NA1 VS NA2 INTAKE DIFFERENCES PLEASE

[TANTO]

I'm slowly gathering parts for a 3.2 build for my 92. Over the years i've purchased two basket job 3.2 long blocks and while i have tons of questions and research ahead, todays question is regarding the OE intake differences as i can possibly purchase a used 3.2 intake unit at a reasonable cost. Assuming i don't give in to a 3.5/ITB's of my dreams, do i want to modify my 3.0 unit or purchase a used 3.2. Is the 3.2 unit a larger bore or is it of little benefit? I'm not concerned too much with OE trim/connectors as i run no cats in my state and will have to eventually address ECU issues. Thanks!

 

[Zoom]

3.2 is drive by wire, but the bore is the same IIRC.

 

[Honcho]

I'm slowly gathering parts for a 3.2 build for my 92. Over the years i've purchased two basket job 3.2 long blocks and while i have tons of questions and research ahead, todays question is regarding the OE intake differences as i can possibly purchase a used 3.2 intake unit at a reasonable cost. Assuming i don't give in to a 3.5/ITB's of my dreams, do i want to modify my 3.0 unit or purchase a used 3.2. Is the 3.2 unit a larger bore or is it of little benefit? I'm not concerned too much with OE trim/connectors as i run no cats in my state and will have to eventually address ECU issues. Thanks!

The 3.0 and 3.2 intake manifolds are identical in their inlet dimension as well as the chamber volume. The major difference is that the 3.2 manifold has welded plugs in the ports for the FITV and EACV idle control modules because those functions are handled by the DBW throttle body on the 3.2. Honda simply pulled a 3.0 intake off the shelf and welded these ports shut. If you are planning on DBW, you'll need to block these ports to re-use your 3.0 manifold. If you are sticking with cable throttle, the 3.0 will work fine. Many racers install the 3.0 manifold on the 3.2 engine block because the throttle response is better on the cable.

 

[TANTO]

For anyone interested AH Parts Dissmantlers Cali US has a used 2004 3.2 intake for $850 (as well as some other stuff), but thanks to the above I'll use my OE part. Analog is firmly in my comfort zone. FWIW i purchased the 24k miles 2004 long block from AH which was originally under said intake awhile ago. The pic's showed that the rear mtr mount was damaged and i thought "I can have that fixed" and after a call to them about the blocks damage, i purchased that block assy quickly. Lesson - old NSX parts at a reasonable price - not!. After getting it i realized that one of the rear bell housing ears was missing a huge 3" by 4" chunk of the block!. If i had that chunk it could have been fixed, but they don't. I'm a better than decent fab guy, but i soon realiized that there was no way i could save that block. I actually had to put it in the trash - ekk! I said a prayer at it's funeral. It was on me however as one of the pics did show this issue - buyers beware of sellers and your own excitement -he-he. I needed a good 3.2 crank and heads, so it wasn't a terrible loss for me and i was able to get a dealer price on the last new block in the US, so i'm good-to-go albiet with a lighter wallet of course. Thanks Honcho

 

[RYU]

I can't speak to a 3.5/ITB setup but I can speak to a 3.6/ITB setup

 

[MotorMouth93]

$850 for an intake manifold is highway robbery.

Sticking with the 92 intake is the way to go, you can use the stock ECU and just tweak the fuel and timing maps that way and have everything still work easily, then do ITBs longer term. 3.2 heads are just 3.0 heads with 36mm intake valves which any decent machinist can do. If you aren't planning on using stock pistons a 3.2 block will need to be sleeved, no way around it. I'm working on a 3.2 build myself if you have questions/concerns I've went down a lot of potential rabbit holes already.