I have a dilemma of sorts on my hands. A local tow company has a small herd of Rovers. A '96 disco, 2 late 90's P-38's and a '88RRC. I have an opportunity to pick up what ever I like for $200 to $500 each. All have titles. The Disco has a broken steering shaft UJ, starts and runs. One of the P-38's has a bad trans and is a 4.6, I think it's a '98. I am thinking of picking up either the RRC (which is pretty gruesome inside) OR the Disco (170K, average to a little better than average inside and out) and the P-38 with 4.6 and using it as a donor for the other one. Here is the question. For those that have done the 3.5/3.9/4.0 to 4.6 swap, was it worth it? The only gas disco's I have had were 3.9's all '94's and '95's.
4.6 litre swap
- Thread starter Leadvagas
- Start date
I pulled a Gems 4.6 from a late model P38 at a salvage yard a little over a year ago. I had it rebuilt and installed this summer. Not a night and day difference but enough to notice and will keep it on the road for a very long time. Easier than an LS or diesel swap I think. More parts were interchangeable than I thought too.
I haven't done the swap myself, but have experienced firsthand the results of a swap. I was navigator in an off-road rally for a driver who put a GEMS 4.6 into his Defender 90. The thing went like hell but between the lousy aerodynamics, thirsty engine, smaller fuel tank, and larger mud terrain tires, it had an effective range of about 125 miles. The performance was a marked improvement over my D1 with the 4-point-slow.
If I was in your shoes I'd do the reverse: cannibalize the P38s to make a GEMS P38 the primary vehicle, but it all depends on what you want in the end.
If I was in your shoes I'd do the reverse: cannibalize the P38s to make a GEMS P38 the primary vehicle, but it all depends on what you want in the end.
Maybe this is bad info but I've also heard...from a few forums that the P38 4.6 is a much better engine than the Discovery 4.6. Maybe because it's an older engine and the aluminum block had better quality control back then. Like I said, might be wrong.
Engine specifications for Discovery and RR went something like this:
- D1 (1996-1999): GEMS 4.0
- P38 (1996-1998): GEMS 4.0 and 4.6
- P38 (1999-2002): Bosch 4.6
- D2 (1999-2002): Bosch 4.0
- D2 (2003-2004): Bosch 4.6
LR used the 4.6 block in the P38 with a GEMS configuration for 3 years until the switchover to the Bosch system. That is why all GEMS 4.6 engines are a direct swap for the GEMS D1. The Bosch 4.6 served for the last 3 years of P38 production until the L322 Range Rover became available with the M62(?) BMW engine. After the introduction of the L322 Range Rover the Discovery inherited the 4.6 block. By then the production quality had deteriorated - worn out tooling or some such - and many 4.6 engines in the D2 suffered from slipped liners or other problems.
I would be more confident in a good outcome from a GEMS 4.6 swap into a D1 than I would from a D2 4.6 swap into a D2.
Nick,
just as interior bits for Range Rovers have always been of better quality than the Discos', so [as the rumors have it] the engine blocks for P38As came from a different supplier than those for D1/D2. Also, the cooling system in P38A seems to have been designed better than D2's.
So, were I to pick one, I'd take a block out of a P38A over that out of a Disco of the same year/same mileage.
Last year I had the chance to buy a 30th Anniv edition P38 with 94K miles - gorgeous color with body-matched trim, interior was in great shape, came with Hawkeye, redone air suspension, owned by a guy I knew who did a lot of work on it himself. Engine sounded beautiful. I'd borrowed it for about a week and was getting to like it. Then I discovered it needed a head gasket job. Up to that point I almost had my wife convinced but that was a deal breaker. I think he scrapped it.
