Radical Computerectomy
#21
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Yes of course, there's a number of threads on swapping engines, but before you do that get a set of compressions to check if there are compromised cylinder liners. If it takes a long time to crank before ignition, that's a sign and also oil in the induction tube/TB, generally the top end of the engine is too oily on a failed Nik unit. Another thing to check is the timing chain tensioners/guides as early units have plastic parts that fail. Pulling a cam cover will confirm which you have fitted, hopefully they'll have been updated to medal. Along with this, the plastic T stat housing is another item to update to metal.
An OBD reader is a great way of locating and fixing things so that's a priority, many are using the ELM 327 OBD reader, all you're after is the codes & fuel trims.
I'm not sure but are the 2 cars different models in AJ26/27 engines? Or do they have the same engine?
#22
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I feel kind of funny answering a question here, since I'm in the company of people who know volumes more than my few days of research have taught me, but it is my understanding that some time after my '99 was made, Jag started putting iron liners in the blocks. They call those the AJ28 engines. I will do a compression check. My car starts right away, no delay. I guess the restricted performance mode could be caused by the transmission problem (A-drum). I was also warned by a veteran X308 owner that vacuum lines on the throttle body are frequent gremlins. Thanks for the heads up on the code reader, I'll check that one out. My main worry is in getting something that doesn't support Jaguar.
#23
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Count Iblis:
So is the fact that the cams are ground for use with VVT what makes the big difference? In other words, if a non-VVT grind were run in fixed mode, could most of that 12% be made up?
I am curious because VVT has the reputation (among gear heads) for being an "emissions gadget" that can't compete with a fixed cam with a "real" performance grind. The VVT seems like it is easy to control, with only a solenoid valve regulating the engine oil to the VVT piston. Also, it seems that this is something that can be experimented with without risking damage to the engine if I get it wrong. Unlike an error in transmission clutch or air fuel ratio control, which can cause catastrophic damage, a VVT control error will just hurt power.
Instead of fixing the cams, I think I'll experiment with a VVT controller.
So is the fact that the cams are ground for use with VVT what makes the big difference? In other words, if a non-VVT grind were run in fixed mode, could most of that 12% be made up?
I am curious because VVT has the reputation (among gear heads) for being an "emissions gadget" that can't compete with a fixed cam with a "real" performance grind. The VVT seems like it is easy to control, with only a solenoid valve regulating the engine oil to the VVT piston. Also, it seems that this is something that can be experimented with without risking damage to the engine if I get it wrong. Unlike an error in transmission clutch or air fuel ratio control, which can cause catastrophic damage, a VVT control error will just hurt power.
Instead of fixing the cams, I think I'll experiment with a VVT controller.
Specifically its the intake valve closing point, mainly, or IVC, at low speeds you want to close it early, at higher speeds you want to close it later. Its true that the cam profiles NEED to be optimized for the use of VVT- typically the optimal duration comes down about 10-20 degs.
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Panthro (03-24-2019)
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