Brazian Cases

[carson]

Anyone useing or have used a Brazian case for drag racing. I have a 2275 motor with a Brazian case and would like to use it, but i'm not familiar with case.
Thanks

[FJCamper]

Hi Carson,

The Brazillian mag alloy cases are just fine, but for high performance appplication need prep work like any other mag case, meaning shuffle pins, reinforced #3 webbing, lifter sleeves, and decking.

Decking is important because all VW cranks don't run in the true center of the case. That means even if you took care to properly C.C. your heads, you have pistons travelling farther into one head than the other.

Your machine shop can measure the exact center of your case and machine one outer side of the case or the other so the cylinders will fit flush and the stroke is equal.

If weight is your concern, aluminum cases are much stronger than mag alloy, but can weigh almost twice as much ... and in the rear, too, right where you don't want it.

Few easy choices in this hobby.

FJC

[Marc]

Biggest problem I have with Brazilian cases is spotty quality-control on the final dimensions. I've even encountered one where they failed to drill the bleed hole in the bottom of the flywheel-end oil-pressure relief valve bore (allowing pressure to skyrocket within a few moments on a cold motor and cooler overpressurization). The metallurgy itself seems to be OK as a rule.
I'm not a fan of shuffle-pinning. It does reduce fretting of the mating surfaces, but only up to a point - beyond that, it only ensures that the main web(s) will crack. Fretting damage can be remedied (at least well enough to put the case out to pasture in a low-performance application) but the cracking is fatal.
IMO one of the best options for a nearly bullet-proof case is what Rocky Jennings builds - he's figured out how to take a wasserboxer block and make it accept aircooled cylinders & heads. You even get an integral oil filter out of the deal. If I was building a serious big motor today, that'd be what I'd choose to base it on, rather than spend a lot on blueprinting a BZ case, or purchasing an aftermarket one.
http://www.rockyjennings.com/ see: "H20 to Air"

[neil68]

My 2332 cc street-strip engine is based on a Brazilian AS41 magnesium case. The only problem I encountered was that one side was 0.010" different in deck.

Therefore, when I set up my shim stack I had to account for this. IIRC, I installed a 0.050" shim stack on one side and 0.060" on the other. That allowed me to set up the deck height correctly for both heads.

I have raced over 600 times on the 1/4-mile plus 49,000 km in city driving, and everything is still fine (I swapped camshafts two years ago, and inspected everything carefully).

[Clatter]

Check the size of the cam bearing tunnel bore.

I have seen two Brazil cases where that was tight.

Also with mains, too, but you would otherwise be looking closely there, right?