Using the new Ford racing BOSS-5.0 iron modular block continued.......
Secondly along with a compression bump on our forged short blocks… as mentioned previously we try to persway our engine job customers into stroking too. By stroking along with a compression bump, and lets not forget some other enhancements like head work and a cam swap etc. You start to see where this is going. The key thing is we don’t want to see our forged short blocks induce a potential power loss just from forging the bottom end due to the heavier rotating components. So by considering stroking it along with our recommended compression bump, this helps insure that your new forged modular short block will not cause a potential power loss right off the bat just because you choose to go for a stronger, heavy-duty rotating assembly
.This finally brings me to the new FRP -- “BOSS-5.0” -- BigBore iron 4.6L replacement block. Starting a few years ago, adding BigBore sleeves to stock aluminum 4.6L blocks was a little bit popular, but proved to be very expensive, and for us caused some durability problems and even head gasket retention problems. I’m a very big proponent of the stock aluminum 4.6L blocks in very high horsepower applications; even stroking them (against what other might believe) has been very good to us.
But for the guy looking to get into a little something more, along with stroking when getting into a new forged short. Or have considered a 5.4L engine conversion. Then this new FRP modular block and its potential, is something worthy of some attention.
This new FRP block is looking real good to us, and we’ve already seen some of its potential. The new BOSS-5.0 iron block starts out at 3.700 bore (stock = 3.55), and when combined with a 3.750 stroker crank (stock = 3.55), you end up with 323 cu in or a 5.3L. Aside from the approximate 90lbs weight penalty… this new block in my opining is something very interesting to consider if the budget allows when looking into a replacement motor in a 4.6L application. This combination gives you a 42 cubic inch bump from the stock 281. Combined with just mild head work and a cam change of some kind, we’ve already seen some impressive results with these “BigBore-Strokers” in a couple of blower applications. |
This in my opining is also a more practical thing to consider if you’re having thoughts about trying to install a dimensionally larger 5.4L where a 4.6L originally was. Especially in Mustangs that were of the 2004 models years and older. Their just isn’t enough conversion parts (header, intakes, hood clearance, front dress, etc) out there to make a 5.4L swap worth the trouble in my opining. And with the BigBore Stroker combo, your only 8 cubic inches shy of a 5.4L, with far more compatibility with the new BOSS-5.0 block which retains all of the standard 4.6L block mounting, and long block geometry.
Just to give an idea of the power potential of the new 5.3L BigBore-Stroker we’re starting to offer. We’ve got a customer’s 2004 Marauder equipped with one of these new motors with no major head porting on the stock 32V heads, and some mild Crower cams. Topped off with an intercooled Trilogy 2.3L twin screw blower, making only 13psi of boost from about 4800rpm and up. Burning only 93 octane fuel, and going through the Marauder’s automatic trans and powertrain… this car produces a touch under 580hp at the rear wheels, with what I feel is a moderately conservative tune with both the A/F and spark. This car has a seriously long and wide torque band.
Not to shabby for only 13psi and 93 octane going through an auto trans! The old saying “No Replacement For Displacement” still holds true with me. Especially in street cars that are looking for more grunt from street light to street light.
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