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Discussion Starter #1
I have heard of members mating a 5M head to a 7M block, or better known as the 57MG(T)E. I have an extra head (everything from the block up) that I am in the process of re-building. I intended to build a high HP 5MGTE. ( extrude hone everything, ss valves, forged pistons, rods, MKIII greddy turbo kit, stand-alone ECU, etc, etc. ) I have yet to buy a block, and it occured to me that If I use a 7MGTE block I could get aftermarket parts for the bottom end, and it is damn near bullet proof. What does this involve???? Will the manual transmission from the MKIII fit in the MKII? I want to use the 5m head because the larger valves take heat better in the turbo application.

Thanks,
Christopher
 

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Well, for starters you would need to change pistons in the 7M block to match your 5M head since the 7M pistons have valve reliefs cut for the 24-valve head. The engine mount location on the 7M block for the MKIII would also have to be changed to allow you drop the 7M bottom end into a MKII. This is no big deal since the MKII engine mount locations exist on the 7M block. Mike Lewitz has done this hybrid build. Maybe he could help you out and give you a few more pointers. OTOH, why not just do the popular 7MGTE conversion and be done with it? There are plenty of MKII owners running 7MGTE conversions without any complaints and are quite happy with the results. :)
 

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Heat really shouldn't be an issue with the smaller diameter valves as long as you keep the air/fuel mix and ignition timing in check, along with a good free flowing exhaust system. William B. has found an excellent source for 1mm oversize stainless steel valves for the 7M head if you're concerned about valve heat and heat transfer issues. :)
 

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Hardest problem you'll have is with the crank pulley. The 7M ones have 3 serpentine belts and the 5M one won't fit a 6/7M crank. You'll need one off a 6M to work. I doubt you'd have to worry about the 7M pistons not working. They have such a huge dish that the valves could probably never hit. The downside is that you'll have a mega low compression ratio. Personally I'd buy a 6M or just use the entire 7MGTE engine (better choice).
 

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Discussion Starter #5
My only concern with the 7m swap is the computer wiring. I do not have the readily available cash to do this entire project all at once, it will have to be 2-3k at a time. That means I will have to run the engine with the stock ecu untill I can put the stand alone ecu in it. If there was a kit available to piggy-back the computers, and it could be done fairly easily, then I agree the 7m swap is probibly the best. However, I am looking for a 12 second car, and if that could be done with the stock MKIII ecu, then I will definately go with the 7m. Does anyone know about the transmission??
 

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um, you should be able to run 11's with the 7mgte ecu and a s-afc. i have done the 7mgte swap, including the donor car, stage 3 clutch, wiring, 3in exhauste. hks smf intake, gauges. etc... set me back about $2500.
william

p.s. i bought a set of 1mm oversized ss valves for the race 7mgte im building, set me back $192 shipped and they are new, not used.
 
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