This is what the people who engineered your once brand new VW went through for just one part that belongs on your car. As you peruse the following page, you’ll find the only brand of automobile manufacturer mentioned in this entire page of complicated physics formulas with numbers and letters going all over the place is …Volkswagen. There’s even a crude picture of a Volkswagen crankshaft – probably the latest type 1 version. Volkswagen makes real reliable crankshafts. We VW people should be flattered. Maybe they just liked VW crankshafts?
Regarding the 2 liter type 4 engine … rod journals 5 millimeters smaller in diameter than any other engine from 1300 cc and up – 5 millimeters smaller than a 1.7 or 1.8 type 4 engine. 2 liter type 4 cranks are subject to fracturing, particularly on the center main bearing journal. This is where the most flex is. I’ve never seen it on any other engine. VW took it to the limit with this one and slightly beyond. If you read the article in the link above, this type of failure is mentioned. Search the page for “fracture”. To prevent this problem, don’t skimp on align boring a type 4 case. Even if someone told you they never need align boring. Saying any part on any car never wears out is like saying there’s such a thing as perpetual motion. Proper fit of the main bearings in the case holds the crank at it’s proper rotational axis (even though it’s always wiggling away from it – always imperfect, never perfect) and that’s what causes this kind of failure. Just imagine what it’s like being the center main journal at the center main bearing interface when the vehicle is cruising down the road at 60 miles per hour – ouch! Proper alignment (new bearings, align bore when necessary) of the crankshaft keeps the crank rotating on the proper axis within the original design (wiggle) .
They used similar procedures and criteria when they designed every single part for the rest of the car – particularly the front suspension and steering. Best thing to do with a VW that you actually want to drive trouble free (it doesn’t have to be a toy – it’s real transportation) is to leave it stock. If you want more power, dual German type 3 carbs (similar and viable renditions are found on 72-74 buses) on a stock 1600 single or dual port engine. I love single port with these carbs – super low end; runs like it’s got fuel injection from a new Lexus. Floor a split bus at 15 mph in third, it’ll take off and ask “Where do you wanna go?” These carbs are fine for any air cooled model beyond any 1200 engine. OE carburetion is designed to supply the proper amount of fuel for proper fuel mixture and lowest emissions, particularly carbon monoxide and minimum stress on the engine.
Hi CO levels tell you that you’re feeding the engine an excess of fuel. This reduces engine life, most directly affecting the pistons and the rings. Original German type 3 type carbs are infinitely adjustable for any stock size air-cooled engine from 66 and up in the right hands. They were even used OE on air cooled Vanagons with the 2 liter type 4 engine in some European markets. And you’ll get 25 percent less maximum top end RPM with the Brazilian copies, even though they are Solex product. Weber ICT’s aren’t much better for high revs and usually worse. And not nearly as tunable. For instance, a stock single port 1600 bus with German type 3 carbs jetted properly will do 50 mph plus in third gear (with the stock gearing, which is preferred for all applications). You’ll only get to 40 mph with the latest Brazilian version and no matter what you change (jets, venturis), they’ll never make it to 50 mph. But the message is … keep it stock (original engineering) everywhere and you’ll go anywhere … and come back. And a hot motor for actually going places is a grenade just waiting to explode or for the clutch to disintegrate from the engines ability to quickly reach much higher rpms than the engine was designed for. Realize a bigger engine or massive carburetion gives you more power because the explosions are bigger. That’s it. With a bigger explosion, you still have the same thing containing it – the head studs and the head. Many remedies have been tried. Even adding a fifth stud for each cylinder, but for reliability, don’t alter the size or the carbs from something originally designed for any variation of the vehicle or the engine. Your reward will be long life and reliability.
And if you’re thinking about changing the wheels or tires from stock for better handling, the smart, German engineers (realize the reason VW’s have been around so long is because of that fabled German engineering) at VW figured that out already probably using the Magic Formula (yeah, that’s right – there’s really and an engineering term for determination of tire size called the “Magic Formula”) found here …
But they probably applied the Magic Formula to determine tire size after they engineered the suspension for safest, predictable handling, effectiveness of braking, and overall compatibility in relation to the whole car in general.
For instance, putting stock Vanagon alloys requiring wider tires on your bay bus of any year will only result in a rougher ride because bigger than stock tires don’t give as much over rough roads or bumps and make it harder to turn steering wheel, particularly at slow speeds like when you’re parking. You’ll also obtain a shorter life of the front wheel bearings, and front end linkage, particularly the steering box. And it’ll be slower to respond to steering changes at higher speeds and result in lower gas mileage and a slower top speed. Of course, if you just wanna park it in the living room, be my guest. Do you wear size 8 shoes? Will size 12’s make you walk faster? Stock tires keep your vehicle nimble. Changing the tires and changing the suspension will not improve the behavior of you car. You may think you’re going around turns faster but lowering the car and adding tiny tires in the front simply because they’re the only ones that fit with minimum rubbing will severely alter (for the worst) the braking characteristics of your vehicle. Tiny tires in the front will make it so the brakes will lock up at a much lower speed than the stock tires. And even when not braking, the will loose traction and begin to slide thus allowing the vehicle to continue in a straight path in an unexpected emergency turn for instance where you instinctively turn the wheel a significant amount quickly while traveling at a high rate of speed to avoid hitting … a ten year old kid, for instance. You might just keep going straight in a case like this. Stock size tires are the best.
For bug, 1.65 R 15
And for bus, 1.85 R 14
Don’t let the tire shop talk you into anything else which they’ll likely try to do because they probably won’t have these in stock and will have to order them so they’ll try to sell you what they have. Don’t let this happen.
Now a test …
Lowering your car so it’s even front to back, not slammed, is the only way to get it go around turns faster and safely. All cars come new with a slight downward rack. This is not really by design, it’s just compensation so that over time or even due to uncontrollable error in manufacturing (small imperfections add up), the rear never looks lower than the front because it looks funny. There’s not a car in the world that’s sold new that’s slammed. Be moderate with tire size increases and let clearance with no modification be your guide. And just for reference, the first 911 Porsche’s equipped with steel wheels came with same size as a VW bug – 1.65 x 15 inch tires.
This entry was posted on Tuesday, July 28th, 2015 at 7:19 am
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