Z5-DE into B5-ZE

[irishkev90]

I was wondering if it would be at all possible to make my Z5-DE into a B5-ZE. I found and compared info of both engines and it looks like all I need is to bore my engine from 75.3mm to 78mm which will take it from 1489cc to 1498cc. 192mL/min fuel injectors and the cams (and gears?) of the B5-ZE.

Those seem to be the only differences I've found, and if I get a 5-speed transmission then the "B5-ZE clone" would make around 123hp. Like I said though, this is only my logic from comparing the info I found on the two engines. I plan to stay N/A, at least for now, so I would also cut back on weight as much as I can and anything else I can figure will increase performance of staying N/A.

I'll probably get flamed or whatever for asking this, but to me this seems possible seeing as the only real differences are the bore, injectors and cams.

[nerd racing]

I believe the heads are different. the B5-ZE is more loosely based on the BP and the B6T. Read old technology versus worse but new technology.

I'm sure the flame wars will start soon, but a good idea none the less!

[irishkev90]

I assume thats's because of the slightly larger cylinders? So my Z5 head doesn't have enough room between the cylinders to bore them an extra 2.7mm? I guess that makes sense, but I just want to make sure I'm understanding everything.

[nerd racing]

yeah it really stinks that we didn't get the B5-ZE here in the states, it would have made for a killer engine power to weight wise for the BHA proteges and other smaller mazda variant vehicles.

[fastmatt1986]

have you seen this?
not the same thing i know but it is obviously the same engine series, and adds a lot of turbo possibilities.

BTW, &%^@

(my flaming, lol)

[irishkev90]

That actually looks like a great idea, if I could find one. I've always been a fan of having something different. However, I read in the beginning that the bore on the Z5 and B6 is the same, then later on someone says they're different. Kind of confusing. Also, since I plan on staying N/A, what kind of internals would I need for high compression? It said that the B6 head would slightly lower compression, not good for N/A. So many unanswered questions, or contridictory answers, but seems like a great idea.

[Beerizfood]

I'll probably get flamed or whatever for asking this, but to me this seems possible seeing as the only real differences are the bore, injectors and cams.[/QUOTE]

Nah, this isnt flame-worthy.Its reasonable speculation.
I think it may be quite a bit of sourcing though .

What i can tell you is that (from what ive learned) is that the 1.6 ZM head from a 99-2000 pro should bolt onto your z5 block .The intake ports on the 1.6 head are huge and there are aftermarket complete turbo setups for the 1.6
as well as exhaust.
What i dont know is if the 1.6 intake will fit in the BH engine compartment.
It should but i havent proven it yet.
This is the path im taking,I hope to get back to it as the weather is getting better up here.

[irishkev90]

I read that thread about bolting the 1.6 head onto the Z5. Seems fairly simple. I'm just wondering what the power output would be. Or could be with a nice N/A set-up.

[Beerizfood]

I read that thread about bolting the 1.6 head onto the Z5. Seems fairly simple. I'm just wondering what the power output would be. Or could be with a nice N/A set-up.

I havent the foggiest what the power would be ,but i assume it cant be any worse then what we have now,The upside is the ability to use a header or turbo, switch to dual cam gears instead of the goofy single system and rattle chain connecting the cams inside the head.Plus those huge intake ports (providing the intake manifold will fit ok)

[irishkev90]

I suppose you're right about the power output.....ok, you're 100% correct, lol. Didn't only some Z5's have the goofy chain set-up and others had dual cam gears? I swear I remember reading something about that, either here, imazda,or mazdas247, can't recall where exactly, but there was a huge discussion about it.

[Beerizfood]

Ya i think the early ones were the goofy chain like mine (96) and the later ones came with dual gears.
Im also under the impression that the cams are all interchangable too between the Z5 and ZM so the next step is to see if there is a cam combination that will aid in making power.

[irishkev90]

I have pretty much all the info for the Z5 cams. I'll see if I can find anything on the ZM. Then I'll let you decipher it because I have no idea how to figure that stuff out, haha.

[irishkev90]

Found a bunch of info on the cams for the Z5 and ZM. Hope it helps somehow. Order from top to bottom is duration, opening, closing, height.

Z5
Intake-
233* @ .003"
1* BTDC
52* ABDC
40.9000mm

Exhaust-
233* @ .003"
48* BBDC
5* ATDC
40.900mm

ZM
Intake-
226* @ .003"
1* BTDC
45* ABDC
41.354mm

Exhaust-
233* @ .003"
52* BBDC
1* ATDC
40.9000mm


Seems like they share the same exhaust cam, just a 4* difference in timing. I don't know how or if this helps, but it's what I found. For stock cams anyway.

[irishkev90]

I'm interested in some stuff again and could use the knowledge of you fine forum members. So instead of starting a new thread, I'm bumping this one because it already has some info that I'd be repeating. Anyway...

As stated earlier, the differences between the Z5-DE (USDM) and B5-ZE (JDM) is the bore (therefore pistons also), cams and injectors.

Section 1: Bore

The bore of the B5 is 78mm. Other engines with a 78mm bore? The 1.6L engines. According to www.protegefaq.net, all of the 1.6L engines have a 78mm x 83.6mm bore/stroke. The stroke is the same as the Z5, 83.6mm. So, in theory, one could bore the Z5 and use any 1.6L engine pistons. Only problem is the compression ratio. The Z5, as well as the B5, has aa 9.4: compression ratio. All the 1.6L engines have a 9.0:1 compression ratio.

So, major questions based on cylinder bore information:
(1) Are there any high compression pistons made for any 1.6L engines? (B6, ZM, Z6)
(2) Would the 1.6L pistons work with the Z5's rods?
...and if not...
(3) Would the 1.6L rods work with the Z5's crankshaft?
(4) Would the cylinder head combustion chamber need to be englarged to match the larger bore of the cylinder?

Section 2: Camshafts

Z5-DE
Intake-
233* @ .003"
1* BTDC
52* ABDC
40.9000mm

Exhaust-
233* @ .003"
48* BBDC
5* ATDC
40.900mm

Overlap-
6*

B5-ZE
Intake-
240* @ .003"
5* BTDC
55* ABDC
40.888mm

Exhaust-
245* @ .003"
55* BBDC
10* ATDC
40.888mm

Overlap-
15*

The camshafts are completely different between the Z5 and B5. Though, according to www.protegefaq.net, the B6-DE (1994-1996) exhaust cam is exactly the same as the B5-ZE. There is no identical camshaft for the intake, however. The B6-DE's intake camshaft would be the closest with a 230* duration instead of 240*. The overlap would be the same as the B5 (15*), but the B6's intake valves would close 10* before the B5's

So, major question based on camshaft information:
(1) Can I use the B6-DE camshafts in the Z5-DE head?
...if not, I could just keep the stock Z5 cams. Would also save money.

Section 3: Injectors

The stock Z5-DE injectors' flow rate is 160mL/min compared the the B5-ZE's flow rate of 192mL/min. The 1.8L SOHC (B8-ME) and the 1.6L SOHC 16-valve (B6-ME) have an injector flow rate of 192mL/min.

So, major questions based on fuel injector information:
(1) Would either the B8 or B6 injectors work with the Z5?
...if not...
(2) Would running larger injectors make the engine run too rich?
...if so...
(3) Would running the stock Z5 injectors make the engine run too lean?

Thank you with putting up with my questions. With the time approaching of taking out the engine and having it redone, my interest in this approach has been re-ignited.

Of course, this all depends on if the machine shop can safely bore the cylinders out that much without causing any trouble, such as cracks in the block between cylinders and the like. And I won't know any of that until I pull the engine apart and take it to the shop.

[bloodyspirit058]

so i'm going to help and hurt at the same time i found some pistons with a bore of 78 mm (since thats the size your hoping to go out to, hopefully there is enough metal on the z5 block) and i came up with some that are for a 1.8L from the 70's (ford 72-79 and mazda 77-78) it was a mazda engine used in ford Courier and mazda b series. dunno engine name as of writing this

EDIT: engine was ub/vb series engine

pistons:
http://www.summitracing.com/parts/UEM-1168-STD/ -set of 4 with wrist pin .866
http://www.summitracing.com/parts/UEM-S1168-STD/ -ea with wrist pin .867
not saying this are a direct swap, with with a domed top you might be able to mix and match rods and pistons and get the compression your looking for, i've talked with the kb service dept before, if you can get ahold of someone, they are really helpful if you want piston specs