Taking the crank down to bare bones, swapping bearings Options

[DNHunt]

Time to get this thing done so, here's how I pulled the gears on the crank and replaced the #3 main bearing.

First I drilled a countersink into the top of an 8 mm bolt to protect the threads in the nose of the crank thtat secures the fan hub.

[Jake Raby]

The cam is another interesting thing... I haveb used the grind MANY times, a derivative of it is even in my 912E and has been for 90K miles... BUT I have always either used it with a stock stroke, or used it with my 80mm crank with a Chevy journal. Both these allow a larger base circle to be ran than with Dave's 78mm crank and the TI rod I set him up with. I really wanted Dave to use this cam because of its characteristics with EFI on the intake side of things...

The exhaust side of the cam is VERY fast on its ramp speed (thats one reason it makes hellacious power) but obviously the .045 difference in base circle (reduction) for clearance purposes with the larger journal was just enough to cause an issue.

I learned a lot from those issues and created another couple of rules that I never had before- its just another case of listening to the engine and learning from it and anyone that pushes the envelope will have that happe from time to time. I replaced the cam and related items (twice) so Dave now has another cam profile that is absolutely proven to work great with the combination he has. It may lose 5HP, but things are fail safe with this camshaft.

FYI_ dave's kit was bought back when I custom made kits based on similar engine combos and did not have the default kits that we have today with standardized parts and procedures. I was trying to maximize his power and the "Grin factor" as much as I could and well, that has a few risks- Thank god Dave wasn't an impatient asshole (like he could have easily turned into if he wasn't such a swell guy) and was willing to let us figure out some things along the way....

This is the reason I refuse to claim the title "Expert" we all learn- all the time and the day we think we know it all, we have just proven that we are idiots.

Today engine kits are 100% fail safe, their components have been used literally hundreds of times together - the downfall is not quite as much power or efficiency but its still plenty enough power to blow your mind everytime you drive it.

Good luck Dave!