In-depth discussion on KF-ZE

[IanL]

The EGR system is for reducing Oxides of Nitrogen (NOx). The cat also does that. I know that the test in the UK does not include NOx measurement; may apply elsewhere.

[lakersfan1]

Originally posted by IanL:
The EGR system is for reducing Oxides of Nitrogen (NOx). The cat also does that. I know that the test in the UK does not include NOx measurement; may apply elsewhere.

Most US states do test NOx.

[Mnemonic]

well most engine importers import engines from japan and not europe, so its pritty safe to say your gonna get the 170 hp kf but there are 2 versions of the kf in japan as well (well there were many versions like the klze) there was one that only had 165 hp

[UrBaNsTyLe55]

yup mnemonic is right and i believe the engines difference between the kf 165hp and 170 is a question yet to be answered since many importers say the engine has 165 and other say 170 both at 7000rpm, so for those who have this engine don't be scared to redline her, the best way to find out is to just dyno your car and see, as for the egr like i said i couldn't answer it since i'm not runing an egr or cat, if you wanted the egr you can simply just use the probe or mx6 intake manidolf since the runners are the same its an easy bolt up, its the manifold i'm using on mine,

[tatsu]

I did a bit of research on this a while back. The difference between a K8 and a KF is the bore (piston) size - 75.0mm for K8 and 78.0mm for KF. That bore gives the KF 1995cc of displacement.

From what I could find out, the difference between the KF and the KF-ZE was higher compression pistons and more aggressive cams. The IM and throttle body were the same. I think it would likely be very hard to tell externally what you have. As far as I could figure, the 165 hp and 170 hp motors are actually the same - it was just varying conversions done from PS to HP. In Japan, both the KF and KF-ZE motors were sold, so even if the motor is from Japan, it might not be a ZE...

The K8 ECU should be able to compensate for the increased displacement with added fuel, because the way the VAF works (IIRC) is like how the KE-Jetronic plate works on older VW's - if it sees a greater volume of air going past, it adds more fuel. I would think there is probably enough leeway built-in to deal with an 8% increase in displacement/power, but it may not be optimally tuned.

What would almost certainly be (at least slightly) different would be the optimal VRIS points, as the resonance characteristics of the 2.0L would probably be different from the 1.8L. With the stroke being the same, though, it might not be that far off...

What I want to know is: Can a K8 simply be bored out to 78.0mm, and have a set of KF-ZE pistons installed? I'm thinking about going that route with our GS...

<small>[ March 24, 2004, 02:39 PM: Message edited by: JP ]</small>

[lakersfan1]

Originally posted by JP:

What I want to know is: Can a K8 simply be bored out to 78.0mm, and have a set of KF-ZE pistons installed? I'm thinking about going that route with our GS...

From what it looks like with the cost of importing raw parts for the KF, I think that'd be prohibitively expensive, and which point you might as well just buy a whole KF-ZE engine. They're only going for $400-$500. One place online even says they'll include the ECU for the $500.

[Custommx3]

Just get the engine... I picked mine up on ebay for 102.50 plus shipping. (and no im not braging Im just saying its more cost effective )

[lakersfan1]

Originally posted by Custommx3:
Just get the engine... I picked mine up on ebay for 102.50 plus shipping. (and no im not braging Im just saying its more cost effective )

I know. I'm hoping to luck out. There is a clean *** looking one on eBay I was hoping to get cheap (but shipping would have been $375 U.S. on top of auction end cost). I would have still taken it if it went under $200, but I think it's over $450 with a day left. But seriously, if anyone's in Toronto and needs a new engine, check this out:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=33615&item=2468035027&sspagename=STRK%3AMEBBI%3AIT

<small>[ March 24, 2004, 04:40 PM: Message edited by: lakersfan1 ]</small>

[UrBaNsTyLe55]

well i got my engine from a shop out here called alljapaneseengines.com i got mine for 450 and that thing was spotless even internally and runs nicely i've had no problems,i've heard that the k8 ecu works nicely on the kf-ze, i don't know for shure since i haven't tried it, i was thinking of maybe using that ecu, but then again my kf-ze runs nicely with my kl-de ecu as well, and i was thinking with the different fuel mappings that the kl-de ecu might be better for me when i go turbo, or would the k8 be, thats a questions i'm still stuck on

[mrspanky79]

the kfze is rated at 165-170hp and the kfde is rated at 145hp. And the k8 dos not use the kf parts the kf motor uses k8 parts mazda biuld the k8 first then made the kf and kl off of that platforms. The goal was to make the smalls v6 and other motors came from that have you ever wondered why all the motors have the same size ports and exhaust manifold the only one that is different is the intake ports on the klze.

[Mnemonic]

Originally posted by mrspanky79:
the kfze is rated at 165-170hp and the kfde is rated at 145hp. And the k8 dos not use the kf parts the kf motor uses k8 parts mazda biuld the k8 first then made the kf and kl off of that platforms. The goal was to make the smalls v6 and other motors came from that have you ever wondered why all the motors have the same size ports and exhaust manifold the only one that is different is the intake ports on the klze.

he is right, but not 100% the intake valves that mazda sales are for the KF (trust me this i know)
but most interals are the same, mainly the difference is the bore, the cams, and the heads are different, me and barry both have a kf and we have different heads, dont know what that means, but we have different heads.

[mrspanky79]

just because the valve has kf marked on the bottom dosnt mean they are from a kf motor. If you go throw the motor you will fined parts mark kl that dosnt mean its from 2.5L they are justs numbers that are put there by the manufacture of that part, could be made by some one othere then mazda. I dont remeber off hand but i know the k8 cams are not marked k8 they are marked kl--- or k1--- somthing along those lines but they was not use in any other k motor.

[Aston Wards]

just to clarify a couple of things, the KF did come with a curved neck manifold too - on the Lantis, also a K8 ecu will only work with an airflow controller, otherwise the ecu just dumps fuel.
The benefits aren't all that obvious, although i had a K8ZE to start with (150HP)

[mrspanky79]

Oh and the reason why there is two ratings out there 165 and 170 is because they changed over from the vaf to a maf (cant remeber what years) to get the 5 more horse power

[UrBaNsTyLe55]

true the kf did come in the lantis with a curved manifold but if you look closely its the curved manifold which is used on the k8, as for ecu if the k8 ecu dumps alot of fuel shouldn't the kl dump even more, i'm using the kl ecu and haven't had a rich problem