Barra Short Engine 4.0L Falcon BA-FGX
PR built 800whp
The PR Barra comes from years of development and testing of different combinations, ranging from pushing factory engines to their limits, to our built combinations producing over 1600hp! And over 8500rpm from a standard bore and stroke!
The first thing that you need to really consider is how the engine/car is going to be used! What turbo will you run and the true power that the car is going to make! The main difference between the 800rwhp engine and the 1000rwhp version is the main cap girdle and cylinder head sealing/head gasket setup.
Both short engines utilise the same rotating assembly and are proven to over 1200rwhp, however we have found the main caps start to walk at around that 800rwhp mark (Depending on RPM, Turbo choice and transmission choice). Let’s say GTX3582 gen2 tapped out, you’re going to be fine with the factory girdle, however something like a PTE 6870 and your starting to push the friendship.
Cylinder head sealing in any boosted application has traditionally proven to be a difficult task, however here at precision we have the solutions for you! As mentioned above, both rotating assemblies are identical so while they will handle big power that does not mean much without being able to keep the combustion in the cylinder. There are many variables that can contribute to head gasket failure, Exhaust Manifold Pressure is a big one, if your exhaust manifold is restricting the exhaust gas flow then naturally it will push past the weak link, which is typically you MSL style gasket. We only use two styles of head gasket, GENUINE factory gasket generally up to 800rwhp and Fire Ring style after that! There are some exceptions where these figures are varied, for example a smaller 35 frame turbo on the stock exhaust manifold that is being pushed hard lets say 25+psi of inlet manifold pressure, you can commonly see in excess of 2.5:1 exhaust manifold pressure, this is going to be pushing the friendship with the factory MLS style gasket and it may fail before 800rwhp, on the other side, if you have a larger frame turbo, such as a 42 frame turbo where you’ll be lucky to exceed 1.5:1 EMP at 25psi and you could be making closer to 1000rwhp without issues.
You will need a good engine core to be built/swap. Or we can supply a core at an extra cost!
PR Exclusive Features:
- Balanced and blueprinted
- Precise, documented hand assembly
- ACL Calico Race Bearings (Rod, Main and Thrust)
- Balanced, turned & polished OEM Crankshaft with PR modifications
- ARP Main Cap Fasteners *does not include head studs*
- PR Spec Nitto I-Beam Connecting Rods
- PR Spec Diamond Forged Pistons (0.225” pins)
- Brass Welsh Plugs
- Modified oil galleries
Exhaust Manifold Pressure is a killer of any boosted engine, note that the power level stated is based off of our aftermarket exhaust manifolds. For guaranteed safety, if running factory BA/F exhaust manifolds this engine should not be pushed further then 620rwhp, and FG factory exhaust manifolds should not be pushed any further then 700rwhp, even on a built engine.
This engine build uses our existing knowledge to build you the best engine possible. This however can be affected when put into the wrong hands.
In all cases, the engine should be installed by a reputable performance workshop and dyno tested or tuned immediately to ensure there have been no mistakes during install or potential issues with boost control, vacuum hoses, breather system or fuel system which could have caused a lean out or blowing out of seals/dipstick causing a fire.
Precision Racing assumes and accepts no liability that your set-up has the appropriate supporting modifications to suit your application. Including but not limited to the following:
• Adequate breather/crank case ventilation system
• Adequate exhaust system and turbine housing size to prevent excess exhaust back pressure which can cause head gasket failure.
• New or cleaned/checked parts within oiling system (oil cooler/lines/turbo/oil feed and drain lines etc)
• If replacing a blown engine- thought must be carried out to ensure there is not an existing problem which will now place your new engine with the same result. (oiling system/back pressure etc)