12 Second N/A Slant 6?
You would spend 2 X that just for a set of exchange ported heads W/stock valves/aftermarket valves springs for a Gen III Hemi.
That is not out of my budget.
Not looking for roller rockers, just a better ratio.
I'm looking to maximize lift W/O a lot of duration.
My custom Crower grind in 5.7 had a very aggressive opening ramp. 113° LSA. Duration was in the same range as the Comp 268 grind for the 3rd Gen Hemi (can't remember spec's off hand) It allowed good cylinder fill (235# cranking pressure) but still pulled to 6250 & didn't fall on it's face. Lots of TQ to pull 4300# down the track in 12 flat.
That's kinda what I am looking for but @ lower peak RPM. Max cylinder fill while holding TQ for 5000-5500 RPM (flat) HP peak. FAT TQ curve that hold as the revs come up.
Get the heads that flow @ the right RPM matched to the proper cam.
Put the proper induction/exhaust that will optimze the same power band RPM then gear it properly (4.10?) W/the right convertor.
ok first thing you need to understand is this is not a gen anything hemi, this is not a gen anything small block, this isn't even a small numbers pontiac...
Slants are built buy people who want to build them, you cant "just" build one because. time involved is much like building a hemi, lots of time picking the right cam to make the motor run. my point is there is very little aftermarket for these, so saying my gen III blah wont get you anywhere but frustrated. you'll have the same or more in a 500hp small block but thats not why we build these.
all of us slant guys are more than willing to help as thats our crowd, but its a small crowd and many will tire quickly so tread lightly.
now here is my build for you.
Intake
offy intake not the aussie, reason being the aussie is a small port (stock port) intake thats roughly twice as long, or MORE restrictive. you could probably make more power all over with no loses with the clifford due to the 240ci but that comes to track times.
Headers
ive heard lots of good things on the aussie headers but never any specs. i dont know tube sizes or length, nothing! thus i run hookers super comps, with 1 5/8" primaries they are a little big for down low but are long enough to make up for it(thinking about cutting some tube off the flange and go 1 1/2 or 9/16) to 1 5/8". my reason being that you want a primary tube the same diameter as the exh valve, that being 1.5" on the biggest you get my drift.
Cam
solid is your only choice until enough people want and will pay for a roller to bring the price down (i may be the first if i build my 300 cube slant).
so you want a low duration cam (as you should) with a 108-110 LSA. i plan on building a similar motor with a 220* @ .050 duration, 108-110LSA, lift as much as you can (this is where a 1" lifter comes in, allows more lift for the same duration) i would like .480 VALVE lift or a .340-.350 lobe lift.
Head Work
never played with nitrous but i would leave the stock exhaust valve size and get a bigger intake valve (1.75 or so) as you can port the exh to the same specs as the intake! so get the intake opened up where it needs to be and port the exhaust as needed (70-78% of intake flow, not 75-85% as is so easy to end up with).
milling the guide down for over .450 lift will get you anywhere you need to be. 1.5" dia BB springs drop in but new retainers and locks will be needed.
Lastly rockers. stockers are plenty strong and if they are nice and tight just shim them to where they need to be (small block shims work).
crane 354lbs springs are perfect.
as for the drivetrain the 904 is plenty strong, just has to built for nitrous, same with the verter, stall i would shoot for 3 grand but i cant tell without a torque curve. same with the rear end, 8.25 will be lighter than an 8.75. in my car with 28" tall tires i would trap at 5 grand with 3.91's so i think 4.10's would be spot on.
anything i missed lol?
