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Discussion Starter #1 (Edited)
Hello guys I am currently building a 7mgte that I found with a damaged crank. I send the block, crank and front timing cover out to the machine shop and sure enough can’t use that crank. My biggest question is what’s a good crank kit for the bottom end, what have you guys used in the past and how reliable has it been as I want to daily drive it. forged internals can be very expensive if not sure what can be used with what as heat matters a lot on these 7ms. I would like to see numbers above 550whp. Thanks in advance guys. View attachment 247848
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Javier, I've moved this to the MK3 section for better visibility, as this is more of a 'completed projects and their stories' section not a build advice, tech support sort of section.

That said, the best bet is to find a known good 7M crankshaft from another engine and build it from there. There are very few aftermarket 7M crank options and all of them are one-off custom jobs that are very, very expensive.
 

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most 7m's use a crank that is stamped 6m. at some point they went to a differently balanced 7m crank. the balancer matches the crank....so make sure to get the right one you need.




like wreckless says any 7m works, turbo or not (same crank). in addition to getting trashed from spun bearings --which is easy to see -- they also like to twist. in a good block you can spin a good crank by hand, even with it sitting on just the block side bearing halves (motor upside down). i ran into the same issue with the machine shop on my rebuild and i had to buy 2 to get one that was good
 

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most 7m's use a crank that is stamped 6m. at some point they went to a differently balanced 7m crank. the balancer matches the crank....so make sure to get the right one you need.
what balancer?

the 6m/7m never had a balancer as it was internally balanced. It had a damper which is to dampen the torsional vibration of the crank because of it's length which is what the ATI damper is.
 

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I see ati calls it :
ATI Street Super Harmonic Damper 7M-GE 7M-GTE Supra Toyota MKIII 1987-92 918525

my brain is always going to want to say balancer right after harmonic lol (though it is not a balancer)


is the oem damper part number different between 6m / 7m cranks ? it appears the ati would fit both as an 87=6m crank and 92=7m crank
 

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I see ati calls it :
ATI Street Super Harmonic Damper 7M-GE 7M-GTE Supra Toyota MKIII 1987-92 918525

my brain is always going to want to say balancer right after harmonic lol (though it is not a balancer)


is the oem damper part number different between 6m / 7m cranks ? it appears the ati would fit both as an 87=6m crank and 92=7m crank
the part numbers should be the same for the OEM damper across 87-92.When I designed the ATI damper, it was to fit both the 6M or 7M crank.
 

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I have a stock crank for a 7MGTE sitting in my garage if you're interested. Pulling it out of the bottom end this weekend.
 

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Javier,

have you asked around you location to see if anyone reconditions crank? What i mean by that is that there are some shops that can recondition the crank by adding material to the journals (assuming that is where the damage is at) and then machining the journals down to the appropriate size. This trick is used by the same shops to make a stroker crank without having to create the crank from scratch from a blank billet.
 

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What i mean by that is that there are some shops that can recondition the crank by adding material to the journals (assuming that is where the damage is at) and then machining the journals down to the appropriate size.
Last time I priced that out it came out to be roughly $300 per journal just for the repair, not including any work done to other journals. Depending on how much welding needs to be done to the journals the crank will need to be re-straightened afterwards which adds to the cost. If all 6 rod journals need to be done I don't think you'll be able to find any reputable shop willing to do the repairs.

Grinding the journals down brings its own set of issues and from the sounds of things that crank will require too much material removal to be usable in the end.

Given that it's the 6M crank the best option would be to find a good crank, or one that just needs a polish.
 
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