*****VQ30 Head Porting*****
 

Just curious to know if anyone could provide me with any suggestions on this subject. I know how resrictive the 3.0 heads are and since I got the motor out I'm planning on doing this job. If you guys can give me some helpful info or past experience tips before I go about doing this.

:idea:

Thanks

Why don't you use the 3.5 heads and manifold? I know that 3.0 heads will give you 11.5:1 of compression instead of 10.3:1 for a full 3.5, which will be good for quite a few hp, but that is really where the advantage stops. Apparently, everything else from the 3.5 head is superior.

I remember SR20DEN said that you could put a 3.5 upper end on a 3.0 bottom end and there would be good gains, EVEN though the 3.5 heads on a 3.0 block would give you 8.9:1 of compression instead of the stock 10.0:1.

So I'm guessing the difference between the 3.0 and 3.5 flow is really quite big.

So, you only need the combustion chamber of the 3.0 head with everything else from the 3.5 head, not just cams. I think you can add material to the combustion chamber to make it smaller and reach ~46 cc to get the same 11.5:1 the 3.0 heads would give you, but with all the advantages that come with the 3.5 heads and intake manifold.

SR also said that 3.5 heads weren't worth porting since they flowed so good from the factory, so if you can reduce the size of your combustion chamber on your 3.5 heads and extrude hone your 3.5 IM it should be the best possible setup.

Plus, with the 3.5 IM you can mount the "V6 3.5" plastic cover in your engine bay and brag about it cause it looks killer under the hood of a 4th gen:loser:

Well I wish I could do this but in my position I can't, to do this kind of work it requires alot of custom fabing grinding using switches all kinds of stuff have to be looked at. It's easier said than done. So I'm trying to work with what I got and make the best of it. Like I said I'm doing this all bymyself with very few set of tools.

Okay. Good luck then, I'm paying someone else to do it. I'm too much of a brick when it comes to internal engine work. If I listened to myself I think I would probably drop the whole OEM assembled engine in and call it a day :nod:

What worries me about the 3.5 heads with the 3.0 stroke is the low comp it becomes if this cant be solved i will just stick with my 3.0 plans

Well low comp is good for boost, otherwise, swap the whole 3.5 or 3.5block/3.0heads like Tilley did.

yeah i know but this is a allmotor forum so its not a asset.

And the 3.5's heads and alittle dicplacement is all i want the full 3.5 is no good for what i want.

What I'm trying to say is for my setup>> PORTED 3.0 HEADS, IM, MEVI
VS. 3.5 HEADS AND IM.

How close will I be or will my heads flow better. I don't no how much I'll take off the heads just yet but I know I will take as much off as possible.??

Well, look at it this way: The 3.0 heads/manifolds was made for 190 hp, while the 3.5 one was made for 255. Obviously they can both handle much more hp and all and I don't know the specs but heads are really the heart if you want NA power. I heard they flow very well from the factory so I highly doubt you will see good gains by only porting them... but if you're doing it yourself, you got nothing to loose. It's just that you already have the 3.5 heads, you payed for them, you got them...

Good luck anyhow. I'm going to talk to the guy who built my dad's 455. He got the compression up to 13:1 for drag racing so I will see how much it could cost to go from 10.3:1 to 11.5:1 to get the same compression a 3.0 upper end would give, except with considerably better flow and more hp.......

So if we were to use the 3.5L heads, that means we could use the 3.5L headers like from hotshot or something?

Couldnt you get high compression pistons and swap those in to counterbalance the compression lost with using the 3.5L heads?

This sounds interesting..... :)

:buttkick: :tardsmash

:buttkick: http://forums.maxima.org/showthread.php?t=296960

His project will require 95.5mm VQ30 spec pistons. Not just higher compression. VQ35 pistons on VQ30 rods/crank will have a 0.6mm deck height at TDC which is not good for the quench design.

I have already posted many of the differences between those heads. IMO you're always better off using the VQ35 heads. But it's your money.
:reading: http://forums.maxima.org/showthread.php?t=315000

With enough money you can make them flow better than stock VQ35 heads but that isn't going to make the valvetrain as good.

Yeah but I got the opportunity to do this at a local machine shop myself $$in my pocket.

Anyways Being that say they do flow better ofcourse the valves are a little smaller. So I figure that my setup with the 3.5 cams the lift would be the same.

Having said that my setup would be better than having stock 3.5 Heads and IM on.

No it wouldn't.

explain>>>>My Wizard
:sadpace:

I don't see why not.

Tillys setup which we all know, with the calculations that I made according to his 1/4 times, speed, weight and drivetrain loss. He should be around 220-240ish FWHP Thats about 260-280 @ the crank. :gotme:

and thats no were near my setup well a little.

I think the using the 3.5 heads on the 3.0 block is the best solution for forced induction. You lower the compression and have a better flowing head.

When you get the deck of the heads machined to fit the block flush do they take enough out to make a significant change in compression? That coupled with a thinner headgasket maybe get you into the 9.0 region? Maybe you can use lower octane gas because of the lower compression?

Sorry but I have provided you all with the information you need. I'm not going to explain it a third time.

Ok even though I read that wards info long time ago the info there doesn't answer my ??. That thread talks nothing of what I asked you not even close.
Or I guess I've misread oh wait I think not.
I'm talking about my Ported setup VS 3.5 Head swap
if my setup will come close or be better than. YES OR NO ??? YOU SAID NO
So Explain yourself.


And if anyone has dyno numbers that has a Ported head job done on there 4thgen that can provide me with some helpful info or any sugg..I can get a good idea of what gains to expect.

To others that obviously don't no READ THE TOPIC your talking abot lower CR and FI.

Yet it looks like I'm the only one that can find out being I'm the only one with this setup so as soon as I'm done I have to head straight to the DYNO. :hyper:

OHH welll but you did say this :::: Originally Posted by SR20DEN
You will never make any real NA power with these inferior heads unless you have some extensive work done to them. :smash:

Well i was never told by you that 100% the piston weight and such would be no problem,im assuming the pistons would be much heavier than stock if not than i need to have this explained to me why it wont be a problem and how it is to be solved.
I need feedback you may have the answers in your head for some problems i dont i need to be put at ease.

The project we have planed is what i sincerly want to follow through with, if i lnew everything you knew i would do it myself but i dont. so i leave matters in your hands.

What would we do about the variable cam timing, and the cam pos. sensor if the entire 3.5 were put into a 4th gen?

That's what Tilly's working on .
But I think SR20 knows also not sure.

Ever since Tilley dropped the 3.5 bottom end in I have been really been craving too do this.

BUT! I'm young soon too be 18, in high school still and work at a restaurant. So yes money is a slight issue. I want too save as much money as I possibly can.

I want too know how hard is it too swap a motor in and out of your car, doing all this in your own garage? This is directed too anybody, but especially japmax because well he's doing this as we speak it looks like.

I love cars and am willing to learn anything and everything, I plan to go to UTI after I graduate from HS.

I've done fairly basic stuff on my car like install intake, brakes, and suspension. Now I would like too know how difficult it is too swap a motor, I would love too get this done before I head off for UTI.

Well ts quite a job i have done internal work on VQs alot so i could all but do it in my sleep. I also have a lift at both of my garages i work at, and all the tools i need.

Bingo.

1234

As I said before, it's easier to raise compression on 3.5 heads and use the superior heads and intake manifold instead of the 3.0 upper end.

The problem is that there is an electronic device that goes in the IM of the 3.0 right before the throttle body and I have no idea how it can be bypassed.

The valvetrain is very different and is much lighter on the VQ35 heads. This data is all posted in that thread. So even if you make the VQ30 heads flow more there is still more mechanical loss which will offset some of the gains.

Plus, it's easier to drop the whole engine in and not have to tear it down.

Ok just got back from the Machine Shop today Ohh what a day it was.
Ok where do I start I spoke with a guy name Ricky OLD MAN, he works at a Nissan Dealership, and happened to be there. I explained to him my project he first said "DAMN WHAT IN THE HELL ARE YOU DOING" Then I laughed and said "I don't know na I'm J/K" Well long story short basically he has 10yrs of experience with all kinds of Nissan’s and told me that my VQ30 Heads are very strong and those last forever. He rather use 3.0 engine over anything.. He doesn't seem to like the new 3.5 engine. He says the 3.5's yes they are more inferior but weak in design, to many recalls on them, blown oil seals stress cracks :russ: :yeahright
He would rather use the 3.0 engine and put the 00' 01' VI ontop and then FI.
But whatever I told him that I'm enjoying this project, I'm one of a very few guys that are doing this. He just couldn't believe that this could be possible and says that I'm crazy "QUOTE by RICKY (sh?T that engine is going to be "crazywild" with the TQ and power your going to have and that CR damn if you use race gas100mix good luck you better wear a Helmet.) and he walks away "DAMN KIDS" :rotz:

Well one more day of machining. :hyper:

hahahahaha that's kinda funny sounds like my nissan mechanic.