Engine Swap. Choices need some opinions

[Dragon1212]

KL-ZE not dumping this yet but I'm not really fond of how large they bored it and as I am told it has problems internally? My dad is reading inbetween car paint coats and has found that these are issues. He used to bore out his V8's then sleeve them back up so that if something broke it would just wreck a sleeve rather than the motor

True are false, Our engine angle is steeper than normal V6's to make it smaller. 60 degrees I believe He read.

Was looking at seeing if a Duratec 35 would fit. http://en.wikipedia.org/wiki/Ford_Durat ... Duratec_35" onclick="window.open(this.href);return false;
I am aware alot would have to change out. Not entirely sure but could someone clue me in to them.
The bonus of this is it Doubles horsepower but also is fairly new so lower km's would be easy to find.

Suggestions welcome. The reason I am looking into these different ones is if were going to do all the work to make the swap then we might as well make the thing really fly

Running a Stock K8 With no mods.
Pro's and Cons of each would be nice.
Thanks for your time.

[Ryan]

Just drop in a ZE. Any non-K series engine will run you quadruple the cost and effort. You'll need welding skills, custom axles, if not CNC machining capabilities.

Even suggesting putting that motor in shows you have zero clue what is involved in a swap. Have you considered electronics, harness, ecm, which transmission, mount locations, which axles, if you can even mount that motor so that the axles won't hit the frame/bind... I'm just getting started.



ZE's are not unreliable, and it was bored to 2.5 from factory, been running many thousands of km's on many engines, with a small failure rate of valve retainers. Not to mention KLDE's are the same bore, and, AFAIK, NONE of these engines have ever had cylinder wall failures, except when run out of coolant. If you want the most reliable and powerful, swap DE heads onto a ZE block, but thats a marginal gain in reliability. Most reliability is not driving it to the 7500k nads all day long.

[Dragon1212]

A little rude of course I have no Idea about it I'm 17 lol and was a computer nerd till I got this car lol. Thats why I'm asking Thanks for the input Though, Supposedly the Duratec was where our engines went after the K8 and KL's

[wytbishop]

The ZE is near bulletproof. The design of the bottom end makes it capable of enormous horsepower without failure if built properly. There are Aussies who have made 1000hp fromt eh ZE with twin turbos and really, really strong aftermarket internals.

Think about this...how ist he Duratec gearbox controlled? You will have to fab cables or a linkage? How is the engine controlled? You will need to splice the engine control unit into the MX-3 or replace it altogether with something aftermarket while maintaining systems like fuel cut and A/C.

If you want to make it really fly and you're considering spending the kind of money and time it would take to do a modern engine swap then spend it on building a 15-20psi turbo ZE and built gearbox. If you're not afraid to drop $5-6k you could make 350-400hp in a ZE. Or you could spend the same amount of money plus do hundreds of hours of fabrication, troubleshooting, chasing electronic bugs and get the same result from a Duratec. It would be cool if you did it, but it's not really an efficient use of time and money.

[Inodoro Pereyra]

I agree with Ryan and Wyt, with one exception: I'd go with the DE, instead of the ZE. This is NOT because of any reliability issue (as Wyt said, K engines are nearly bulletproof), but because I read of so many people dumping $1K on a ZE, just to find out (sooner or later) it was a DE they could've gotten for about $200, I just wouldn't take the risk.
Besides that, the DE is slightly more boost friendly than the ZE, and the model specific parts (pistons and camshafts) are much easier to find, and cheaper.

Other than that, as they said, installing a Duratec would mean a tremendous amount of work, and expense, for little gain. not to mention issues like weight, overall dimensions, etc. And all of that to get...what? 285 HP? You can get that power with a BP, and that's an example of reliability, if I ever saw one.

To answer your other question, yes, the DE/ZE are 60 degrees V6s, and so is the Duratec. That is not only because of size constraints, but because a 60 degree V6 vibrates less than a 90 degree one. Most V6s in the market today are 60 degrees because of that.

http://en.wikipedia.org/wiki/V6_engine#V_angles

[Daninski]

Gee I got a ZE for $150 The KLZE is the best choice because any DE you find probably has high mileage on it. Unless you plan to race the hell out of it the ZE is very reliable but then again if you have the bucks install DE valve retainers if you like. Plan on modding your ECU or sourceing a KL31 or KL36. Now go to the Fax section and read Colemans engine swap writeup.

[Inodoro Pereyra]

Gee I got a ZE for $150 The KLZE is the best choice because any DE you find probably has high mileage on it.

Yeah...feel free to rub it in our faces, anytime...
Anyway, with any luck, I'm planning on proving you wrong soon enough. The mileage on an engine is relative. K engine blocks are very sturdy, and, I'm pretty sure for the money difference you can replace the internals, and even get the DE to give more power than the ZE.

But, so far, like most everything else in my life, that's just a dream...

[MrMazda92]

Gee I got a ZE for $150 The KLZE is the best choice because any DE you find probably has high mileage on it.

Yeah...feel free to rub it in our faces, anytime...
Anyway, with any luck, I'm planning on proving you wrong soon enough. The mileage on an engine is relative. K engine blocks are very sturdy, and, I'm pretty sure for the money difference you can replace the internals, and even get the DE to give more power than the ZE.

But, so far, like most everything else in my life, that's just a dream...

Looking at it from a compression standpoint, the ZE will always pump out more power than the DE unless compression is changed, will it not?

The valve retainers are different, so I've heard(this has been mentioned in this thread, as well as many others), yet I don't understand exactly HOW they are different.

The IM and heads are ported differently on the ZE as well, allowing more airflow.

In theory then, the only way to make a DE more powerful than a ZE, is to swap out almost everything that makes it a DE, therefor making it a ZE. :/

I am probably off on multiple points in this post, but from what I've gathered thus far, I feel that's an adequate(if not thorough) explanation of the differences between the 2 engines.

The way I see it, the DE is considerably cheaper(high miles, needs a rebuild but who cares I have to anyways eh?)

I have a DE myself, and am leaning towards a KLG4 IM, bigger cams, H beam rods(Probetalk has a thread, very interesting and I can't wait to hear the results), and higher comp. pistons(ceramic coated ZE pistons would work), as well as PnP. So long as it can handle the boost, I'd be comfortable with 250 whp street and 300-325 track.

[wytbishop]

The reasoning is that because the DE is manufactured with lower compression that it has greater potential under forced induction. While it is true that it is capable of managing more boost and therefore theoretically will ultimately make more power if trubo'd and tuned properly, I would humbly suggest that a ZE on 10psi will be almost as strong on the top end, and far more powerful in the midrange than a DE on 15psi.

IT's the same reason that the GTX guys and other B6T users rebuild with 10.6:1 compression Miata pistons over the stock pistons. The added compression while reducing the amount of boost you can put in without causing detonation and other bad things, dramatically improves mid range torque.

IF you have a decent budget with which to build an engine, find a used ZE and rebuild it for turbo.

[Inodoro Pereyra]

You gentlemen are both absolutely right.
MrMazda92: the compression ratio difference between the DE and ZE is actually pretty small (9.2 vs. 9.5:1), so, even when that does make a difference, is not really that big.
'98 (I think) and up millenias have DEs with ZE's heads. ZE heads account for a 10HP difference alone, even with the DE camshafts.

Wyt: I may be wrong, but I was under the impression that DEs were preferred for boost due to stronger internals (specifically the valvetrain), and a better in-cylinder flow because of the cupped pistons.

Either way, I don't like turbos for street use. Too delicate.
I'm confident that, starting with a Millenia DE, and after some (labor intensive, for sure) old school mechanics, I can get in the neighborhood of 240-250 BHP, without swapping a single part, other than adding a megasquirt.

But we'll see. Right now, I have to take care of other issues, before getting to it. But I'm hoping to get it done before year's end.

[MrMazda92]

@wytbishop

Correct me if I'm wrong, lower compression means higher tolerances for variables in tuning doesn't it?

Therefor, a higher comp. engine with a solid tune would beat out a lower comp. engine with the same tune?

I'm still trying to figure it all out, as I haven't even broken open my own DE yet(I don't have the money to do much yet, so I don't see a point.)

@Inodoro

Really? I thought the gap was larger than that. :/ I am still trying to figure out my best route for balancing cost with benefit on my own build. There are so many factors to take into consideration, every time I feel I've made headway something blows it out of the water. I'll get it someday, I hope!

[Inodoro Pereyra]

As far as I know, that's the difference. And it makes sense, if you think about it. Mazda went to a lot of trouble, changing the head and the camshafts, besides the compression ratio, just to get little more than a 20% power increase. I guess they wanted to keep the engine compatible with 87 octane gas, and keep it non interference, and those are the reasons they kept the CR difference so low.

Don't worry about the money. We're both in the same boat. I actually don't even have a car anymore, so I'm in worse shape than you.
I am (with any luck) looking to move out of Florida soon. Then, once I get a job (been unemployed since last December), tweaking the DE is my main priority. Meanwhile, I can only pray that, for the first time in the last 4 years, things happen the way I planned them...

Anyway, if everything goes well, I will post a writeup soon enough...

[MrMazda92]

Alright, well it seems logical enough to me. No complaints, they turned out 2 amazing engines either way!

I'm sorry to hear that, I don't know what I would do in your situation. :/ I love driving, even moreso since I got this car.

I am battling a BIG ticket, or I'd be putting a little more money into my car. Reckless driving... Bleh.

Good luck, I can't wait to see the writeup!

[Nd4SpdSe]

You gentlemen are both absolutely right.
MrMazda92: the compression ratio difference between the DE and ZE is actually pretty small (9.2 vs. 9.5:1), so, even when that does make a difference, is not really that big.
'98 (I think) and up millenias have DEs with ZE's heads. ZE heads account for a 10HP difference alone, even with the DE camshafts.

Wyt: I may be wrong, but I was under the impression that DEs were preferred for boost due to stronger internals (specifically the valvetrain), and a better in-cylinder flow because of the cupped pistons.

Either way, I don't like turbos for street use. Too delicate.
I'm confident that, starting with a Millenia DE, and after some (labor intensive, for sure) old school mechanics, I can get in the neighborhood of 240-250 BHP, without swapping a single part, other than adding a megasquirt.

But we'll see. Right now, I have to take care of other issues, before getting to it. But I'm hoping to get it done before year's end.

Actually, the compression on a ZE is 10:1, DE is 9.2:1

Your right, a Millenia DE is just that, which adds the extra power over a regular DE.

DE's are only perfered for the valvetrain and the compression. People talk like the ZE valvetrain is brittle, but if you never go beyond redline, you'll never have a problem. If you do however plan on running boost or being aggressive, it doesn't hurt to put in a DE retainers. On the flipside, the DE has less flowing heads and intake manifold. As for compression and boost, as for Wytbishop said, there's a saying; low compression is a poor excuse for poor tunning.

I hope you're talking turbo, cause if you're sticking N/A, there's no way you're going to get 240-250bhp with jsut megasquirt. It takes quite the investment to get a KL to make that kind of power N/A. 200whp is realistic and had been done.

[wytbishop]

@wytbishop

Correct me if I'm wrong, lower compression means higher tolerances for variables in tuning doesn't it?

Therefor, a higher comp. engine with a solid tune would beat out a lower comp. engine with the same tune?

I'm still trying to figure it all out, as I haven't even broken open my own DE yet(I don't have the money to do much yet, so I don't see a point.)

The scientific reason that a higher compression engine makes more power is in the physics of combustion. Frome Wikipedia...cuz thermodynamics is hard and I don't explain it well...

"A high compression ratio is desirable because it allows an engine to extract more mechanical energy from a given mass of air-fuel mixture due to its higher thermal efficiency. High ratios place the available oxygen and fuel molecules into a reduced space along with the adiabatic heat of compression–causing better mixing and evaporation of the fuel droplets. Thus they allow increased power at the moment of ignition and the extraction of more useful work from that power by expanding the hot gas to a greater degree."

I agree that it is probably easier to tune a lower compression engine, but I think that is more because the limit of performance is lower and therefore easier to get close to. On a higher compression engine the maximum possible power is higher but harder to reach.

This table shows the affect of increasing compression ratio. The increase in Brake Thermal Efficiency is what causes the increase in energy output. These percentages are the increase from 5:1 which they are using as the baseline. Although 10:1 is only 1% higher then 9:1, that equates to a greater increase in power than 1%. I have read in other places that a 1 point change in compression equates to as much as 20% power increase however it's not linear, so goign from 7:1 to 8:1 will net more improvement than going from 9:1 to 10:1.

Compression......Octane Number....Brake Thermal Efficiency
.....Ratio.............Requirement.........( Full Throttle )
......5:1 ................72.......................-
......6:1.................81.....................25 %
......7:1.................87.....................28 %
......8:1.................92.....................30 %
......9:1.................96.....................32 %
.....10:1................100....................33 %
.....11:1................104....................34 %
.....12:1................108....................35 %