læs lidt på nettet om hvad de andre kører med, så sparer du selv de dyrt købte erfaringer - der er for mange meninger om hvordan det skal gøres - men over 180 skal du ha ALT nyt - forvent et sted mellem 40 -100000 alt efter hvordan du vil ha det skal holde.
topstykker ca 10000
krumtap ca 5- 10000
blok ca 3 - 5000
karbs ca 6 - 12000
tænding ca 2-4000
cylindersæt 2- 5000 osv osv osv
og dette er jo kune en lille del af det hele
jeg har selv begrænset mig til ca 100 hk - jeg syntes simpelthen det er for dyrt - og chansen for at det springer i luften 1 gang - den er der jo hvis man har sparet bare et enkelt lille sted..
der er mange timers læsning - og snakken inden du køber ind...
[b:1a2754eca5]I think building a large displacement VW engine has almost become an art form. Bore, stroke, rod length, and compression can all be combined in so many different ways that once you throw in the human factor you will usually end up with a different and unique motor every time.
I know when I build a new motor that I'm always thinking for a new angle. With so many heads, carburetors, exhaust sizes and cams available you can choose your "state of tune" or the RPM range that the motor will operate at. Other engine marks don't have this flexibility. Even the famous smallblock Chevy that also has an entire aftermarket industry behind it falls short of the aircooled VW in parts choice sometimes. So many parts choices are a great thing but of coarse it can be confusing sometimes.
The best thing I can tell you is look, listen and learn. Sooner or later you will start to figure out who knows what they are talking about and whose parts work the best. For those of you who don't want to wait that long I will list some proven motor combinations later in this article.
There are basically two kinds of people that want to build a more powerful VW motor. There is the person who wants the fastest thing they can build and there is the person who wants a reliable everlasting motor. I will try to bring these people a little closer together. First of all the main goal is more power. So if you're going to build a more powerful motor there's no sense in not going far enough. It costs about the same amount of money to build an 1800cc stroker motor as a 2275cc stroker motor. And they will both last if they are assembled correctly. With the same carbs, heads and exhaust they will basically make the same horsepower but the 2275 motor will make it at a lower RPM and be much more fun to drive. Also a motor that turns 6000 RPM will out last a motor that turns 8000 RPM all the time. So the point is bigger is better when done correctly.
There are some basic levels of performance with a VW engine. Things like heater boxes, boring and stroking determine how much performance you can obtain at a certain level. The first decision you need to make is do you really need your heater boxes? Are you going to be driving in cold climate for long periods of time? I did, and it sucked with no heater but at least my car was fast! :-) I eventually built an oil-cooled heater and all was fine. But don't kid yourself, it took me a long time to build a custom heater and I froze my butt off until then. If you choose to run heater boxes then I don't recommend stroking your motor or running it at sustained high speeds. The boxes are very restrictive and cause heat to build up in the heads and will eventually crack them, in some cases severely. Even a stock motor with cleaned up exhaust ports and a competition header instead of heater boxes will run cooler under extreme conditions.
The next step is boring the case for bigger pistons. If you're going to bore your case for 88s then why not bore it for 94s? It costs the same amount. Just remember that you must adjust your compression ratio as the motor gets bigger. If you just slap stock heads on a 1900 it will have 9to1 compression and that's too much. I ran a 94x69(1914cc) 7to1 compr. with Kadrons in my bus for years and it was a great motor as well as simple to build. Whether or not you can go to the larger 94 pistons depends what year case you are using. I don't recommend using 94s with the early 10mm head stud cases. The later cases as well as all new cases come with 8mm head studs and can be bored for 94s safely. While I'm talking about head studs I use chromoly 8mm head studs on all my motors. They can easily be torqued to 25lbs or more and do not come loose. The stock 8mm studs can be used but they will only torque to 18lbs. and if you are buying after market 8mm studs they are usually substandard so just pay a little more and get the chromoly ones. If your case comes with 10mm studs, the stock ones are fine.
As far as big bore pistons are concerned the only ones that need help are 92s. If you have a 10mm stud case, these are the biggest pistons I would use. The tops of 92 cylinders are too thin so if you want to use them I would have them sleeved up to 94 bore size. A good VW machine shop will know how to do this. I will also sleeve 94s up sometimes because it gives a better seating surface in the head. When boring a case for larger cylinders its best to have it cut for wide base cylinder shims. This also gives a better seating surface. Sleeving the cylinder and using wide base shims keeps the cylinder from eating into the case or head. I've taken apart daily driver 2332 size motors after years of service and the heads were still torqued to 30 lbs.
Next is stroke. The way I see it if your going to stroke it then STROKE it! Buy at least a 78mm crank and I prefer an 82. An 84 and larger crank should really have longer rods so Ill get to that in a minute. A 74mm crank is better than a 69mm and if you get one for free I would think about using it. The thing is if you're buying a crank it only costs a small amount more for an 82. An 82 crank with stock VW rods is an awesome combo! An 82 stroke with any bore and some OK flowing heads will smoke the tires as far as you want! It will also pull a bus and a trailer up any hill. The 82 crank combined with a stock length rod creates a shorter rod ratio than a stock 69 crank with the same rods. This short rod ratio causes the piston to snap harder at top dead center and in turn makes the heads breath harder. In short what you get is a high torque motor that pulls hard and has excellent throttle response. This combination coupled with some big pistons and a good set of heads and a medium size cam will make a great street motor or even an excellent bus motor. If you go with a big cam and heads you will have a real screamer capable of quarter mile passes in the 12s The key to this whole combination though, is a properly ported set of heads and the short rod ratio.[/b:1a2754eca5]
læs lidt på dette link
http://www.cal-look.com/index2.html
og der er mange flere af den slags
jeg er ikke selv en motorhaj - jeg gider ikke sætte mig ind i alt det - der er simpelt han alt for meget , så jeg hører og ser hvad de andre gør , og laver noget mage til , det er meget nemmere og billigere, men en ting er sikkert når du går over de 100 så fordobler du mere eller mindre prisen hver gang du ligger 20 hk på - hvis det skal holde - derofr lader jeg selv være med at gå derover - og bekymrer mig egentlig heller ikke om hvordan og hvorledes det skal gøres..
hvis der var en egentlig opskrift på hvordan man lavede den perfekte maskine, så ville de nok allesammen vel være ens - men sandheden er , at der faktisk ikke er to der er ens, hver enkelt motor er ligeså individuel som vi mennesker er det , og vi laver jo heller ikke børn efter en opskrift.
så der ER desværre ingen opskrift på den optimale motor, det er op til dig at drage erfaringer , og lytte - også selv bestemme hvad du vil ha, eller lade dem bestemme også blive sure på dem når det ikke holder alligevel.
god fornøjelse
det er nok også en god ide at jeg svarer fordi jeg måske ved lige så lidt om motorer som dig, dem der er dygtige til det har tendens til at komme med et hav af løsninger , så man bliver helt skræmt fordi man slet ikke kan følge med i hvad de snakker om, de har allesammen mange godr tips og ideer , men der er IKKE to af dem der kan blive enige om ret meget, og kommer de med hver sin ide om hvordan tingene skal laves, er du sikkert så forvirret når du har snakket med dem alle sammen at du faktisk er længere fra en egentlig løsning enddu var inden de forklarede dig noget som helst, så ved du det...
og de fleste har sikkert ikke engang gidet at læse alt dette her igennem, meget tekst skræmmer folk , de vil bare ho nogle hurtige løsninger på bordet nu og her , at være så lidt seriøs, er allerede det første tegn på at man skal lade være med at rode med motorer - det kræver timers læsning at danne sig et overblik om hvad der er godt og vad der er skidt , man kan selvfølgelig også prøve at drage sig erfaringerne selv , men så får man ikke noget der virker før om 20 år... og for hver gang du er færdig med en motor ved du allerede hvad du vil lave om næste gang, det er et evigt skruen , og samle viden at køre med tunet motor - derfor gider jeg ikke over de 100, man bliver aldrig helt tilfreds , der er altid noget der liiige kan laves lidt bedre
