Right, Think I am going to put all this info into one thread and put it in this category, It should help out new members and members that want to upgrade their car to the 2.5 engine. There is also lots of information on the other engine more for reference for the other guys.
The majority of the information below will be about the KL series engines
As we all know there was a few variants of the Mazda K series engine, K8, KF, KJ-ZEM, KL
Starting with the K8 there was two variants as follows.K8-DEThis engine is fitted to the standard MX-3, It is 1845cc has a bore size of 75mm and a 69.6mm stroke. It has 130bhp in standard trim. This engine uses a distributor ignition system.
K8-ZEThis is the JDM version has the same bore and stroke but due to different intake manifold and cams produces more power. It started life as 135bhp and ended it’s life with 144bhp. As above this uses a distributor ignition system.
The next engine is the KFKF-DEThis engine is fitted to all the U.K spec 323F, It has a bore of 78mm and stroke of 69.9mm to make and engine with a capacity of 1995cc , It started off life producing 140bhp and later on this was raised to 144bhp. Both produced 179nm of torque. This engine uses 220cc injectors, It again uses the distributor ignition system.
KF-ZE This is the JDM version of the above engine producing 160bhp and 179nm in standard tune and in the Lantis Type-R produced 170bhp and 190nm of torque. Again this uses 220cc injectors. Again this uses a Distributor ignition system.
The next engine up is the KJ-ZEMKJ-ZEMThis engine is originally fitted to the Mazda Millenia and Xedos 9. It has a bore of 80.30 and stroke of 74.20mm to make an engine with a capacity of 2255cc. It uses a twin screw supercharger and uses either 280cc or 320cc injectors ( more about this later ) to fuel it. Power output is now upto 217bhp and 280nm of torque.
The next engine is the last and is the most common engine, The KL.KL-DEThis engine is found in the standard MX-6 and Ford Probe, It had a bore of 84.5mm and a 74.2mm stroke to give an overall engine size of 2497cc, Known more commonly as the KL-03 is has 164bhp in standard trim, it too uses 220cc injectors and the distributor based ignition.
KL-ZEThis is the JDM version of the above engine with bhp ranging between 190bhp and 199bhp and 224nm of torque it is the most powerful version of the KL engine. It achieved this by using a different shape intake manifold, more aggressive cams and a higher compression of 10.0:1. The only difference I can find so far with the valve train is that the KLZE uses larger intake valves and therefore HLA’s than the DE and G4 .Please be aware that there is some curved neck engines with a lower compression of 9.5:1 and this is also the same with the cams. All this means is it does not have as much power.
KL-G4This is the last incarnation that Mazda did of the K series engine, Updating it with Electronic ignition, Solid lifters and a different shaped manifold. To produce 170bhp and 220nm of torque. This engine was produced in 1998 and was used in the Mazda 626 although I believe this should have also been put into the Mazda 323F BJ.
Here anr for reference the vacuum diagrams for the KL-DE and the KL-ZE engines.
KL-DE
KL-ZE
This is what the VRIS does for the engine.
PerformanceNow we are familiar with the K series engines that Mazda produced I can move onto the Performance side of things.
Basic performance items for all these engines are Cold air induction kits ( CAI ), A decent Exhaust manifold, Decent spark plugs and leads and something that can be done by almost anyone is a bit of manifold and throttle body polishing. Things that are a little more difficult are knife edging VRIS points and the Throttle butterfly, This should be left if you don’t know how to do it.
Other than that keeping the engine in good order is the key to a long lifespan I.E regular oil and filter changes etc.
There are many other small bits that can be done and that I am looking into at the moment to improve reliability and performance.
There is not a massive amount at the moment but I will add to it as and when I find out other information.
InjectorsThere are a few easy upgrades as far as the fuelling is concerned, As stated above the stock injectors are 220cc and the milly injectors are 280cc+ depending which ones you go for. As far as I can work out there is no need to upgrade the injectors until you are reaching a higher power i.e for an N/A car running 260bhp at the crank would require the larger 280cc injectors
I think 260bhp is quite a reachable target for the KLZE, with some good upgrades.
If you were to look at running a turbo or supercharged engine at 220bhp which is a very easy target you would need to be running 280cc injectors.
Both the above injector / bhp ratings I worked out using 43psi fuel pressure, I can't remember for the life of me what it is as standard, If anyone can fill this bit out it would be appreciated.
So far I am doing a bit of research on solid lifters and how easy they would be to fit and the cost and maybe a fitting guide ?
Eventually there will be a guide for putting the V6 into the BJ ( it’s rightful home
)
Any comments are welcome and this will be getting updated with other info as I need to J
Hope its all very useful to you guys.
Thanks
Stu
I am not taking the credit for the information in this post, All I wanted to do was post everything in one place to make it easy for people to find and use easily
I know some people may already know everything I have posted here but this is more to help some of the newer members or people who are not as " hands on"
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