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Stock VW Crank, Use It?

Posted: Wed Jan 26, 2005 9:52 pm
by AirJose
I am building a 1914 and intending in balancing the motor, I just opened the AE block for the first time, the engine was all stock inside, all vw parts, bearing, oil pump, etc... and the case has no ridges. originally 52k on the motor in an abandoned KG. But since is such an original crank, should I get a counterweight crank? or use this one. by the way I will not exceed 5,500 RPMs. I need your opinions. Thanks in advance, Jose :roll:

Posted: Wed Jan 26, 2005 11:03 pm
by vwee
I will not exceed 5,500 RPMs. I need your opinions. Thanks in advance, Jose
Do you know how hard that is to do in a 1914.

I am not saying the stock crank will not work, becouse it will but even 5k rpms is pushing it, the motor would have great power compared to a stocker.
(my opinion) The C/W crank and a few other minor upgrades if you want to even begin to see the potential of a 1914.

Posted: Thu Jan 27, 2005 4:00 am
by 2332 baja
I agree with vwee. You can get away with using the stock style crank but you will need enormous amounts of self control :) BUT I would have it checked before even considering it in a 1914 project. You will be buying or machining the heads and case and buying new p&c's, bearings, etc. And it would be sickening to loose the investment because of a crank. A good german stock crank is stronger than a lot of the aftermarket cast cranks, so getting counterwieghts welded on is always an option if the crank is in good condition.

Posted: Thu Jan 27, 2005 11:16 am
by Clatter
If you plan on keeping the motor otherwise mild/stock, then it would be fine to use the stock crank on a 1914.

The stock heads probably wouldn't flow much past 5500 anyway.

If you run it with IDAs, SuperFlos, and a 1 3/4" exhaust, on the other hand...

Using the added displacement in conjunction with stock valve sizes and a mild cam, can make for a nice torquey street motor.

If that's what you're going for, I'd say do it.

Posted: Thu Jan 27, 2005 12:52 pm
by RoWaMe
A few years ago I spoke to a good type 1 engine builder in Bavaria, Germany. They, and other tuners over there, get away with stock cranks on mild hi-po engines by balancing them; in his experience the stock, balanced crank was good for 5000r's steady and 5500 "briefly". So if your other 1914 parts are on the "mild" side (like Engle 100 cam, single-throat carbs) and you usually shift by high 4's, then IMO stick with the stock crank. But have a good machine shop (does not have to be VW) balance it. Best would be to also have the rods (balanced end-for end and overall weight), pistons, flywheel and pressure plate done at same time.

Posted: Thu Jan 27, 2005 9:35 pm
by fish
I took a couple of cranks to a local crankshaft guy to get turned a while back. One of the cranks was counterweighted & he told me that the VW guys were the only ones adding weight to their cranks. He said that he was constantly taking weight off the V8 guys as well as the Porsche cranks. I run 2 type 4 drag motors with no counterweights (I know the type 4s are different) & launch at 7000rpm shifting at 8000 to 8200, and after season after season have yet to see any excessive main bearing wear. Balncing on the other hand is esential. my 2 cents.

Posted: Fri Jan 28, 2005 7:08 am
by mschilling
V8's and Porsches are different engines wrt the crank and counterweights. E.g., VW cranks don't use weights attached when they are balanced like V8 cranks do. Berg wrote in his catalog that he had good luck using a stock crank with a harmonic damper on the pulley end, even when revved (to a point, of course). Usually the counterweights are added to engines when they want it to run smoother, with less vibration, but with a bug motor, they're added to help stop the crank from flexing.

Posted: Fri Jan 28, 2005 7:26 am
by mharney
There are a few things I would not skimp on for the shortblock. One is the crank. The crank needs to be strong for long life. If it flexes due to RPM (and with a 1914 you're gonna be hard pressed to keep the revs down), or takes a beating because you have big heavy pistons to move and absorb, it's gonna beat out the case, among other things.

If you really intend to build a mild engine and keep the revs down, the stock crank is probably ok. Just make sure you get a GOOD balance on your parts. Raby does a prime job of it.

The other things to pay good attention to in the shortblock:

Lifters - get good ones if you're going with more than a stock cam.
Oil pump - make sure it is NEW and in very tight specs. I like mine at 0.001" gear clearance or less. Use an aluminum pump (I like Schadeks the best) with a steel or iron cover.
Flywheel - I would NEVER use a cast flywheel on anything other than a stock engine, and even then, only in a lighter car.

The rest needs to be decent, but these are the prime items to pay attention to in a mild engine like yours, IMO.

Posted: Fri Jan 28, 2005 7:41 am
by mschilling
Why worry about over-revving it?All you need is a rev limiter. I've used the ones that fit in the dist, and it will remind you that you cheaped-out on your crank, guaranteed, haha!