the new legend

Hello everyone marry belated x-mas and whatnot. I'm just about done with my parts research. So, it's almost time to buy parts. I hope I can start ordering parts next week. Anyway, I've spent a week looking up cam info and I am still not 100% on what I'm get.I am still in between 256,264 kelford cams So...in the mean time, I was planing on swapping in a diff. cam from some other b6 motor for a temp. upgrade but I haven't been able to find the spec for any oem cam but the miata 1.6l.
Question:

1. Do anyone know the duration @0.050 of any 1.6l b series motors( mazda mx-3 b6 dohc, 1.6l us gt-x,mercury capri xr-2 and any others I don't know)?

2. Is there a common oem swap that i may have over looked?

Thanks in advance. Sorry if this info is here and I haven't found it.

the new legend

This is the info im going off of:
The best measurement for comparing camshaft size seem to be duration. Duration values expressed at .050" lifter rise state the exact point the measurement was taken. (Lift is the distance the valve actually travels ex: 9mm)These are the only duration figures that are consistent and can accurately be used to compare camshafts size. Duration is the deciding factor to what the engine's basic RPM range will be
The camshaft's basic RPM is the RPM range within which the engine will produce its best power.

the new legend

When selecting a new camshaft, you can raise or lower the engine's basic RPM range. It is important to be sure the drive train is capable of matching your selection. The cruise RPM at 60 MPH is a way of rating your rear end gearing and tire diameter to determine if these components match the RPM potential you are desiring
when i did the math its looked more like a rpm number(clearly i was not paying any attention to what i just read...right). then i checked a cam manufacture specs specifically kelford cam it was the middle of the new power band or basic rpm.So,

the new legend

What i got from that is:
divide duration by 0.050 (d/0.050=the center of engine new basic rpm range lets call this cbrpm)to find the center of the engine's basic rpm range.
torque more or less kick in 2000rpm before said value and end or don't grow much more at the number stated.
hp more or less start at number given and end or stop growing much about 2000rpm later.

every digit on the duration move the rpm up or down 20rpm
so instead of dividing by 0.050(d/0.050=cbrpm ) multiply by 20(dx20=cbrpm )
so for ex: stock miata exhaust cam duration 204 @ 0.050
so...
204 x 20 (or / by 0.050)=4080(cbrpm)
the start of the torque power curve is minus 2000 so...
4080-2000= 2080
(make me wonder if i need to be launching my miata near that rpm)
the start of the horsepower power curve is at the new cbrpm but end 2000rpm later so plus 2000 so...
4080+2000=6080
(no wounder that's why i don't feel much or shift in that last 1000rpm there no extra power just more rpm ...1.6l miata's rev to 7200rpm)

this is me summing up and guessing sorta i could be way the f@#$ of I think all of you may be more knowledgeable on this

Leafy

iTrader: (1)

You want 99+ miata cams to swap in. You also want the entire engine to go along with the cams.

pdexta

iTrader: (17)

The miata community as a whole really doesn't typically do cams. I doubt you'll find a OEM cam that's going to get you any power that would be worth removing the valve cover for. The gains vs cost just don't make cams a reasonable option for all but the most extreme builds.

Like Leafy implied, for the cost of aftermarket cams you can come pretty close to buying an entire BP-W4 motor that's a much better motor all around.

18psi

iTrader: (76)

Its because our old engines don't flow worth a crap, and don't rev worth a crap, and making them do both those things requires a very healthy chunk of change.

Anyways OP like these guys say stop stressing tiny pathetic gains and just focus on something significant like a NB engine swap

Savington

iTrader: (31)

Yes. Any 99+ BP 1.8L motor.

the new legend

I was keeping the 1.6 just to try things out in. I'm going to transplant all 1.6 upgrades to my gt-x before i get rid of that motor. I was planning to swap in a 1.8 at some point. It just trip me out that every one is so hell bent on the 99 head and motor is it the best of all the 1.6-1.8? Is the 99 even better than the msm 1.8? The msm was the 1.8 I wanted to swap in.

codrus

The MSM motor basically *is* a 99 motor. Minor differences in the intake manifold and intake cam, some rumors about shot peening of rods, and a crinkly-red valve cover.

--Ian

tpwalsh

This. I've poked around and the MX5 motors have the most lift/duration that I've seen on the B6 motor. I'm interested in what aftermarket solutions you find since I'm limited to the B6 due to my class.

Leafy

iTrader: (1)

Can you head swap one of the Z engine heads on with your class. Theres a thread in the build threads that looks really interesting.

tpwalsh

No head has to be original to the car(or on the same line). The block can be alternate, but must be of the same material. I have wondered though if it would be worth the 200lb penalty to go with the 99 motor. I think to make it work you'd have to be over 200hp (see relevant 949 thread)

I did look at that ZM head and it looks to be a good one, if that cam could be changed out for something that doesn't look like it came out of an RV, and a new intake manifold that doesn't point into the firewall, it would be way better than the B6. OTOH there are WAY better motors out there than the B6/ZM hybrid if I bumped up to XP. KL, F20c, 1.4T Ecotec all come to mind with various advantages and disadvantages.

the new legend

I was told that the stock miata intake cam is 192 @0.050 lift. The stock miata exhaust cam is 204 @0.050 lift. I could be wrong but I think hommie said get a extra exhaust cam and swap out the intake cam so you'd have two 204 cams. i think it should be a 10hp swap, again could be wrong. I'd have to check miata.net again to find out. There could be different cams though out the whole b series line but im not shur where to find the oem spec at 0.050 to even check. I know you can swap in gt-x ,mx-3 and capri cams but i don't know the specs to know if there is any benefit. I have to disagree with Mr. 18psi tho. A little power here and a little power there still add up to more power. Me... I'm a get it wherever I can.

18psi

iTrader: (76)

The first thing you should do is take some English, grammar, and punctuation classes so you don't sound like a complete and utter moron hoodrat on the internet and can effectively communicate with other human beings.

concealer404

iTrader: (3)

I'm wondering exactly what MX3 cams you're going to swap in.


Based on that little statement, i'm guessing that you don't actually know anything.



[edit]

Ok i did a little more research and it seems that later MX3 RSs DID come with a DOHC 1.6 that made a ground pounding 106hp.

Woo.

I mean really... da fuq.

Impuls

iTrader: (1)

VICS(99-00) vs VTCS(****)
Tell that rumor of shot peening to my MSM rods.
THE VALVE COVER SAYS TURBO ON IT!

iantboyd

iTrader: (11)

While that is true there are still some possible issues with the mx3 cams. Its b6 dohc engine is a bit of an update compared to the one in the miata and 323 gtx. The distributor drive is on the exhaust side, much like the 1.8, in the mx3. The other 1.6 variants have an intake driven distributor. The only thing I can assume is the cams are identical and can be swapped from intake to exhausts no problem. Or he is using the mx3 head.