MX-3.com

I've seen yet another claim that "True curveneck ZE" engines produce 200 BHP, while "Millenia ZE" engines only produce 170 BHP.

If anything, I would say that the straightneck manifold WITH the KL31 cams MIGHT explain a spread of 30 BHP between the two engines, mainly due to the larger plenum and larger VRIS openings(I've gutted and cleaned both styles of manifold, and can produce pictures if you want to call BS).

If it's true that KL31 cams net 30 BHP over KL01s, why don't aftermarket regrinds put you "True ZE" owners in the 200 WHP range, with no other modifications?

One of you "true ZE" proponents should front me dyno expenses, and I'll swap my own KL01/KL31 cams back and forth between runs to settle this for good.

EGR deleted Millenia engine, for all intents and purposes identical to a "True KLZE", with a chipped ECU thrown in to sweeten the deal.

If the KL31 cams net a 30 BHP difference, I'll give you my entire brake upgrade setup, estimated completion the 20th of January, just for proving me wrong. That is 4 modified MX6 spindles, 5 lug hubs, and massive calipers/rotors both front and rear.

After 3 years of browsing, reading, and posting on this forum... I want this idiotic rumor to die, once and for all. Who agrees?

I don't think the curved neck vs straight neck manifolds make a massive difference. I made 185whp 203fwhp with a 'curved neck' with kl31 cams, ze pistons and ze heads. Will probably try the straight neck dynoed some time too. Though I'm megasquirted with other mods.

I'll take you on your bet, if your dyno results show a gain of any more or less then exactly 30bhp I get your new brake setup


hahahaha

I think your forgeting the fact that only some millenias came with the kl101 ZE heads, particularly the 95 model. Not only that there is also the issue of egr and that true ZE's came in japan where it is most likey they were tested when they were "new" on a higher octane thats available in the states. So you have a combination of more than just cams and intake, but head design, valve and porting sizes, ecu maps, emissions and octane to consider.

Personally for me it has to be from japan to be a true JDM KLZE designation with a straight neck, kl101 heads and kl31 cams for me to consider it a ZE. And again, personally, I dont think the millenia motor should be called a ZE, its like calling your cousin your brother just because your in the same family, theres similarities but who cares?

Moral of the story, take your DE/ZE/G4 or whatever hybrid you have and make the most of it, its what you make of it and a good engine builder can account for a mere 30hp. Or if your that concerned about whp just rip it out and get a BP-t, just ask aaron

Rob, to take the bet you would need to front me the cash for dyno time.

Marco, those numbers are realistic, and don't support the "True ZE" myth. I'm not surprised at all by your numbers, thank you for posting them!

Sleeper6,

A few people have attempted to feed me that "fact" thus far, and none have shown more than text to support it... "Oval port curveneck manifolds" have never been photographed "in the wild". They are the sasquatch of the K series world. Mazda never sold an oval port engine with a square port manifold either. That argument died before it began.

The only oval port "KLZE" manifolds I have EVER seen, were welded up(i.e. CUSTOM) square port manifolds, modified to transition smoothly into an oval port set of heads. One such manifold is for sale on ProbeTalk currently. THESE MANIFOLDS ARE VISIBLY CUSTOM, AND YOU CAN TELL WITH CLOSE INSPECTION THAT THEY WERE MODIFIED.

What makes a KL a KL? KL block. KL heads. KL manifold. That's over-simplified, but you get my point I think...
Millenia vs. "True KLZE" block, identical. Same crank. Same rods. Same pistons.

Millenia vs. "True KLZE" heads, identical(save the cams, and supposedly the cam CAP shape in later Millenia models).
The variations between heads that are DOCUMENTED, and not FANTASY, are the following:
- Valvespring shape, diamond vs. rounded. This was changed later in the series supposedly. I have found no substantiated claims as to effects on seat pressure, valve float reduction at high RPM use, weight, or anything else notable. The diamond shape "bit into the retainers", causing "premature wear", and dropped valves.
- Retainers, claims have been made(sensibly so) that later years of the Millenia KL(tied in with ValveSpring changes, supposedly) came with more durable retainers. Likely an offshoot of the "diamond vs. rounded" VS debate.
- Camshaft profiles, The lift profile of the KL31 camshafts is slightly different than the KL01, and the duration is noticeably longer. Example:
KLDE cams and KLZE cams have the same cam profile for intake and exhaust.
KLDE cams have 244deg. @ 0.004", 196deg @ 0.050", 67deg @ 0.300". Max. lift is 0.338"
KLZE cams have 246deg @ 0.004", 200deg @ 0.050", 84deg @ 0.300". Max lift is 0.350".
Quoted directly from http://www.davidandjemma.com/mazda/KL.htm, the website of our very own David Coleman. Many of you remember his name, no doubt.

Let's use your cousin/brother metaphor real quick.
I'm 5'10, 165 pounds.
Let's pretend I have an identical twin, with slightly more or less muscle mass than I, nothing else differentiates our appearances and physical ability.

Now imagine my twin and I follow the exact same exercise/health regimen for 6 months. We are effectively "identical" in every way at this point.
Would you say we aren't identical, because at one point, IN THE PAST, we weren't? -.-
There's the argument against a KL31 cam swapped Millenia engine for you. We may as well say my '92 is red, because the factory color is the only one that could ever grace her panels. Check my signature for verification of that.

If having a "True ZE" is about bragging rights, then those who own them should brag about battling sleazy importers for months to find a quality engine, worth dropping into their car. They should do so without spreading any more misinformation and bad numbers.

This thread exists for one simple reason. No living person has yet to explain(scientifically, not with 3rd/4th/5th/6th/etc. party hearsay) why KL31 cams/lack of EGR supposedly make a 30 HP difference over KL01 cams/EGR.

One final note Sleeper6,
The Millenia engine is IDENTICAL to the "True KLZE", minus the EGR and KL31 cams. This is established fact, backed up by more than a decade of photographic evidence in the form of worklogs and build threads, not to mention earlier attempts by others to do exactly as I am now doing.

Nobody takes into account exhaust size, ECU selection, VAF selection, or octane ratings when they bandy the term "True KLZE" around loosely, advising others to spend exorbitant sums of money to buy from an importer, because they don't know any better. How many of you did exactly this, only to later realize you could have had the same engine for half the price, and inspected it yourself, without a sleazy importer trying to rip you off? - All it would have taken was a $500 TOPS engine, and $100-125 for KL31 cams. Minus the saltwater boat ride, of course.

Did the Japanese MX6 make more power than the American model Millenia? YES!

Did 30 BHP come from KL31 cams and the lack of an EGR? NO!
Any realistic, genuine difference came from a combination of factors, far broader than the 2 that are loosely bandied about in an effort to brag.

mrmazda92 you seem to have missed my point, I am not arguing against what your saying just against why your trying to prove something this trivial. If you want to know the real difference its simply in part #s.

MrMazda92 wrote:
What makes a KL a KL? KL block. KL heads. KL manifold. That's over-simplified, but you get my point I think...
Millenia vs. "True KLZE" block, identical. Same crank. Same rods. Same pistons.

Again I will agree with you, a KL is a KL, hence why my car is running a KLDE and not a KLZE. However I believe your argument was about the more important KL designation and what makes it a ZE/G4/DE. The difference is in the cams and heads and valves and lifters (solid vs hydraulic). Does it really matter? No.

I read the whole thing and still don't fully understand whats so big about it all...

This is what I understand... You are wondering why you can't take a north american millernia KLDE install KL31 cams.. Run an chipped ecu for a KLZE and make fairly close to straight neck KLZE power?? maybe 5 - 10hp less due to the differences in the intake...

Why does everyone put up a big stink about getting a straight neck ZE and thats the only way you'll make the "big" power??

My thoughts on the whole post....

You seem to forget about the pistons and higher compression in all your talking.... I don't think the intake manifold and the cams make up the 30hp difference... Toss in compression ratio and tunning into the mix as well as the intake manifold and cams, now you have your 30hp difference...

With a clean fresh motor your EGR valve does nothing to take away power... It doesn't matter if the car has an EGR valve on it or not...

Entirely likely... I'm sorry that I snapped at you man. I've been a bit short tempered after the negative experiences in December on this board... It's easy to forget sometimes, that real people are behind the forum handles... *Deflates a little* I'll try to keep it more mellow from here on out.

The only argument that I see propagated by nearly everyone who "talks the KL talk" is the "Real ZE vs Millenia ZE" argument... They are comparing a luxury vehicle equipped with a 95% identical engine to a sports coupe with 30 more horsepower at it's disposal.

The problem I see is simple... Many of us can see this right off the bat... The Millenia engine is almost IDENTICAL to that of the Japanese "KLZE". Effectively, it IS a KLZE with KL01 cams and a federally mandated EGR system.

If you took the "200 BHP KLZE", and bolted it into an equivalent Mazda Millenia... You would not see 200 BHP. Period. You would be damned lucky to see a bump of 30 BHP going from KL01 cams to Colt 218s with $500/hour professional tuning, on an otherwise stock engine.

This is what people should be thinking about. I've tried to find these answers, and been frustrated with little luck:
What size exhaust does the Millenia run, with a KLZE equipped?
What size exhaust do the Japanese MX6(and other J-spec KLZE equipped vehicles) run?

What resonator/muffler combo does the Millenia KLZE come equipped with?
What resonator/muffler combos do the J-spec KLZEs come equipped with?

Factory spark timing advance for the Millenia KLZE?
Factory spark timing advance for the J-spec KLZEs?

How far does the factory ECU retard the timing when knock is detected for the Millenia KLZE?
How far does the factory ECU retard the timing when knock is detected for the J-spec KLZEs?

Which spark plugs are used in the Millenia KLZE?
Which spark plugs are used in the J-Spec KLZEs?

There are more questions that could be asked as well, this is far from an exhaustive list...

crazycanadian wrote:I read the whole thing and still don't fully understand whats so big about it all...

This is what I understand... You are wondering why you can't take a north american millernia KLDE install KL31 cams.. Run an chipped ecu for a KLZE and make fairly close to straight neck KLZE power?? maybe 5 - 10hp less due to the differences in the intake...

Why does everyone put up a big stink about getting a straight neck ZE and thats the only way you'll make the "big" power??

My thoughts on the whole post....

You seem to forget about the pistons and higher compression in all your talking.... I don't think the intake manifold and the cams make up the 30hp difference... Toss in compression ratio and tunning into the mix as well as the intake manifold and cams, now you have your 30hp difference...

With a clean fresh motor your EGR valve does nothing to take away power... It doesn't matter if the car has an EGR valve on it or not...

I am wondering nothing. Read my newest post, I believe it was far better explained than my previous ones.

For what it's worth, the Millenia KLZE has the same heads, block, crank, and intake as the "True KLZE". This means identical static CR. I "forgot" nothing.
Looking at ONLY THE ENGINE, the differences are limited to KL31 cams and EGR. Period.

If people said "The J-Spec MX6 produces 200 BHP, and the A-Spec Millenia produces 170 BHP", they would be giving honest information. Stuff a "Real KLZE" into a Millenia, changing nothing else, and you will see maybe 185 BHP.

The only way to truly find out the exact number is to put the engine on an engine dyno instead of putting the car on a chassis dyno. That way, it eliminates drivetrain loss, variances in exhaust size and you could easily find out if there is a difference between EGR on and off. That is usually more expensive and takes more time for set up and break down, but it also makes it much easier to experiment with timing, spark plug gap, even changing cams and intake.

That is exactly what I am saying.

However, the exact same car with a Millenia engine, and EGR deleted would be 95% there.
I also have both KL31 and KL01 cams at my disposal, so swapping them would effectively make it a "real KLZE".

Same exact engine. The claim has always been that the ENGINE produces 200 BHP. Never mentioning any of the ancillary equipment, because doing so would invalidate the claim that they have a 200 BHP MX-3 after nothing but a KL swap.

It's always been about bragging rights, never fact.

I don't care enough to do the looking...but I'm fairly sure that there are different pistons, with different compression ratios between the North American Millenia 2.5L and the J-spec Straight or Curved neck ZE.

A 30hp increase from 170hp in what is essentially the same engine can only be explained by compression. If you want to spend some time and energy on this you should spend it verifying compression ratios.


EDIT: OK I looked...
Club323F.com has the SAE paper posted which states that the compression ratio of the ZE is 9.2:1
http://www.club323f.com/?page_id=443

This Australian artical says that the ZE was manufactured with 10:1 compression but makes no mention of the North Americal models it appears in.
http://autospeed.com.au/cms/title_The-M ... ticle.html

It is clear that engines called "ZE" were made with different compression ratios. Combine that fact with the affect of a sharper cam with longer duration and you can easily explain an additional 30hp at the flywheel.

ZE's were 10:1, DE (K8 too) is 9.2:1. late model ZE's went down to 9.5:1

Also remember; These are old engines, and can lose HP, depending on a lot. You could dyno 2 exactly same curve neck ZEs, and get very different numbers. My take on the whole thing is: rebuild an engine with the best parts you can afford, that work best together, according to your research. A decent engine builder can get +30HP, just by paying attention to detail.

Y U NO Research compression with all UR Faq's