Jaguar XJ12 Build Thread
Posted: Sat Feb 25, 2012 12:36 am
Hello FreeEMSers!
Edit: The comment thread can be found here.
The project I am planning is a Jaguar V12 engine transplant from a 1989 XJ-S HE with GM TH400 into a 1972 XJ6. Originally I had planned it for a later car in my possession, my 1979 XJ6L, but some other factors came up, locally. I’m fairly versed in wrenching and a lot of details on these cars. I know plenty of people that look under the hood and just don't know where to begin.
Technology has just jumped a good margin between then and now and I haven’t done a lot in regards to modern custom-EFI tuning, but I'm enthusiastic. I've still got a decent amount of knowledge and practice in DIY electronics. I’m not an electrical engineer by trade, but sometimes I do think about going back to University for it.
I’m short the original ECU & the harness that runs through the car for this project. I’ve got access to my fathers 1982 Daimler Double-Six (UK-spec) and 1985 Jaguar Sovereign HE (Euro/German-spec) for reference, in addition to a 1977 Jaguar XJ12L that has the D-Jetronic EFI setup with the original flat-head design. I'm curious to see how tight modern-EFI and tighter ignition timing (and potentially higher compression) can bring up the MPG numbers on that motor, because it sure was a guzzler.
Above all, the cars share a common chassis, so fitting the motor and transmission will be a bolt-on affair, although I will need to change the springs if I don't want a saggy ride height. I’m versed with a ton of the change between the years of production, but I’m going to need to scavenge at my local junkyards to solve some of the other parts needs that are going to come up. I’ve also got some mechanical schematics to come up with for some of the other adapters I’d like to come up with, since I’d like to make it a fairly open door for other Jaguar owners to go down this path if they desire to, with some of the big issues worked out. I’ve got a few iterations/milestones that I’d like to go through for academic purposes to show the outcome from it.
Basic Transplant Logistic issues to solve:
-Optional: Springs from XJ12 to fix ride height
-Fuel Tank & Pump Transplant from later Series XJ with fuel injection
-Running replacement fuel lines (IE: return line to prevent/minimize vapour lock issues)
-Drive shaft modifications
-Rear diff swap (ratio differences)
-Cooling control
-Tachometer, Speedometer and other gauge issues
-Diagnostic read-out in car)
The Car
Mine actually isn't as nice as the stock photo, presently. It sat for 10+ years in Louisiana with the intake manifold off, and baking the interior, and then has been sitting in my Dad's garage since we came across it in 2000. This must change. The original motor is completely seized and I don't have much hope for it, so my project has a mix of restoration issues to along with the rest of the installation.
----
Tools to obtain (short-list):
-Fuel pressure gauge
-New vacuum gauges
-Multi-channel Logic Analyzer
-Oscilloscope (been jonesing for one for years and need it for my other Jaguar care work)
-Two Wideband O2 sensors for tuning purposes
----
Milestone Overview:
Phase 1:
-One TA Card
-Batch-Fired Injection in 4 groups of Three Injectors (Duplicating the stock ECU grouping)
-Injectors will be wired independently for future stages
-May use resistors for short-term (increasing dead-time) until low-z driver board created/sorted
-Dual VR sensors (60 degrees apart) w/crank wheel
-Optional?: Dual-EDIS VR Conditioner Board
-Conditioner board can drive 6-cyl coil negative inductively driven tach/rev counter
-12 Cylinder Tach appeared for only 1973 and might be shared with the Series 3 E-Type and made of unobtainium
-Some concern on maximum advance available with EDIS
-Use stock throttle position sensor. Replace with stock part if dead-spot is discovered to have known issue with a dead spot
-Dual MAP sensors (one per bank)
-TBD on Control: Fan Relay controlled by FreeEMS
-Use stock aux air valve with balance pipe to regulate cold idle (would like to implement dual IAC later)
-Use stock pair of O2 sensors
Stage 2:
Items to be developed:
-Crank-driven (essentially) Distributor-mounted CAS adapter (mostly for a drop-in solution for other owners)
-IAC adapters for per-bank idle control (bank A and B draw is not balanced in regards to vacuum load)
-Need to source coil-near-plug ignitors for project
Two TA-card build
TA card 1 - Fuel control (semi-sequential)
TA card 1 - Ignition
Breakdown of components TBD
-May spec Hi-Z injectors at this phase, due to single-cycle fire of low-z stock injectors. (Previous generation was specified to fire twice per cycle and low-z, last generation on 1996 XJ12 were high-z Nippon Denso, but made of unobtainium)
Stage 3: One custom board build:
I’ll cross that bridge when I get there, but sequential fuel injection and sequential spark would be nice.
I'm also looking into going from the GM TH400 and doing a 5 or 6 speed manual conversion for the car around this stage. Maybe in stage 4.
Edit: The comment thread can be found here.
The project I am planning is a Jaguar V12 engine transplant from a 1989 XJ-S HE with GM TH400 into a 1972 XJ6. Originally I had planned it for a later car in my possession, my 1979 XJ6L, but some other factors came up, locally. I’m fairly versed in wrenching and a lot of details on these cars. I know plenty of people that look under the hood and just don't know where to begin.
Technology has just jumped a good margin between then and now and I haven’t done a lot in regards to modern custom-EFI tuning, but I'm enthusiastic. I've still got a decent amount of knowledge and practice in DIY electronics. I’m not an electrical engineer by trade, but sometimes I do think about going back to University for it.
I’m short the original ECU & the harness that runs through the car for this project. I’ve got access to my fathers 1982 Daimler Double-Six (UK-spec) and 1985 Jaguar Sovereign HE (Euro/German-spec) for reference, in addition to a 1977 Jaguar XJ12L that has the D-Jetronic EFI setup with the original flat-head design. I'm curious to see how tight modern-EFI and tighter ignition timing (and potentially higher compression) can bring up the MPG numbers on that motor, because it sure was a guzzler.
Above all, the cars share a common chassis, so fitting the motor and transmission will be a bolt-on affair, although I will need to change the springs if I don't want a saggy ride height. I’m versed with a ton of the change between the years of production, but I’m going to need to scavenge at my local junkyards to solve some of the other parts needs that are going to come up. I’ve also got some mechanical schematics to come up with for some of the other adapters I’d like to come up with, since I’d like to make it a fairly open door for other Jaguar owners to go down this path if they desire to, with some of the big issues worked out. I’ve got a few iterations/milestones that I’d like to go through for academic purposes to show the outcome from it.
Basic Transplant Logistic issues to solve:
-Optional: Springs from XJ12 to fix ride height
-Fuel Tank & Pump Transplant from later Series XJ with fuel injection
-Running replacement fuel lines (IE: return line to prevent/minimize vapour lock issues)
-Drive shaft modifications
-Rear diff swap (ratio differences)
-Cooling control
-Tachometer, Speedometer and other gauge issues
-Diagnostic read-out in car)
The Car
Mine actually isn't as nice as the stock photo, presently. It sat for 10+ years in Louisiana with the intake manifold off, and baking the interior, and then has been sitting in my Dad's garage since we came across it in 2000. This must change. The original motor is completely seized and I don't have much hope for it, so my project has a mix of restoration issues to along with the rest of the installation.
----
Tools to obtain (short-list):
-Fuel pressure gauge
-New vacuum gauges
-Multi-channel Logic Analyzer
-Oscilloscope (been jonesing for one for years and need it for my other Jaguar care work)
-Two Wideband O2 sensors for tuning purposes
----
Milestone Overview:
Phase 1:
-One TA Card
-Batch-Fired Injection in 4 groups of Three Injectors (Duplicating the stock ECU grouping)
-Injectors will be wired independently for future stages
-May use resistors for short-term (increasing dead-time) until low-z driver board created/sorted
-Dual VR sensors (60 degrees apart) w/crank wheel
-Optional?: Dual-EDIS VR Conditioner Board
-Conditioner board can drive 6-cyl coil negative inductively driven tach/rev counter
-12 Cylinder Tach appeared for only 1973 and might be shared with the Series 3 E-Type and made of unobtainium
-Some concern on maximum advance available with EDIS
-Use stock throttle position sensor. Replace with stock part if dead-spot is discovered to have known issue with a dead spot
-Dual MAP sensors (one per bank)
-TBD on Control: Fan Relay controlled by FreeEMS
-Use stock aux air valve with balance pipe to regulate cold idle (would like to implement dual IAC later)
-Use stock pair of O2 sensors
Stage 2:
Items to be developed:
-Crank-driven (essentially) Distributor-mounted CAS adapter (mostly for a drop-in solution for other owners)
-IAC adapters for per-bank idle control (bank A and B draw is not balanced in regards to vacuum load)
-Need to source coil-near-plug ignitors for project
Two TA-card build
TA card 1 - Fuel control (semi-sequential)
TA card 1 - Ignition
Breakdown of components TBD
-May spec Hi-Z injectors at this phase, due to single-cycle fire of low-z stock injectors. (Previous generation was specified to fire twice per cycle and low-z, last generation on 1996 XJ12 were high-z Nippon Denso, but made of unobtainium)
Stage 3: One custom board build:
I’ll cross that bridge when I get there, but sequential fuel injection and sequential spark would be nice.
I'm also looking into going from the GM TH400 and doing a 5 or 6 speed manual conversion for the car around this stage. Maybe in stage 4.