AJ27 to an AJ26 swap with a twist!
 

I just did this swap from an AJ27 to an AJ26!

I accidentally purchased an engine from an 98 XJ8 for an 99 XK8 & had to do the conversion!


Parts from AJ27 put on the AJ26 engine


Crank shaft pulley


Oil pump /oil sump / lower part of engine that the sump is attached to


Timing chains / TC tensioners both lower & upper / sprockets on camshafts to match the new chains ./ TC guides / VVT sensors showing through the top of both front valve covers / valve covers / Exhaust camshaft on both banks


Flex plate

Front engine cover


Plastic upper intake & throttle body


Question:
I haven’t changed the knock sensors!
I haven’t installed the PAS bank camshaft position sensor (located on the heads next to the firewall) as there is no provisions for it!


Are there be any issues or workarounds that you gentleman know of?
Thank you in advance.

Great thread!

With resolution to all the issues a great addition to the library!

Sometimes it can be difficult to relay technical issues in text format. I apologize if i have offended you or other members with N00b questions or for posting in the wrong section. I am a Jag N00b & did try very hard to find answers through the search feature of the forum prior to posting.

I add my welcome to the forum, and thanks.

I would have thought you would get cam position error codes with that CPS missing. The earlier engine had two position VVTS, and yours, the ones you put back on, are proportional position control. Therefore, they use feedback to determine where they are.
Are you getting any engine codes?

I'm sure others will chime in but I believe you will have to swap the heads. The vanes are different on the camshafts and the lack of the provision is a bummer, unless you can somehow get the ecu programed not to use an input from that sensor.

That was a sincere comment. Having all the swap details in a single thread is a great one to paste into the FAQ stickies.

Only the INTAKE cams need to be swapped (exhaust are the same) but you will need the 'A'bank CMPS mounted or you will get a DTC for that.

bob gauff

Thank you for the welcome. I only lowered the engine in the car & just connected it to the trans but nothing else. I understand this part but am concerned the missing cam position sensor on the left side head. There is no provision for the sensor on the earlier head.

I have already swapped in the later engine AJ27 camshafts with (4 vanes) on both heads. I hope i dont have to swap heads too as most opf the valve seats on the original AJ27 have dropped due to overheating.

Thank you sir.

Thank you. i'll do it & post up pics.

I see noone chimed in on the Knock Sensors. Definitely swap them as I believe they are different. The AJ26 screw in and the AJ27 mount on a stud IIRC.

You never got back with those pics lol. How did the job go? I may be having to do one myself now so just curious what else I may need to know.

Seems like a lifetime ago I remember no details other than I got so involved in the job I didn't have time for pics & It turned out to be a mess for me & an expensive one at that. I gave the car back to the owner. I suggest you lease a new car and donate your jalopy to a firing range. If you have plenty of time on your hands, are inclined to do hours of research on the internet, spend $ on tools that you'll use just for this one job. Make multiple trips to the hardware store, loose some blood & still end up with a pos engine in a finicky English car worth less than a few thousand then good luck!

I started to look into this type of change a while back
thinking there was only a diffrence with the stroke (crank shaft) to make a 3.2 a 4.0 but o! boy was I wrong, heaps of changes from flex plate to heads cams vvt electronic modues to sump
I think if you had a crack in a block then maybe the only part of a AJ26 would be to use the Block and throw the rest away.