Ranger 2.3 Duratec vs. Escape 2.5

[BBlue]

I am toying with the idea of replacing my Ranger 2.3 with a 2.5 Duratec. They share external block dimensions, so the switch should be relatively painless, but not a drop in. The purpose of the swap would be to gain a smoother, more powerful engine. The first part is a no brainer, the 2.5 has balance shafts, the 2.3 does not. But after that, things get a little murky. Some items in the mix to be considered:

In addition to the balance shaft, the 2.5 uses a heavier crankshaft and crank pulley.
The 2.5 breathes better, due in part to much larger intake ports.
They would use the same flywheel and clutch assembly.
The 2.5 employs VCT to boost perfromance figures.

I would have to either block off the VCT circuit or control it in an all or none fashion. Would that be possible?

I could modify my intake to mate with the head, but would the larger ports kill low rpm torque? The 2.3 power drops off drastically in the upper rpm range, so the larger ports should be an improvement, but I'm not willing to lose low end performance.

Comments??

Bill

[a.moore]

I would think the extra displacement would help with low-end performance.

Any idea if the VCT is triggered off of oil pressure?

Either way I'll be watching what you're doing. 2.5 parts intrigue me, especially the head.

[BBlue]

I would think the extra displacement would help with low-end performance.

Any idea if the VCT is triggered off of oil pressure?

Either way I'll be watching what you're doing. 2.5 parts intrigue me, especially the head.

The VCT is prety much of a black hole for me. It is computer controlled and powered by oil pressure. That's about all I know about it. I get hints that the stock setup enables the computer to continuously control the amount of cam advance.

Bill

[a.moore]

Well based on your previous thread about going with a MS, I would imagine there is something there that could control it. The MS3 has PWM outputs. I'm using one to control my fuel pump (albeit it to run at full); assuming the cam is controlled the same way I don't see why you couldn't brew up something.

Without the variable cam I'd have to wonder if it would be "out" of the powerband when you really wanted it unless a 2.0 or 2.3 non-VCT cam could be fitted?

[BBlue]

Andrew, it seems to me that without knowing the purpose of the VCT (extra power, extended power band, emissions or something else), I am dead in the water. Even if I did know, I'm thinking that I'd be drifting downstream at warp speed.

Bill

[BBlue]

I found a post on the Focusfanatics site where a guy unplugged the VCT on his 2.5 Escape without noticeable issues.

Bill

[JPS Europa]

or maybe something like this http://www.diyautotune.com/catalog/vvtuner-c-80.html

[Driven5]

While it's almost always tempting to go all-out on the 'best' option, simplicity is often the name of the game. For a bit smoother and more powerful experience, the Focus 2.3L should get you most of the way there while being much more of a plug-n-play solution. It has a better flowing head, more heavily balanced crank, and the addition of balance shafts relative to the Ranger 2.3L. No it doesn't have quite the kick a 2.5L would have, but it's no slouch either. And if there isn't enough power stock, the 2.3L has plenty of aftermarket support as well.

[BBlue]

As near as can be determined without actually buying and installing the damned things, the issues between the Focus (or Ranger) 2.3 and 2.5 are:

VCT on the 2.5
Crank VR sensor (2.3), Hall (2.5)
Larger intake ports (2.5)

I'm thinking that I could swap the Ranger VR sensor onto the 2.5, control the VCT on an all or nothing basis and use my intake manifold. This would allow the use of an MS II with EDIS ignition and I would not have to grow another brain to have the major benefits of VCT. I think controlling the VCT that way would suffice, just make sure the changeover point is above normal cruise rpm.

My intake should be up to the job, it has about 15% more cross section area than the Ranger intake.

Speaking of EDIS, would I be better off keeping the Hall sensor and using MS III with COP? It appears the cost would be nearly the same.

Bill

[Off Road SHO]

Bill,

I think that once you drive your car with the variable valve control, you will never go back. Having 80% of your maximum torque at such low rpm's is addictive. I have it on 4 of my Fords and love it. I'd go with the 2.5.

Tom

[Driven5]

As near as can be determined without actually buying and installing the damned things, the issues between the Focus (or Ranger) 2.3 and 2.5 are:...

If going with the 2.5L, I would definitely lean towards MS3X. I believe it should even allow full VCT control as you get deeper into tuning the engine. But realize that you're only allowed to go the this route if you promise to keep us up to date on every detail of the process.

A successful D25 installation could easily turn my D20 into little more than an oversized paperweight.

[BBlue]

Justin, there is a big hangup with going the MS3X and full tuning route. Me. I have no idea what the proper curve would look like and do not have the ability to determine one, as it would undoubtedly require constant loading of the engine, which means a full bore test cell. Even if I knew the proper cam advance curve, there is no way I'd be able to write a program that would employ feedback from the cam sensor. May I introduce you to the term "Computer Stupid"? Its all or none.

There is no reason to not use the 2.5 in a build. Physically, it is about 3/4" taller than the 2.0. All other differences can be worked out during the build.

In the meantime, I have an oil pan clearance issue to attend to. This may all come to naught.

Bill

[Driven5]

Correct me if I'm wrong, since my understanding of MS is very limited, but it seems to me that MS3X should not be significantly more difficult to learn than MS2X. And you don't have to use the VCT tuning capabilities at all, but the option is still there should you later choose to pursue it, even if just in the simple on/off fashion you brought up. Then if the time ever come to explore it further, I would think that it could be tuned within reason using the same iterative type data log road tuning process, just with another variable involved.

The fractional price and exponential availability are two of the biggest factors that drove me to choose the D20 over the D23 for my build...With the bonus of a naturally (without balance shafts) smoother operation, 'revvier' nature, lower hood requirement and increased fuel economy in addition to the very reasonable power output. However, if it turns out to be straight forward enough, the extra advantages of the D25 might actually be enough to tip the scales in favor of spending the extra money when the time comes.

[a.moore]

D20 with D25 head, lock out the VCT, and use an available non-VCT cam. Just saying....

Why not try the MS3 on your current engine first? The ITBs and the MS really woke up my engine.

[mgtmse]

hello everyone!! interesting project you have going on!

have you ever taken a look at miataturbo.net? it has a wealth of information on tuning and there are several discussions on vct (called vvt in the miata). the megasquirt boxes are well known by mt.net community as well as other boxes like the hydra which i know is vct capable. you are sure to find answers to many of your questions in that forum.

please be sure to use the search function!! i can tell you for sure your questions have been discussed at mt.net.

like you i am a computer caveman, i can build with the best but 0110101 confuses me, with that said you may be able to find a mt.net member who has dealt with your problems that is local to you or someone that can direct you to a shop/person who can fix you up with a good tune.

as for the tune if you decide to go with the 2.5L vct engine, you may be able to get a base map for a NC miata to get you running and then get it tuned at a local dyno shop.

hope that helps!

robert