Similarities between 2.8 and 2.7T?

[Bendy]

I've been trying to find detailed engine info between different Audi engines and I'm particularly curious about the V6 line. I have a 2.8 30v and I'm curious how far back and forward this basic engine design has been used. Is the 2.8 12v the same basic engine design all the way up to the current 3.2 or 3.6? Were there any complete redesigns in the last 10 years? In particular, is the 2.7T any relation to any of these?

My biggest question is this. Could one take turbo manifolds from a 2.7T and associated hardware and bolt it all on to the 2.8 30v and then run custom engine management? In the Nissan SR20 world, it is not so uncommon to turbo the USDM SR20DE with similar turbo parts that come on the JDM SR20DET, albeit with higher compression and therefore more conversative timing and fueling. Why can't I do the same thing with my 2.8? Find the turbo parts off a 2.7T, bolt them on, and then tune my car to run those turbos? Yes, I'd need more than the turbos. Injectors, intercooler(s), plumbing, etc. Similar stuff that comes with the PES G2 kit, just turbos instead of a supercharger.

This of course depends upon the 2.8 30v and the 2.7T exhaust ports being pretty much identical and the heads/blocks being similar enough for everything to clear.

Discuss. :)

[Nebone]

You can use 2.8 heads on 2.7T so the exhaust ports will line up. 12V V6 has the same block as 30V V6 as far as I know. Im not sure how the 3.0 and 3.2 are compared to the 2.8 thou. 3.6 is a VR6 engine so its completely different.

[317ssayzarc]

2.8s are iron and the 3.0s are alloy blocked iirc

[djwimbo]

2.8(30V) and 2.7T heads interchange. The 2.8(30V) crankshaft is the same as the 2.7T's. Transmissions are both "Multibolt" designs, so they'll interchange as well as retain the same mounting points. Both 2.7 and 2.8 can become 3.0L w/ a simple overbore.

I don't know much about the 3.0 and 3.2, but it's a different breed. The engines changed a lot.

The 2.7T guys swap to the 2.8(30V) heads to lower compression IIRC. I don't think there's a flow difference.

[Sigma 3]

the motor in doestic 240s is a ka motor not an sr motor. The 2.7 block started life as a 2.8 but they thickened the cylinder walls for that massive amount of boost pressure that that the stock s4 puts out. If you want forced induction on the 30 v get the super charger and a southbend stage 3 clutch. a very fun combo and smooth factory like power delivery. The g2 does not come with intercooler nor is it possible to do so. Just bolting on the 2.7 manis is not possible from what I was told (wich doesnt mean squat so check for yourself),but if you couls do it anything beyond 15 pounds might do somthing nasty to your motor due to the comp ratios. Go to scaudi.com ask a guy named 4rings your qustion he is very savy when it comes to the 2.8. good luck.

[T3hD0gg]

the motor in doestic 240s is a ka motor not an sr motor.

He never mentioned the 240SX.

Nissan Sentras and Infiniti G20's came with the SR20DE in the states.

[1fstavant]

been wondering that same question....because as stated above the heads are interchangeable so everything else should be the same


now a question id like to ask if any one would know is the vw passat 4motion 30v the same design as the 2.8 or 2.7t

[Nebone]

What year Passat?

I have not seen many B5 Passats 4-motion but many B5.5 Passats 4 Motion and those have the 3.0 30 Valve engine.

This passat type would have a 2.8 30 Valve motor so similar to the 2.7T w/o turbos.


This passat type has the 3.0 30 Valve engine (aluminum block, different design)

[NK2007]

One thing about turboing a 2.8 is that the 2.8 block has only 2 bolt mains. Whereas the 2.7 block has 4 bolt mains.

The 2.8 caps have 4 holes, i believe, and several people have simply drilled and tapped the second set of holes in the block.

Although i am not sure about the rod strength, i do know that the 2.8 has i higher compression ratio, so if you were looking to turbo the 2.8 you may want to look into an aftermarket rod/piston combination.

There are several threads around, where people have built 2.8s. You might want to take a look at those and see what they have done.

[GetAwayFromMe]

What year Passat?

I have not seen many B5 Passats 4-motion but many B5.5 Passats 4 Motion and those have the 3.0 30 Valve engine.

This passat type would have a 2.8 30 Valve motor so similar to the 2.7T w/o turbos.


This passat type has the 3.0 30 Valve engine (aluminum block, different design)

B5.5 Passat has the same 2.8 30v engine like B5. They changed engines in the 02 A4's but not passats. 2.8 engine is used all the way til year 05 4motion or not.

[Stampy]

Completely off topic.... The manifold from a Mitsu 4G63 bolts right up to a Honda H23. I did it to my old lude.

[Bendy]

One thing about turboing a 2.8 is that the 2.8 block has only 2 bolt mains. Whereas the 2.7 block has 4 bolt mains.

The 2.8 caps have 4 holes, i believe, and several people have simply drilled and tapped the second set of holes in the block.

Although i am not sure about the rod strength, i do know that the 2.8 has i higher compression ratio, so if you were looking to turbo the 2.8 you may want to look into an aftermarket rod/piston combination.

There are several threads around, where people have built 2.8s. You might want to take a look at those and see what they have done.

Lots of great information! Yes, I wasn't talking about the KA24DE. Check out sr20forum.com for info about this motor. I'm so used to the SR in that the bottom end is the same strength in the NA and turbo motors that folks have boosted the NA motor (stock 140hp) to over 400hp with no bottom end upgrades that I forget that not all engines are as overbuilt.

Where can I find more information or pictures of 2.8, 2.7T engines, external and internal, and maybe comparisons of the stock versus aftermarket rods between the two?

If these engines are sisters, then I don't understand why people don't take advantage of 2.7T parts for the 2.8. The compression ratio is only 1 point different (10.3:1 vs 9.3:1) which isn't massive. The SR20DE was 9.5:1 and the SR20DET was 8.3:1, so this is the same ballpark. Bolt those turbos on, get an exhaust, maybe 2.7T injectors if the 2.8s are smaller, maybe 2.7T MAF if the 2.8 one doesn't flow enough, and boost that sucker. Junkyard turbo kit. :)

Yes, I know the PES G2 exists, but I've ridden in a couple of supercharged vehicles before (Grand Prix GTP with pulley, F-150 Lightning) and they just aren't my thing. I love turbos. :)

[1fstavant]

the passats a 2001 so its a b5 nd i have tried searching for that info with no avail so i appreciate the responses, the wifey mite be getting a nice christmas present

[Siena]

The 3,0 / 3,2L V6 motors are completely different to the 2,4 / 2,7 / 2,8L 30V units.

Besides the V configuration, they have nothing in common.

Most obvious change is the loss of 1 valve per cylinder, so 24V.
The cranks are completely different too, as is the aluminium block.

[AudiA4_20T]

The 2.7T guys swap to the 2.8(30V) heads to lower compression IIRC. I don't think there's a flow difference.

WRONG, guys slap on 2.8 heads for flow, why would they lower CR?

One thing about turboing a 2.8 is that the 2.8 block has only 2 bolt mains. Whereas the 2.7 block has 4 bolt mains.

The 2.8 caps have 4 holes, i believe, and several people have simply drilled and tapped the second set of holes in the block.

Although i am not sure about the rod strength, i do know that the 2.8 has i higher compression ratio, so if you were looking to turbo the 2.8 you may want to look into an aftermarket rod/piston combination.

There are several threads around, where people have built 2.8s. You might want to take a look at those and see what they have done.

This is a decent difference. However, 1.8T guys have run up to 1000hp on 2 bolt mains. The S4 middle mains actually have 6 bolts holding them in, overkill IMO but there was no expense spared on that motor

The 2.8 motor is weak in comparison with its internals. S4s can handle 500awhp on a stock block when some 2.8s have had trouble running too much boost with a S/C

The 3,0 / 3,2L V6 motors are completely different to the 2,4 / 2,7 / 2,8L 30V units.

Besides the V configuration, they have nothing in common.

Most obvious change is the loss of 1 valve per cylinder, so 24V.
The cranks are completely different too, as is the aluminium block.

WHAT? The 30V is a 30V just like the 2.7.... And the block is cast iron just like the 2.7....?

In conclusion, you might just want to start with an S4 block. find a spare one, throw rods in it, and swap it out with yours down the road.

Also, you would have to do standalone, but you knew this already

PM me if you want to brainstorm, I have done some research on this

[dougyfresh]

Both 2.7 and 2.8 can become 3.0L w/ a simple overbore.

Nope. The 2.7 needs a 3.0 crank (added stroke) in addition to an overbore to hit 3.0L.

[legionvr6]

wow never skim a thread cuz things get weired. starts out all audi then randomly nissan engines pop in lol.

to the OP the 3.2 and the 3.6 are TOTALY diffrent. the 2.8 is a 90 degree V. the 3.2 and the 3.6 are actualy veriants on the VW VR6 engine the are 15 degree if i remember correctly and they only have 1 head

[Nebone]

B5.5 Passat has the same 2.8 30v engine like B5. They changed engines in the 02 A4's but not passats. 2.8 engine is used all the way til year 05 4motion or not.

Hmm that seems correct; I've always thought it had a 3.0 motor.

[keeganhartman]

Yeah he's right i have an 02 passat motor in my car right now

[Bendy]

The 2.8 motor is weak in comparison with its internals. S4s can handle 500awhp on a stock block when some 2.8s have had trouble running too much boost with a S/C

References about this? Obviously Audi built up the 2.7T for some reason - I am just out to find out how "weak" the 2.8 is in comparison and just how similar they are. I'd still love to be linked to some pics of each engine if someone has any.

I've never priced all these parts. Any ideas how much used 2.7T turbos, manifolds, injectors, piping, intercoolers, and all the other associated parts may run me? Maybe it would be more cost effective going for aftermarket parts? I thought maybe someone doing a big turbo upgrade on their S4 or A6 or something would have this stuff laying around and would sell it inexpensively. Or maybe someone who popped their motor and has some of this stuff they are parting out.

Folks mentioned using the 2.8 heads on the 2.7T because of better flow. What about cams? Do folks place the 2.7T cams in the 2.8 heads? I'm curious about overlap between the turbo and non-turbo cams.

"Factory-turbo" your 2.8 - has a nice ring to it

[CycloSteve]

As noted with most of the above posts, basically the OE 2.8 pistons will self-destruct at 11psi of boost or above. Plenty of info regarding boosting engines on the scaudi.com site; read 4rings' story and you will understand the perils of high boost. The issue is that the high compression cast-pistons crack around the top ring, and the motor self-destructs. The 2.8 motor was just not built for boost, thus can not handle "safely" anything beyond 9psi or so.

Personally I will replace the bottom end of my 2.8 with a built 2.7t shortblock someday, keeping the 2.8 heads, so that I can up the boost of the PES G2 safely to a much higher figure, perhaps 10-12psi.

The main reason why some S4 folks change over to the 2.8 heads, is that they are "large port", same size as in the B5 RS4, while the 2.7t's use smaller intake ports.

My advice if you want a turbo V6 is to sell the A4 for an S4.

[Sigma 3]

References about this? Obviously Audi built up the 2.7T for some reason - I am just out to find out how "weak" the 2.8 is in comparison and just how similar they are. I'd still love to be linked to some pics of each engine if someone has any.

I've never priced all these parts. Any ideas how much used 2.7T turbos, manifolds, injectors, piping, intercoolers, and all the other associated parts may run me? Maybe it would be more cost effective going for aftermarket parts? I thought maybe someone doing a big turbo upgrade on their S4 or A6 or something would have this stuff laying around and would sell it inexpensively. Or maybe someone who popped their motor and has some of this stuff they are parting out.

Folks mentioned using the 2.8 heads on the 2.7T because of better flow. What about cams? Do folks place the 2.7T cams in the 2.8 heads? I'm curious about overlap between the turbo and non-turbo cams.

"Factory-turbo" your 2.8 - has a nice ring to it

Audi a4 is right, a stock 2.8 is not capable of the boost load that a 2.7 can handle. just adding 9 pounds of boost many of the scd guys started seeing metal shavings in there oil. I told you to check out scaudi.com 4rings bllew his intercooled g1 at only 15 lbs. There is a company in Canada that ttd the 2.8 they sid it cost around 16k. I cant remember the name but the owner is on vortex.

[Bendy]

Found the post. Reading it now. Link for others to follow:

http://scaudi.com/sc/index.php?showtopic=3540

[Nebone]

All the stock parts would be rather cheap as many S4 owners remove all the stock parts and replace them with aftermarket, even manifolds.

[audispeed]

The problem is the pistons and the high cr. Swap in some lower compression pistons and you will be fine.

[AudiA4_20T]

References about this? Obviously Audi built up the 2.7T for some reason - I am just out to find out how "weak" the 2.8 is in comparison and just how similar they are. I'd still love to be linked to some pics of each engine if someone has any.

I've never priced all these parts. Any ideas how much used 2.7T turbos, manifolds, injectors, piping, intercoolers, and all the other associated parts may run me? Maybe it would be more cost effective going for aftermarket parts? I thought maybe someone doing a big turbo upgrade on their S4 or A6 or something would have this stuff laying around and would sell it inexpensively. Or maybe someone who popped their motor and has some of this stuff they are parting out.

Folks mentioned using the 2.8 heads on the 2.7T because of better flow. What about cams? Do folks place the 2.7T cams in the 2.8 heads? I'm curious about overlap between the turbo and non-turbo cams.

"Factory-turbo" your 2.8 - has a nice ring to it

Used stuff will be cheap. K04s would be the way to go. Expect to spend $7k Id say, you have to do standalone and get it tuned. People use the 2.8 cams in both the 2.8 and 2.7 heads because they have a nice grind for making power

IMO the best setup would be a single turbo 2.8... I would source a 2.7 block (although I would like to see a 2.8 block done) and get standalone. Anything is possible. There are a few (including me) working on single turbo S4 setups right now and I would assume it should just drop in because its essentially the same motor and engine bay

[Nebone]

My buddy is building a 12V 2.8 N/A. It will feature an overbore and other exclusive goodies.

[audispeed]

Used stuff will be cheap. K04s would be the way to go. Expect to spend $7k Id say, you have to do standalone and get it tuned. People use the 2.8 cams in both the 2.8 and 2.7 heads because they have a nice grind for making power

IMO the best setup would be a single turbo 2.8... I would source a 2.7 block (although I would like to see a 2.8 block done) and get standalone. Anything is possible. There are a few (including me) working on single turbo S4 setups right now and I would assume it should just drop in because its essentially the same motor and engine bay

Definitely one option to consider, you know I am interested. Eagerly awaiting the results. I have to wonder if you could just drop in an S4 harness and ECU at that point?

[AudiA4_20T]

Definitely one option to consider, you know I am interested. Eagerly awaiting the results. I have to wonder if you could just drop in an S4 harness and ECU at that point?

lol probably would be worth it at that point. Might be tough to get it to run with the A4 gauges and god knows inspection would be a nightmare but so would standalone lol

[CycloSteve]

For those wondering what high boost and a stock 2.8 equals...



...this is piston #5 from Tomasz' motor.

[Sigma 3]

For those wondering what high boost and a stock 2.8 equals...



...this is piston #5 from Tomasz' motor.

Tomas is "4rings" that i was talking about. He is a wealth of info on the 2.8.

[Jroc81]

the 2.8 and 2.7 crank and rod part numbers are the same. That means that 2.8s have forged cranks and rods. The s4 bore is 80.5mm, if you bore a 2.7 block 60 over it becomes 82.5mm, Which is a 2.8's standard bore size. If you order 82.5mm s4 pistons, the comp ratio will be lower than a 2.8's since they will be meant for the s4, and they will drop right into a 2.8, no drama. Happy boosting

[sean1.8t]

^the 2.7t's rods are not forged. which means, the 2.8's rods are still not forged.

but everybody already knew that

[Jroc81]

^the 2.7t's rods are not forged. which means, the 2.8's rods are still not forged.

but everybody already knew that

either way, my point is that with both engines having rods of the same part no, the 2.8s rods are no weaker. Thanks for not being a prick about it though.

[Bendy]

So it looks like the only important internal to worry about are the pistons. No biggie then. At least the crank can stay in the block. The head and cams are good. What about fueling? Are the MAFs the same? Injectors? Obviously the fuel curves are different which would take at least a piggyback controller.

So to turbo a 2.8, change the pistons to S4 82.5mm pistons, grab some used turbo manifolds, turbos, an exhaust, intercoolers and associated plumbing, and possibly S4 injectors and MAF, and a piggyback computer. I wonder how different the wiring harnesses are and if an S4 ECU is close to plug n play?

[AudiA4_20T]

So it looks like the only important internal to worry about are the pistons. No biggie then. At least the crank can stay in the block. The head and cams are good. What about fueling? Are the MAFs the same? Injectors? Obviously the fuel curves are different which would take at least a piggyback controller.

So to turbo a 2.8, change the pistons to S4 82.5mm pistons, grab some used turbo manifolds, turbos, an exhaust, intercoolers and associated plumbing, and possibly S4 injectors and MAF, and a piggyback computer. I wonder how different the wiring harnesses are and if an S4 ECU is close to plug n play?

Think about all the differences here though,

1. No Oil squirters in the 2.8
2. Your pan is not tapped for return lines (might want to get an S4 pan)
3. You dont have coolant feeds or returns either
4. The S4 has 2 EGT sensors in the manifolds and 4 02 sensors (does the 2.8 have them also?)
5. if your pulling the pistons out, slap some rods in there too

[somebody5788]

So say I knew where I could maybe get a supercharged 3.0 A4 with a burnt up piston. Would I be able to get a 2.7t block with crank and pistons and mate it to the rest? I would expect they would be willing to sell it since he now has an 05 S4.

[audi til I die]

I'll take advantage of the resurrection here.

WRONG, guys slap on 2.8 heads for flow, why would they lower CR?



This is a decent difference. However, 1.8T guys have run up to 1000hp on 2 bolt mains. The S4 middle mains actually have 6 bolts holding them in, overkill IMO but there was no expense spared on that motor

The 2.8 motor is weak in comparison with its internals. S4s can handle 500awhp on a stock block when some 2.8s have had trouble running too much boost with a S/C



WHAT? The 30V is a 30V just like the 2.7.... And the block is cast iron just like the 2.7....?

In conclusion, you might just want to start with an S4 block. find a spare one, throw rods in it, and swap it out with yours down the road.

Also, you would have to do standalone, but you knew this already

PM me if you want to brainstorm, I have done some research on this

My main question here is: is the S4 a 4 bolt or 6 bolt main??? I was also under the belief it was a 6 but other guys think otherwise? I searched and came up blank.

[Pete@IE]

I was gonna say- In order to calc out to 3.00 L i had to spec the 3L 92.8mm crank as well as 82.5 or 83mm pistons. So to REALLY get 3.00L you have to bore AND stroke.

Its a shame there isn't a 95 or 100mm crank for them.


Not to start anything, but that piston was clearly melted not damaged from detonation. I'd wager that with more fuel, those pistons would take quite a bit more of a beating.

[audispeed]

I was gonna say- In order to calc out to 3.00 L i had to spec the 3L 92.8mm crank as well as 82.5 or 83mm pistons. So to REALLY get 3.00L you have to bore AND stroke.

Its a shame there isn't a 95 or 100mm crank for them.


Not to start anything, but that piston was clearly melted not damaged from detonation. I'd wager that with more fuel, those pistons would take quite a bit more of a beating.

yes, but the car was running quite a bit of fuel. pete, you know if your S4 rods will fit in the 2.8? Need a tester?