2.7i vs. 2.7i with super eta pistons and rods

[squidmaster]

I would 2.7i the e block. The i parts just enhance the torque of the longer stroke. Its feels like a different engine to me, mid range torque is instantaneous. I used the 731 head from a EU 323i to keep compression up, and the cam they used on that model is fairly aggressive. I opened up the intake and exhaust ports some, just gasket matching the openings. BavAuto long tubes and free flow 2.5" exhaust. Took my buddy in a Z06 12 runs to beat my times in a NCCC Corvette sanctioned autocross last weekend, so its a quick motor that I run to 6,850 all the time and it loves it.

That and a super-cool Sssquid Tune ;)

the 2.7i is a great upgrade for the eta, and can give you better performance if the 2.7i is tuned. But taking the m20b25 and doing a stock eta bottom end isn't the best option. Like sad before, custom work on the m20b25 would be a better option.

[ForcedFirebird]

The eta bottom and i head yields 8.4:1 compression if the head is not shaved.

Most power we ever got out of the 2.7i is 148whp/170tq (no clutch fan/ac/ps). We dynoed the stock eta, then put an i head on with eta manifold (i TB), then i manifold/tb, then headers - tuned each configuration. My 200k mile b25 made 148/145 with my custom chip only, with the ac ps belts on, and clutch fan still attached.

Had a SETA with b25 cam, manifold, tb, m30 AFM and 19lb injectors ready to tune on the dyno last week. First pull the speed limiter kicked in (wasn't paying attention to the 525 DME), unplugged the speed sensor on the diff and a rocker arm broke on the second pull. Curious to see what we will get from that one.

[TheTacoMan]

2.7i is decent upgrade, but to me the gains are not huge. Definitely fun though.

[Bullet Ride]

You've got the i pistons, the e rods... just grab yourself an M52 2.8L crank and you've got all the parts for a 2.8L stroker (assuming you make the crank spacer out of the timing sprocket). Google M20B28 or M20 2.8L stroker and you'll find all the info you need.

My 2.8 is currently putting down between 180-190whp which is roughly somewhere between 207-218hp at the crank.

[ForcedFirebird]

That and a super-cool Sssquid Tune ;)

Super cool? Do you have dyno results for your chips?

[timmyr77]

ya. after talking to more people, the 2.7i is not worth it with the money i will be putting in to rebuild everything. For 2k, i could buy an s50. Also heard m52 with s52 cams was a good setup, but i want to stay obd1. i really cant decide now what i want. I love the idea of having a 180hp m20 powered e30, but a 24v swap is really starting to sound like a better bang for the buck. Im putting off any build for now. Im going to save a few grand, and once i have the money to pull the trigger, ill decide then what i want to do. Thanks for the input everyone. Ill post something when i decide what i will be doing, and will most likely do a build thread.
Thanks again,
Tim

[redlightpete]

You've got the i pistons, the e rods... just grab yourself an M52 2.8L crank and you've got all the parts for a 2.8L stroker (assuming you make the crank spacer out of the timing sprocket). Google M20B28 or M20 2.8L stroker and you'll find all the info you need.

My 2.8 is currently putting down between 180-190whp which is roughly somewhere between 207-218hp at the crank.

In my experience you also need to get the crank cut down to clear the pistons and rebalanced. That cost me about $250.

[Bullet Ride]

In my experience you also need to get the crank cut down to clear the pistons and rebalanced. That cost me about $250.

Yeah, I didn't list all of the details involved. Reading though some build threads will highlight either machining the crank or the pistons or both. Getting the required clearance has been done in those ways.

I machined my crank myself and then got it re-balanced. Cost me about $90.

[Regnar75]

my 2 cents

90% of what you read about the 2.7i build is by people who have never done it and probably never driven in one. I just built mine using all 'I' top end parts and flat top pistons with a 525 ecu and custom 2.7i chip. And still have the 2.93lsd and it pulls like a train all the way to red line. The eta would get loud but not really pull in upper rpms just like the I pulls in upper but not really lower. No matter where I am at it pulls. I don't have to downshift to put me back in my seat...just press the gas. With a more aggressive diff it'll be even better. And m20b25 guys seem to talk dyno numbers but never dyno power curves. So from first hand experience the 2.7i is 100% worth it for ETA owners. Idk how much better the seta is though. Not first hand anyway

[ForcedFirebird]

90% of what you read about the 2.7i build is by people who have never done it and probably never driven in one. I just built mine using all 'I' top end parts and flat top pistons with a 525 ecu and custom 2.7i chip. And still have the 2.93lsd and it pulls like a train all the way to red line. The eta would get loud but not really pull in upper rpms just like the I pulls in upper but not really lower. No matter where I am at it pulls. I don't have to downshift to put me back in my seat...just press the gas. With a more aggressive diff it'll be even better. And m20b25 guys seem to talk dyno numbers but never dyno power curves. So from first hand experience the 2.7i is 100% worth it for ETA owners. Idk how much better the seta is though. Not first hand anyway

Um, I did this to my eta a few years ago, and backed up everything on a dyno. Mine went from just over 100whp to 132whp/140tq using the eta exhaust and all stock "i" components. A tired b25 makes about the same, but most stock b25's are upper 130's/lower 140's. Have done the swap, played around with compression ratios, tunes, exhaust etc. As I mentioned earlier, the most we ever got was 148whp with headers, head shaved quite a bit, adjustable cam gear and custom chip - with no a/c p/s and only a resonator on the exhaust.

[Regnar75]

^

Obviously you wouldn't be who I am talking about. What I was saying is the general 2.7i 1.3 moronic sticky is littered with hearsay and Generally negative 2.7i posts when in actuality its a very solid build idea. But I'm sorry for bringing this thread into this topic instead of differences between the seta and eta 2.7i

[digger]

yeah but this is not a guy with a eta engined car wanting to slap on an "i" head.....he has a B25 to start with.

i remember test driving quite a few 2.7L before i got my B25 in 2005. the basic 2.7L were more torquey than the B25 but they never really came alive on the topend. I happened to come across an Alpina c2 2.7 and it had noticeably more grunt down low than even the budget 2.7 but pulled alot harder than B25 at the top as well.

[603Racing]

Regnar nailed it. The 2.7i build is all about the power curve, not peak power.

[Noshow20x96]

My 2.8 is currently putting down between 180-190whp which is roughly somewhere between 207-218hp at the crank.[/QUOTE]


Want more details!!!!!

I currently have a eta and want to do the I head. I'm going to get a complete I motor swap from a friend so I should have everything. If I can get that much power, I would be happy.

[digger]

Want more details!!!!!

I currently have a eta and want to do the I head. I'm going to get a complete I motor swap from a friend so I should have everything. If I can get that much power, I would be happy.

http://www.r3vlimited.com/board/showthread.php?t=243359