b) There were 150 Napier Sabre engines found and Kermit bought them all to equip his new Napier Sabre racing team..
                    ...but I believe my original thoughts are right on target.
                    Chris...

                    Comment


                    • #55
                      Re: Kermit Weeks Napier Sabre hot-rod?.

                      Believe?
                      What is the validity of your data set re number of Sabres in existence?

                      Kermit Weeks has a stated ambition to fly his Tempest..& he has Sabres..

                      Ok, so - a hot-rod race Sabre powered Fury is a bit of a fantasy/wish deal..

                      But flying a Sabre for the 1st time in 50+ years would be best done in a Fury airframe..

                      So it is possible..

                      Comment


                      • #56
                        Re: Kermit Weeks Napier Sabre hot-rod?.

                        Well, this site shows the s-l-o-w way the Brits do things, but there are some pix of pretty complete Sabres..

                        Albeit the Englanders claim " 1.5 -2.0. million pounds" [!] "with no guarantee" to get a Sabre running..

                        Jeeze.. at that rate..

                        I `d reckon the Kiwis ought to get the airframe gig & Mike Nixon the mill work...

                        Comment


                        • #57
                          Re: Kermit Weeks Napier Sabre hot-rod?.

                          I am going by Kermit's past statements about his engines and the fact the airplane is not going forward. You obviously like the engine and wish that it fly but the fact of the matter is that Kermit has had that airplane and his engines a long time and the engine availability is the reason the airplane has not been worked on. I left the door open for you to illuminate new facts about the engines Kermit has on hand and a change to that long and well known scenario. That's all.
                          If you have no new knowledge on that front then the scenario of a flying MkVI Tempest is unchanged, Kermit's is essentially in storage. We just heard from the most likely engine builder, Mike Nixon and he says he's two years out on new projects, if Kermit would like to contact him, seems that means Kermit has not.
                          Too bad, it would be really neat to see it come to fruition.
                          Chris...

                          Originally posted by J.A.W. View Post
                          Believe?
                          What is the validity of your data set re number of Sabres in existence?

                          Kermit Weeks has a stated ambition to fly his Tempest..& he has Sabres..

                          Ok, so - a hot-rod race Sabre powered Fury is a bit of a fantasy/wish deal..

                          But flying a Sabre for the 1st time in 50+ years would be best done in a Fury airframe..

                          So it is possible..

                          Comment


                          • #58
                            Re: Kermit Weeks Napier Sabre hot-rod?.

                            Stuntflyer, you`d be better informed than me, re Kermit Weeks attitude to Reno racing..

                            [He was more of a 'stunt flyer' too, right?]

                            However, since K.W. has so many projects on the go, & the Brit attitude
                            often presents as 'can't do', then it is still a bit of fun to evaluate scenarios..

                            Even if its a fantasy at this point.. Nile expedition anyone?

                            Who knows for sure.. where some of those thousands of Sabres built are now..

                            What is for sure, is that a well-fettled Sabre-Fury combo would make a welcome
                            & formidable Reno racer.. say.. if maybe Oracle gets bored with racing yachts...

                            Comment


                            • #59
                              Re: Kermit Weeks Napier Sabre hot-rod?.

                              For some comments on the robust Sabre's suitability for hot-rodding/Reno racing..

                              Comment


                              • #60
                                Re: Kermit Weeks Napier Sabre hot-rod?.

                                Check out the Speed/height graph for the 'Standard Tempest 6 ' running the Sabre 7 at +17.25lbs..

                                ..435mph @ Reno altitude..

                                Many stockers run around Reno at those speeds?

                                Last edited by J.A.W.; 05-03-2013, 07:30 PM.

                                Comment

                                Working...
                                X