2.8l stroker for future turbo setup q's

[TexasTerp]

To answer your original question, the 86mm overbore is not recommended for turbo applications. the thinner sidewall will be more prone to HG issues and you could possibly crack the cylinder walls with a high boost application. I highly recommend staying with the 84mm bore. Since you are boosting, it's really not as necessary to worry about displacement, compression is FAR more important.



Here's the list I have on my 2.7i boost build:

I'm going a bit more over board on my boost setup so take that with a grain of salt. For $2000 I'm completely rebuilding my engine which includes $750 on all new seals, gaskets, bearings, bolts, etc, etc.

$500 on Maxsil Seta Pistons

I'm spending about $400-500 for a machine shop to chem tank, clean, and hone my block. Oring the block for a stock HG, balance crank, and a full installation of my bottom end. (It's easier for them to put it all together for me.)

I have another $250 or so allotted for miscellaneous expenses. So here's My list:

Maxsil Seta Pistons
2.7 eta crank
130mm eta rods
Stock Head Gasket
885 "i" head (brand new rebuild from one of my donor engines!!!)
"i" Intake manifold
173 ECU.

The compression ration will be 8.5:1 which is perfect for a higher boost. I'm aiming for 350-400whp.

You should PM FrozenSolid about his build. He's running MS on a stock HG outputting 440whp!!


For boost I'm running an expensive system:
TCD Stage 2 (or 3) Turbo
TCD Bottom mount turbo manifold
Tial 38mm Wastegate
Haltech SA Management system
Turbosmart eBoost electronic boost control
35# injectors
GM Coil Packs (subject to change)

[acolella76]

No, it doesn't NEED lot of boost. I am running mine N/A right now and it's fine, you can't really tell there is a difference in compression. The lower compression just means you COULD push a lot of boost into there if you so chose. Higher CR = lower boost level before your motor starts to knock/detonate, lower CR is the opposite.

[Kozworth]

So an eta based build would require a lot of boost to be potentional? Theoretically, I would like to pay 4k for the engine and setup.. anymore I cannot offord I am going to be getting my own place. I just want the feel and a little more of a punch in my m20.

[acolella76]

You'll still need to bob the crank though, but that's an amazing price on the parts.

His is a custom grind 280 cam.
http://www.r3vlimited.com/board/showthread.php?t=221655

Yeah I am still bobbing the crank! I am just buying short skirt pistons because lightweight race car 8|

Actually, an eta with an I head drops the compression ratio to 7.9:1

It has been proven that the low compression stroker is actually closer to 8.4:1, multiple times.

[Myster-E]

2k into your bottom end?

thats a lot for idk what!

lower compression=good for boost, you want boost, than run eta block with i head, gives 8.3.1 compression, boost to 13lbs with cometic/mls headgasket, run some arp head studs, boom 270hp

you are welcome

Actually, an eta with an I head drops the compression ratio to 7.9:1

[MR 325]

I am building a new bottom end for boost as well, and while I am buying all the parts I just said screw it and have a M52 crank and short skirt "i" pistons lined up for onle $110. Thats so damn cheap I couldn't stay away. BTW, what cam does myster-e have?

You'll still need to bob the crank though, but that's an amazing price on the parts.

His is a custom grind 280 cam.

http://www.r3vlimited.com/board/showthread.php?t=221655

[acolella76]

I'm most definitely with you. The parts can be found very cheaply to build this engine. Find a good machine shop to do the mods to crank and pistons and you'll have yourself a great engine. My good friend (Myster-e on here) built this engine and did 185whp with his with potential for more with a bit more tuning time and intake changes. This is a NA engine of course.

If you want to keep it super cheap, just to the Eta bottom end with a fresh rebuild and ARP hardware. This along with a nicely built 885 head and boost will produce nice power.

I am building a new bottom end for boost as well, and while I am buying all the parts I just said screw it and have a M52 crank and short skirt "i" pistons lined up for onle $110. Thats so damn cheap I couldn't stay away. BTW, what cam does myster-e have?

[Kozworth]

Ok, that definately makes sense now. I was reading it as the area from tdc to bdc, but since the rods were shorter it would be the same. Thanks

[LJ851]

^ Rod length has no effect on displacement. Bore, stroke and # of cylinders= displacement.

[Kozworth]

One thing I don't understand is if a 2.5 has a 135mm rod and 76mm crank, and an eta has a 130mm and a 81mm crank, wouldn't the displacement be the same since the rods equal since ones shorter.

[MR 325]

My favorite all-stock stroker combo is the 2.8 with M52 crank, eta rods, and 325i pistons. Cheap and easy. And with a budget of 2k that gives you PLENTY of room for extra go fast stuff like MegaSquirt.

I'm most definitely with you. The parts can be found very cheaply to build this engine. Find a good machine shop to do the mods to crank and pistons and you'll have yourself a great engine. My good friend (Myster-e on here) built this engine and did 185whp with his with potential for more with a bit more tuning time and intake changes. This is a NA engine of course.

If you want to keep it super cheap, just to the Eta bottom end with a fresh rebuild and ARP hardware. This along with a nicely built 885 head and boost will produce nice power.

[acolella76]

well, i figured this is going to cost more then i could expect. I want a solid, safe boosted car. thats basically running eta crank, 130mm rods, and 325i pistons correct?

That's good. A lot of people think 'budget' builds will end up being budget but in the end cost 2x more than they were expecting. It's refreshing to see someone have some realistic goals.

That is running eta crank, rods, and pistons and the 325i head. The CR is closer to 8.5:1. It is good for boost because low compression = more boost before you get detonation and knocking. But again, with your power goals you don't need a CR that low since you won't be pumping 40psi boost through the motor. My favorite all-stock stroker combo is the 2.8 with M52 crank, eta rods, and 325i pistons. Cheap and easy. And with a budget of 2k that gives you PLENTY of room for extra go fast stuff like MegaSquirt.

[Kozworth]

2k into your bottom end?

thats a lot for idk what!

lower compression=good for boost, you want boost, than run eta block with i head, gives 8.3.1 compression, boost to 13lbs with cometic/mls headgasket, run some arp head studs, boom 270hp

you are welcome

well, i figured this is going to cost more then i could expect. I want a solid, safe boosted car. thats basically running eta crank, 130mm rods, and 325i pistons correct?

[devon.818]

2k into your bottom end?

thats a lot for idk what!

lower compression=good for boost, you want boost, than run eta block with i head, gives 8.3.1 compression, boost to 13lbs with cometic/mls headgasket, run some arp head studs, boom 270hp

you are welcome

[Kozworth]

Sorry, I just realized why the s50 rods wont work. I keep thinking the bigger the better but I realize that s50 rods on an eta crank would put me 5mm above tdc.

Not that this can be measured, but building a super eta on an 885 head, would this really give me that much performance for just .2l more? Would this hold up a lot better for boosting then a regular 2.5?

Ultimately I am looking to boost, Im looking more to 300whp or so. Im debating whethor building a 2.7 would give me that much of an advantage over a 2.5i m20, or if I should look into a more complex stroker to yield more suitable results.

My budget to get my bottom end done is around 2k about if that helps any.