Missed a couple of SC 5.0's I shoulda grabbed and now the market is quite sparse it seems. Made me wonder.....would a SC 3.0 or NA 5.0 be ok for what I need(as opposed to what I want....u know how that is I'm sure)? i've seen lots about getting more juice from the SC5.0 but not much about the SC3.0 or NA5.0. Excluding the SC5.0, which of these engines has most upside power potential while remaining acceptable/reliable as a near-daily driver? What is a reasonably achievable max horsepower output for each of these motors? Thanks fo any input! MFT

 

I doubt a SC 3.0 would get you anywhere near the power of a SC 5.0, even with mods. And modding a NA can be done but can be costly and gains are marginal? Having dabbled a little with modded engines in the past, my recommendation would be wait for an SC 5.0 if it is power you are really after. It will be potentially be more reliable (designed for that output) and worth more on resale. I needed to wait 18 months to find mine... Worth the wait though.

 

Marco, do not quote me on the numbers, but these should be pretty close to what you can get when maxing out the motors. The 5.0L SC motors are going to max out at 620 hp no so much due to the motor, but due to the transmission. You can get above 620 hp, but you are going to cause excessive wear on the tranny. I seem to remember that the tranny in stock form is limited to like 576 ft-lbs of torque (something in that neighborhood which relates roughly to the max of 620 hp when you look at the curves. So, unless you plan on doing some upgrades to the tranny too, it looks like 620 hp is a good number to keep in mind. This is pretty much a new pulley and a tune. You do aftermarket exhaust or something like that, then you can step above 620 hp.

As for the 3.0L engine, the highest number that I can recall hearing is someone got their motor up to 416 hp with a tune and pulley. I think the motor can probably take a little bit more since it is based on the V8 block, but you only have 75% of the cylinders. So, getting up in the 460-470 hp range I think would be a safe area to go to. Now, with this being said, assuming you have an AWD car, this is going to destroy the transfer case. I got talking with some Jaguar engineers and high ups while I was in London and we got talking about adding AWD to the 5.0L. I was told it had been considered, but the transfer case was limited to 458 ft-lbs of torque (I remember this number specifically). So, they were going to have to at a minimum de-tune a 5.0L to handle the AWD system. hence why you never saw an AWD 5.0L SC car. In theory you should be able to do it to a NA 5.0L engine, but those got stopped in 2014 with the onset of the 3.0L engine. The bolt patterns and block positioning of the 3.0L and 5.0L engines are the same since the blocks are the same size (yes, the 3.0L engine has spots for cylinders 7 and 8, but they are just blanked out with extentions to make things reach across the "gap").

As for getting power upgrades for the NA 5.0L engine, I think you are going to find that it is pretty much a tune and exhaust without going wild into the motor. The gains on the 5.0L engine are going to be very similar to what you are going to get out of the 3.0L supercharged engine. So, which engine you go with, you are going to end up at about the same point. Now, having driven both the NA 5.0L and the SC 3.0L, the transmissions make a world of a difference. The 5.0L I had was mated to a 6 speed. The 3.0L was mated to an 8 speed. I prefer the 5.0L wit the 6 speed because when you went to pass someone, you simply eased into the throttle, the car maintained the gear and around you went. The 8 speed seems to need to downshift a gear to get the RPMs up and allow you to get around. A little more on this. At 70 MPH, the 5.0L engine was turning around 2000 RPM as I recall, the 3.0L is only turning 1500 RPM. So, the 8 speed tranny is definitnely geared a little higher which I find a little oximoronic as the 3.0L is speed limited to 130 MPH where the 5.0L was speed limited to 155 mph.

Hopefully this information will give you something to ponder. Both motors get about the same mileage wise with maybe a slight edge to the 3.0L being slightly better. But, that should be expected with the newer programming and smaller motor.

As for which motor you should get, hard of an answer for me to tell you what to get. All I can say is I find it very rare that I am asking for more power from the car than what it has in stock form. So, the 3.0L or the NA 5.0L is going to be more than adequate. Sure, having the 620 hp 5.0L SC beast would be fun to have. BUt, sit back and honest think about how often you are going ot use that power. Is it worth the extra cost and maintenance?

 

Call me Miss Daisy, but I think my five hundred horses are plenty.

 

The 8 speed ZF tranny is max torque 516 ft/lb

 

If you can wait, just hold out for a V8.

I have noticed what you have, that the late model V8's have dried up. When my Tesla Model S broke down a few months ago, I made a decision right then to replace it with a desirable vehicle that is designed and built to be more reliable, and one that you can fix its weak points to avoid break downs, For me, that was the V8 version of the XJL. I was a bidder on the very nice white 2017 XJL on Bring a Trailer, but the dealer wanted $50K, which was too much for it IMO. I set automatic searches on all the typical car sales sites, and got very lucky when a 2019 V8 Collection popped up in me email box. I immediately called the Mercedes dealer that had it and put a $1000 deposit on the spot. I was able to get it for $46K with 2 years of factory warranty and maintenance remaining and with only 24K miles. Plus, it was local, so I didn't have to pay $2K in shipping, and I didn't have to pay $2500 in auction fees. I don't think that Mercedes dealer knew what they had, especially with 2 years of warranty and being a final edition XJ, so I got very lucky. But since then, nothing good has come up in those automatic searches, so I would have been stuck if I missed it. I am sure something will pop up for you, so don't make the mistake of buying a V6, and then seeing a nice V8 for sale shortly afterwards.

 

If you are ok with a short wheel base, this one is worth a look that just popped up in my inbox today:

https://www.autotrader.com/cars-for-...fd5c2621efd9e6

 

lotusespritse......Thanks much for your input and the tip on the SWB XJ. I keep vacillating on swb vs. lwb but lean more to the big boy for reasons unknown as it would mostly b 2 of us in the car so don't really need a bigger back seat. However, I will take your advice and wait for the right v8. thanks again!
MFT

 

Sorry Thermo but I must disagree on a few of your points!
Firstly, the V6 is much much much easier and cheaper to tune for increased horsepower and torque than the NA V8 (and they start from pretty much the same point), coz SC vs NA.
Secondly, 416 HP out of the V6 is simply the Stage 1 tune from VAP (tune only no pulley), then you have Stage 2 (crank pulley plus tune, 450 HP, wot I have) and Stage 3 (upper pulley as well, 475 HP), so getting up near stock V8 SC power of 503 HP.
Thirdly, lots and lots of XF, XJ and F-Type V6 owners, including those with AWD, have gone with the VAP Stage 2 tune and to the best of my knowledge not one has reported any problems. Dunno about the Stage 3 tune yet, too early to tell.
Fourthly, yes all Jags scrapped the 5.0 NA and switched to the 3.0 SC around 2012/2013, EXCEPT for the XK which soldiered on with the 5.0 NA until 2015.
Last but not least, ZF trans max torque ratings are extremely conservative so I strongly suspect the same for the AWD transfer case ratings.
Bottom line - the OP should not rule out the V6.

 

Hard to believe but that is another late model X351 someone installed a hood leaper on?
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performance mod

 

They do sell leapers with just double sided tape to hold them on. We can only hope at this point...

 

I do love the leaper and had one on my old S-Type but they just look out of place on the modern X351 models.
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Check this one out. Late model long wheel base V8 with nice color combo and good options, only 3500 miles and no accident history!

https://www.autotrader.com/cars-for-...fd5c2621efd9e6

 

lotus, the same dealership has an almost identical car (same year, motor, etc) only with 25K miles on it for $42K. The one you listed they are asking 53K for. Ouch.

 

Huge difference between 3500 miles and 25000 miles. Huge.

I personally would be more than happy to pay that difference for a much newer car of one that you can no longer get new.

 

Here's another nice looking V8 XJL from a private seller:

https://www.autotrader.com/marketpla...fd5c2621efd9e6

 

It’s not even close I’ve had both a 15 XJ SCV6 and my current 16 blacked out XJR. I’ve got both pulleys dual intake cold spark plugs totally customized exhaust by velocity AP and they tuned it and I’m around 680hp and im thinking I’m going to pull my supercharger in the next week or 2 and see if I can’t get it ported and grab another 60-80rwhp. Mine already sets me back in the seat and puts your seat and you can feel the slight G force. It’s so fun. Up there with my friends performance Tesla. Talk about some pull. Don’t settle for less than the supercharged V8 and for $3k you can add about 150ish horsepower. In the bolt one and tuning. Wait if you must don’t settle.