TECH Feature: Balancing the Moving Components at DPR Machine Shop

To achieve building a perfectly smooth-running motor without unexpected vibrations, precisely balancing the moving parts is a must. Even though the manufacturer states that the rotating parts are pre-balanced, it’s always a good idea to double-check them before the assembly.
When we built a 1488cc Hot Rod 36hp motor, We brought the 74mm crankshaft, rods, 80mm pistons, flywheel, clutch pressure plate, and crank pulley to DPR Machine Shop in Santa Ana, California.
Special thanks to Jose Alvarez at DPR Machine Shop for taking care of these parts and showing us the technique to get them balanced.
Contact [phone] or visit dprmachine.com/

[@davemurton736]

Proper old school 👍 Brilliant

[@vayabroder729]

This is a great machine shop. They are legends.

[@mikegreen2229]

His German OE welded and remachined products are top notch. Highly recommend him. I finished 2 engines last year with his rotating assemblies. One is a stroked 40hp that runs super smooth. This is the guy to send your stuff to and can handle unique projects

[@calescapee9642]

Freaking Amazing!!!!

[@bobmeyer7009]

This guy knows what he's doing. Okrasa is high quality - I built a turbo engine years ago with an Okrasa crank and Carrillo rods - you couldn't break that bottom end with a sledgehammer. 🙂

[@calescapee9642]

I'll be sending some stuff to him.

[@rabidfarmer9765]

And the rods have to be weighed for the bigend should be perfectly horizontal. If the rod is hung like that w/ smallend down, you are basically weighing the entire rod.

[@blkcoupequattro]

First time I’ve watched someone do it the Old School way…

[@briantimberlake3114]

Very interesting video. Always wondered how they did this.

[@frielocity6286]

It's WitchCraft!! How is the crank able to spin just sitting on those four rollers? OH,..I see the band. Spins so fast and quiet...like an electric VW powered motor...JK,..great video, and Yes Jose is an artist. Think about how many people run a crank/components that is not balanced this thoroughly and takes lots of time.

[@reyhanmar]

You know your rotating parts is in good hands w/ Jose the man! 🫡

[@joe-hp4nk]

If you grind from the end of the weight, it takes less to balance.

[@jimmywilkinson9190]

the CW crank to begin with compared to a OEM ?

[@mikegreen2229]

I believe this is a 36hp stroker engine. An original crank like that is very rare

[@hotvwsmagazine]

Crankshaft from Wolfsburg West 74mm stroker for 25/36hp engine.

[@rabidfarmer9765]

The heavy spot does NOT move. If you do not really know where it is - you will end up drilling all over the place. Get a first read on where the heavy spot is supposed to be. Then do a challenge on the opposite side - the light side gets the weight. If you find zero - then you know exactly where the heavy spot is. Old strobe machines have to use trial weights on the light side or you will end up w/a part looking like Swiss cheese. LOL> Computerized balancers can tell you exactly which angle to drill and how far from center. But those strobe machines - you have to know how to use that one. And the heavy side on the LEFT side is missing the woodruff key which obviously is the light side. I have used strobe machines a long time - What machine be this you are using, sir?