Im looking to do a build to be capable of 275-300 HP. not saying it will see that much power, but thats more then enough for what I think the blower can do.

WIll be powered by a ported and polished m62 with a 2.9 or 3.0 pulley.

looking to spin to 7200 rpm maybe 7300

Gimme opinions people!

lemme see what YOU would do. keep its all 2.2 ECO! i want a 2.2 block, and 2.2 head. not looking for custom crank trigger wheels or anything.



Edited 1 time(s). Last edited Wednesday, March 21, 2012 6:06 PM

why not go 2.8 pulley



Sig thanks to bxmobkrazey on gmscf.com

because with a 2.9 at 7200 rpm, the blower is super close to being over spun already.

^^I wouldnt worry much about that really. Its overspun on anything over 10psi...so anything other then stock according to the cobalt guys.

For your engine id just do the bare minimum. Depends how cheap you want to go....budget????

I'd remove the ballence shafts, head studs and lsj heah gasket and put new rings one stock pistons with a boost friendly gap@

JUCNBST wrote:I'd remove the ballence shafts, head studs and lsj heah gasket and put new rings one stock pistons with a boost friendly gap@

you are saying keep stock pistons but put on new rings and keeping stock rods? then taking out the shafts, getting head studs, using a LSJ head gasket?

You could probably get away with 02 pistons with the larger landing. Personally id put atleast rods and pistons in...plan on doing it shortly

Philly D wrote:^^I wouldnt worry much about that really. Its overspun on anything over 10psi...so anything other then stock according to the cobalt guys.

For your engine id just do the bare minimum. Depends how cheap you want to go....budget????

Thats not an accurate way to judge the blower efficency, a stock exhaust n head vs. A ported head, header and full 2.5 exhaust with the same pulley will net a drop in psi. Positive displacement blower produces the same amount of air per revolution, it is the resistance in the system that raises or lowwers the psi. Thats also why eaton has charts that state what eff % the blower makes at x amount of rpm.

JUCNBST wrote:Thats not an accurate way to judge the blower efficency, a stock exhaust n head vs. A ported head, header and full 2.5 exhaust with the same pulley will net a drop in psi. Positive displacement blower produces the same amount of air per revolution, it is the resistance in the system that raises or lowwers the psi. Thats also why eaton has charts that state what eff % the blower makes at x amount of rpm.

my thoughts exactly! i've been looking for the chart all day cant find it...maybe im not looking in the right spots.

Evofire-thats exactly what I'm saying, the stock ring gaps butt up against themselves and crack the ring lands with stock gapping and can cause the ringlands to give way. I made 249whp on stock everything internally stock. I'd be willing to bet if turbo guys can do 300whp on a stock eco that with a good tune n ring gap the pistons would be just fine for your goals. Maybe swap rods just to be safe as the gm build book states at 250 you should upgrade rods.



Iirc john higgens tuned that stock eco that made 300whp with the ld9 computer and blower reflash.

so im thinking....stock block. stock crank. 10 or 20 over 10:1 pistons, rings with proper gap stock head cleaned up. maybe valve springs. good tune blower.....good to go.

At the very minimum I would do rods and pistons, LSJ HG and ARP studs, and P&P head. It would be asinine to replace either rods or pistons and not do both.

But for not much more effort or $$$, you could also do the balance shaft delete.

And don't forget new main and rod bearings, upgraded timing chain set, water pump, and other misc things.




Currently #4 in Ecotec Forced Induction horsepower ratings. 505.8 WHP 414WTQ!!!
Currently 3rd quickest Ecotec on the .org - 10.949 @ 131.50 MPH!!!

You might not even need to overbore the cylinders, check to see if the stock hone marks are in the bores still. My spare eco motor had a fubar head due to oiling issues but the cylinder bores were perfect as were the crank mains. It was a high milage motor too. My machinist said oversized pistons weren't needed. Just make sure you get some quality rings that are made to handle the heat from boost. My Weisco's are getting hellfire rings.

I'd suggest a sping upgrade as stockers might run into float at 7k+ with boost just to be safe since our motors are interferance motors and a valve making contact with a piston would ruin your day. I'm sure you'll be fine for your goals with what you got planned out.

sounds good....why the LSJ gasket though?

Roofy- I agree with what you are saying, I was going off Evo's request at the bare minimum, and the lsj hg is better suited for boost than a stock l61 gasket.

so i need to shop for rods, pistons, good rings.....

then shop for a head and do some mild p&p on it.

get a l61 gasket set, and then a lsj head gasket?

Sounds good, if your building a spare block have your machinist look it over before getting pistons as they might be able to get you a good deal and also make sure you don'y buy bigger pistons when not needed.

JUCNBST wrote:

Philly D wrote:^^I wouldnt worry much about that really. Its overspun on anything over 10psi...so anything other then stock according to the cobalt guys.

For your engine id just do the bare minimum. Depends how cheap you want to go....budget????

Thats not an accurate way to judge the blower efficency, a stock exhaust n head vs. A ported head, header and full 2.5 exhaust with the same pulley will net a drop in psi. Positive displacement blower produces the same amount of air per revolution, it is the resistance in the system that raises or lowwers the psi. Thats also why eaton has charts that state what eff % the blower makes at x amount of rpm.

I agrere on that....supose I worded t badly. Apparently anything over stock pulley on the Eaton is overspinning it. Only when you get down to the 2.5-2.6 range do you get to diminishing returns.

Also for the $175 for the balance shaft delete id be doing that as well, and maybe even the oil pump gear if you plan on uppping the rpm's

Anything over 7,000RPM on any eco I would get the GM hardened oil pump gears. Since those gears hate high RPM, and hate two steps or bouncing limiter.




PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

If ti was me I would do a stock bottem end, some nice headwork, cams, springs etc...

2.8 pulley, and meth.

I also agree if you going to tear into the bottem end then might as well do pistons and rods. I would do stock compression piston's or slightly higher, with balance shaft delete, and the hardened oil pump gears.


I also tuned a ported M62 on a bone stock Eco (cams, TB, everything stock) with a 2.8 pulley, NO METH, and made 236whp. With meth we could have made more, and with cams and a larger TB could have made more.



FU Tuning

So it looks like the concensus is that the stock bottom end freshened up, with a built head is the way to go. So if rods and pistons have to be bought anyways, i think that a stock SIZED bottom end with forged pistons and rods, and a head with springs, valves, and cams sounds good.

To answer your question, the LSJ headgasket is better because itmis a 3 layer embossed gasket compared to our stock 2 layer gaskets. And ARP studs are definitely recommended.




Currently #4 in Ecotec Forced Induction horsepower ratings. 505.8 WHP 414WTQ!!!
Currently 3rd quickest Ecotec on the .org - 10.949 @ 131.50 MPH!!!

EvoFire wrote:So it looks like the concensus is that the stock bottom end freshened up, with a built head is the way to go. So if rods and pistons have to be bought anyways, i think that a stock SIZED bottom end with forged pistons and rods, and a head with springs, valves, and cams sounds good.

Sounds close to what im going to be doing for the Harrop.


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