AJ26 vs AJ27 The difference please?
Discussion
The biggest change was the variable valve timing: from the two-stage (on or off) variable cam units to the continually variable cam timing design.
The pistons have bigger cut outs to accomodate the 8 deg earlier intake valve opening (although not on 3.2 and supercharged cars)
The AJ27 has 3 angle valve seats and therefore flow marginally better but doesn't make a lot of difference. The intake cam period changed from 240 to 230.
The injectors are air shrouded and atomise better with larger number of holes- only benefit is getting the engine through emissions.
Different (four-wire) coil packs (two-wire previously).
Physically under the bonnet you'll see the AJ26 engined cars have a large throttle vacuum recepticle resevoir that you dont get on the later AJ27s as the cruise control was electronically controlled by the ECU on the 27.
Higher capacity oil pump is used to feed the new design VVT units with more oil pressure.
EGR valves elmintated for naturally aspirated models and retained for supercharged models only.
Lots of other detail differences.
The pistons have bigger cut outs to accomodate the 8 deg earlier intake valve opening (although not on 3.2 and supercharged cars)
The AJ27 has 3 angle valve seats and therefore flow marginally better but doesn't make a lot of difference. The intake cam period changed from 240 to 230.
The injectors are air shrouded and atomise better with larger number of holes- only benefit is getting the engine through emissions.
Different (four-wire) coil packs (two-wire previously).
Physically under the bonnet you'll see the AJ26 engined cars have a large throttle vacuum recepticle resevoir that you dont get on the later AJ27s as the cruise control was electronically controlled by the ECU on the 27.
Higher capacity oil pump is used to feed the new design VVT units with more oil pressure.
EGR valves elmintated for naturally aspirated models and retained for supercharged models only.
Lots of other detail differences.
Edited by SV8Predator on Saturday 16th November 15:00
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