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geoffreywh

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Everything posted by geoffreywh

  1. geoffreywh
    QUOTE "how about a 50hp or so four stroke engine to compete with the two strokes." Please excuse my ignorance, But I thought that particular size was very well served. I can think of 4 There's the HKS and the American flat twin, whose name escapes me , then the NZ paralel twin, and of course great plains jobbies....What did I miss?....
  2. geoffreywh
    To my regret, yes, I used to sit on a street corner in London "collecting" Car rego numbers. A "coloured" car (ie: not black) was written in blue ink ! ( you had time to change writing instrument between cars) ..... also remember quite clearly the first car in our street. It was a new Rover 75 Cyclops, black of course. I lived near North Weald where they had NF Meteor's stationed, Plus the occasional Dragon Rapide over our rooftop...How nice that was........
  3. geoffreywh
    Brings back memories "pinking" and "knocking" old friends from long ago before fadec and knock sensors.... I used to live on a steep hill and you would hear Morris's and Hilman's pinging their way up the hill with the old drivers tring to stay in third....
  4. geoffreywh
    I like the mag. I like having it around. I like passing it on to my Doctor, Dentist ect., I don't want to have to read it online...I think 30 bucks a year is a bargain.............I don't want it changed...
  5. geoffreywh
    I read Merlins had a service life around 1937 of 600 hours. The TBO varied enormously with the duties it performed. Better look at the Bristol Hercules sleeve valve radials with a TBO of 5000 hrs...or the Napier Lion broad arrow That had (I believe) the longest TBO of any aero engine..BUT I heard news yesterday that the new 3300 had MANY sensible improvements, Very encouraging indeed....
  6. geoffreywh
    it's obvious that riding motorcycles has some beneficial effects in flying aeroplanes....Does the same apply with model aeroplanes as well? I flew free flight glider in competitions for many years and I believe that the knowledge gained from that was incredibly useful in learing to fly. Especially the aerodynamiocs and controls....What do you think?
  7. geoffreywh
    Got my bike license in '61... I still ride almost daily.. 1500 Drifter..Flying is just just bike riding...just no speed restrictions!
  8. geoffreywh
    the poor bloke's gone and his worries are over, I sympathise for the lady left to grieve and ponder what might have been for the rest of her life...........No wonder she's in court.
  9. geoffreywh
    That rubber does not look right ..............it's a real shame, they can be so good. But not straight out of the box....David's J230 circumnavigates Australia without missing a beat...Someone I spoke to today mentioned that a new 6 cyl. has solid lifters. (hooray) aircooled motor clearances (at last) pressure fed rockers ( so they should have) and various other "updates"...........go figure
  10. geoffreywh
    She rang me and said "why don't you come over? nobody's home!" So I went over and nobody was home...............
  11. geoffreywh
    too many big wheels
  12. geoffreywh
    at least with motorcycle tanks you will not get rust holes appearing. the ethanol will absorb the water, hooray!...................................Really???....... can the water, absorbed by ethanol precipitate out and form ice???? as Ultralight says.. I would have thought that once in soultion it (water) would tend to stay in solution, But I'm not a chemist
  13. geoffreywh
    It all sounds very interesting. I know how smooth a 120 degree triple can be (at speed) and the delicious sound they make. I'll tell you what though, the crankshaft to camshaft gears are going to have to be very very good...The load as far as camshaft drive is nothing compared to transmitting 100hp to a prop. There's going to have to be a very sturdy casting carrying some really good bearings (plain I guess) to make it work safely.... that's going to be a very difficult part of the design....Although that big gear will give you somewhere nice to mount the starter!...Hmmm, maybe not, just put a ring gear out in the open at the other end??
  14. geoffreywh
    Out of the many 2.2's and 3.3's I have seen and measured there were four that stood out as low charging jobbies... I asked Jabiru about it and they said "some do that, turn everything off whilst taxiing except pump and radio" As soon as the take-off starts you are OK and run what you want...two of those motors were brand new...It's not all of them, many are just fine. The difference is ( I think ) in windings tolerances and permanent magnet differences. If you get a "stack up" of end of tolerances you get low voltage. Or if lucky you get a good charge at lower revs....Although a volt meter is not the same as an ammeter is tells a similar story, just not as quickly....or as accurately...As long as you use the same method to measure all the time you can arrive at the same conclusions..... PLUS quote" My Yuasa motorbike battery (in my bike) is still going strong and it is 10 years old." Answer? Yes of course it is, that's what I have been saying , your bike charges like a wounded bull.................Yuasa are great batteries.
  15. geoffreywh
    half the distance....
  16. geoffreywh
    seen a few with 12v at 2000rpm.................They have to taxi with everything off except the radio (and /or fuel pump)................but they're ok at 2800rpm. trouble is it's a motorcycle alternator. Needs lots of revs to make decent power. At 7 or 8000 rpm they are the ducks guts..
  17. geoffreywh
    There is a very interesting working model of the four stroke opposed piston concept (BUT with different valving.) at http://ridders.nu ... look under 'Verbrandings Motoren"
  18. geoffreywh
    A problem may be that the charging voltage of the Jab series engines is somewhat on the low side. Those Odessey ( AGM. "Gel Mat" ) batteries are supposed to be charged at 14 + volts. SOME Jab engines just dont charge that much. (Just above 12v if you are lucky) Consequently the battery aquires a low volt memory and a shortened life. I have used , with GREAT success a battery manufactured by "Long River" similar sizes as Odessey. Half the price.....The 625 version swings my 0-200 hot or cold quite easily (With a non use period of 5 months!) If it ever fails I will go with LIFE04 type. Now about 250 dollars...(and rising) Correction ......it's FULL RIVER
  19. geoffreywh
    Ha Ha , very funny. now here's a question, If the bore and stroke are 70 x 70 that's 270 cc per Cylinder. 540cc per "pair" 1620 for a flat "six" But the combustion space would be then 66 or so cc per pair of pistons. That's about 35 mm of bore space. So at TDC there would be 35mm between pistons IF there were no valves... But there are valves and they would have to be about 32 mm inlet and 30mm exhaust .... to open and close they must protrude somewhat into the space between the pistons otherwise compression is too low... So how is that arranged. The drawing shows . a sort of diamond combustion space that looks like it might have some severe side thrust effects ( someone already mentioned this.).....Have you built a test engine as per Harry Ricardo ?
  20. geoffreywh
    The thread was a discussion about a NEW Australian Engine. Not an old fogie discussion forum on the merits of nasty old aeroplanes (Which I have flown in thank you.) Lets get back to it. For a start would someone (other than me, ) please work out the shape of the combustion chamber. Given that the approximate size would have to be around 50 cc. and bore / stroke? say 85 x 80mm ... I'm tired from painting the baby's bedroom and bailing out the cellar....
  21. geoffreywh
    I did a bit of a search on youtube and the Junkers Jumo seems to be the closest to what you have drawn But with a head planted on the centreline. Looks unique. The Jumo was a very successful engine....Will the cranks rotate in opposite directions? No, too difficult...... I answer my own question. Sorry if I ramble on, I do like a new good design, old world flat fours and sixes are a bit boring....As for a name? How about Wun Tin Lung
  22. geoffreywh
    Looks like a suicide to me.....
  23. geoffreywh
    Wow, now I see the configuration, so cross section-wise, it's going to be "inverted T" sort of. How daring . It looks terrific , inlet and exhaust are very easily planned and so unobtrusive. rocker lube thru' the rocker shaft/s ? ....Symmetrical valve timing too? I've seen that work 20/50/50/20....Dry sump?... Where's the material to take the head bolts? Are you going to have through bolts? ( not a serious question)...sorry for all the questions.. . Congratulations, I hope it's all you design it to be....I'd love to change out my 0-200 for something that actually makes some power...............Another question, looking at your first drawing why does the l/h and r/h "crankcase" not follow the shape of each crankshaft more closely? If the stroke is about 40mm? then i would expect the crank throw and clearance to be no more than 250mm in the vertical plane..Your drawing seems to show it to be bigger than this ( or am I looking at it wrong?)
  24. geoffreywh
    very low amp fused, switched wire,would sort that out too..Or if you are REALLY paranoid, then use a cable operated microswitch at the battery....
  25. geoffreywh
    except when you go for the back brake and stamp the bike into second. LOL. I often drove L/H and R/H drive vehicles on either side of the road. The biggest problem was grabbing the window winder instead of changing gear....Or remembering which side to get in!....
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