The Dunklenator (Poor Man's Z8 Project)

[Cos270]

Call me pessimistic but looks like a valve cover gasket replacement would be engine-out work...still looks like a cool build if you can pull it off!

[BimmerBreaker]

pics or it didn't happen :p

Pics of anything in particular? Theres a longer writeup here as well: https://www.ascfabrics.com/post/_z3v8

Call me pessimistic but looks like a valve cover gasket replacement would be engine-out work...still looks like a cool build if you can pull it off!

Haha, so itll be just like any factory car with an N62! ...they were not known for having lots of space to work. Note the valve cover trims here. They arent broken. They are designed like that because of how tightly it fits in the E60 it came out of





Plus, if I can put it in, I can take it back out

[kolosy]

weird -- they weren't showing up before. sweet!

[ProductUser]

Are you going to address any of the engine's problem area(s) before the final install? Assuming this engine, like most, has a list of problem areas.

[BimmerBreaker]

Are you going to address any of the engine's problem area(s) before the final install? Assuming this engine, like most, has a list of problem areas.

Of course - before final installation I will do a basic gasket reseal plus a new clutch kit and address this engine's problem areas - notably the valve stem seals, coolant pipe and alternator bracket gasket o-rings. Ideally I would find a good 4.8L from a 550i or 750i to use instead of the 4.4L but waiting on a few sellers to respond...

[ProductUser]

Of course - before final installation I will do a basic gasket reseal plus a new clutch kit and address this engine's problem areas - notably the valve stem seals, coolant pipe and alternator bracket gasket o-rings. Ideally I would find a good 4.8L from a 550i or 750i to use instead of the 4.4L but waiting on a few sellers to respond...

Gotcha.

[amancuso]

Valve Stem Seals already done? If not do them now.

[BimmerBreaker]

Some solid progress today. Lots of uncertainties have been confirmed... Pics soon

[BimmerBreaker]

ABS lines done





M54 Z3 A/C compressor mounted on N62. Rear bolt needs a spacer and longer bolt but otherwise fits and belt lines up properly





Transmission crossbrace - hodgepodge using parts from other BMW models. Nothing was modified. Bolts on directly





Trans is in it's final place so engine height is set to determine driveline angle







Oh and the hood closes!



Stock steering linkage seems like it has ok fitment... the stock headers merge in the middle and hug the block... heading down to oil pan, before moving rearward. Hopefully going down, then behind the steering rack!





One bad thing... with the engine in place, I couldn't fit the alternator... I am hoping this means installing the engine with the alternator installed, not notching the framerail, but I am open to whatever gets this show on the road...

I will also have to notch the rear of the stock subframe very slightly. But the good news is, the stock control arms and steering rack will be in the stock locations. No subframe spacers or anything like that, I am just not a fan of those personally. I don't want to compromise the suspension feel of the Z3 in any way...

[amancuso]

Sweet. Since you can't deal with the alternator with the engine in the car, also take care of the Alternator bracket gasket!

[nevan]

Following... I can tell that this is going to be an awesome thread.

[IndianaRoadster]

Keeping up also. Looks like it's going to be a fun ride, nothing like getting slammed back in the seat when putting the pedal to the metal!

[BimmerBreaker]

I have events planned this weekend with friends and family and im just thinking that I want to be at my shop. I could figure the alternator situation out or start the wiring or start the manual swap stuff or...
Bah, its ok. Couple days off cant hurt I guess

Sweet. Since you can't deal with the alternator with the engine in the car, also take care of the Alternator bracket gasket!

What about coolant pipes? Do those too?

Following... I can tell that this is going to be an awesome thread.

Keeping up also. Looks like it's going to be a fun ride, nothing like getting slammed back in the seat when putting the pedal to the metal!

Im mostly just excited to hear that V8 rumble with the top dropped and feel that amazing throttle response from the N62. Really excited to feel the N62 power in a smaller chassis too. I have been alternating daily driver duties between my N62 powered X5 and my Z3 3.0... trying to imagine what the N62 will feel like in the Z3 lol

[Cos270]

Looks like you're making great progress! This will be like a home-brew Z8 when you're done with it. Hope you're planning on making some heatshields for the engine mounts since they're going to be right next to the headers. I'd also look into swapping the steering linkage for the E34 variety, since it's all metal. Not sure if it drops in on the Z3s, but it's a common swap on E36s.

[BimmerBreaker]

Looks like you're making great progress! This will be like a home-brew Z8 when you're done with it. Hope you're planning on making some heatshields for the engine mounts since they're going to be right next to the headers. I'd also look into swapping the steering linkage for the E34 variety, since it's all metal. Not sure if it drops in on the Z3s, but it's a common swap on E36s.

Exhaust side mount already has a heat shield, and even though the V8 headers actually sit farther from the mount than the stock headers, I will be using the heat shield and also adding one to the other side. And yes, this is my poor man's Z8 build
E34 steering linkage won't fit - firewall to subframe distance is different on E36 vs. Z3's. That means if I was doing this swap on anything BUT a Z3, Id be modifying the firewall so sit the engine where it currently is (which is mostly pre-determined based on trans location, which bolts on using OE BMW parts)

I will either run the steering linkage flipped - so the rubber puck is against the firewall (anyone know why running it like that would or wouldn't be ok?) or build a heat shield around it. I would prefer to keep the stock linkage, as most of the aftermarket options (except that $400 one) don't have any provisions to crumple in an accident.

Earlier today I went ahead and ordered a new engine harness - not sure if I mentioned it before but this one was damaged, a few wires were cut. So a new engine harness is on the way and I also ordered the Valvetronic DME.

I've been looking for viable parts cars but it seems like just enough changed between 4.4 and 4.8 (technically the later ones are N62TU models, I didn't even know the N62 had a "TU" before researching into all this) that some of my research wouldn't apply as readily. And if I already had a 4.4 on hand I didn't see a point in sourcing another (although I am still on the lookout for one for the right price... have my eye on a crashed 80k mile 645i, that'd be awesome in my 86k mile chassis!). I am also not sure if sensors changed between TU and non-TU, and engine harness compatibility becomes a concern at that point. At any rate - I am committing at this point to running this as a 4.4 - but I'm going to keep doing research as if this works out I would like to build more, eventually I'll figure out how to get a 4.8 installed (with the fancy DIVA intake... most "TU" motors switched from the DIVA intake to a 2-stage DISA which isn't as cool).

So 333hp and 450n-m of torque on the stock 4.4

Now let us take a little detour from the sane world, into my brain of deductive logic and half hearted reasoning...
AKA I saw a dual intake 750 the other day and was like "Hmm" then spent the past 40 minutes today trying to apply incoherent logic to gratuitously rounded data. Yay

Please note, the below is a lot of "hopeful" logic based on assumptions - the biggest assumption of all being that BMW stated their power figures somewhat accurately. BMW has been known to round by amounts way larger than my threshold of accuracy below. However, the core of the logic is sound as long as the reported numbers are somewhat representative of these engine's power differences in relation to one another. AKA the numbers and %'s I give may not be accurate, but as long as the numbers BMW provided are somewhat accurate themselves (ie. engines they claim make less power do in fact make less power) then the logic is sound, the specific numbers may not be though.

I am talking about two things below - the DIVA vs DISA intake and the dual intake from the 750
Dual intake 750i (2006-2008)


Source for these power figures HERE
Stock 745 (4.4) makes 333/450 with the DIVA manifold and single intake
Stock X5 4.4 (4.4) makes 320/440 w/ the DIVA manifold and single intake
Stock X5 4.8is (4.8) makes 360/490 w/ the DIVA manifold and single intake
Stock 550 (4.8) makes 367/490 with the DISA manifold (not DIVA) and single intake
The 750 (4.8) makes 367/409 on paper with DISA and the dual intake pictured above (either the dual intake didn't do anything or BMW didn't care to publish different results for something that was probably within 1-2% of the power of the others)

Some observations - it seems the X5 version is the least powerful (likely due to the restrictive exhaust manifolds on the X5 vs. other models)
The same 4.4 engine and same DIVA/single intake setup in an E60 545i made 12hp an 10tq more than that same 4.4 setup in the X5. This represents a 4% increase in HP and about a 2% increase in torque. I use percentages instead of raw numbers for comparisons, because power differences are a factor of overall power, as opposed to net numbers.

What I mean by that, is if 545:X5 4.4 is a 4% difference in power, I expect a 550:X5 4.8is to have a similar difference in power if equipped the same. However, the TU motors dropped the DIVA intake so direct comparisons are not available (for cost reasons most likely, as the DIVA was the only production intake manifold in the world with a continuously variable length intake manifold and it was expensive to produce and hard to package).

Some deductive reasoning here...
The X5 4.8is if equipped with the DISA and single intake (same as the E60 550i) should make ~4% less hp and ~2% less torque than the E60 which makes 367/490. This would mean about 350hp and 480 tq. But the 4.8is has the DIVA intake, which gives it +10hp and +10tq over those expected figures, as it makes 360/490. This represents a gain of 3% in HP and 2% in torque with the DIVA intake compared to the expected values. So lets say the DIVA intake manifold adds 3%/2% over the DISA manifold.

The most powerful version of the N62 doesn't use the "best" intake manifold (the DIVA manifold). Nor does the best DIVA-equipped engine come with the cool 750 dual intake design.
Its hard to say what the dual intake system actually does as for power as it isn't rated at any more than the 550 and 650 which have a single intake box. Though very large, these single intake boxes can't possibly flow as much as the dual setup


I added this image merely to break up the wall of text. But this is a diagram of a DIVA intake. Oooh, aaah

My thinking is eventually I will use a 4.8L (the ones making 367 and 490 tq) then add a DIVA intake AND the dual intake setup from the 750 to make the ultimate N62

The stock DISA 4.8's make 367/490. With the DIVA increasing these figures 3%/2%, we get to 378hp and 500n-m. Assuming (for no reason whatsoever, other than I want it to be true) the 750 dual intake adds another 1%/.5%, we get to 381hp and 502n-m of torque using my fudgey math

Lets use an alternate method to try to determine the numbers - we determined earlier the E60 makes 4%/2% more than the X5 chassis. The X5 4.8 with DIVA made 360/490. A 4%/2% increase gives us 375hp and 500n-m

Both the above methods got us to almost the same figures - 375/378hp and 500n-m with a DIVA manifold and single intake
As such - I think its fair to realistically expect around 375-380hp and 500n-m of torque out of the N62 4.8 with DIVA and dual intake

For now though, on this swap with the 4.4, I'll be making due with a mere 333hp and 450n-m

Some points of comparison:
S62 394hp and 500n-m
N62 367hp and 490n-m (4.8 stock)
S65 414hp and 400n-m
N62 333hp and 450n-m (4.4 stock)
S54 315hp and 341n-m
M62 282hp and 440n-m
S52 240hp and 320n-m
M54 228hp and 300n-m (3.0)
M52 168hp and 245n-m (TU 2.5, what I took out of the Z3)

Also note how the S65 kind of stands out a little bit? I've said a long time that I prefer the S62 over the S65 and those figures are why. The S65 is definitely more fun around a track, but with 100n-m more torque, the S62 is better everywhere else. You also have to rev the S65 to the moon to make power... that just doesn't fit my driving style. I'm really more of a cruiser - drive slow, enjoy the scenery. The torquey N62 should compliment my driving style very well.

By the way, if anyone is curious why I love the N62 so much and it's "DIVA" intake manifold (or you are just wondering what the hell a DIVA is because you thought that was a term for a famous female singer) I wrote about it a bit here: https://www.ascfabrics.com/post/intake

Also - I will be ordering a 750 dual intake setup to try to retrofit on this 4.4 as well. So that may be good for a few extra ponies as well. 333hp? Ha! More like 335hp!!!
Honestly I just think the dual intake looks cool as hell too and will look especially nice under the Z3 hood if I can make it fit

[rf900rkw]

COUGH COUGH COUGH n74 COUGH COUGH COUGH COUGH 535hp COUGH COUGH 750nm@1500 Cough....


excuse me, sorry for the interruption.Carry on.

[SchnellZ3]

COUGH COUGH COUGH n74 COUGH COUGH COUGH COUGH 535hp COUGH COUGH 750nm@1500 Cough....


excuse me, sorry for the interruption.Carry on.

Do you need a lozenge?
Yes N74 is best over other choices. Many BMW V8 have problems but fun.
This plan for unusual not best reliable power I guess.
Otherwise add boost to reliable 6 cylinder.

[BimmerBreaker]

The V12 would add a lot of weight to the front, plus an enormous trans and no manual option that I am aware of. Also with an engine that big and with such enormous cooling requirements (as Im sure you know Randy, horsepower = heat) I dont know where youd fit the radiator since the whole engine bay would be taken up by the enormous engine

Edit I also just read the N74 doesnt have Valvetronic. Booooo!!!!

Also the N62's reputation for being unreliable is, imo, poorly earned. It will smoke and leak but it will smoke and leak pretty much forever. It doesnt have a "kiss of death" in the same way all the other BMW V8s do (M62 timing chain guides, S62 rod bearings, S65... Where do I start). Plus as I mentioned earlier I will be addressing all of it's main problem areas.

I will say - along the idea of the N74... N63/S63 seems like it may actually fit in a Z3 with very minimal modification. I have enough clearance to see the top of the trans, few inches of clearance between firewall and rear of engine/trans on all sides. I could see a couple turbos fitting easily where the massive DIVA intake is and the downpipes squeezing in between the firewall.

As far as weight vs. power I prefer the N63/S63 to N74. If this swap actually works out... Maybe ill try something like an S63 swap down the road. Maybe ill try it in something like an E53 first though. S63 RWD E53 with the ZF 8 speed sounds fun

Wiring is done now, at least most of it. Still need the wires for electronic pedal and some for IVM. Pics later

[z3forlife]

It looks like you’re going to have this done in pretty short order. I’ve been waiting to hear something on the M6 V10 swap but he must be held up on finishing his wiring.

[BimmerBreaker]

You are gonna jinx me man

[z3forlife]

I have faith in your determination.

[BimmerBreaker]

Thanks. I am just trying to put one foot in front of the other with this swap and keep things moving...

Wiring...





Printed some nice little tags at home to label the changes I was making all neatly





Then realized on some tags I should have printed two labels, as the other side needs to be labelled too - like for the lower radiator hose coolant sensor signal/ground... so I wrote some ugly ones in sharpie. I made a ton later too, when I realized I had completely not accounted for an entire set of 4 harnesses... lol





Also a big thanks to Randy, for answering my questions about CANBUS systems! There were four CANBUS lines on that IVM which seems really weird - usually you only see two CAN lines running into modules/DMEs, but I think it's been figured out... at least for the most part

Before leaving for the day to go home and research IVM wiring stuff, I hacked the cats off the headers and test fit them



No dice quite yet...



O2 sensor was in the way. Going to try again tomorrow after removing O2 sensor and lifting engine a little bit



Also stumbled across the above diagram while looking for some other stuff for the N62 electrical system and couldn't help but notice... the #2 looks like a smaller alternator? I wonder if that would fit in the framerail as it is. Currently researching what engine/model this came on (was grayed out so no part number available). It did just occur to me that the European market got a smaller displacement N62. Maybe I should start there...

[rf900rkw]

Heat is a function of power and time. Typical cars of a N74ique conversion clan have plenty of power, but no time... being driven only the short distances of on to and off of the trailer and on to the dyno.

[BimmerBreaker]

I was anticipating a low RPM joke but thats even better. Well said haha

[cyberman]

By the way, if anyone is curious why I love the N62 so much and it's "DIVA" intake manifold (or you are just wondering what the hell a DIVA is because you thought that was a term for a famous female singer) I wrote about it a bit here:

Thanks for that write-up, you moved my understanding of these engines, and their evolution up a couple of notches. I'm following this thread with interest and awe. Wish I had your knowledge and about 30 years less wear on my body.