4.0 in a 1995 PWB?

[Serg]

I am looking at a 1995 LWB that has a new engine. The engine was put in by a RR dealer, but it is a 4.0... The owner said they did not want to spend the money on a new 4.2 ($10k) so they put in a new 4.0 ($6k). As far as I know there was only a 3.9 and a 4.2 available for these in the US, with all LWB models getting the 4.2...

What is the 4.0 from? A P38??? How will this engine compare to a 4.2?

Serg

[OkieRover]

Yeah that's a p38 engine.
4.0 and 4.6 were offered.

[Serg]

Ok... so answer this for me:

Is it really cheaper to get a 4.0 than a 4.2 and what is the power output difference on the 2?


Serg

[TerryS]

Serg,
4.0 block came out in 1996, and used in all Disco series 1, then used in early series 2, but in a modified version (cross bolted main bearings) Early, Gems p38 engines were same as Disco series one engines.

4.2 engines are just a longer stroke 3.9, and were used in TVRs, Morgans, and LWB Rovers between 93-95. They are virtually all gone today, and have a completely undeserved reputation for crank failures. They have significantly more low end torque than the short throw 3.9 brother, and 4.0. While there is a noticeable difference in autobox Rangies, a 4.2, coupled to an R380 is a very pleasant improvement, though not nearly as much as a Bosch managed 4.6.
I recently built a 100K 4.2, from scratch, including standard bearings, improved cutter rings, aftermarket cam with similar duration to the LR (soft heat treatment) and replaced the 3.9 in my 110 with it. What a nice change, it can really get out of it's own way now, and pulls hills in 5th hitherto needing 4th and even 3rd.
A 4.0, modified to use older lucas (distributor) ignition, where timing can be advanced, is a nice motor, and provided there is a ready supply for a while, gives live to all our old Buick V8 Rovers a new lease on life.

[Serg]

Thanks Terry... but my question is still not answered... how will this motor fare in a LWB Classic? I am considering purchasing this Rover to replace mine as it has a new engine.. will it be down on power compared to my 4.2?


Serg

[TerryS]

Originally Posted by TerryS

They have significantly more low end torque than the short throw 3.9 brother, and 4.0. While there is a noticeable difference in autobox Rangies, a 4.2, coupled to an R380 is a very pleasant improvement, though not nearly as much as a Bosch managed 4.6.

Sorry, I guess what I said previously needs to be reversed to get to what you want. Yes, you will notice less low end torque, acceleration at lower speeds, without downshifting. Apart from that, not anything else to be concerned about

[Disco Mike]

I agree with Terry, and would suggest that you drive it and see how it feels for you. If you are OK with the power, don't worry about it. As for will it hold up, yes probably alot longer then you will own it.
Mike J.

[Serg]

Gotcha.. thanks.... I started a new thread about some air suspension questions I had..

serg

[Serg]

As I posted in my other post, the owner has put in $10k in the last 6 months and now wants to sell.. there is a rebuild transfer case and a brand new dealer installed 4.0 The rest of the vehicle has 132k on it.. she is asking $5300 obo.. I think for $5k it would be a steal. I can swap over my wheels and tires and some interior bits, as both are same color inside and out...

Any thoughts?


Serg

[Serg]

I bought it for $4900! It runs awesome! .. more details and pics later... I am off to work..


Serg

[OkieRover]

Nice job.

[Serg]

Yeah I can definitely tell the difference... I drove the 4.2 today and it does have more bottom end grunt than my 4.0. However I am happy to have a brand new motor, even if it is down on a power a tad. It just makes too much sense to keep the 4.0 LWB and sell the 4.2 LWB, even though I will miss some of the torque.


Serg

[son of lucas]

serg, you may be interested to know, that, to the best of my knowledge, the 4.0 liter engines are basically rebadged 3.9's....i think land rover merely "rounded up" the displacement, thus giving the 3.9 a more impressive name........this seems to be accurate, as my service manuals list the same bore, stroke, and total displacement for both engines......although there is a difference in the later 4.0 blocks, that being the cross bolted mains, the engine is essentially the same. i could be wrong about this, and if anybody knows for sure, please correct me
and yes, the 3.9/4.0 is not as powerful as the 4.2, but this may not be a problem for you if you dont tow or need to pull the hills on a regular basis, as the 3.9 runs quite well under most circumstances(although you gotta love the 4.2...its a great engine)

[Serg]

Yeah as I read on I realized it is just that... a rebadged 3.9.. dang it, I want more power... but is sure nice knowing I have 6k miles on a dealer installed engine...

Now if I can just figure out what that gear whine is on the freeway under accelerations... grrr...


Serg