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For Sazam, Bentley W12TT Engine VS. Pheaton W12 Engine VS. Audi A8L W12 Engine
Hello @sazam ,
As to your question about the Phaeton W12 NA engine being used in your GT if needed in the future, I say, no..
There are so many differences between the Bentley, Phaeton, and the Audi A8L engines, besides just the turbo chargers.
The Phaeton W12 depending on the year, and what you read, has differences in HP and CR, the first Phaeton W12's had 420 HP and 10.5:1 compression ratio, and suffered from bad crankshafts, other info shows it as a de-tuned Audi A8/L D3 W12 at 444HP, with 10.5:1 or 10.7:1 compression ratio, where as the Audi D3 A8/L W12 has 450HP and 11.0:1 compression ratio, (not to be confused with the Audi 6.3 liter naturally aspirated W12 that went in the D4 A8/L at 500 HP) but then the Bentley W12TT has a lower 9.0:1 compression ratio to accommodate the turbochargers.
You will see below that the Phaeton W12 and the Audi A8L W12 use a higher compression piston compared to the deep dish lower compression Bentley W12TT piston.
There are many other internal differences between all three brands, and many just alone with the Bentley W12TT's from 2004 to 2014 that I have personally seen.
I have never personally had a Phaeton W12 in my possession, so I cannot comment on the internals, only as to what I have gathered from reading online as to specs and faults.
The Bentley W12TT on the other hand, I have had and fully disassembled the 2004/2005 BEB version, along with both the 2007 and 2008 BWR version, and have had the 2014 CVA version, I ended up installing the 2010/2011 BWR Supersports version in my GT.
The internal differences on the BEB VS. the BWR are as follows.
The BEB had the double wide/double sprocket timing chain setup, it had the wider rod width from the big end to the small end, basically the rod maintained it's width from the wrist pin until it got to the big end, but, it's center was honed out much more than the forth coming BWR version, the BEB crankshaft also had smaller oil galley drilling, and much smaller chamfering on said ports VS. the BWR.
Other items that matter between the 2004-06 BEB and the 2007- 2010 BWR, are yhat the BEB has the electronic thermostat, the electronic engine mounts, the sensors at the bottom of the turbo waste gate diaphragms, the BWR does not have these items, therefore causing some issues in wiring, or the use of resistors to fool the system, on top of that, the BWR also uses a different size cam position sensor for all four, therefore the wiring harness from one engine (BEB) to another (BWR) is different, and you can't swap the sensors from one head to the other, just as I found out that I couldn't swap the BWR VVT'S with the CVA VVT'S, as not only was the plug different, but the internals as to o-ring count, along with the bore size in the heads to receive said VVT solenoids was different, and I am sure there is more that I can go on, on.
Bottom line, if you are buying a replacement engine, get the same exact year of your vehicle, if it is a split year, double check all items such as cam position sensors, VVT'S, engine mounts, thermostat wiring, etc.
If you purchase an engine of a newer non matching year, then be sure 100 % to get the complete engine, complete engine wiring harness, intake manifold with matching throttle bodies, the matching engine ECU'S, meaning, everything from the same vehicle as a package, that is what I did after researching all the engines I had during my rebuild.
Even getting the complete package is not without issue, I have two minor issues to contend with, my SAI's both work, but I have a have + to ground for the SAI sensors, the other issue, which I kind of like, is the cooling fans run along with the after run turbo cooling pumps for 7 minutes after I shut the engine down, the pumps should behave like this, but not the fans at 850 watts each, so I have to trace a yellow/brown wire from the front to the ECU'S to look for breakage or short, as the extra run time is not good for the house battery, although I am sure it's great to reduce heat soak in the engine, and the engine compartment.
Johnny,
As always, great write up and very, very informative. If a car has been flooded, which a lot of the Bentley's I have seen lately on Copart are flood cars from Florida, do you have an idea of how high the water level can get but not harm the engine? The reason I ask is if someone is considering buying an engine that is taken out of a car, what damage will saltwater/water do to the engine if it is not totally submerged. I have spoken with one dismantler that said that they pretty much take the engine out of the flood cars, drain the oil and refill it and unless something really looks wrong such as milky oil coming out when they drain it, they sell the engine as good.
My car is one of the ones that was on Copart after the flood. To give you an idea of the water level the engine was exposed to, the water came up to the top of the headlights and half way up the seatbacks inside. You can see the water level over the headlights in this pic:
04-30-2023 | 02:07 PM
