Ray Hall

I asked this question elsewhere on this forum and got no response, so I thought here would be better place to ask this.

Does any one know if the RS6 5.0L V10 engine is odd fire. I other words the crankshaft rod pins are offset so the cylinder spacing is not an even 72 deg between TDC.

Ray.

1stGOAT

Even fire - Good article for you

Ray Hall

Thank you. But my engine if not the 5.2L BXA engine. I know that the 5.2Lis even fire. It is the 5.0L BUH engine in the RS60 that I now has a 18 deg offset and is odd fire.

1stGOAT

From Wikipedia (not Audi doc)
The engine (parts code: 07L, identification code: BUH) of the RS6 was what Audi claimed to be the first all-aluminium alloy even firing 5.0-litre (4,991 cc (304.6 cu in)) 90° V10 twin-turbocharged ("biturbo"), Fuel Stratified Injection (FSI), with a dry sump lubrication system. This engine is related to the naturally-aspirated V10 found in the Audi R8, S6 and S8, and the Lamborghini Gallardo, but the RS 6's engine has around 400 unique parts


BUH 5.0 TFSI V10 engine: Audi C6 RS6

Ray Hall

The 5.0L V10 BUH engine is odd fire. I has to be as the engine is 90 degV block with two oposing cylinders shareing the same connecting rod pin. The engine roates 720 degess to fire all 10 cylinders. So for even fire 720 / 10 = 72deg spacing. 72 deg cannot work with a 90 deg V as you cannot get all 10 pistions at TDC every 72 deg. The cylinder spacing is 90-54-90-54-90-54-90-54-90-54
This is the position of TDC for each cylinder.
1 = 0
6 = 90
5 = 144
10 = 234
2 = 288
7 = 378
3 = 432
8 = 522
4 = 576
9 = 666

Thank you for your help.
Ray.

1stGOAT

Pretty sure it is even fire (crossplane crankshaft with split 18 degree offset crankpins) The offset allows for the 72 degrees needed for even fire.

Ray Hall

The 5.2L had the split cank pins and a ballance shaft. The 5.0L engine just has a shared pin like the V8 engine has and no balance shaft.
Any way I just changed the cylinder TDC angles to odd fire and the engine sound much nicer and stronger when reved. I will put it back on my dyno and retune it of the next few days and wil report back here on the difference.

Ray