BohnsZ

Hey all, new forum members here and long time lurker. I want to build a NA motor capable of spinning to 8000rpm for my 2006 350z and would like your guys' input on my plans and parts list that I've come up with so far. Here's the list I'very put together.

Shortblock
Custom Arias Extreme Pistons (11.0:1 or 11.5:1)
Pauter H-beam Rods
ARP Rod Bolts
ARP Main Studs
ARP L19 Head Studs
Block inspected and cleaned
Block redecked
Block Bored and Honed using a Torque Plate
Rotating assembly balanced
Crank magnafluxed and the journals micro-polished
New Moly coated Race Spec main bearings installed
New Moly coated Race Spec rod bearings installed
Block assembled
Cometic Head Gaskets

Heads:
Heads inspected and cleaned
Heads redecked
Ported exhaust and intake runners
JWT C8R Cams
Ferrea Intake and Exhaust Valves
Ferrea Heavy Duty Valve Springs
Ferrea Titanium Retainers
Ferrea Valve Spring Locators
Ferrea Valve Locks
3 Angle Valve Job
New Viton Valve Stem Seals
Valve Stem Heights set

Intake:
Custom 4" Intake with Integrated MAF Housing
Custom Heat Shielding Box for Air Filter
NWP 75mm Throttle Body
Kinetix Velocity Racing Intake Manifold
Port Matched Lower Intake Manifold

Exhaust:
PPE Long Tube Headers with Formed Merge Collectors
Motordyne XYZ with High Flow Cat
Custom 3" Exhaust split into two 2.5" pipes and high flow mufflers with 4" tips

I do powdercoating for work so all intake and Exhaust components will be coated in special high temp powder. Headers will also be heat wrapped and air box and other misc. Items will be wrapped in Heat Reflective Tape in order to maximize heat management. Please inform me of any parts you see listed that you think are overkill or need changing. Any other tips to help me reach my goal would be greatly appreciated. I know FI is better bang for buck and yields much higher numbers, but I want a NA screamer so FI is off the table.

Tuning will be done via a custom reflash by Osiris Uprev for the break in period and until I can afford a standalone that can take full control of the cam phasing to maximize power passed 7000rpm.

I have a few questions for you guys. Has anyone run 11.5:1 cr on 91 octane pump gas, or should I play it safe and go 11.0:1? Also is there any point where os valves, 5 angle valve jobs, or bowl work have proven beneficial in na applications with 272 degree or less cams? Roughly how much whp can I expect with everything I've listed? I'm a mile above sea level where I'm located so take that into account.

I've also tossed around theach idea of borino out the cylinders 100mm and running Darton mid sleeves to increase the displacement to 3.7 without effecting the stroke. With the same parts listed above and maybe the extra head work that I'm curious about I could see something like this making around 350whp at this elevation with peak being somewhere between 7500-8000rpm. I'm just guessing what that increase in displacement would yield, but I don'the know of any potential problems that might occur if I attempted this. What do you guys think?

Sorry for the length, I just want to be clear enough for you to get a general idea and understanding of what I'm shooting for. Any inputs are a huge welcome, unless you're going to try to convince me to go FI. Been there done that on my last car, I want to change it up this time. Thanks guys! -Ryan

iideadeyeii

iTrader: (6)

lolz

Ok for some real input. You're going to need higher compression, stroked with ITB's.
No point of building block up since you won't even be breaking 300 torque

BohnsZ

I was referring to a built motor if it had been bored out to 3.7l when I said I could see 350whp being possible. What makes you think I'd need higher compression? An AP1 Honda S2000 uses an 11.1:1 cr and has a redline of 9000rpm, so please explain to me why 11.0:1 would not work for my goals. Stroking isn't necessary nor ideal for spinning to 8000rpm due to the increased stress on the cylinder walls. Though it's possible to safely rev that high with a stroker, I'd rather increase the bore and sleeve the block to reinforce the cylinder walls if I'm going to up the displacement. What do you mean no point in building the block? You do realize how high of tolerances the engine has to sustain to consistently rev to 8000rpm right? Regardless of forced induction or not, the stock bottom end is not designed to rev that high, mainly the rods and rod bolts. I plan on doing ITB's at some point in the distant future, but in the mean time I still don't think I'd have a problem making power up top with the short individual runner style intake manifold, larger throttle body, and 4" ID intake. That paired with long tube headers and a good exhaust would leave little in the way of bottlenecks in terms of bolt ons, and on top of the C8R cams I should be able to make good power to 7500rpm at least. By the way you should check out some of Sasha's threads. He made just over 320whp if I remember right with only long tube headers, 90mm throttle body, custom plenum and cams (don't remember which ones) on the stock bottom end revving to 7000. This was prior to him building a 3.7l that made 400whp and revved to 8500rpm, although that motor used ITB's of course. Last I heard he's gone up to 4.0l, but I could be wrong

iideadeyeii

iTrader: (6)

Go by other thread then. You're asking questions that no one is going to be able to answer since there is only 1 Build breaking 350whp n/a

There was a lot of custom plenum work (100+ hours) to get the 400whp they achieved and it was with Itb's and it was stroke with stock block/head/custom cam being used.

but honestly 350whp with 270tq isn't impressing anyone for the amount of money it's going to cost to achieve that.

BohnsZ

I referenced that thread to show that going all out with ITB's, 12.0:1 cr or greater, and extreme headwork is not the only way to make decent numbers NA. I really don't care what numbers I end up with anyways, as long as the motor performs in the behavior I want it to. I simply am looking for pointers on what would help me rev that high and increase the peak hp within the extended review range. I don't expect to have a motor that will pull like a bat out of hell up to 8000rpm, but if I can make the power curve more linear up there rather than drop off like a stock motor would. I think once I have a Haltech to really play with cam phasing it wouldn't be too hard to see some gains up top with the parts listed. I'm not trying to impress anyone, I simply want to try something different from forced induction for once and I like the idea of a responsive and rev happy motor for all out feel and driver enjoyment. I like forced induction don't get me wrong, but in my opinion a well built na motor with a fraction of the power of a big turbo or supercharged car is much more enjoyable and rewarding to drive. You clearly favor FI, which is fine, but that doesn't mean you can't appreciate someone else's build or ideas rather than discourage them by saying it's a waste of time. Not everyone is looking for the highest hp numbers

iideadeyeii

iTrader: (6)

http://www.superstreetonline.com/how...-engine-build/

BohnsZ

I referenced that thread to show that going all out with ITB's, 12.0:1 cr or greater, and extreme headwork is not the only way to make decent numbers NA. I really don't care what numbers I end up with anyways, as long as the motor performs in the behavior I want it to. I simply am looking for pointers on what would help me rev that high and increase the peak hp within the extended review range. I don't expect to have a motor that will pull like a bat out of hell up to 8000rpm, but if I can make the power curve more linear up there rather than drop off like a stock motor would. I think once I have a Haltech to really play with cam phasing it wouldn't be too hard to see some gains up top with the parts listed. I'm not trying to impress anyone, I simply want to try something different from forced induction for once and I like the idea of a responsive and rev happy motor for all out feel and driver enjoyment. I like forced induction don't get me wrong, but in my opinion a well built na motor with a fraction of the power of a big turbo or supercharged car is much more enjoyable and rewarding to drive. You clearly favor FI, which is fine, but that doesn't mean you can't appreciate someone else's build or ideas rather than discourage them by saying it's a waste of time. Not everyone is looking for the highest hp numbers

travlee

iTrader: (8)

your posts are hard to read, not because of wording or language barrier, but because it all runs together.

BohnsZ

Not entirely sure what you mean, but I apologize for the confusion. Sometimes I try to go into too much detail and just end up rambling haha. Basically I want a high comp. NA motor that revs freely to an 8000rpm redline and can make power to at least 7500rpm without ITB's. The reason I want it to rev to 8000rpm is because I DO eventually want to get ITB's and hopefully make power up there. That won't be for awhile though, and I want a strong NA motor in the mean time that will make a good building platform for when that day comes. So what I'm asking is for people with a good knowledge of vq35 na builds to comment on my part selection and suggest anything that I could "cheap out" on if you will, leave out entirely, or areas that could use more attention. For instance, can I settle for a 3 angle valve job and no bowl work and still yield good top end power, or would that be a critical factor for letting the engine breathe efficiently at that high of rpms?

travlee

iTrader: (8)

no i get what you are trying to do, but with one huge paragraph, it makes it hard to read

would be easier if you split it up some.

KingBaby

iTrader: (3)

contact reputable VQ engine builder...setting a plan is easy. Spinning a rod or something breaking on the first pull is even easier...

Syner

Yes, like this:

terrasmak

iTrader: (8)

Very similar to what I'm about to build. I'm going to run Eagle rods , no need for the ARP L19 IMO and I'll have an undetermined cam, Tomei most likely.

your goal, I would probably bump to 12:1 and run E85. I bet it will get you closer to your goal.

BohnsZ

What sort of headwork are you having done? From what I've seen, oversized valves and 5 angle valve jobs are really only ever on drag motors or race motors that are running wild cams or just trying to squeeze every last pony out of the motor. I'm curious though why cosworth uses a 3 angle valve job on the intake side and a 5 angle radius valve job on the exhaust side on their long block. Anyone know the reasoning behind this?

iideadeyeii

iTrader: (6)

The heads are not the restriction here. It's the intake manifold. Cams are all you need. I found this out spending 2 minutes reading Sasha's article.

BohnsZ

I'm aware of that, hence why I listed a larger intake, tb, and velocity manifold. I was just curious why cosworth did the valve job with the exhaust side being more heavily reworked than the intake side. Cosworth knows how to build good engines obviously so there's gotta be valid reasoning behind it.

iideadeyeii

iTrader: (6)

. . . when you're forced induction the air is being forced into the intake side...you need help getting the air OUT of the engine, which is why they probably work more on the exhaust side

macs350z

iTrader: (1)

Agreed ^^^ I'm planning my NA build also. I spoke to Daelen MAMotorsports, and he told me the same about the heads, not really any benifit, Just do cams and retune.