AccueilGalerieRechercherDernières imagesS'enregistrerConnexionNouveaux messages depuis dernière visite
Rechercher
 
 

Résultats par :
 
Rechercher Recherche avancée
Qui est en ligne ?
Il y a en tout 104 utilisateurs en ligne :: 13 Enregistrés, 1 Invisible et 90 Invités :: 2 Moteurs de recherche

88 daytona, Alain Gwada, bartau, BauGG, cat, Dob27, j.mispeed, JH42, Joel Enndewell 2424, la denrée, lolec, spreyer, taliesin

Le record du nombre d'utilisateurs en ligne est de 539 le Mar 19 Mar 2024 - 11:10
Derniers sujets
» [Oldies] Moto Elf
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 16:46 par Marc

» [Oldies] Quizz (29)
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 16:33 par Apriliabarth

» [Bla bla bla] ePower : Y va-t-on vraiment ? N° 2 .
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 16:20 par thierysp

» [Oldies] Honda 125 CR93 /1963
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 15:53 par bubu

» [Oldies] Bourg en Bresse 1973
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 15:46 par bubu

» [Oldies] Kesako et quelle année?
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 15:32 par Dan42

» Martin de course???
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 15:21 par Apriliabarth

»  [WSBK] Espagne , Catalunya 2024 , les 22 , 23 et 24 Mars 2024 .
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 13:24 par Charly

» [oldies] Honda 125 CB93 1963-1966 /racing kit.
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 13:09 par DidierF

»  [MotoGP] Infos , nouveautés , potins , tests et plus pour la saison GP 2025 ...
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeAujourd'hui à 10:21 par Mykeul

» [Oldies] Michel ROUGERIE, 30 ans déjà !
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeHier à 20:16 par corki2

» [Oldies] Questions (vitesse 1947-1976)
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeHier à 17:58 par berlu

» BMW : 100 ans de championnats, 70 ans de BMW RS et autres anniversaires
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeHier à 17:31 par Lothar M.

» André Luc Appietto
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeHier à 15:00 par momodedale

» [Oldies] Renzo Pasolini, photos insolites
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeHier à 7:29 par Ala Zorro

»  [GP] GP du Portugal 2024 sur le circuit de Portimao les 22- 23 et 24 lMars 2024
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeMar 26 Mar 2024 - 18:17 par doum

» controle technique moto
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeMar 26 Mar 2024 - 9:38 par Charly

» [Endurance] Saison 2024 .
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 25 Mar 2024 - 16:48 par crigar

»  [SORTIES] Sunday Ride Classic 2024 .
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 24 Mar 2024 - 9:40 par yves kerlo

» Construction d’une moto électrique, base moto 3
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeSam 23 Mar 2024 - 18:13 par Ed

» [Technique] Vous avez dit "Distribution"?
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeSam 23 Mar 2024 - 8:32 par panerai

» [Technique] Rayonnage...
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeVen 22 Mar 2024 - 18:55 par Joel Enndewell 2424

» [Oldies] Angel Nieto Mike Hailwood (part 6)
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeVen 22 Mar 2024 - 8:39 par Dan42

» [Oldies] Fergus, Geoff, Libero et les autres (vitesse 1946-1960)
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeMer 20 Mar 2024 - 12:47 par Charly

» [Oldies] Restauration de mon side-car des années 70, la suite!
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeMar 19 Mar 2024 - 17:26 par Joel Enndewell 2424

»  [MotoGP] GP 2024 du Qatar à Losail les 8 - 9 et 10 Mars 2024
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 18 Mar 2024 - 19:10 par damelydie

» [Oldies] Jack Findlay, pilote de légende
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 17 Mar 2024 - 23:45 par jack177071

» [Oldies] Gérald Motos
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 17 Mar 2024 - 10:45 par collecto

» GP Canada Mosport 29 & 30 septembre 1967
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 17 Mar 2024 - 8:13 par Adco

» [Technique] Bielle de Formule 1 tout à fait passionnante
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 17 Mar 2024 - 8:13 par Dan42

Mots-clés
moto ducati RACING suzuki motos 1976 rouge 2013 artisanales francaises ROAD bourg Mans yamaha aprilia wanted side coupe zone charade 1973 oldies bresse classic inventaire motobecane
Meilleurs posteurs
Marc
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
EDOUARD Jean
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
philwood
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
Pierre"PhilRead"
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
mickey
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
yves kerlo
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
bubu
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
Fügner
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
Dialmax
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
Jarno
aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting16aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting13aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Voting15 
La réclame...
Le Deal du moment :
Aliexpress : codes promo valables sur tout le site
Voir le deal

 

 [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)

Aller en bas 
+102
barbazan
desmofr16
ridley
ridgeback
luca.valeri.7
vin97
Panas
hervefaure
Rallyfinnen
CVS
Apriliabarth
melvyn trevor
nortumph
cassandre
pierre95
bengui
{mRk}
gpracing
Larry Wiechman
el castor
ktuningteam
peter1962
Paul Olesen
philou
Charles Kaneb
Motors31
florent.doublet
Polinizei
dutch
Dan42
Makr
nine-thirtysix
jfn2
Encierro
patouille
190mech
Seb4LO
Mestre
Muciek
dutch fisher
Truls221
Martin1981
nick gill
Captain Scarlet
Bob van der Zijden
seattle smitty
CRECY
granjoie
Maurice Specken
Haufen
yeahhim
m4grity
ice t
Lef16
Marc
motoholic71
alcatelko
uniflow
gilles27
micowoy
bentou
yesyes
tjbw
Paul Gane
zeze
Toop
Ian Harrison
senso
Tim Ey
Ollies930
maccas
Filandro
Howard Gifford
GtG001
pfpraider
fpayart
Ken Seeber
lodgernz
oxracer
moadoc
ambike
williamsmotowerx
Stephane
pagi
JanBros
GrahamB
Senne s
brokedown
Sanderhoutman
LucF
Institute of TwoStrokes
roost
romeuh80
koenich
RAW
Jan Thiel
Forgi
Manuel Rainer
Piquer
Vortex
Jarno
Frits Overmars
106 participants
Aller à la page : Précédent  1, 2, 3 ... 21 ... 40  Suivant
AuteurMessage
RAW




Nombre de messages : 86
Localisation : Australia
Date d'inscription : 05/05/2012

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeSam 12 Avr 2014 - 22:46

LucF sorry I have no weights, this is all data from the vehicle I worked on over several years
Revenir en haut Aller en bas
LucF




Nombre de messages : 110
Age : 80
Localisation : Pays Bas
Date d'inscription : 25/05/2011

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 13 Avr 2014 - 9:05

RAW a écrit:
LucF sorry I have no weights, this is all data from the vehicle I worked on over several years

Thanks RAW, I will try to figure out with the information I have in a simulation.
Revenir en haut Aller en bas
http://www.geocities.ws/lucfoekema/indexNL.html
Sanderhoutman




Nombre de messages : 51
Localisation : netherlands
Date d'inscription : 23/12/2012

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 13 Avr 2014 - 9:36

In 2011 minimum weight for top fuel was 2320 pounds. After the run the projectile had to be on or above the limit set by nhra.
Revenir en haut Aller en bas
LucF




Nombre de messages : 110
Age : 80
Localisation : Pays Bas
Date d'inscription : 25/05/2011

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 13 Avr 2014 - 9:43

Sanderhoutman a écrit:
In 2011 minimum weight for top fuel was 2320 pounds. After the run the projectile had to be on or above the limit set by nhra.

Ok Thanks Sander
Revenir en haut Aller en bas
http://www.geocities.ws/lucfoekema/indexNL.html
Sanderhoutman




Nombre de messages : 51
Localisation : netherlands
Date d'inscription : 23/12/2012

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 13 Avr 2014 - 12:02

LucF a écrit:
Sanderhoutman a écrit:
In 2011 minimum weight for top fuel was 2320 pounds. After the run the projectile had to be on or above the limit set by nhra.

Ok Thanks Sander

Google Luc. Sometimes works like a charm aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 980796 
Revenir en haut Aller en bas
brokedown




Nombre de messages : 151
Localisation : usa
Date d'inscription : 29/09/2013

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 13 Avr 2014 - 16:03

hi frits i have a question about this picture. with a cylinder that has A,B,C,D ports (A,B,C are in the side of the cylinder and D is in the rear), would it be best to have A,B,C ports aimed to the area where the black circle is ??

also do you have some advice for what upward angle the A,B,C ports should have  ? the piston crown is 7* angle just so you know.  thnx


[Vous devez être inscrit et connecté pour voir cette image]



heres what i have right now

[Vous devez être inscrit et connecté pour voir cette image]
Revenir en haut Aller en bas
Frits Overmars

Frits Overmars


Nombre de messages : 2611
Age : 75
Localisation : Raalte, Holland
Date d'inscription : 12/10/2010

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 13 Avr 2014 - 17:05

brokedown a écrit:
hi frits i have a question about this picture. with a cylinder that has A,B,C,D ports (A,B,C are in the side of the cylinder and D is in the rear), would it be best to have A,B,C ports aimed to the area where the black circle is ?
More or less, yes. It's hard to say just looking at your sketch, with only an impression of the radial angles and without numerics. What also strikes me, is that the leading and trailing port flanks don't converge.
It also seems like you let a lot of real estate between C and D lie fallow. Why? Awkwardly situated ring pegs?
Citation :
also do you have some advice for what upward angle the A,B,C ports should have  ? the piston crown is 7* angle just so you know.
It's all in the picture, Brokedown. Look at the α up-values for the axial scavenging angles.
Revenir en haut Aller en bas
brokedown




Nombre de messages : 151
Localisation : usa
Date d'inscription : 29/09/2013

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 13 Avr 2014 - 19:24

Frits Overmars a écrit:
What also strikes me, is that the leading and trailing port flanks don't converge.
It also seems like you let a lot of real estate between C and D lie fallow. Why? Awkwardly situated ring pegs?

after im done all the port angles will converge and aim to a location aprox at the black circle in the previous photo.

the ring pegs are near the D port and in a fine location. we can only assume all the dead space between C and D was just poor design on ktm's part.   

they didnt make good use of the available wall area but im going to fix that  lol! 

[Vous devez être inscrit et connecté pour voir cette image]

the rear is welded so C port can be much wider

[Vous devez être inscrit et connecté pour voir cette image]

also i wanted to test what happens when the exh floor is raised a few mm. this is just a rough idea of what i was thinking. lower rear portion of the aux exh ports were welded also which allows a better shape with alot less short circuit from the crankcase to the pipe when the piston hits TDC.

[Vous devez être inscrit et connecté pour voir cette image]

Citation :
It's all in the picture, Brokedown. Look at the α up-values for the axial scavenging angles.

ok so if my piston dome is 7* i should have C port at 7*. A port should be around 25-30*. B port should be somewhere in the middle perhaps about 15* ?  thnx for help frits
Revenir en haut Aller en bas
Senne s




Nombre de messages : 56
Localisation : Austria
Date d'inscription : 02/03/2014

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 13 Avr 2014 - 21:27

Frits and Jan, I want to thank you for your previous replies. They have sure helped me and other people who admire your work a very big deal! Elsewhere it was said that blowdown should be as big as possible, but doesn't this make the engine's powerband to narrow? Should it really be as big as possible in all racing engines? Is it the same story as with the exh port timing of 190degrees: as long as you have a good pipe and a transmission to keep you in the powerband, it is good for a racing 2stroke?

Also I was wondering if I was right thinking that it wouldn't make sense to use a toroidal head on a 6speed gokarting engine, because they utilise a very small squishband to make the combustion process slower as they can not use variable ignition timing. And a toroidal head would only make the turbulence by the squishband bigger, so that both effects kind of equalize each other?
Revenir en haut Aller en bas
Frits Overmars

Frits Overmars


Nombre de messages : 2611
Age : 75
Localisation : Raalte, Holland
Date d'inscription : 12/10/2010

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 14 Avr 2014 - 8:42

Senne s a écrit:
Elsewhere it was said that blowdown should be as big as possible, but doesn't this make the engine's powerband to narrow? Should it really be as big as possible in all racing engines? Is it the same story as with the exh port timing of 190degrees: as long as you have a good pipe and a transmission to keep you in the powerband, it is good for a racing 2stroke?
Blowdown depends on four factors: exhaust timing, transfer timing, total exhaust port width and exhaust flow coefficient.
I'll ignore the flow coefficient for now because that deserves a book in itself. And Jan should write it  Wink.
 
Exhaust timing should be 180° effective; about 190° geometrical, for optimum resonance. And yes, as long as you have a good pipe and a transmission to keep you in the powerband, it is good for a racing 2stroke.

Transfer timing should be such that cylinder pressure has dropped below scavenging pressure by the time the transfer ports start to open.

Total exhaust port width: the more you utilize the total circumference of the cylinder bore, the more blowdown angle.area you'll get, but very wide exhaust ports increase the danger of losing fresh charge through short-circuiting.
 
The typical two-stroke powerband results from the pressure fluctuations in the exhaust pipe. When everything is optimal, around the rpm of maximum torque, the pipe will create a low pressure in the cylinder at around BDC in order to help scavenging, and a high pressure between transfer closure and exhaust closure in order to supercharge the cylinder with fresh mixture that got washed through earlier in the transfer phase.

At low revs, especially around 2/3 of maximum torque rpm, the high pressure from the pipe arrives too early at the cylinder, when the transfer ports are still wide open, and this pressure will push the fresh mixture from the cylinder back into the crankcase, causing a gap in the torque curve. The higher the transfer timing, the greater this unwelcome effect.
Citation :
Also I was wondering if I was right thinking that it wouldn't make sense to use a toroidal head on a 6speed gokarting engine, because they utilise a very small squishband to make the combustion process slower as they can not use variable ignition timing. And a toroidal head would only make the turbulence by the squishband bigger, so that both effects kind of equalize each other?
You may be right there. I haven't done much work on kart engines, amongst other things because I don't like the dumb rule of having to use a fixed ignition timing. It was once introduced to keep the sport affordable, but the effect has since long become negative. Every second-hand MX-engine has a variable ignition, but if you wish to use it on a kart you'll have to buy a new ignition with a fixed timing  Sad .
Revenir en haut Aller en bas
RAW




Nombre de messages : 86
Localisation : Australia
Date d'inscription : 05/05/2012

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 14 Avr 2014 - 9:41

Sujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 3) Aujourd'hui à 10:42
Senne s a écrit:
Elsewhere it was said that blowdown should be as big as possible, but doesn't this make the engine's powerband to narrow? Should it really be as big as possible in all racing engines? Is it the same story as with the exh port timing of 190degrees: as long as you have a good pipe and a transmission to keep you in the powerband, it is good for a racing 2stroke?
Blowdown depends on four factors: exhaust timing, transfer timing, total exhaust port width and exhaust flow coefficient.
I'll ignore the flow coefficient for now because that deserves a book in itself. And Jan should write it .

Exhaust timing should be 180° effective; about 190° geometrical, for optimum resonance. And yes, as long as you have a good pipe and a transmission to keep you in the powerband, it is good for a racing 2stroke.

Transfer timing should be such that cylinder pressure has dropped below scavenging pressure by the time the transfer ports start to open.

Total exhaust port width: the more you utilize the total circumference of the cylinder bore, the more blowdown angle.area you'll get, but very wide exhaust ports increase the danger of losing fresh charge through short-circuiting.

The typical two-stroke powerband results from the pressure fluctuations in the exhaust pipe. When everything is optimal, around the rpm of maximum torque, the pipe will create a low pressure in the cylinder at around BDC in order to help scavenging, and a high pressure between transfer closure and exhaust closure in order to supercharge the cylinder with fresh mixture that got washed through earlier in the transfer phase.

At low revs, especially around 2/3 of maximum torque rpm, the high pressure from the pipe arrives too early at the cylinder, when the transfer ports are still wide open, and this pressure will push the fresh mixture from the cylinder back into the crankcase, causing a gap in the torque curve. The higher the transfer timing, the greater this unwelcome effect.
Citation :
Also I was wondering if I was right thinking that it wouldn't make sense to use a toroidal head on a 6speed gokarting engine, because they utilise a very small squishband to make the combustion process slower as they can not use variable ignition timing. And a toroidal head would only make the turbulence by the squishband bigger, so that both effects kind of equalize each other?
You may be right there. I haven't done much work on kart engines, amongst other things because I don't like the dumb rule of having to use a fixed ignition timing. It was once introduced to keep the sport affordable, but the effect has since long become negative. Every second-hand MX-engine has a variable ignition, but if you wish to use it on a kart you'll have to buy a new ignition with a fixed timing .

Frits what if we road race our kart and have a variable ignition ? What is the generic effect of the toroidal head upon a 2 stroke ? Let's assume we've all got an rsw or rsa for ease of clarity
Revenir en haut Aller en bas
Senne s




Nombre de messages : 56
Localisation : Austria
Date d'inscription : 02/03/2014

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 14 Avr 2014 - 11:47

Thanks a lot Frits, I think I understand now.
I hope I can once reach the same level as yours!
Revenir en haut Aller en bas
Frits Overmars

Frits Overmars


Nombre de messages : 2611
Age : 75
Localisation : Raalte, Holland
Date d'inscription : 12/10/2010

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 14 Avr 2014 - 12:15

RAW a écrit:
Frits what if we road race our kart and have a variable ignition ? What is the generic effect of the toroidal head upon a 2 stroke ?
There are two issues here: a variable (preferably prgrammable) ignition and the shape of the combustion chamber.  
Once you have a variable ignition, you no longer need to provoke a slow combustion in order to generate hotter exhaust gas at high revs; you can do that by retarding the ignition timing.
You want to keep the thermal load on the engine as low as possible, which means that you want the shortest possible combustion phase. This will limit the heat transfer of the combustion to the surrounding metal, improving both the thermal soundness of the engine and the efficiency of converting fuel energy into horsepower.
Squish helps a lot in spreading the flame and you can get the best squish with a head shape like this:

[Vous devez être inscrit et connecté pour voir cette image]
Revenir en haut Aller en bas
GrahamB

GrahamB


Nombre de messages : 3456
Age : 62
Localisation : Lyon
Date d'inscription : 19/08/2011

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 14 Avr 2014 - 12:51

Ah, so this is the reason for the sharp transition at the edge of the squish: to avoid the boundary layer following the surface of the head "around the corner"?
Revenir en haut Aller en bas
JanBros




Nombre de messages : 351
Localisation : Belgique
Date d'inscription : 05/12/2011

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 14 Avr 2014 - 14:26

Frits Overmars a écrit:

[Vous devez être inscrit et connecté pour voir cette image]

2 questions Frits :
- at point 2 : do you end the arc 90° after point 3, or do you end perpendicular on the piston crown ?
- when playing with different head volumes, the only thing you change is the diameter of the arc ?
Revenir en haut Aller en bas
Frits Overmars

Frits Overmars


Nombre de messages : 2611
Age : 75
Localisation : Raalte, Holland
Date d'inscription : 12/10/2010

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 14 Avr 2014 - 16:35

JanBros a écrit:
at point 2 : do you end the arc 90° after point 3?
Yes.
Citation :
when playing with different head volumes, the only thing you change is the diameter of the arc ?
I usually keep the 50% squish area and the 90° and I vary the radius of the arc and the position of its center.
Revenir en haut Aller en bas
JanBros




Nombre de messages : 351
Localisation : Belgique
Date d'inscription : 05/12/2011

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeLun 14 Avr 2014 - 16:36

tnx !
Revenir en haut Aller en bas
Jan Thiel




Nombre de messages : 517
Age : 83
Localisation : Bangkok
Date d'inscription : 12/10/2010

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeMar 15 Avr 2014 - 6:42

GrahamB a écrit:
Ah, so this is the reason for the sharp transition at the edge of the squish: to avoid the boundary layer following the surface of the head "around the corner"?

There was no particular reason!
We tried a number of head designs, maybe 30-40 different ones.
And discovered that having no radius was better....
Revenir en haut Aller en bas
pagi




Nombre de messages : 30
Localisation : montpellier
Date d'inscription : 10/02/2014

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeMar 15 Avr 2014 - 18:17

Mr Overmars, Mr thiel, have you a picture, or a drawing that explains "raising the duct floor" of the exhaust duct,
how much it s   good to raise this exhaust duct  aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 55116
Revenir en haut Aller en bas
Stephane

Stephane


Nombre de messages : 433
Age : 54
Localisation : 29 - Finistère
Date d'inscription : 27/12/2008

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeMar 15 Avr 2014 - 20:04

remonter le plancher du conduit d’échappement : c'est ce qu'a fait Brokedown
=>
regarde ses photos quelques messages avant le tien : on voit très bien qu'il a remonté le plancher grâce a de la soudure

le but étant de conserver suffisamment de vitesse aux gaz sortant, c'est pas essais successifs que tu pourras déterminer de combien il est bon de remonter le plancher (si c'est nécessaire)
Revenir en haut Aller en bas
pagi




Nombre de messages : 30
Localisation : montpellier
Date d'inscription : 10/02/2014

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeMar 15 Avr 2014 - 20:40

merci stephane, car j avais cru comprendre que c etait pour creer un "mur" au gaz frais lors de la vidange!!! mon anglais est nul (comme google translate d ailleurs !!!)
Revenir en haut Aller en bas
brokedown




Nombre de messages : 151
Localisation : usa
Date d'inscription : 29/09/2013

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeMer 16 Avr 2014 - 0:32

hi pagi. im not sure what is the correct amount to raise the exh floor but i think frits said its good the have the exh outlet about the same area as the blowdown. thats how i understand him anyways  aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 771973 


i have worked on this alittle more but im not finished yet. the red line is original



[Vous devez être inscrit et connecté pour voir cette image]
Revenir en haut Aller en bas
pagi




Nombre de messages : 30
Localisation : montpellier
Date d'inscription : 10/02/2014

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeJeu 17 Avr 2014 - 18:39

Mr overmars, Mr Thiel

what do you think about the location ( at this beginning) off the separation between the A and B ports, because i have see many options ?(like 500NSR beginning very late)

and what is the best radius for this separation ? (3,4 mm, more....)
Revenir en haut Aller en bas
williamsmotowerx




Nombre de messages : 15
Localisation : usa
Date d'inscription : 24/12/2012

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeJeu 17 Avr 2014 - 23:02

What did you weld that with?

It looks like the stuff you weld with a propane torch... Low melting point.
Revenir en haut Aller en bas
ambike




Nombre de messages : 57
Localisation : DFW,Texas
Date d'inscription : 15/11/2013

aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitimeDim 20 Avr 2014 - 4:44

williamsmotowerx a écrit:
What did you weld that with?

It looks like the stuff you weld with a propane torch... Low melting point.


Well, it certainly puddles nicely !
Revenir en haut Aller en bas
Contenu sponsorisé





aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Empty
MessageSujet: Re: [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)   aprilia - [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4) - Page 2 Icon_minitime

Revenir en haut Aller en bas
 
[GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 4)
Revenir en haut 
Page 2 sur 40Aller à la page : Précédent  1, 2, 3 ... 21 ... 40  Suivant
 Sujets similaires
-
» [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 5)
» [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 5)
» [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 2) (Locked)
» [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 1) (Locked)
» [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 3) (Locked)

Permission de ce forum:Vous ne pouvez pas répondre aux sujets dans ce forum
 :: ACTUALITES :: [GP] :: [GP125 (et 250 Snif!)]-
Sauter vers: