N73B60 V12 Swapd E46 (ITB's, General Knowledge, Goals, Concerns, Innovations & more)

[ProjektCarModz]

Figured I'd come to the big house for some proper advice; honestly hoping someone knows something about something Yes solid Build thread coming one day.


I'd like to mention I have a CNC machine, 3d Scanner, & competence so pretty pretty please use a progressive/suggestive approach rather than semantics.
I'm mostly pissing in the wind on "select things" before I just say F-it & turbo the motor with proper HG & say done. we all know it's that simple.


Thruth be told I'm bored & am wanting to develop something I can put my name on.
I have another good (spare) n73 engine on the side for this.


I seek to answer some questions, concerns, & set goals in one place before I start divulging to find this information myself & keep it all a secret LOL. You help me I'll be transparent with the public simple.


1. Factory Cam upgrades Anyone know lift values etc for other N73/N74 engines?
1a. Will N74 Heads fit? If so compression numbers? Hows the valve sizes vs N73 etc?
2. I'd rather get rid of Valvetronic given the limitations (hence the N74 heads) sure I could just remove it & tune out on N73 any info on this?
3. I already have a set of 12 FI-ITBs 52mm for the engine simple adapters are easy to make just unsure of factory intake inlet diameter (havent dissassembled spare engine as nothings wrong with it. Any decent ECU recommendations? Wiring/pinnig is of no concern just need an affordable/no corners cut solution no extra features needed just engine function (So many options Idk what to choose nowadays)
4. Hows factory oil baffling? My base car will be a drift car should I rush to get the dry/accusump or better baffling done given there's oil 2 pickup points on base engine (to be transplanted next month)
5. RPM Limits N73B60 (89.0 x 80.0) 6k Rev limit currently? & N74B66 (89.0 x 88.3) 7K - Rev Limit. Crank is forged is this a crankshaft/rod limitation? or just a simple cam based handicap? I've heard of people revving them to 8k which should be possible. (Idc about not making power up there 1 step at a time)


Concerns: None honestly


LONGTERM Goals/intentions:
I'd like raise the comp ratio & rev to 8k & later-8500 rpm if possible making between 550-600 before head work to 7-800 on E85 later.
My example is Hartley Racing Engine Toyota 1GZ 5.0L V12 (81.0 x 80.8) 9.5k Rpms 700HP E85
Again obviously I'd need a ATI Damper etc again lets leave the bolts-ons obvs solutions alone.
1. A dry sump oil pan is actually extremely easy with the cnc & retired nascar dry sump, containers etc $900-$1k All said & done.
2. ITB's Easiest part initially byfar besides when the tuning aspect comes.
3. I would like to get rid of the front chain & use Planetary? style gears to run all the things.
there's a few more but these are the main few simple things.


My example is Hartley Racing Engine Toyota 1GZ 5.0L V12 (81.0 x 80.8) 9.5k Rpms 700hp
We're up 1Litre & down 1k-1500rpms


Further Details/Etc :
1. Why not N74 (I'm not rich I just have ambition & have worked for what I have up to this point plus it's also much to soon imo)
2. Swap kit incoming from Poland to adapt the N73 to a ZF GearBox. Leaving only motor mounts to be made. Originally & eventually will CNC/drill a button clutch & optimize for application, but mehh I had the cash so no need to reinvent the wheel yet there giving me time to focus on fun areas I'd prefer too atm.


Ik it's alot.. thanks for the read just exploring lmk if you guys know anything & feel free to ask reasonable questions i'll be back tonight to respond.

[BimmerBreaker]

Short answer is simply that if an N74 is too expensive for you, building an N73 like you want is most likely too expensive for you too.


Longer answer is that there is virtually no aftermarket support for the N73. Nor is there much understanding regarding cross-compatibility of N73/N74 stuff, because nobody really dabbles with those engines in that way. I can answer just a few of your questions though from the technical documentation I have - N73 valves are 35mm for intake and 29mm for exhaust, N74 is 33.2mm for intake and 29mm for exhaust. Compression ratio on N73 is 11.5:1 and N74 is 10:1. There are no off the shelf camshaft upgrades for the N73 or N74. Cylinder spacing is the same so - maybe the heads could be swapped? But if you want to just turbo an N73 why not just buy an N74 and have a stronger engine from the get-go and already have all the turbo stuff built out and ready...

Regarding management systems, the N73 in factory configuration used a whopping five engine control management modules. Deleting Valvetronic would remove one of those from the equation, but if you end up losing VANOS with an aftermarket ECU, you will also lose a ton of torque. And the N73 is direct injection, something - at least last I checked - that a lot of aftermarket ECU's struggle with. Converting to port injection will likely negatively affect power, anywhere from a negligible to a significant amount. Many standalone ECU's also struggle with running V12's. The best bet financially, at the expensive of some power, would likely be converting to port injection and running 6 cyl management with wasted spark.
The *best* options for maintaining stock power levels would likely be mid-higher end MoTec's. I think an M150 can do *most* of what you want - but those start at $3,700 and a more capable M190 will is over $5,000. And that's not including building out the engine side harness.

Unlike the Toyota V12 you mentioned, which is basically just two 2JZ's mated together; the N73 is more closely related to the N62 which itself has hilariously poor aftermarket (and OE level) support. Essentially, the N73 is built as a longer N62, but run similar to two N52's with D/I.

The core of the problem with these engine swaps is how highly strung and deeply integrated all their systems are. To run an N73 as standalone management you'd most likely have it performing like a 4 valve/cylinder M73 (aka significantly less power than in a stock application). It gets prohibitively expensive to work on these engines - even if you can do 90% of the stuff yourself that 10% adds up very, very quickly. And due to the extremely low demand for any performance mods for these engines, it's not like you can recoup the investment by selling your ITB adapters or whatever it may be. And of course, I didn't even touch on the physical fitment... but that's the simple part compared to the rest of it (and physical fitment is certainly not that straightforward either). Ultimately, "if you have to ask, it's too complicated for you" will most likely be the case here. I do hope you prove me wrong, it would be an awesome swap but to really do this right - and perhaps at all - you would need very very deep pockets and long arms willing, and perhaps eager, to reach deeply into those pockets.

[ProjektCarModz]

Appreciate the knowledge/information you gave.. Def a lot of semantics (literally first sentence) which were to be expected here.
Anyhow to bounce back the progressive stuff & toss ya some insight & fight back too XD.

1. The engine has already been fitted into an e46... First thing on google search. "N73" + "E46".
2. The difference in price between the n73 to n74 is SUBSTANTIAL $14k being the normal starting difference. (Bought a whole running/driving 760i with 80k for $2k & my spare motor for $1300 minus alternator literally all within within the last month with receipts. Cheapest N74 around is $11k (Pre taxes) On ebay & 13k Locally... so that old school forum "buy the big engine" mindset is dead".
2a. At that point a proper aftermarket ECU that can do it all can be had (It existing is my issue). As well as knowing you can make stock n74 power with a stock n73 on 93 octane & 700 SAFELY on e85 stock internals. I figured that much would be general knowledge looking at both the basic engine(S) information this is what I meant by "don't have the money" to end up at that point with stock ECU & turbos. I'm far from purist & didn't wanna sound like a douche by saying not "willing to" so I too the less standoff-ish route.
The point of the FI ITB's were just to notate any additional minor fuel need for the NA Application or even meth inj (rather not) etc etc (incase) the injectors from n74 could not be sourced reasonably or could not fit. N74 heads are $4k each fyi

Not concerned about turning a profit, this is for the love of passion; if it takes off cool... No harm no foul it'll exist & ill have on shelf spares rather than 1 off parts I can't replace trackside.

Note: My goal is bout 500 NA with redline raised to 8k Atm with the other stuff mentioned being the longer term goal (fingers crossed) which would be top end pulled off the spare development engine; leaving bottom end up for last.

Either way thanks for your information was certainly appreciated. Semantics Semantics BC Old man Forums XD No goals on proving you wrong just personal goals not forcing anything because racecar on jackstands.
You may keep up with it ahead of time @ProjektCarModz I'll post a build thread within the coming months.