1200RS

Canthoine n'en parlais pas??? si il n'en a pas parlé, va falloir que je cherche. Mais il me semble que ce n'ets pas trop les pertes en charges qu'on prend en consideration, c'est plutot le rapport de pression.

les cames symetriques sont symetriques, c'est à dire que la courbe qui correspond à la fermeture est identique à celle de l'ouverture. les asymetriques ont des rampes qui ne le sont pas, et sont taillées de telle maniere qu'elles ont une rampe d'acceleration tres violente(ce qui aide à mettre le turbo plus vite et plus tot en pression) et des rampes de deceleration tres douces, ce qui evite les chocs sur les sieges, et permet de detarer legerement les ressorts de soupapes, si on prend soin de limiter le regime. ça permet aussi de conserver des sieges de dureté convenable(58 à 60 HRC de memoire) et rend l'utilisation du bronze au berellium inutile(et quand on vois le prix, c'est pas mal de ne pas avoir à le payer).

un ac ayant des rampes assypetriques ne reagit pas du tout pareil à un autre ayant les memes durées et levées, mais en rampes symetriques. dans le cas de rampes assymetriques, on peut diminuer le LC, on aura pas plus de turbo lag. là où le LC reste important, c'est pour les normes antipollution.

Glyco, je deconseille pour les arbres à cames, je prefere le Bugpack, car sur les Glyco, il n'y a pas d'ergo, aucun ergo, ça ne tient que pas le serrage lateral, je n'ai pas confiance, malgré que ce soit ce qui etait(est???) vendu par Berg. Sinon, le Mahle est bien sur les ac, en double epaulement bien sur

diametre trop petit, il faut mini une durite de retour de 25mm(c'est la norme)

à mon avis, il vaut mieux faire de 3 angles avant les finitions de la chambre.

tu as la reponse et l'adresse d'une bonne pharmacie pour le doliprane

oui, tu as raison, j'ai dit une betise, avec un ratio faible, il faut augmenter le LC.(fatigué le fred ) Pour revenir aux histoires de LC qui passe de 108 à 103, c'est l'angle à l'arbre à cames, donc il faut multiplier par 2 pour avoir la valeur par rapport à l'angle vilo, donc 5° à l'arbre, c'est 10° au vilo, donc 5 à l'AOE et 5 au RFA.

ça ressemble à cette annonce: http://www.freebugriders.com/viewtopic.php?t=820

attention, il faut que le retour d'huile du turbo soit au dessus du niveau d'huile

j'ai retrouvé http://www.aircraftspruce.com/catalog/mepages/metalinfo.php

Pour manu, l'ac, c'est secret. Pour ce qui est d'Elroocky, c'est tout à fait juste, mais en retardant ton ac de 2 à 4 degré, tu feras grimper la puissance et decalera la courbe de couple vers le haut. Sur ce, sur un turbo, les culasses se travaillent differement, peu importe la vitesse, seul compte le debit, debit en relation avec les données des turbines. En gros, ça se resume à ça. Pour tom, un 108, car compte tenu de la cylindrée, le couple sera là, meme sans sural. Sur ce, pour eviter le turbo lag, si on ne veut pas une plage dementielle d'utilisation, on peut tout à fait jouer sur le trim et l'AR. mais on s'ecarte du sujet. revenons au LC en atmo..quoique, comme vous voulez

voilà ce que j'ai, j'essaye de retrouver l'adresse: 1010 This is one of the most widely used low carbon steels for low strength applications. It is best suited for parts whose fabrication involves moderate to severe forming and some machining. Its weldability is excellent and it can be case hardened for wear resistance by cyaniding. 1018 is a popular carburizing grade of steel. It can be strengthened by cold working or surface hardened by carburizing or cyaniding. It is relatively soft and has good weldability and formability. 1020 is a general-purpose low-carbon “mild” steel. It is easy to fabricate by the usual methods such as mild cold or hot forming and welding. It is weldable by all processes and the resulting welds are of extremely high quality. 4130 This chromium-molybdenum alloy is one of the most widely used aircraft steels because of its combination of weldability, ease of fabrication and mild hardenability. In relatively thin sections, it may be heat treated to high strength levels. In the normalized condition it has adequate strength for many applications. It may be nitrided for resistance to wear and abrasion. 4140 This chromium-molybdenum alloy is a deep hardening steel used where strength and impact toughness are required. It has high fatigue strength making it suitable for critical stressed applications. It may be nitrided for increased resistance to wear and abrasion. 4340 This chromium-nickel-molybdenum alloy is a widely used deep-hardening steel. It possesses remarkable ductility and toughness. With its high alloy content uniform hardness is developed by heat treatment in relatively heavy sections. Its high fatigue strength makes it ideal for highly stressed parts. 6150 This chromium-vanadium alloy steel is similar to 4340. It has good hardenability, good fatigue properties and excellent resistance to impact and abrasion. 8620 This is a “triple alloy” chromium-nickel-molybdenum steel. It is readily carburized. It may be heat treated to produce a strong, tough core and high case hardness. It has excellent machinability and responds well to polishing operations. It is easily welded by any of the common welding processes, although the section should be heated and stress relieved after welding. 9310 This chromium-nickel-molybdenum alloy is a carburizing steel capable of attaining high case hardness with high core strength. It has excellent toughness and ductility. 4620 This nickel-molybdenum alloy is a carburizing steel capable of developing high case hardness and core toughness. It can be forged similarly to the other carburizing grades. Because of its relatively high nickel content, it is not as readily cold-formed. 5160 This carbon-chromium grade of spring steel has a high yield/tensile strength ratio, excellent toughness and high ductility. It is very difficult to machine in the as-rolled condition and should be annealed prior to machining. It is not readily welded, but it can be welded by either the gas or arc welding processes if the section involved is preheated and stress relieved after welding. 52100 This high carbon-high chromium alloy is produced by the electric furnace process and then vacuum degassed to meet the rigid standards of the aircraft industry for bearing applications. It develops high hardness and has exceptional resistance to wear and abrasion. BENDING OF 4130 STEEL Specification MIL-S-18729C states that 4130 steel .749 inch and less in thickness shall withstand bending without cracking at room temperature, with the axis of bending transverse to the direction of rolling, through an angle as indicated in the table. Condition N materials shall be bent around a diameter three times the thickness of the material. Test samples are bent cold either by pressure or blows. In the event of dispute, bending shall be by pressure. Paragraph 4.5.3 of the specification states that the formation of cracks not over 1/16" in aggregate lengths at the corners on the outside of the bend shall not be cause for rejection. STANDARD AISI and SAE STEELS Studies have been made in the steel industry for the purpose of establishing certain “standard” steels and eliminating as much as possible the manufacture of other steels which vary only slightly in composition from the standard steels, These standard steels are selected on the basis of serving the significant metallurgical and engineering needs of fabricators and users of steel products. STANDARD CARBON STEELS Definition. By common custom. steel is considered to be carbon steel when no minimum content is specified or required for aluminum, boron. chromium, cobalt, columbium, molybdenum. nickel, titanium, tungsten, vanadium or zirconium, or for any other element added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 per cent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60. Numbering System. In the AISI system of identification. the prefix “B” is used to designate acid bessemer steel. The letter “L’’ within the grade number is used to identify leaded steels. A four-numeral series is used to designate graduations of chemical composition of carbon steel. The last two numbers of which are intended to indicate the approximate middle of the carbon range. For example, in the grade designation 1035, 35 represents a carbon range of 0.32 to 0.38 per cent. It is necessary, however. to deviate from this rule and to Interpolate numbers in the case of some carbon ranges and for variations in manganese, phosphorus or sulphur with the same carbon range. The first two digits of the four-numeral series of the various grades of carbon steel and their meanings are as follows: 10xx Nonresulphurized carbon steel grades 11xx Resulphurized carbon steel grades 12xx Rephosphorized and resulphurized carbon steel grades I5xx Nonresulphurized high manganese carbon steels. STANDARD ALLOY STEELS Definition. Steel is considered to be alloy steel when the maximum of the range given for the content of alloying elements exceeds one or more of the following limits: manganese, 1.65 per cent; silicon, 0.60 per cent; copper, 0.60 per cent; or in which a definite range or a definite minimum quantity of any of the following elements is specified or required within the limits of the recognized field of constructional alloy steels: aluminum, boron, chromium up to 3.99 per cent, cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium, zirconium or any other alloying element added to obtain a desired alloying effect. Numbering System. In the AISI numbering system, the prefix letter E is used to designate steels normally made only by the basic electric furnace process. Steels without a prefix letter are normally manufactured by the basic open hearth or basic oxygen processes, but may be manufactured by the basic electric furnace process with adjustments in phosphorus and sulphur limits. The last two digits of the four-numeral series are intended to indicate the approximate middle of the carbon range. For example, in the grade designation 4142, 42 represents a carbon range of 0.40 to 0.45 per cent. (Where a five-numeral series occurs, the last three digits indicate the carbon content.) It is necessary, however, to deviate from this rule and to interpolate numbers in the case of some carbon ranges, and for variations in manganese, sulphur, chromium, or other elements. The first two digits indicate the type of alloy according to alloying elements as follows: 13xx Manganese 1.75 per cent 40xx Molybdenum 0.20 or 0.25 per cent 41xx Chromium 0.50, 0.80 or 0.95 per cent — Molybdenum 0.12, 0.20 or 0.30 per cent 43xx Nickel 1.83 per cent — Chromium 0.50 or 0.80 per cent — Molybdenum 0.25 per cent 44xx Molybdenum 0.53 per cent 46xx Nickel 0.85 or 1.83 per cent — Molybdenum 0.20 or 0.25 per cent 47xx Nickel 1.05 per cent Chromium 0.45 per cent 48xx Nickel 3.50 per cent Molybdenum 0.25 per cent 50xx Chromium 0.40 per cent 51xx Chromium 0.80, 0.88, 0.93, 0.95 or 1.00 per cent 5xxxx Carbon 1.04 per cent -- chromium 1.03 or 1.45 per cent 61xx Chromium 0.60 or 0.95 per cent -- Vanadium 0.13 per cent or 0.15 per cent min. 86xx Nickel 0.55 per cent --Chromium 0.50 per cent-- Molybdenum 0.25 per cent 87xx Nickel 0.55 per cent -- Chromium 0.50 per cent -- Molybdenum 0.35 88xx Nickel 0.55 per cent --Chromium 0.50 per cent -- Molybdenum 0.35 92xx Silicon 2.00 per cent EFFECTS OF COMMON ALLOYING ELEMENTS IN STEEL By definition, steel is a combination of iron and carbon. Steel is alloyed with various elements to improve physical properties and to produce special properties, such as resistance to corrosion or heat. Specific effects of the addition of such elements are outlined below: Carbon (C), although not usually considered as an alloying element, is the most important constituent of steel. It raises tensile strength, hardness and resistance to wear and abrasion. It lowers ductility, toughness and machinability. Manganese (Mn) is a deoxidizer and degasifier and reacts with sulphur to improve forgeability. It increases tensile strength, hardness, hardenability and resistance to wear. It decreases tendency toward scaling and distortion. It increases the rate of carbon-penetration in carburizing. Phosphorus (P) increases strength and hardness and improves machinability. However, it adds marked brittleness or cold-shortness to steel. Sulphur (S) Improves machinability in free-cutting steels, but without sufficient manganese it produces brittleness at red heat. It decreases weldability, impact toughness and ductility. Silicon (Si) is a deoxidizer and degasifier. It increases tensile and yield strength, hardness, forgeability and magnetic permeability. Chromium (Cr) increases tensile strength, hardness, hardenability. toughness, resistance to wear and abrasion. resistance to corrosion and scaling at elevated temperatures. Nickel (Ni) increases strength and hardness without sacrificing ductility and toughness. It also increases resistance to corrosion and scaling at elevated temperatures when introduced in suitable quantities in high chromium (stainless) steels. Molybdenum (Mo) increases strength, hardness, hardenability and toughness, as well as creep resistance and strength at elevated temperatures. It improves machinability and resistance to corrosion and it intensifies the effects of other alloying elements. In hot-work steels, it increases red-hardness properties. Tungsten (W) increases strength, hardness and toughness. Tungsten steels have superior hot-working and greater cutting efficiency at elevated temperatures. Vanadium (V) increases strength, hardness and resistance to shock impact. It retards grain growth, permitting higher quenching temperatures. It also enhances the red hardness properties of high speed metal cutting tools and intensifies the individual effects of other major elements. Cobalt (Co) Increases strength and hardness and permits higher quenching temperatures. It also intensifies the individual effects of other major elements in more complex steels. Aluminum (Al) is a deoxidizer and degasifier. It retards grain growth and is used to control austenitic grain size. In nitriding steels it aids in producing a uniformly hard and strong nitrided case when used in amounts 1.00% - 1.25%. Lead (Pb), while not strictly an alloying element, is added to improve machining characteristics. It is almost completely insoluble in steel, and minute lead particles, well dispersed, reduce friction where the cutting edge contacts the work. Addition of lead also improves chip-breaking formations. HEAT TREATMENT OF STEEL By thermal treatment, steel may be made harder or softer, stresses induced or relieved, mechanical properties increased or decreased, crystalline structure changed, machinability enhanced, etc. The terms used to describe such heat treatments and their effects are listed below. NORMALIZE Normalizing consists of uniform heating to a temperature slightly above the point at which grain structure is affected (known as the critical temperature), followed by cooling in still air to room temperature. This produces a uniform structure and hardness throughout. ANNEAL When not preceded by a descriptive adjective, annealing consists of heating to and holding at a suitable temperature, then allowing to cool slowly. Annealing removes stresses, reduces hardness, increases ductility and produces a structure favorable for formability. Full Anneal - This term is synonymous with annealing and is used to differentiate anneal from bright anneal, stress relief anneal, etc. Spherodize Anneal - This treatment is similar to full annealing except the steel is held at an elevated temperature for a prolonged period of time, followed by slow cooling in order to produce a microstructure where carbides exist in a globular or spheroidal form. Soft Anneal - When maximum softness and ductility are required without change in grain structure, steel should be ordered soft annealed. This process consists of heating to a temperature slightly below the critical temperature and cooling in still air. Stress Relief Anneal - Stress relieving is intended to reduce the residual stresses imparted to the steel in the drawing operation. It generally consists of heating the steel to a suitable point below the critical temperature followed by slow cooling. Bright Anneal - This process consists of annealing in a closely controlled furnace atmosphere which will permit the surface to remain relatively bright. QUENCH Quenching consists of heating steel above the critical range, then hardening by immersion in an agitated bath of oil, water, brine or caustic. Quenching increases tensile strength, yield point and hardness. It reduces ductility and impact resistance. By subsequent tempering some ductility and impact resistance may be restored, but at some sacrifice of tensile strength, yield point and hardness. TEMPER Tempering is the reheating of steel, after quenching, to the specified temperature below the critical range, then air cooling. It is done in furnaces, oil or salt baths, at temperatures varying from 300 to 1200°F. Low tempering temperatures give maximum hardness and wear resistance. Maximum toughness is achieved at the higher temperatures.

la plupart des fabriquants se callent sur le callage d'origine, et de plus, le 108 est la moyenne entre 100 et 115 à un chouille pres

le reniflard est fait pour evacuer l'air en mouvement, si tu jettes de l'huile dedans, tu va avoir une pulverisation, à moins que tu ne fasses une separation pour eviter l'emulsion

suivant le ratio de flux, on mets plus ou moins de LC(lobe center). Plus on augmente le LC, plus on diminue l'angle de croisement, et inversement. en general, on considere qu'avec 80, 85% de ratio, il faut tourner aux alentours des 108 de LC. Le ratio de flux est donné par le quotient entre le debit de l'echappement par celui de l'admission, debit en general pris à la pleine levée. là, les ennuis commencent, car on conseille de choisir l'arbre à cames(donc le LC chez certains constructeurs comme Webcam) en dernier. Le probleme, c'est que la pleine levée varie d'un ac à l'autre, donc pas facile de prevoir en travaillant les culasses un hypothetique ratio suivant une hypothetique levée. Qui plus est, le ratio de flux varie suivant chaque etape de la levée, de la fermetue à la pleine ouverture, et c'est loin d'etre une constante. en debut d'ouverture par exemple, on est à quasiment 100%, le diametre de la soupape n'intervenant que tres peu et le conduit n'etablit pas de saturation, il s'agit juste d'une situation de fuite. Par la suite, en pleine levée, le conduit etablit la saturation, ou plus exactement, son dessin, les asperités, les soupapes, les agnles des sieges ou des portées.... sans compter que si on a testé les conduits avec ou sans les pipes, avec ou sans les carburateurs, les cornets... tout ceci change... tout comme à l'echappement, si on teste avec ou sans l'echappement. la raison sont les perturbation qu'engendre la passage d'un conduit à un milieu ouvert qui doit etre aussi progressive que possible à l'admission, et à l'echappement, ce pour le flux, mais il y a les probleme d'accords et de detente aussi brutal que possible à l'echappement, pour obtenir une onde aussi forte que possible, ce qui permet de vidanger dans un premier temps(on de depression, ce qui voudrait dire gros debit des le depart), mais aussi onde reflechie de pression pour eviter que trop de gaz frais passent directement dans l'echappement sans avoir balayé la chambre, ce qui est nefaste à son refroidissement tout comme à la pollution, au rendement, ... on attaque là les gros problemes. Il faut avoir de gros debits en debut d'ouverture et tres peu en fermeture, avec exactement le meme probleme à l'ouverture. pas simple d'avoir le bon ratio!! en plus, en jouant sur le LC, si on passe de 108 à 103° de LC par exemple, en supposant le callage symetrique de l'arbre à cames, on perd 5° en avance à l'ouverture à l'admission et 5 ° en retard à la fermeture à l'echappement, ce qui est prejudiciable à la puissance à haut regime, mais benefique à bas regime. sur ce LC, le ratio intervient, car pendant la phase de croisement, plus le ratio est proche de 100%, plus la soupape d'echappement peu gerer de gros debits en theorie, donc gere la fin de l'echappement qui doit etre le plus complet possible, tout comme le debu de l'admission qui doit se faire le plus tot possible pour esperer approcher le remplissage maxi, qui dans le cas des atmos depasse rarement les 80 à 95% du volume de cylindre, et de ce volume introduit depend principalement le couple et la puissance. Inversement, plus le ratio est faible, plus on a interet à diminuer le croisement, donc prendre un LC grand. Ceci represente toute fois un avantage dans la recherche de puissance maxi, car celà permet de travailler à plus hautes temperatures en phase d'echappement, donc d'avoir une difference de temperature plus importante entre le debut de l'admission et la fin de l'echappement, et comme le rendement d'une machine thermodynamique est proportionnel à la difference de temperature, on comprends vite l'interet.... le soucis de ce chemin est la tenue des element sous forte temperature qui ne peu durer longtemps sans emener des casses. En turbo par contre il faut voir les choses differaments, mais on verra ça plus tard. Donc, pour en revenir à ta question Thomas, en cas de ratage, il faut voir comment est le ratage. Si c'est la ratage standard, à savoir on fait des conduits comme des vaches, à l'admission comme à l'echappement, il y a de fortes chances pour que le ration soit paradoxalement à peu pres convenable, mais come on a des debits tres importants et des vitesse de gaz faible, il faut diminuer la taille de l'arbre à cames par rapport au comportement moteur qu'on veut(par rapport aux "standards habituels). Si le conduit d'admission est trop gros, l'echappement etant raisonable, la ratio est fable donc il faut diminuer le LC inversemant, si l'echappement est trop gros par rapport à l'admission, il faut diminuer le LC, ce qui ne sera pas sans poser de soucis en cas de controle antipollution, si le vehicule y est soumis, car le taux d'imbrulé sera tres important, car passage direct de l'admission à l'echappement. enfin, donnée importante, le LC ne peut varier que de 100 à 115°(ceci determiné experimentalement) et le LC VW T1 est de 108°.

non, le top pour un T4, c'est d'avoir une gros debit de T1 Par contre, il faut verifier qu'elle passe sans rien toucher-niveau arbre à cames

conseillé je pense, mais je ne connais pas la taille des T4 d'origine

je vous demande de vous arreter

là, il marche. sinon, http://www.geocities.com/euxineseaweed/saemetalchar.html

je ne sais plus, et comme tu a le carter

j'ai eu les memes echos. Ils existent aussi en cote Fomoco, Mopar...

allez, un doliprane http://www.me.unlv.edu/Undergraduate/coursenotes/PROPERTIES%20OF%20WOOD%20and%20METALS.htm

tiens, lis ça, il doit y avoir ce que tu veux: http://www.onlinemetals.com/merchant.cfm?id=255&step=2

et un soft gratuit à telecharger, avec tout, y compris les tubes à utiliser, ceci sur les horizontaux, mais bien peut de difference avec les verticaux. http://rcma.free.fr/escort/choixweber.htm