ok here is another theory as the porus block/slipped liner only happen to 3.9/4.0/4.2/4.6 what do all these engines have incoman? lambda sensors! non cat models do not suffer the same engine failure fate
gems stands for generic engine managment it thinks and learns and adpts to the engine compensating to wear
thor is the next level and is fully generic ecu

thus chips that are available for the gems do not make that much difference.
one of my customers has had one of my cruiser engines and a mark adams chip already fitted it is no quicker than the same engine without the chip!

on the thor engine it cannot be chipped and with happily adpt to all the mods you do to the engine
I really cant understand why you keep banging on about lambda sensors wrecking v8's - its just not true.The only reason I can think of why more closed loop engines failed is because there were alot more made and used in more applications.Saying they run lean is crap - using the oxy sensors of the time they could only control around a narrow window of Stoich.If you monitor any of these engines with wideband sensors you can easliy see how they go open loop, drop down to 12/1 under heavy throttle/load and cycle nicely around 14.7/1 when cruisng or at idle.And the Motronic engines hang on to closed loop alot harder than Gems when you push them.So if what you say is true alot more Thor engines should die than Gems.
You just have to face the fact that ANY of the 94mm bore Rover engines CAN have block problems.If they had done top hat liners from the start this discussion would never have started.There simply isnt enough material behind the liners to support the original design,typical cheapskate Leyland. What they should have done is scaled the whole engine up,making the upgrade start at 4.5ltrs with enough room to go out to meet up with a Chev mouse at 5.7ltrs - 350 cu in.
 
I really cant understand why you keep banging on about lambda sensors wrecking v8's - its just not true.The only reason I can think of why more closed loop engines failed is because there were alot more made and used in more applications.Saying they run lean is crap - using the oxy sensors of the time they could only control around a narrow window of Stoich.If you monitor any of these engines with wideband sensors you can easliy see how they go open loop, drop down to 12/1 under heavy throttle/load and cycle nicely around 14.7/1 when cruisng or at idle.And the Motronic engines hang on to closed loop alot harder than Gems when you push them.So if what you say is true alot more Thor engines should die than Gems.
You just have to face the fact that ANY of the 94mm bore Rover engines CAN have block problems.If they had done top hat liners from the start this discussion would never have started.There simply isnt enough material behind the liners to support the original design,typical cheapskate Leyland. What they should have done is scaled the whole engine up,making the upgrade start at 4.5ltrs with enough room to go out to meet up with a Chev mouse at 5.7ltrs - 350 cu in.

What they really should have done for the P38 is binned the ancient Buick based lump and either bought in a decent engine or had one designed for them along the lines of the Lexus quad cam V8.
 
What they really should have done for the P38 is binned the ancient Buick based lump and either bought in a decent engine or had one designed for them along the lines of the Lexus quad cam V8.

Or just kept the penny pinching accountant dudes away from the whole process.
 
What they really should have done for the P38 is binned the ancient Buick based lump and either bought in a decent engine or had one designed for them along the lines of the Lexus quad cam V8.
Sort of,but if you look back at what they needed then,it would have been so cheap to have just scaled it up - there was then no need for it to be multivalve,just reliably bigger,like the LS1 Chev.GM did the same thing for years with the mouse and rat motors,BSA and Triumph did it with the C15 engine,made it a 350,440 and 500.Then CCM made a 580 out of it,simples.
 

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