You mean just the opposite...Why did they go with a dry sump system on the V8?

99.5% of all cars are wet sump, so they didn't 'decide' to go with a wet sump on the V12.

 

I'm also curious why Aston didn't go dry sump on the V12V. It would be better in terms of enabling a lower center of gravity and avoiding problems due to hard cornering. I guess it's because the DBS (which was designed many years ago and from which the V12V engine comes) didn't have dry sump.

 

No, I meant exactly what I said. The dry sump system has several advantages for track cars (Porsche has been using it for decades). As RacerX comments...

1) The engine can be mounted lower to lower the center of gravity.

2) Better lubrication under hard cornering.

3) Better cooling.

On a car with limited space for the V12, it would have been the choice, I would have thought, unless it was carried over from another model.

 

That's the point, it is the same motor as in the DB9/DBS. No way were they gonna' dry sump it.

And there are plenty of instances of motors with dry sumps blowing up on the track due to oil starvation...it isn't a panacea. Ask Z06 owners...

 

Porsche seems to be doing well with it , did you see the number of them at the Rolex 24hr?

 

I'm sorry...are you trying to equate a dry sump system designed for racing use with one designed for street use?

I'm not questioning the benefits of a dry sump for racing, only that having a dry sump on your street car is no guarantee that it'll keep your motor from oil starvation when used for track days. Like I said, go ask Z06 owners if the dry sump on their cars kept their motors from grenading on the track. A dry sump for a street car is really just a marketing gimmick.

 

Why is that? First I've heard this.

 

Okay I can answer this having a prior track racing/instructing/engineering backgound and owning both dry sump Metzger engine GT2 and wet sump V12 DB9.

My take is that yes dry has advantages for sure, especially on track where you are forcing oil through the engine from a tank where things like braking, throttle and lateral g's will not effect your oiling. Other advantages pointed out are absolutely correct, mounting the engine lower in the chassis and more effective heat transfer from frictional rotating assembly surfaces. It's great to have but is it better or worse...I it 100% depends on the situation and the intent of the car, it's use and as stated before the origin of the engine if it is a carry over or has been used in other models.

The Aston V12 is a long standing engine the 6 litre in the DB9/DBS was developed on the DB7 I guess...Aston may have felt that for the anticipated load the oiling system was adequete. I asked this same question to an Aston expert once who had rebuilt many of their engines over time in London. He told me that the v12 6L engine has more capacity and aggresive windage system and creates more scavenging and better oil circulation and cooling than that of many other v12 designs. He didn't go much into detail and I've never seen the v12 apart in front of my own eyes so what I gather from this is that Aston my not have seen it advantageous to change that on the current V12 lineup, regardless of which chassis it's plunked into. On the street a wet sump is fine and for a Sports GT it's more than adequete I would suspect.

 

Another benefit, beyond allowing a lower center of gravity via the lower mass of the engine , is a lower hood height. A lower hood height translates into improved aerodynamics. The negative, more parts, more difficult to assemble, more cost to the manufacturer. All in all I'd say the Vantage dry sump application worked out very nicely.

 

It's not a gimmick at all for a street car. The lower center of gravity benefits handling on street and track, and the oiling system itself is better also, especially in a road car that may be taken on track. It's not rendered a gimmick because the Z06 may have some problems. An added bonus with the V8V is you get to look at the beautiful dry sump itself.

 

Agreed that dry sump lubrication is not a gimmick there are clear advantages as you and others have listed, however that said one would have to justify it's expense, complexity, and involvement in implementation from a mass manufactuing processes standpoint, hence the lack if it on many street cars (one of the large factors anyway). I simply don't think it's neccessary on a street car at all. Heck if you have a street car and you take it one track and you're worriend plumb up an accusump by Canton products and you're just fine on the racing circuit. My race car doesn't have a dry sump and I have yet to have oiling issues, and it's going on 10 years with car on track

 

Sunir,

Certainly, the additional cost and complexity is why very few road cars use dry sumps. Porsche cheaped out with the water-cooled "street" flat sixes -- the "integrated dry sump" as they called it was, IMO, simply false advertising. As you obviously know, the real dry sump was retained on the Metzger-engined cars, for which using the best oiling system was what mattered, and cost was less of a factor.

 

yup 100 percent agreed. But your best comment was by far...that is unmistakably true!

 

I talked to Mike with Bamford Rose about this and he said in regard to the V12V that unless you put slicks on the car and drive the car extremely hard (well), you don't need to worry about oil starvation issues on the track.

 

my DB9 will never see track time...the GT2 and my race car are there for that! ...

Bamford rose is spot on with their assesment, I dunno the Aston v12 as well as some others but I do know that most engines and starvation is predominantly due to poor windage disigns on a wet sump motor driven to the point where the pickups are not able to draw or scavenge oil properly. If that cirtical area of an engine is designed well oil starvation even on track should not be an issue.