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STM317
STM317 Reader
3/7/16 3:12 p.m.

I've got a NS 2.3 Duratec in my truck, and it never had balance shafts. Maybe I'm just an uncivilized hillbilly that's used to cheap trucks with poor NVH that were designed in the 90s, but I've never thought that the Duratec needed balance shafts.

Cosworth and Crower make nice cams for the Duratecs. If you don't want to spend the extra to put a 2.5 in your NC, some cams and a tune would do wonders for a 2.0 and cost about the same as the 2.5 swap stuff.

Knurled
Knurled GRM+ Memberand MegaDork
3/7/16 4:36 p.m.
alfadriver wrote: FWIW, back when this engine family first came out- there was an actual difference in a 2.3l Ranger engine and a 2.3l in a car. The ranger had shorter and lower cams just to "help out" the low end.

And there was a roundy-round company in Kansas or Missouri that was playing with the Ranger engine. 12:1 compression, good rods, mechanical fuel injection, and a decent header, they were making 250hp at 5500-8000rpm. This with stock cams and untouched heads. More cam made the powerband look more natural and over 300hp was achieved.

So IMO the cams would be the LAST thing I'd touch.

PumpkinHead65
PumpkinHead65
8/31/17 7:19 a.m.

In reply to GSmith:

I have an '06 MX-5 Sport with the 6AT. Not sure what you meant by "death rattle" but I may have the exact same issue. It is my daily driver.

The day it happened: My morning commute was perfect. When I left for lunch that was this "tapping" sound that is most prominent under a neutral throttle: not accelerating nor decelerating. Also, you hear it between gear changes. My mechanic thought it was in the valve train. I didn't but I trusted him. He ended up replacing both camshafts and re doing all the lifters so the fit was perfect on them all. It changed nothing. Being the incredibly honest guys he is, he didn't charge me a penny because his diagnosis, and subsequent repair, was wrong. Anyway, it led us back to what I originally thought it may be: a bad wristpin bearing. Thinking that's what it was, and that it would die catastrophically very soon, I took it off the road until I could afford to replace the engine. After a few months, my awesome wife encouraged me to at least enjoy it til it dies, cause "ya never know how long it might go". Well, 7000 miles later I'm still driving it and it's still noisy but it still runs fine. I now think it may be a fractured piston ring. Either way, rebuilding or replacing are my only options. I plan to replace it. I'm seriously considering a new 2.5 as it is plug and play from dynotronicstuning and quite affordable.

Does this sound like the same thing you experienced?

What did you end up doing?

GSmith
GSmith HalfDork
8/31/17 1:07 p.m.

I currently have a rattle from the gearbox / exhaust area i need to troubleshoot. That one goes away in neutral with clutch in, but comes back with the clutch engaged. I think it's an exhaust heatshield - I'm over 140k on the car now.

The noise I had was a very loud tat-tat-tat rattle when coasting or under no throttle load. even light throttle would make the noise go away. I nursed it along for probably 10k+ (15k?) miles by making sure it was under load as much as possible.

My mechanic (also a friend) wasn't in favor of the 2.5 swap and the Philly shop that would do it is hours away. I say "not support" but I mean, clearly well out of factory, so issues like custom tuning, etc is just out of his wheelhouse. This is a nearly daily driver / commuter car for me.

He diagnosed it to #1 (front cylinder) removed the oil pan and the head. Checked the head, noted the #1 bearing between the connecting rod & crankshaft) was the issue. That bearing had worn through 3 very thin layers of metal but did not damage the crankshaft in the process... just was slowly wearing away & leaving miniscule metal bits in my oil, i'm sure.

Replaced the #1 piston assembly (the piston was gorgeous still, other than carbon on the combustion side, and is still on my desk - we could probably have gotten away replacing just the bearing itself, but we ordered the whole assembly). Piston, rings, con rod, bearings all included.

Crankshaft checked out. the other 3 cylinders checked out. I've put another 30k on the engine so far and still going...

PumpkinHead65
PumpkinHead65 New Reader
9/14/17 9:07 a.m.

In reply to GSmith:

Gotta check my account settings as I never got a notification that you replied so quickly.

My reading has led me to the conclusion that the 2009+ 2.0 engines are a little better than the 2006-2008 units so I'm gonna swap rather than rebuild as the swap is actually less costly.  I found a 2013 2.0 with 16k on the clock for $1500 so I'm going to go that route.  At the moment, I'm seriously thinking about driving from Raleigh, NC to New Braunfels, TX to have Dynotronics Tuning (provider of the 2013 motor) do the engine swap and tuning for me.  If I had the extra $ I'd definitely do the 2.5 but that's another $1000 and right now, that makes a difference for me  :-(    I'm still not 100% certain of the actual problem in my motor but it is definitely related to the #1` cylinder as well.  I have to confess that I had been running regular gas in it as the cost difference around here is 60 cents per gallon.  I have never heard or sensed ANY pre-ignition or performance difference between the 87 octane regular and 93 octane premium ethanol-free gas (which is more like $1.50/gal more than reg).  I still think the factory ECU was adjusting the timing sufficiently but I don't know that for sure.  Dynotronics will custom tune this 2013 motor ECU to prefer 87.  I may give up a little bit of power but being that I drive this car at least 1000-1500 miles per month, I do not want to be paying that much more for fuel.

Curious, since we may have the same problem, did you run reg gas or only premium 92-93 octane?

purplewombat
purplewombat
3/26/21 11:37 p.m.

Wondering if those who have performed this swap may be able to answer a few questions. Engine I would be deleting would be a 2.0 from a 2007 Miata, but it is in a 1976 Triumph Spitfire. 

A) The videos I have seen on 2.5 into Miata swap all indicate need to swap intake runner and throttle body. Am I correct in assuming that this is necessary on Miata because throttle body comes out on main pulley end on 2.0, but on flywheel end on 2.5 and would cause interference problems? 

B) how much more vibration is there if the countershafts are removed? I already have a bit more vibration than I care for with 2.0 in current installation. If I have room and it does not affect performance too much I may retain that feature.

C) Can I use existing 2.0 ecu with a reflash or am I better off with ecu from 2.5?

D) Are the wire connections identical between the two motors? Not a big deal if I need to lengthen some wires, but if plugs/connections are different that will give me some headaches. 

E) Are locations for oil filter, starter motor, alternator, front pulley all the same? Limited room to spare.

F) in regards to front pulley, most videos show that being swapped as well. What is difference/reason for swapping?

I am thinking that if I have clearance I can just use an unmodified 2.5 in my application.

Any help is appreciated!

 

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
3/27/21 8:51 a.m.

In reply to purplewombat :

The 2.5's throttle body is co-spatial with the firewall in a Miata, or any other traditional rear drive car.  It MIGHT pose issues for you, it might not, but signs point to "probably".  Even if it technically fits, you'd still need to get air to it.

wspohn
wspohn SuperDork
3/27/21 11:59 a.m.

Has anyone done an Ecotec swap?  Not sure how difficult it is but these guys seem to make the stiff needed to do it.

https://www.ecotecmiata.ca/

 

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