NA engine build?

[wantasvx]

has anyone done a normally aspirated engine build? what kind of power did you make? what kind of parts did you use? Standalone engine management? Any and all info would be great.

[cdigerlando]

I think Mike from ECUtune is trying to develop interest in such a development. He can offer cams, valves, springs, pistons, injectors, EMS to achieve such goals. That coupled with a 5 speed WRX tranny would be wonderful.

[wantasvx]

any idea on a hp goal or redline?

[TomsSVX]

If I were to put together an N/A engine I would have the crank precisely machine. Use the Eagle rods we are using in our FI engine builds along with ECUtune's CP pistons. Compiled with the ECUtune cams to spin about 8k rpms... Just for giggles I would estimate an aprox. 230 wheel hp... which is nothing to sneeze at. You would want to run the ECUtune stage 2 w/ the 370cc injectors and Z32 MAF... Its not like I have been thinking about it

Tom

[wantasvx]

how much would you expect a complete kit to sell for?

[TomsSVX]

kit?? huh??? There is no such thing... a fully built N/A engine could sell from anywhere between 4k and 6k depending on what parts you use and what you have done... Its not a wrx where you can buy pre-built engines... these are a tear down and build up with a lot of down time... unless you have someone rebuild an engine and once all is said and done, send your core back...

Tom

[wantasvx]

no i didn't mean like a "kit" i meant for all the parts how much would it cost and i'd do all the work

[TomsSVX]

ok... this is all rough figures but here goes

Pistons if you get in on the group buy now... $800

Rods... somewhere in the realm of $570

Bearings... $200

Valves, springs and cams- $1500

Then factor in the machine work and assembly costs... $1000-$2000

Thats a total of 4070-5070

Tom

[NikFu S.]

Honestly who here hasn't spent at least that much anyways? 5k is nothing and the car wouldn't even be trackable yet.

I'll be building my engine NA, kinda shooting in the dark here, no goals, just adding things on. I've got stage 2 coming and will probably get the cams unless young Tom or Mychailo gets back to me on the Koni/GC sometime this year *hint hint*
I won't be running a higher redline because I'll be using the 3.54. I guess I do have a goal, to get into the 14s with an NA 3.54.
After that, I honestly don't see the point of staying NA unless you just want to avoid clustering the engine bay up.

[wantasvx]

what kind of superchargers do you guys use? are they all custom? i have an eaton m90 and a m62.

[XT6Wagon]

I wouldn't be worried too much about the bottom end in reving. IIRC the EG33/EJ22, can turn 9,500 rpm or so to have the same level of acceleration on the piston as a Integra Type-R's B-18C. For those that want just brutal rpm the old pushrod/shoc 1.8L motors (and XT-6 engine) is close to 11,000rpm IIRC. Obviously with higher piston wieghts in the EG33, you have to lower it some, but we have far better bottom ends than the honda engines so long as the bearings get thier oil. Still a proper balance on the crank and checking bearing clearences is cheap insurance. DON'T lighten the crank. Every broken subaru crank I've see was a lightened one.

The ***** we run into is headwork. Converting to solid lifters is going to be manditory for 8,500 common use just for the removal of mass from the assembly. Valvesprings that don't resonate in any rpm band you might see. Cams with proper profiles for power, but also for not floating valves. Next up is porting. I really wish subaru went ahead and make a EJ257 based 6cyl fro the 08 tribeca, but given that they didn't, you are still stuck with whats effectively the prototypes for the WRX heads. Damn sight better than the legacy turbo heads of that era with rocker arms and high failure rates, but still a 1st attempt at heads. Porting should be worth alot of power here once you have the cams done. This isn't something to DYI unless you are just doing a light cleanup at the very entrance to the intake ports for a gasket match. On the exhaust side, you want the exit into the manifold to remain smaller than the exhaust gasket, gasket matching the exhaust port is bad plan. Gasket match on the header side is more acceptible.

The intake manifold looks decent, but if you want to spend the money, I'm sure there is power to be found there. The main thing is to get the throttlebodies OFF the firewall and a clean entrance to them. Honestly if I was starting from scratch, I'd pick one of the common ford TB patterns(oval cobra, twin inlet truck, etc) that has good selecting of aftermarket replacements, and whatnot. Our low hood hieght here is going to be murder on getting a good intake done. If you reall must have this relocating the alternator with that part of the ECUtune supercharger kit would open a decent gap for a smooth inlet, but in this case you would loose the 2X3 style intake as a conventional rount intake would be better. Many other options are avalible if you are going all out.

[shotgunslade]

Spoke with Jack, of XX Tuning in CT, who runs the EG33 powered Impreza RS track car. he is building an NA engine for his car. Really big lift cams, 10mm, long duration and overlap. Not street friendly He is replacing the hydraulic followers with solid buckets. He actually is fabbing larger cam covers. Custom pistons with deep reliefs for valve penetration. High compression, 11 to 1 or better. Stand-alone engine management. Expects 270 to 280 at the wheel.

He is getting a lot of input from the guy who runs the EG33 drag Impreza, dual turbo-charged. He's running 13mm lift intake cams with much lower compression. Getting about 450-500 hp.

[longassname]

I personally feel the way gasoline is going these days that an na build for the street should have lower than stock compression (somewhere between 9.2 and 9.5). I'm trying to put together enough orders to get a batch of such forged pistons made for NA use with those specs and zero interference with our cam package. If you're looking to build an NA engine it would be great if you jumped in on it. As soon as I get a couple more people in on it we'll be able to get them for $800 a set and I'll accept the orders and place the order.

[longassname]

I wouldn't say not to be worried about over revving a stock bottom end. The allowable factory oil clearance ranges include insane numbers. It needs to be propperly set up to run high rpms.

That said, the eg33 really wants to run higher rpms. It's highly over square and the head/valve train lay out is begging for it. I personally feel the engine the svx was released with was the low performance, tuned down version they were opening with and had it sold in any real #'s they would have released the performance version of the same engine a couple years later. When I was taking all my measurements to design my cam and valve package it was like the original engineers left me little notes saying grind here to this specification. The engine really was just begging for exactly the cams I made it.

[benebob]

We're expecting in the 200-215whp range for our build using stock parts so its all in what you'd want to spend realistically. Since we might see 200 miles per year we should be fine without the need for street strength.