You don't need more HP for towing. You need more torque. HP only really becomes a consideration over 3500 RPM. Everything below that is reliant on torque because HP is really only torque at speed.

I'll tell you what may be an even better option for you; look into a set of 4.11 gears. Lowering your gear ratio will give you a ton more usable low end and would be cheaper than any engine swap. Call up Lucky 8 on Monday and talk to Erik or Justin about your options as far as gear sets go. I'm betting that you'll be in the $1000 price range for a set of front and rear gears.

Hell, I'm going to be going to like 4.56s or 5.13s in my Disco and 4.30s in my Silverado at some point. Already have 4.10s in my Mustang and I loved them when the car was still running. Just one more project.

 

thanks for that. I'm beyond doing my own work but I will talk about that option with my shop.

 

Unfortunately the stock 4.0 and 4.6 are down on torque as well so it's a mute point. With any under square engine the torque and hp curves are relatively parallel so it's safe to talk hp numbers if you assume that the cam choice is sane.

​​​​​you trade overdrive rpm for gear multiplication so take that into account.

 

That's not quite true. The 4.6 only made about 215 hp, but laid down around 300 lb/ft torque at the crank. I think when I measured mine (somewhat innacurately, albeit) she recorded 235 hp and 315 torque at the wheels, following all the work I had done to it. Cam, port/polish, intake, and exhaust work. That was before headers which also gave a noticeable bump in power.

300 lb/ft is plenty usable and its definitely down low on these engines. Plus, the disco has around a 4.10 final drive from the factory. It has 3.42 or so gears, but the transfer case is lower than 1:1. The 4.11 gears would actually take it to about a 4.5X or something if I remember the math I did correctly.

 

I don't agree that 300ft/lb is enough torque. It's barely suitable for the vehicle itself, let alone the one you tack onto the back. Not to mention the nice big flat spot in the curve around 3,000 rpm.

No, I would much prefer something closer to 400 ft/lb at 23-2500 and still relatively smooth curve up to red line.
​

 

How about a Boss 302?

 

A smoother curve would be nice, but even my 08 Silverado only puts down about 290 lb/ft at the wheels in stick form. The new ones rated at like a 10,000lb tow capacity probably only do 30-40 lb/ft more than that and they're geared higher and weigh more than the disco.

 

Check out todco in Georgia or acr across the pond for engines. They are as good as turner and are cheaper with various option on the Thor engines from the 4.0 up to the 5.0. They offer a 4.8l stroker that has great torque around the curve.

Price for the engine is as below. This is as per our special
web offer.

4.8 SHORT STROKE HI TORQUE 240 – 245 BHP @ 5300 RPM, 285 –
290 FTLB @ 2700 RPM FULL PACKAGE STRIPPED ENGINE

ACR’s Hi torque version of the well regarded Sports variant.
Superb upgrade for late model Range Rover P38 models where this
engine fits straight in with no other modifications. Power is
right where its needed at low to mid speed RPM. Built with the
same robust bottom end as the
sports engine, including forged pistons, the Hi Torque
utilises a milder camshaft and either our stage 1 ported heads,
or for a little extra cost upgrade to the CNC ported big valve
heads.
Supplied as a stripped engine.

With Stage 1 heads exchange £ 3799.00
With CNC big valve upgrade £ 4327.00


Core charge as no exchange is £ 450.


The ECu rechip is £ 385. Need your ECU to do. Its a soldering
job.

 

I have yet to come across any D2 whether V8 or TD5 that has problems towing. IMHO there seems to be another problem somewhere. Admittedly in mine I could have gone faster than 80mph but it then guzzles fuel. It depends what sort of speeds one wants to achieve both uphill and on the level, I reckon there is some problem with the trailer on the overrun brakes causing them to bind. For towing you obviously need torque rather than HP but there is a correlation between HP and torque. A long stroke engine, like the D2, should create sufficient torque to tow a trailer up to the stated weight quite comfortably so all I can imagine is another problem, possibly the trailer braking system, causing the tardiness of the rig. If the D2 is OK without the trailer there should be no problem with the trailer IMO.

 

Just a standard coyote with different intake and cams. And tune.