As the title says is there any difference between them? I know on my old 135i the n54 was a much beefier build than the n55 people making over 750WHP on stock engine with fueling and big turbo kits.

just curious to know.

 

The N18 engine is much better and a significant improvement over the N14. I had a N54 135i too, the N14 doesn't have anything over the N18 like the N54 had over the N55 in Bimmers.

It would be wiser to go for a late model N18 engine which has most of it's quirks worked out and you'll be happier with the ownership experience.

N14 vs N18:
http://new.minimania.com/MINI_Cooper...son_N14_vs_N18

 

Well said. 2013-2015 N18 is perfection in my opinion.

 

I was more interested in if the JCW were beefier internals than non JCW. Or if n14 or n18 was the beefier engine able to hold more power safely. N54 engine was the first in my experience that could hold double and more power over stock on the completely stock internals. Lol its that kind of pampering that spoils you.

 

N18 wins over the N14. The N18 in the JCW is the more winning engine. Here are all the additional things JCW engine has over the Cooper S:

• 211 bhp (207 hp) & 192 ft lbs or torque (207 ft lbs with overboost)
• Upgraded/Optimized Turbo Pistons
• Thicker cylinder walls
• Lower compression ratio (10:1 vs 10.5:1)
• Four piston brakes (adapted from the MINI Challenge race car)
• Upgraded Air Intake (same as dealer installed kit)
• Revised 6 speed Manual Transmission
• Upgraded Clutch
• Upgraded Full Cat-back JCW Exhaust
• Fully Optimized ECU
• JCW “Challenge Spoke” light weight alloy wheels (21 lbs)
• Electronic Differential Lock Control
• New speedometer to allow for higher maximum speed (148 mph)

 

Also, a bigger turbo and valves.

This is for sure a better start for those who want to invest in mods.

 

Ok thicker cylinder walls good! Are you sure upgraded pistons in the cylinders? Ported intake and larger valves I have read about.

Honestly upgraded piston/crank/rods&bearings i was hoping for... but ill take any advantage the 1-2k premium will buy over a used S.

Second thing any stiffer lash aresters or improvements on the valvetrain? Alot of tuning advantage can be gained simply by adding 500-1k to the redline. In some ways it will smooth out the mid range torque. Possibly start to notice some boost taper in the last 500. But the higher rpm adds a bit of flexibility on the shift point.

Regards
Tom

 

Overall the N18 is probably the better choice if your not planning a seriously high power build. There's not much difference in the bottom end other than some oil passage/control changes. Same reinforcing in some of the webbing of the JCW block, same nodular crank, same powder forged rods, same compression ratio with reinforced pistons. The N18 piston has greater clearance around the exhaust valve though since the exhaust valve timing varies with VANOS. Another difference is the oil pump output on the N18 is controlled by the ECU rather than mechanically controlled on the N14. One limiting factor on the N18 bottom end to be aware of though is the limited availability of aftermarket forged pistons. I believe only Supertech and JMTC produce N18 pistons. IIRC both are also hypereutectic pistons and only available in 10:1 and 10.5:1 CR. I do believe however that CP will make you a custom piston for the N18 if you ask nicely and have recently sold a kidney.

The really big difference between the two engines is the top end. The N18 uses Valvetronic to vary intake valve lift. This acts as the throttle when the engine is warm so pumping losses are reduced. In addition as noted above the N18 has VANOS on both the intake and exhaust cams unlike the N14 that only has it on the intake. Combine these two changes together and you get the HP difference. The ECU on the N18 also reduces valve overlap in certain instances which helps reduce carbon accumulation. Another nice addition to the N18 JCW top end is that all of them have the Bosch HPFP which is less prone to failure.

So that's the good about the N18 top end. The down side of having a Valvetronic head though is your RPM limited to about 7,200 RPM. After that valve float becomes a problem especially when combined with raised boost levels. This is because you can't install higher performance aftermarket valve springs. With Valvetronic you also can't install higher lift, longer duration cams. So your performance potential is more limited. You can still port and polish the N18 head though which will produce some nice results.

 

Thank you sir always eager to learn from a fellow motor head :-)

 

Your welcome Tom. Personally I think the advantage of the fJCW internals along with all of the other additions is more than worth the difference. But I will also freely admit I'm just a bit biased. As far as boost taper goes, the JCW turbo holds boost great till about 5,500 - 5,700 RPM. After that it tapers off to around 18.5 to 19 psi at 6,800 RPM. Pushing the wastegate duty cycle any further than that will result in the turbo seriously exceeding its design spec of 170,000 RPM. Doing that can result in bad things happening.

 

I simply want to learn as much about the platform as possible before i purchase it. That way i can plan around any issues with the platform. And this way i know exactly what to expect.

 

So with a big turbo or hybrid turbo whats the max you can expect to safely push the stock internals? I see some threads where guys are running hybrids on stock internals. I see a few claims of around 300 stock... but others claim 300 is too agressive on the stock internals. 300 would be a good point i feel on this chasis considering its lightweight. Slightly larger injectors a hybrid turbo with a proper tune should get me to around 300. My concern is will it cause failures or not?

 

This is just my personal opinion but on stock internals a JCW should hold 270 hp and an S 240 hp all day long if driven intelligently and well maintained. The last part of that sentence being the most important. My JCW is putting 291 to the wheels with meth injection and our 51mm hybrid on stock internals. Could it make more? Absolutely. You can make any car hellaciously fast...once, but this is also my daily driver. By the time you take into consideration a 12% drivetrain loss that equates to 330 BHP. I'd call that a bit more than a modest increase from the factory 207 BHP.

300 WHP being a round number has a nice ring to it though.

 

I wasnt even considering 300Whp but you give me hope man! Hmmm what other mods besides hybrid turbo, meth, downpipes and intercoole on your car?

 

Nothing too radical. Upgraded coils, 3" custom exhaust by CM Performance and I did upgrade the factory rod bolts to ARP. More of a safety investment since the factory rod bolts start to stretch when getting close to 300 ft/lb torque. I'll also be installing a ARP head stud kit soon. We did one pull at 1.75 bar and smelled coolant afterwards. No external leaks or residual fluid were noted so the only conclusion I could draw would be that the head lifted slightly over pressurizing the coolant system causing it to vent. Videoscope and subsequent driving indicates no residual effects but I'd say were right at the limit of what the factory head bolts can handle. There a thread here for more details on the mods I've done.
https://www.northamericanmotoring.co...ly-member.html

 

Interesting. Anyone know differences between N14 S and N14 JCW motors? I know turbo and intake (and ECU map) are different. Are any internals different as well?

 

If you read the entire tread, Tiger2011 has answered your question. The stronger JCW engine block, pistons and valve train is able to pump and breath better no matter N14 or N18 version.

 

What a great thread. Thanks all for posting. New to Minis; not new to engine swaps/mods, performance set up & driving. Nice to have found a thread that gets to the point without, first, having to read through pages of fluff.