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Replace 4.6 Thor with a gems engine.

1968 Views 6 Replies 6 Participants Last post by  jteuvonnen
Is it possible to fit a gems engine to a Thor vehicle bearing in mind I know I will have to swop a lot over including all sensors
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Blocks are the same except for the crank position sensor mount so you'll need to modify that as well as using all the sensors and the Thor cam sprocket.
don't forget there no mounting for the GEMS Ecu. which is the case and battery cover on the right front you'll need the case behind the battery and the entire engine harness and ecu harness... then figure out how to pair your rigs Bosch BeCM with the GEMS ECU...Then you have to figure out what do about the Bosch ECU on the firewall with the dang cooling fan the bearings fail in and the Bosch ECU harness

considering the amount of work, time involved, custom work... why on earth would you want to do this?

Btw we need to know what year Bosch and what year GEMS.... On this side of the pond we call them Bosch because of the change to Bosch management under BMW. No p38a has ever been "thor" after a day of off roading.:lol:

there is very mature joke in there but I don't dare post it or the higher ups will ban me.
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As the OP mentions swapping over sensors, I took it that he wants to fit an earlier engine but using the Thor ancillaries, so effectively making a replacement engine but using an engine from a GEMS car as the basis. In which case, he would still be using the original Bosch ECU, just swapping the mechanical bits.

The change to Bosch Motronic engine management was nothing to do with BMW, they'd owned Land Rover since 1994, it was due to the GEMS engine management being sufficiently OBD compliant to keep the NAS regulators happy when it became mandatory in the US in 1996 but not sufficiently compliant when OBD2 became mandatory in Europe in 2000. Hence the change in mid 99.
That’s what I understood too Richard... thanks for clarifying. It seems with the ODB compliance to aid in repairs People in the US just junk there River and buy a new one. Europe seems to care and replace parts and hold on to older trucks longer... the P38 guys are the exception.
Isn't OBD mainly concerned about emissions? It might help with some engine problems but I don't think that is the main focus. When Europe lowered emissions standards the manufacturers had to come up better engine management systems and GEMS could not do it so we got Motronic. OBD2 was added to make sure all the new stuff worked correctly.
Why would you swap the Thor engine for a GEMS? It's a major re-wiring project, best done with a donor car. You will need to swap a lot of electronics and do a lot of wiring.

If the Thor engine is dead and you have a healthy GEMS motor, you it easier and faster to repair the Thor engine using parts from a healthy GEMS motor. Just find somebody who knows his way around a TIG welder, cut the crankshaft position sensor bracket from the Thor block and weld it to a GEMS block. If the Thor engine had SAI (Secondary air injection) you may have to swap the heads from the Bosch engine to keep SAI operational.
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