Let's talk engine alternatives again - what are the possibilities for the 3.0L engine in our car?
09-29-2006, 04:55 AM
#1
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Let's talk engine alternatives again - what are the possibilities for the 3.0L engine in our car?
Since Snowtrooper was talking last night about being able to get a 3.0L engine I thought it might be a good time to discuss (again) the possibilities for this engine in our car.
First, what would fit? The advantage as far as I can see is the weight savings of the aluminium block vs. our cast iron block. A secondary advantage is that it is stroked for 10% more capacity. So would it be possible to just use the block and other heads? Or would it be necessary to use the long-block?
Second, if one were to use the aluminium block, what would be the best heads to mount to it? What are the options? If only the originals make sense, then how much of a power hit would that cost?
Third, what do you think the maximum reasonable power would be with this engine combination? And what do you think the maximum that the block would be able to handle? My personal feeling is that the combination can probably be made to make the same amount of power and that the block probably isn't quite as strong but that it can still handle it.
Last, how much of a weight savings will this block actually give?
Thoughs?
Stephen
The photos were provided by a friend. The first is the 3.0L engine:
<img src="http://pictureposter.audiworld.com/66531/30_na_base_web.jpg">
The second is our 2.7L engine:
<img src="http://pictureposter.audiworld.com/66531/27tt_1_web.jpg"><ul><li><a href="https://forums.audiworld.com/s4/msgs/2486404.phtml">Snowtrooper's thread from last night.</a></li></ul>
First, what would fit? The advantage as far as I can see is the weight savings of the aluminium block vs. our cast iron block. A secondary advantage is that it is stroked for 10% more capacity. So would it be possible to just use the block and other heads? Or would it be necessary to use the long-block?
Second, if one were to use the aluminium block, what would be the best heads to mount to it? What are the options? If only the originals make sense, then how much of a power hit would that cost?
Third, what do you think the maximum reasonable power would be with this engine combination? And what do you think the maximum that the block would be able to handle? My personal feeling is that the combination can probably be made to make the same amount of power and that the block probably isn't quite as strong but that it can still handle it.
Last, how much of a weight savings will this block actually give?
Thoughs?
Stephen
The photos were provided by a friend. The first is the 3.0L engine:
<img src="http://pictureposter.audiworld.com/66531/30_na_base_web.jpg">
The second is our 2.7L engine:
<img src="http://pictureposter.audiworld.com/66531/27tt_1_web.jpg"><ul><li><a href="https://forums.audiworld.com/s4/msgs/2486404.phtml">Snowtrooper's thread from last night.</a></li></ul>
09-29-2006, 05:10 AM
#2
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I'd like to play with one but the diff in the mains/lower webbing and even Alu vs Iron says
ours is much better suited to high HP applications. The biggest concern I'd have is the undersquare configuration and all the thrust on the mains under high pressure.
Now the 3.0 may make a good HP option if you shortened/squared the stroke and rev'ed it to the moon. That would likely work ok.
Now the 3.0 may make a good HP option if you shortened/squared the stroke and rev'ed it to the moon. That would likely work ok.
09-29-2006, 05:12 AM
#3
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I thought revving was what put the big stresses in to a block?
One of the reasons I was thinking that it probably could take it was that our engines never rev very high because of the turbocharging.
Stephen
Stephen
09-29-2006, 05:33 AM
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Well thats true, but more harmonics related. The big stress item we have I think is the long
stroke-high thrust characteristics. I have not calculated rod ratio on ours but I'm pretty confident the geometry is suited to the 3000-6000rpm range of operations.
I think if you pressurized the 3.0l to our levels and left the displacement/stroke the same your crank/mains would turn into ovals, or chew up the bearings constantly.
Are the 3.0l thrust mains x-bolted like on ours and the 2.8l iron block? I can't tell from the pic.
I think if you pressurized the 3.0l to our levels and left the displacement/stroke the same your crank/mains would turn into ovals, or chew up the bearings constantly.
Are the 3.0l thrust mains x-bolted like on ours and the 2.8l iron block? I can't tell from the pic.
09-29-2006, 05:41 AM
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Just from memory...
The 3.0L is cross bolted on all four mains while ours is cross bolted on only two mains.
Also note how much thicker the casing is on the 3.0L. The end caps themselves should be just as strong. The bearing surfaces are the same. So the only issues would be whether the case was rigid enough and whether the hardwear was strong enough to avoid a catastrophic failure.
Stephen
Also note how much thicker the casing is on the 3.0L. The end caps themselves should be just as strong. The bearing surfaces are the same. So the only issues would be whether the case was rigid enough and whether the hardwear was strong enough to avoid a catastrophic failure.
Stephen
09-29-2006, 05:56 AM
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I'm betting the front/rear are not x-bolted, would be no reason to unless the engine had a
balance problem. The metallurgy would be the Alu concern as it will flex and give more, which could be a good thing in some designs... I'm not qualified to assess that.
09-29-2006, 06:52 AM
#7
Fixed I'm interested in this and have been thinking about it (not as long as MJTaylor) however
3.0 block, stock crank and 2.8litre heads..
But the alum worries me, while it's lighter it's also softer, would worry about what light pinging, detonation would do to the aluminum (unless the block was sleaved I guess).
I don't know enough about why alum would in fact be suspect in a high boost application.
But I'm more then interested
But the alum worries me, while it's lighter it's also softer, would worry about what light pinging, detonation would do to the aluminum (unless the block was sleaved I guess).
I don't know enough about why alum would in fact be suspect in a high boost application.
But I'm more then interested
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09-29-2006, 07:19 AM
#9
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Looks like Audi switched from bolts to studs on the 3.0L, unless that one is already modded?
When I built my Firebird motor we only had a two bolt block, but we put in ARP main studs and my engine builder said that setup was just as strong or stronger than a stock 4 bolt setup. Due partly to the superior strength of the studs/nuts themselvs, but also the better clamping force of the studs.
Not sure if that applies here, but perhaps Audi researced that a quality studded "two bolt" block is just as strong as a standard "four bolt" block.
Not sure if that applies here, but perhaps Audi researced that a quality studded "two bolt" block is just as strong as a standard "four bolt" block.
09-29-2006, 08:21 AM
#10
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I bet it would make a great tractor engine. :-p
They might have designed it for multiple purposes but have they ever used it as a diesel? I don't think so.
Stephen
Stephen