I just got a MkIII for my 16th birthday. I was reading some post, before the forum was down, about how the 6M crank makes power on a 7mgte. Where can I get a 6M crank from?
-thank for your help
-thank for your help
6M Crank
- Thread starter suprasonic
- Start date
what year mkIII do you have? 86.5-early 89 MKIII's have the 6m crank already....
they don't necessarily make more power, but they rev faster than the 7m cranks
they don't necessarily make more power, but they rev faster than the 7m cranks
is the 6 any diffrent from the 5me crank?? a friend of mine said a guy by the name of Tom Brown (white supra out of jersey i think, makes like 700 hp) wanted his crank out of his MX73 cressida which has a 5mge because it was a better crank then the 7mge? is that true? the only real reason i could see using a 6 or 5 is because the stroke is shorter and would allow the motor to run higher rpms and rev quicker. which wouldnt be a bad thing for road racing or drifting.
The only difference between the 6M crank and the 7M crank is the 7M crank is fully balanced. This makes it heavier. More reciprocating weight. So Toyota lowered the redline on the 7MGE & GTE engines to 6250 RPM. The 7MGE & GTE with the 6M crank had a 6500 RPM redline. All 7MGE & GTE motors made before 1989 (and some that were made during 1989)had the 6M cranks. The 5M crank will not work in this motor. IRC it's to short length wise. I don't know much else about the 5M crank, But I'm sure it's not a better crank than the 6 & 7M cranks. Few people have found the HP limit on these cranks. And if there is one I have yet heard about it.
6m cranks work in 7m's? This will save me a lot of money when I do a rebuild. (Need a new crank for 7m) These forums are sweet.
If you wish to destroke a 7M the 5M crank is what you use. There is an engine that is like the blacksheep the 6MGE. It is a 3.0 stroke version of the 5MGE, it has about 190 hp. Never came state side, it is one of the best swaps for a MKII. Thats were the 6M crank comes into play. The 7M is the 24V version of the 6M.
I did a little digging and found that Defiant 7m was right about the 5m crank. Not that I would question Defiant on anything to do with this motor, especially where stroke is concerned. But I needed to know more about the 5m crank before I opened my mouth again. Like Defiant 7m said the 5m crank can be used to destroke the 7m motor(rev happy any one?). The only problem arises with the fact that the 7m crank pulley won't fit on the 5m crank. But the 5m crank pulley doesn’t have the same belt pattern as the 7m.
86.5-89 Supras have the 6M crank
89-92 Supras have the 7M crank
There are no power differences, the only noticable differences would be the 6M is slightly more rev-happy. The 6M-equipped 7M's had a higher rev-limit, but that's ECU limited, and changing your crank would do nothing without changing the ECU.
It was done to make the engine feel smoother, with less vibrations, the same reason the engine mounts changed.
6M/7M engines are basically stroked 5M engines, the 5M crank would "fit".
89-92 Supras have the 7M crank
There are no power differences, the only noticable differences would be the 6M is slightly more rev-happy. The 6M-equipped 7M's had a higher rev-limit, but that's ECU limited, and changing your crank would do nothing without changing the ECU.
It was done to make the engine feel smoother, with less vibrations, the same reason the engine mounts changed.
6M/7M engines are basically stroked 5M engines, the 5M crank would "fit".
Yeah, 6ms destroy the POS 5ms. Never again will I drive a 5MGE powered Supra... EVER. I'm still glad that I dont have to get the 7m crank turned, or buy a new one... although I guess it still would be a good idea to.
either my tach is off or i dont have a rev limiter. i have had my cress up to 6500 or higher on my 7m. maybe its because it was an automatic? but anyway, yeah, the 5m crank would be ideal for my car but then i would have to deal with the pulley issue.Jeff Lange said:
I will try to post pics of the 6m and 7m crank. Notice on the 7m that the no 2 and no 5 journals have small balancers on them. I would think a smoother running engine is better than a lighter shaft. I also had my rotating assembly balanced and they did remove some little weight from my crank to balance it. They also balanced my new act clutch preasure plate. Each had some little divits cut to remove weight.
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Toycoma said:
Rev limit is slightly higher than redline. Tach inaccuracy is pretty common as well.
Here are a few pics. The newer (silver) crank is a 7M crank. Which is the crank I stroked because of its added balance. The other is a 6M crank, the pics are okay. You should be able to se the differences.
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dirgle said:
Other problems include getting custom rods and pistons to maintain the desired compression ratio (you could use 5m rods, but would you trust them to high rpm duty?). I've looked into it, and its by no means impossible -- just an expensive way to loose low-end power (while gaining the ability to rev jz-style)