Page 927 of 2625 FirstFirst ... 427827877917925926927928929937977102714271927 ... LastLast
Results 13,891 to 13,905 of 39365

Thread: ESE's works engine tuner

  1. #13891
    Join Date
    12th May 2011 - 23:52
    Bike
    razor scooter(pink)
    Location
    Australia
    Posts
    371
    Quote Originally Posted by chrisc View Post
    Found this in Bert's links


    GRP125 made into a 170 and home built EFI. Made 29hp, not extensively ported/tuned.
    Unfortunately a lot of the earlier image links are dead but I think it was a carb replacement type injection rather than a transfer port injection type.
    Have a look, I haven't trolled the thread much yet but man there are some idiots on that forum.

    http://www.125ccsportsbikes.com/foru...c=63480&st=320

    125cc sportbikes is just for 16yr old dreamers

  2. #13892
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street 765RS/GasGas/ etc etc
    Location
    Wellington. . ok the hutt
    Posts
    20,500
    Blog Entries
    2
    you mean the forum. I used to frequent the Derbi 50 one years back. but not for long when I realised who was posting
    Don't you look at my accountant.
    He's the only one I've got.

  3. #13893
    Join Date
    17th April 2014 - 17:54
    Bike
    Frepin Yamaha TZ350
    Location
    Littleport. England
    Posts
    1

    Frepin

    Quote Originally Posted by wobbly View Post
    Yea maybe a bit like Beck poking his tongue out at Clapton, a respectfully intellectual exercise .

    But in a dissimilar vein here is some pervage for the boys,this isnt on track, its on the rubbish tin - and yes I know the floor needs sweeping.
    Pre 82 Classic Frepin copy frame I have FEA corrected with TZ400 and S model fairing Billy is hoovering up now.
    Coming together for Philip Island next January.
    Late model Yamaha blue - tank/fairing will be a bit like Roberts colours.
    I have the original Peter Pinion Frepin. It has a couple of extra tubes in it at the rear engine mount and between the top frame tubes. It houses a TZ350 G spec motor with G forks, ARE front wheel and a SMAC at the back (could not afford Campags).
    I gather Peter bought the frame, swinging arm and tank back to England to have them copied, left them at a frame builder and never surfaced again. It has been round the houses a bit since then and at the Stafford Classic Bike show a couple of years back I talked to a previous owner who found the frame etc at the frame builders and bought it, not knowing anything about its' history. Built it as a 250 and raced it as a Yamaha in the TT. He said then he fitted a 350 engine and did the frame mods as the rear engine mount broke.

    Murray DeLacey has one and some replicas.

    Also a NZ contact was going to email me some photos of his but never did.

    It always draws attention at shows and will be at Stafford again next weekend (26/27th April)

  4. #13894
    Join Date
    12th May 2011 - 23:52
    Bike
    razor scooter(pink)
    Location
    Australia
    Posts
    371
    Quote Originally Posted by F5 Dave View Post
    you mean the forum. I used to frequent the Derbi 50 one years back. but not for long when I realised who was posting
    Yes no amount of experience or logic is equal to a cut n paste of the internet

  5. #13895
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,473
    Quote Originally Posted by 2T Institute View Post
    ... cut n paste..
    Click image for larger version. 

Name:	Cut and Paste.jpg 
Views:	81 
Size:	90.8 KB 
ID:	296421

    "Cut n Paste" ... replica of a 2T concept originally posted by Frits ....

    Quote Originally Posted by Frits Overmars View Post
    how can we prevent a scavenging column from toppling over to the exhaust side like the leaning tower of Pisa? Not by pushing against its basis, but by pushing higher up.
    Follow the link to read the whole story and see the original pictures.

  6. #13896
    Join Date
    8th February 2007 - 20:42
    Bike
    TZ400
    Location
    tAURANGA
    Posts
    3,885
    Does anyone know if Pinion is still with us.
    One of the frames I have came from Fred McLeans estate I believe, but I have never had any info re Peter.
    Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.

  7. #13897
    Join Date
    13th June 2010 - 17:47
    Bike
    Exercycle
    Location
    Out in the cold
    Posts
    5,624
    Quote Originally Posted by wobbly View Post
    Does anyone know if Pinion is still with us.
    One of the frames I have came from Fred McLeans estate I believe, but I have never had any info re Peter.
    My impression is that Fred was based in ChCh around that period - i may be wrong. I'll ask a couple of oldies i know not on here who may have some info on PP. At least one had a Frepin - and i've got the tank.

  8. #13898
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,473
    Unlike finicky carburetors, with fuel injection there is not the over enriching problems you get when the inlet stream bounces back and forth several times in the inlet tract. Passing the carbs needle jet several times and picking up fuel on each pass. With EFI I don't have to be so conservative with the rotary valve timing and can experiment a little.

    Click image for larger version. 

Name:	Rotary Valves.jpg 
Views:	75 
Size:	135.0 KB 
ID:	296434

    I have cut the top valve to have the same area but with a soft opening and closing effect.

    Click image for larger version. 

Name:	Rotary Valve soft opening.jpg 
Views:	148 
Size:	132.4 KB 
ID:	296436 Click image for larger version. 

Name:	New RV 012.jpg 
Views:	147 
Size:	132.7 KB 
ID:	296432 Click image for larger version. 

Name:	Rotary Valve soft closing.jpg 
Views:	97 
Size:	124.4 KB 
ID:	296435

    Soft Opening - Fully Open and Soft Closing.

    With the inlet opening at the bottom of the port first I am hoping to encourage the flow to adhere to the port floor, that way I think there will be a greater total flow through the port.

    Opening at the inlet port floor first is an idea that Jan Thiel talked about, I hope I can make it work for me. Looking at the Aprilia pictures it looks like Jan offset the RV a little sideways in relation to the inlet port and that way he was able to cut the RV so it opened from the bottom first much more neatly than I can manage with the GP.

    And soft closing at the top because I think the bulk of any blow back will follow the inlet port floor. And having the valve close the bottom first will block it.

    Click image for larger version. 

Name:	Rotary Valve and Boost Bottle.jpg 
Views:	98 
Size:	137.8 KB 
ID:	296433

    Looking into the inlet tract you can see how the boost bottle directly feeds the inlet port as the RV starts to open it.

    Click image for larger version. 

Name:	EFI Injectors.jpg 
Views:	97 
Size:	131.1 KB 
ID:	296437

    All the fuel injectors, hoses and plugs fit, thank goodness... ... I was a bit worried.

    Anyway I have no real idea if any of this will work but I guess the dyno will tell us soon enough.

    now to figure out all the wiring.

  9. #13899
    Join Date
    8th February 2007 - 20:42
    Bike
    TZ400
    Location
    tAURANGA
    Posts
    3,885
    As I understand it Pinion and McLean did the Begg F5000 cars and the Frepin was a sideline.
    But I would like to nail down the history and chat to the horses mouth if possible.
    Even the butchered frame I have that had a 500 in it is mirky in that I have also heard the motor was a 700, but again - who rode it
    and who did the crap job of fitting it together.
    Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.

  10. #13900
    Join Date
    8th February 2007 - 20:42
    Bike
    TZ400
    Location
    tAURANGA
    Posts
    3,885
    TeeZee, I spent days on the dyno at ZipKarts running a Rotax tandem 250 trying all the ideas we had seen with various rotary valve opening/closing scenarios.
    I tried convex and concave opening and closing edges, singly and tandem curves in all manner of combinations - initially all with the same timings of 140/88 but
    later when getting no results I tried curved edges with less and then more timing as well..
    Several ideas changed the full power egt and this was re jetted for, but none of the weird shapes made any more power, many made less.
    Then years later, Ii read that Jan had said somewhere when asked about the RV shapes being used on the leading edge only of the Aprilia
    that the angled shape had nothing to do with power, but helped ameliorate the rapid wear on the case that was caused by the unsupported
    valve being pushed against the open port area by the inrushing column of air.
    This may have changed later, but I sure could not find any hidden horses but ruined a heap of perfectly good discs.
    Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.

  11. #13901
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street 765RS/GasGas/ etc etc
    Location
    Wellington. . ok the hutt
    Posts
    20,500
    Blog Entries
    2
    Thus stimulating the Austrian economy and promoting world peace, so not a total loss.
    Don't you look at my accountant.
    He's the only one I've got.

  12. #13902
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,473
    Quote Originally Posted by wobbly View Post
    I sure could not find any hidden horses but ruined a heap of perfectly good discs.


    Thanks for the heads up, I had to give it a go but will only try this one then maybe re fit the original one and save face by calling it a back to back test....

    Quote Originally Posted by wobbly View Post
    Ii read that Jan had said somewhere when asked about the RV shapes being used on the leading edge only of the Aprilia
    that the angled shape had nothing to do with power, but helped ameliorate the rapid wear on the case that was caused by the unsupported
    valve being pushed against the open port area by the inrushing column of air.
    Makes sense.

  13. #13903
    Join Date
    20th June 2012 - 00:17
    Bike
    yamaha
    Location
    Australia
    Posts
    207
    Quote Originally Posted by wobbly View Post
    TeeZee, I spent days on the dyno at ZipKarts running a Rotax tandem 250 trying all the ideas we had seen with various rotary valve opening/closing scenarios.
    I tried convex and concave opening and closing edges, singly and tandem curves in all manner of combinations - initially all with the same timings of 140/88 but
    later when getting no results I tried curved edges with less and then more timing as well..
    Several ideas changed the full power egt and this was re jetted for, but none of the weird shapes made any more power, many made less.
    Then years later, Ii read that Jan had said somewhere when asked about the RV shapes being used on the leading edge only of the Aprilia
    that the angled shape had nothing to do with power, but helped ameliorate the rapid wear on the case that was caused by the unsupported
    valve being pushed against the open port area by the inrushing column of air.
    This may have changed later, but I sure could not find any hidden horses but ruined a heap of perfectly good discs.
    bad results are still good data. Im glad to hear the results you got it saves me trying what I had in mind

  14. #13904
    Join Date
    27th January 2011 - 11:30
    Bike
    RS125, TZ80, RS50, RS50, FXR
    Location
    AKL
    Posts
    908
    I thought I had read that same info re the soft opening Rob. What you say wobbly makes a whole lot of sense though. I wonder if others have had the same experiences re the shapes.

  15. #13905
    Join Date
    5th April 2004 - 20:04
    Bike
    Exxon Valdez
    Location
    wellington
    Posts
    13,371
    Unrelated question. Do two strokes drink enough oil, to pump it in through the crank and run shell bearings?

Thread Information

Users Browsing this Thread

There are currently 14 users browsing this thread. (1 members and 13 guests)

  1. gamma500

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •