Anyone have specs on the aj41 (4.4) I'm gathering lift is the same aj34 and they run a slightly different profile (guessing) however would be nice to know what's in my engine

 

Since this is the Jaguar Forum and not the Rover forum, I'd presume that no one on this forum has actually measured the 4.4L cams. Since the 4.4L was a N/A engine, JLR would most likely try to use the same VVT and camshaft profile/lift. They might have played with the inlet cam timing and cut the timing flats on them different from the 4.2L N/A engine's. You are aware, that the 4.4L heads use a lash cap/bucket that is a different OD than the 4.2L caps that had separate valve clearance shims. This single piece cap made them use valves with longer stems.

 

I was aware of that. One thing I wssnt aware of until I stripped it down is the 4.4 has no dividers in the inlet ports compared to the 4.2 which has them .

The reason I've posted in the jag forum is I was hoping I'd get a JLR tech that would have possibly worked on that particular project.

I would also like to mention that the aj34s built for the range rover also has these heads along with the longer valve stems and different buckets , I was initially under the impression it was only the n/a that only had this head set up and range rover simply used a aj34s straight from a jag with a different/ new sump design .



Aj41 inlet port (no divider)

Aj34 inlet port (dividers)

The cams in question !

 

Count Iblis explained the reasoning for inlet port separators in a thread many years ago. Basically JLR playing around with tumble and swirl into the chambers. It had limited results, so they abandoned this approach in other engines. If you look at 4.0L heads, the inlet ports enter perpendicular to all 4 chambers. On 4.2L engines, the outer ports have an angle going into the chambers. As far as I know, the 4.4 heads flow better without the separators. But if you use 4.4 heads on a 4.2 engine, you need to rework your inlet manifolds. The 4.4L heads are a bit better casting and a little stronger, so are better for higher hp builds. But this doesn't help answer your cam question. You could pull a pair off and have them measured. We would all like this knowledge.

 

Unsure if your aware the heads on the aj34s range Rover are the same design to aj41 so that's the ones you'd put on a jag aj and there wouldn't be any misalignment issues with the bore/combustion chambers/head gaskets As I'm seeing it the aj41 was built first for the range Rover then block modified rrsleve to accommodate the small pistons

I'm thinking the best option to get the camshaft specs is to send two cams over to a shop that have a cam doctor and have them measured

 

After more digging I discovered the land Rover 4.2sc had fixed cams for its first year then switched to vvt corresponding with its power increase .


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No dividers in the inlet ports thats land rover head