2.8 heads on a 2.7t

[me235]

I've been searching this for a bit and I cannot seem to find a definite answer. I've read you can put 2.8 heads on a 2.7t, but I've read it's a direct swap, and I've also read it take alot of other parts. One thing that is in every article I read is that the 2.7t valves need to be put in the 2.8 head but that's about the only consistent thing I've read.

I just had a cam flatten and take out a few lifters in my s4. And 2.7t heads are hard to find for a decent deal around here but 2.8 heads are everywhere so I'd be very interested in doing this if possible. Or even if just the 2.8 cams and lifters would fit my 2.7t heads?

Thanks in advance

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[zillarob]

Pretty much a direct swap.

2.7 valves load the springs a little tighter so would be better, but you dont "have" to.

Read up on what secondary air injection (sai) is, you may need to plug the ports on the 2.8 heads.
Id plug them and get rid of that crap regardless.

[WESLIFE]

If your problem is only the lifters and cams, you can take the lifters that are bad out and replace them with some lifters out of the 2.8 head. After you are done with the lifters, swap in the cam from the 2.8 head. You should be good to go after that!

[me235]

Awesome thanks! That's exactly the answer I was looking for. I was. starting to zero in on I can use just 2.8 cams and lifters in my head so that answered my question!

So are the 2.8 heads never worth going to unless you're going big turbo?

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[FlyboyS4]

So are the 2.8 heads never worth going to unless you're going big turbo?

Good luck finding something reliable to evaluate that alternative setup.

[zillarob]

I dont think the heads themselves make much of a dif either way.

My guess is the cams are what people feel, and may not be ideal with smaller turbos because of the overlap being optimized for a NA motor with much less backpressure, or even some ex scavenging.

[narth327]

i just did this swap. direct bolt on, only difference is the SAI ports, which u can buy 034motosports or integrated engineering block offs kit, or just tap for npt pipe threads and you're good to go. people suggest swapping the exhaust valves as the ones in the 2.7t are sodium filled to handle the higher temps of the turbo. i'm not sure on this, as i upgraded to supertech springs, but i'd imagine the valve springs on the 2.7 are higher rates than the 2.8 to handle the boost. if you have the time and already have the heads, i'd recommend doing the complete swap, as the 2.8 intake ports are way bigger, then i'd port match the stock intake manifold or upgrade to rs4 intake manifold.

[demonmk2]

^have you been able to drive it since the swap?
What's your take on the gains? ( butt dyno )

[narth327]

unfortunately i changed a ton of stuff while i was in there, so theres no fair comparison. turbos, downpipes, smic, etc etc

[zillarob]

2.8 is sodium also.

The dif is the preload on the spring.

[FlyboyS4]

I dont think the heads themselves make much of a dif either way.

My guess is the cams are what people feel, and may not be ideal with smaller turbos because of the overlap being optimized for a NA motor with much less backpressure, or even some ex scavenging.

I would hope that nobody putting 2.8 heads on does so without having a 3-angle valve job done, and then comparing to stock 2.7 heads is a less than insightful comparison.

[zillarob]

What exactly are you saying there Jeff?

[FlyboyS4]

What exactly are you saying there Jeff?

Gains w/ a set of 2.8 heads w/ a valve job compared to stock heads may result from the valve job and not the port differences. For a decent comparison of port affects both heads should either have, or not have, a valve job, but who would swap to 2.8 heads and build the valvetrain and NOT have a valve job done. Or conversely, who would go to the trouble of having a valve job done on a set of 2.7 heads to later remove them to be replaced with 2.8 heads?

I question if the gains from 2.8 heads are attributable to the port differences or improvements made to the valve seat area when building the 2.8 heads.

[AudiTechS4]

Well very soon were going to have 2 srm k24 cars here at my work complex. one on all stock 2.7 and the other on 2.7 with rods and built 2.8 heads and the same tuner. so we will see if they make a difference

[FlyboyS4]

Well very soon were going to have 2 srm k24 cars here at my work complex. one on all stock 2.7 and the other on 2.7 with rods and built 2.8 heads and the same tuner. so we will see if they make a difference

In my opinion there's too much going on between two cars to make a determination that the heads were the source of any differences.

Will either set of heads have a 3-angle (or greater) valve job done to it?

[zillarob]

Nice, keep us posted!

My guess on the 2.8 heads is there may be some minor gains due to the larger ports, but the cams can go both ways depending on turbos/ex mani psi.
I would imagine that the larger the overlap, and the smaller the hotside, the worse it will be.

Have a buddy with a big cam t3/t4 on a vr6 that is considering getting the cast log style mani extrude honed.
Now I aint saying he wont see any gains, but I think he would net much more with a larger, more efficient hot side running with less ex mani psi.

For a typical 2.7, my guess would be that dropping the comp ratio to allow for more timing/boost would be more beneficial than 2.8 heads.

[Zerstorer]

Question on topic, but needing answers for my own build is will a 2000 S4 intake or 2001.5 for that matter bolt up to 2.8 heads? Would I have any issues with that?


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[zillarob]

Bolts right on.
2.8 heads have some plastic guide pin bs instead of a bolt in a few holes.
Its tapped like the others, but make sure you get all of the plastic out or the bolt can bottom out and strip the hole.

Ports are larger on the heads than the mani so most do some kind of transition.
034 transition spacers are popular.

[uponone nogaro]

Good Info guys

[AlexHurley]

Well very soon were going to have 2 srm k24 cars here at my work complex. one on all stock 2.7 and the other on 2.7 with rods and built 2.8 heads and the same tuner. so we will see if they make a difference

Any more info on this? I'm curious how the 2.8 heads work with those turbos, what valvetrain is being used?