ehall
September 14th, 2008, 11:49
My old beater with 338k miles on it is tired and has a few problems, so rather than try to fix it I have decided to replace the whole powertrain. A local reclamation house is clearing out old inventory, so I picked up a '99 engine with 51k miles for $500 and a '94 AW4 with 71k for $200. I'm also going to replace my 231 with a 242 and add an HD chain and Tom Woods SYE, but I have not decided whether to rebuild one myself (about $900 in parts) or buy one custom made from drivetrain.com (about $1500 shipped).
The transfer case and tranny will drop in with no mods required, but the engine will need some effort to retrofit into my '91, and I need somebody to check my plans. I am trying to split this into MUST versus SHOULD categories so I can keep initial costs down--I can do more work later, but some things have to be done before installation can be completed, while some things have high penalty for later replacement so they are essentially MUST items.
Some of the things that MUST be done are dictated by engine differences. For example, the '99 sensors are incompatible with the '91 computer, and most of my old ones are nasty, so those really must be replaced. Likewise the '99 injectors and fuel rail are incompatible, and my old ones are nasty, so those must be replaced too (any recommended replacements appreciated too). Internal cooling parts like water pump and thermostat are mandatory, and of course there are obvious things likd filters, fluids, spark plugs, etc. I do not know of any other parts that must be replaced for the swap to work, so if anybody knows of anything I'm missing here please advise.
Some of things that SHOULD be done and have a high penalty for deferment are motor mounts and brackets, oil pan gasket, rear main seals, timing chain, and the exhaust headers (the intake will be mostly disassembled for fuel rail and engine swap anyway). I am thinking that it would be beneficial to reset the clock on these items by doing the replacement now, and it will be cheaper and easier to do it now instead of later, but I need to keep costs down. Which of these are most important?
Some of these things also have cross dependencies... The timing chain gasket pretty much goes with the oil pan gasket if I understand correctly, so doing one means go ahead and do the other. If I replace the exhaust headers now, I should also replace the rest of the exhaust or else I will need to bridge from 2.5" outlet to 2.25" inlet, plus I will gain nothing from the higher flow if I keep the old cat and muffler. Likewise, the higher flow through the new manifolds will not be utilized with the stock airbox and throttle body, so those should also be replaced quickly too. On the other hand, I can do that stuff later easily enough, I do not NEED the improved performance to complete the engine swap, and I do need to keep the initial costs down. Same thing, it would be easier to replace the battery, alternator, starter, and associated wiring now, but I can do that later too, and there are not even any other major dependencies.
Any advice here appreciated. Motor is coming in Tuesday (I think) and I will not do anything until I can get a real close look at it.
The transfer case and tranny will drop in with no mods required, but the engine will need some effort to retrofit into my '91, and I need somebody to check my plans. I am trying to split this into MUST versus SHOULD categories so I can keep initial costs down--I can do more work later, but some things have to be done before installation can be completed, while some things have high penalty for later replacement so they are essentially MUST items.
Some of the things that MUST be done are dictated by engine differences. For example, the '99 sensors are incompatible with the '91 computer, and most of my old ones are nasty, so those really must be replaced. Likewise the '99 injectors and fuel rail are incompatible, and my old ones are nasty, so those must be replaced too (any recommended replacements appreciated too). Internal cooling parts like water pump and thermostat are mandatory, and of course there are obvious things likd filters, fluids, spark plugs, etc. I do not know of any other parts that must be replaced for the swap to work, so if anybody knows of anything I'm missing here please advise.
Some of things that SHOULD be done and have a high penalty for deferment are motor mounts and brackets, oil pan gasket, rear main seals, timing chain, and the exhaust headers (the intake will be mostly disassembled for fuel rail and engine swap anyway). I am thinking that it would be beneficial to reset the clock on these items by doing the replacement now, and it will be cheaper and easier to do it now instead of later, but I need to keep costs down. Which of these are most important?
Some of these things also have cross dependencies... The timing chain gasket pretty much goes with the oil pan gasket if I understand correctly, so doing one means go ahead and do the other. If I replace the exhaust headers now, I should also replace the rest of the exhaust or else I will need to bridge from 2.5" outlet to 2.25" inlet, plus I will gain nothing from the higher flow if I keep the old cat and muffler. Likewise, the higher flow through the new manifolds will not be utilized with the stock airbox and throttle body, so those should also be replaced quickly too. On the other hand, I can do that stuff later easily enough, I do not NEED the improved performance to complete the engine swap, and I do need to keep the initial costs down. Same thing, it would be easier to replace the battery, alternator, starter, and associated wiring now, but I can do that later too, and there are not even any other major dependencies.
Any advice here appreciated. Motor is coming in Tuesday (I think) and I will not do anything until I can get a real close look at it.