Max hp 4 dowel crank flywheel

[Alstrup]

A couple of things.
A turbo engine is not nearly as hard on the gland nut as a similar HP N/A engine is. Once "things are rolling" it can handle incredible amounts of power if assembelled correct.

I´m not saying that a stock gland nut can´t hold more than 80 hp. I´m saying that from thereon up you are in grey country. I´m sure that a Scat/CB or what ever quality 38 mm bolt along with a larger washer will improve holding power a good deal. How much I do not know. Berg senior tried it out some, but I don´t think he ever published anything about his findings. My guess is that it was is because the gains were minimal. I could be wrong though.
Also, back when beetles were used for rally the engines typically pulled about 125 hp. And since it was not legal to remove anything from the crankshaft they had to use higher torque on the stock 4 dowels. - USUALLY - they held together, but every once in a while a bolt let go and the flywheel & crank was destroyed. Again, these engines were not so hard on the parts in the starts, because it was often on gravel and the engines only had 150ish Nm torque and again, once they were rolling it wasnt so bad.

The term "We did that 30 years ago. It worked well" doesnt hold in a lot of situations. In this case I will also say, barely. Reason is, that today we build engines which produce A LOT more usable torque than what was built at an average back then. And it is the torque that kills it, not the hp. - Well, if you get enough hp it will, but you´ll catch the drift.

Last. The surface versus torque is progressively proportional, so 8 properly installed dowels can hold about 200% more than 4 stock dowels torquewise. In a shock load I am not sure what the factor is, but it is at least 100% (I´m sure there is an engineer who knows this or can dig up the numbers)
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[buguy]

I agree. My turbo engine didn't make much power right off the line. I never tried building boost on the 2 step before launching. I still had the stock 4.37 trans so first gear was almost unusable so i just rolled through first and then once i was in second i would let it rip. So i never did shock it.

[c77owen]

[Ohio Tom]

I have stripped a few stock gland nuts with over-torque.
Never, not once seen a Chromloy one fail.
Stock gland nuts will rip the threads off.
If you ever remove one and the threads are sharp enough to cut you?
It's about to fail....

It's a sad sight to see someone build a nice race motor with 8-dowel crank. Only to use a stock gland nut that fails.

Yes, adding a chromoly gland nut to a stock 4 dowel crank is an upgrade.

Very common to do the same to Porsche 356 engines.
It's about the only part that's OK to use "non stock" on a 356 restoration.
Even the Anal guys are OK with gland nut upgrades...

[scfwb]

Might be a bit off topic but since you guys seem to know more about this... I thought I would ask - I have a 1915 engine with 8 dowel crank and lightened flywheel (bought this from a friend as a complete engine). Since I'm putting this in a bus I thought that I would prefer a full weight (stock) flywheel. Question is - do I have to drill/ream the stock flywheel for the 8 dowels or can I just use it with 4 dowels with he 8 dowel crank? Thx in advance

[chrisflstf]

8 is better, but 4 will work. I would use a chromemoly hd nut and washer. If you go with 4, you will need to remove 4 dowels from the crank if installed. That may not be easy