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Anyone Want More Power?


Renboy
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I think the KJ cams are so different they cant be reground to be similar to Otto Cycle cams. Either way I think the compression ratio would shoot up way to much for the engine to handle.

 

How can it be so different.

As far as I know, it is called miller cycle because the duration last longer. If you can reground the cams so to reduce duration until compression cycle occurs, it should be turned to otto-cycle. no?

 

Yea but think about it when you regrind regular Otto cycle cams its only to change intake and exhaust timing by very small amounts of degrees, i think Miller cycle cams are problably so different since the intake valve stays open for almost 10%(IIRC) of the compression stroke that they cant be reground properly. Not sure though, we need Renboys input on this.

 

IPB Image Try to picture that here in this Otto cycle.

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On another note...

 

What happens if you drop KJ cams into KL engine?

 

No these cams are specific to the Miller Cycle engine and work only on this engine. If you were to try to use them succesfully on a NA engine you would have created the Atkinson Cycle Engine which is more efficient but slower. Like the engine in the Toyota Prius.

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I don't see why you can't reground KJ cam, since KJ cams just has a wider lobe to make duration last longer. Unless lift is also different, which just make it more complicated.

 

And logically, you can reduce duration without welding cams.

 

Isn't Atkinson cycle a different way of connecting piston to crankshaft? 1 crank rev=4 piston cycles

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I dunno maybe.

Atkinson cylce is exactly like the MCE but with no S/C.

 

Uhmmm.. no! a MCE without a supercharger loses a lot of compression in the cylinder.

 

From what I read, Atkinson's has different kind of connecting rods.

 

otto engines; 1 engine rev = 1 cycle

atkinson engine; 1 engine rev = 4 cycles

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There are several different Atkinson designs.

 

"The Atkinson cycle may also refer to a four-stroke piston engine in which the intake valve is held open longer than normal to allow a reverse flow of intake air into the intake manifold. The compression ratio is reduced (for a time the air is escaping the cylinder freely rather than being compressed) but the expansion ratio is unchanged. This means the compression ratio is smaller than the expansion ratio. Heat gained from burning fuel increases the pressure, thereby forcing the piston to move, expanding the air volume beyond the volume when compression began. The goal of the Atkinson cycle is to allow the pressure in the combustion chamber at the end of the power stroke to be equal to atmospheric pressure; when this occurs, all the available energy has been obtained from the combustion process. For any given portion of air, the greater expansion ratio allows more energy to be converted from heat to useful mechanical energy meaning the engine is more efficient.

 

The disadvantage of the four-stroke Atkinson-cycle engine versus the more common Otto-cycle engine is reduced power density. Because a smaller portion of the intake stroke is devoted to compressing the intake air, an Atkinson-cycle engine does not take in as much air as would a similarly designed and sized Otto-cycle engine.

 

Four-stroke engines of this type with this same type of intake valve motion but with forced induction (supercharging) are known as Miller cycle engines.

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I dunno maybe.

Atkinson cylce is exactly like the MCE but with no S/C.

 

Uhmmm.. no! a MCE without a supercharger loses a lot of compression in the cylinder.

 

From what I read, Atkinson's has different kind of connecting rods.

 

otto engines; 1 engine rev = 1 cycle

atkinson engine; 1 engine rev = 4 cycles

 

This is more related to number of cylinders and engine type. In I4 typically 1 expansion is 180degrees, in milly V6 1 expansion is 120degrees.

 

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  • 1 month later...

so in recent weeks my milly decided to slip into a coma....the water pump blew a seal and then the temp went sky high and the head gasket went boom.... i have plans to rebuild the mazda would this be an opportune time to try our experiment?

if so there are a few questions i have about the engine first

1) is the engine an Interference or Non-interference engine? Aka when the timing belt breaks are the valves in the way of the pistons and risk getting bent all up or are the cylinders set up in a way that the valves can never get touched by the pistons?

2) what are the specs on the L series cams? and what if i had cams machined for the S engine with those specs thus guaranteeing that they fit in the motor? not as much of a risk i think.

3) and if you can get that much horse power out of basic cams then why not have real performance cams made for it instead and get even more power.

4) dose anyone know where you can get custom gaskets machined i want good strong ones that will be able to handle the full boost of the MCE super charger. remember now that it is a normal engine and not a miller cycle more boost will really mean more power and speed

 

i may have got this car when it was broken but i would sure love to see it run again

let me know your thoughts, concerns, or problems you see with this idea/plan.

 

 

 

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1. No, it is a non-interference engine, valves will not touch the piston.

2. Not to sure, but I believe that the KL-ZE uses KL-31 cams.

3. You could try that but that may be expensive.

4. The OEM gaskets from mazda should be good enough, if not you can make your own if you order the material, press on the part and cut it out with an exacto.

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1. No, it is a non-interference engine, valves will not touch the piston.

2. Not to sure, but I believe that the KL-ZE uses KL-31 cams.

3. You could try that but that may be expensive.

4. The OEM gaskets from mazda should be good enough, if not you can make your own if you order the material, press on the part and cut it out with an exacto.

 

so if the engine is a non-interferiance engine the only real steps to doing this mod would be getting custom cams and the ECU flashed to specs for those cams right?

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