Jesh
Well-known member
whats the most horsepower anyone has heard of 4g63 putting out (reliably) using the stock crankshaft? (i don't care about pistons and rods, i just need to know what the crank can take)
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crankshaft strenght?
- Thread starterJesh
- Start date
Lonewolf64
Well-known member
The crank can handle everything you'll throw at it. It is probably the strongest stock part of the entire engine.
Jesh
Well-known member
thats what i wanted to know. i've heard of people snapping them with 400awhp and wondered if that was just a fluke.
1941Galant
Well-known member
I've never heard of someone snapping a 2.0 crank, but I've seen a few cases where the 2.4 broke.
Mike Reichen made 1098 whp in his Evo2 that has a 6bolt in it with a stock crank.
rgeier11
Well-known member
Like everyone else has said, the 2.0 crank can take anything you throw at it. The 2.4 crank that is used for stroker kits, breaks much easier. I have seen 2 cases where the 2.4 has broken at the #4 rod.
My neighbor's good friends with John Shepherd and told me a while back that John was still running stock crank all the way into the 8s (switched to eagle 4340 crank now). You ain't gonna break one.
punisher
Well-known member
The only reason I have heard of people snapping them is by not running a harmonic dampener.
RedTwo
Well-known member
7 bolts love to crack /ubbthreads/images/graemlins/laugh.gif
holeshotmoe
Well-known member
Reviving this. Came across this thread while searching to find out how I broke a crankshaft, at #2 rod. I didn't build it but I don't think it's a 2.4 crank. Can anyone ID by the casting numbers?
fuel
Well-known member
6 bolt or 7 bolt?
4G63 2.0 has a 88mm stroke while 4G64 2.4 has a 100mm stroke - surely you would know if your engine had a displacement of over 2L or not. You can measure the stroke by measuring the distance from the center of the crank to the center of the rod journal - will be 44mm for 2.0 and 50mm for 2.4 (ie half the stroke).
4G63 2.0 has a 88mm stroke while 4G64 2.4 has a 100mm stroke - surely you would know if your engine had a displacement of over 2L or not. You can measure the stroke by measuring the distance from the center of the crank to the center of the rod journal - will be 44mm for 2.0 and 50mm for 2.4 (ie half the stroke).
holeshotmoe
Well-known member
It's a 6 bolt, and I'm pretty certain it's not a stroker. but will measure the throw tonight. Was operating about 3500 rpm when it started knocking. Shut it off right away so it didn't have time to eat through the bearing. The rod is fine. Thus, I think it must have been cracked and finally just gave up. Luckily when not under heavy load. Just want to make sure I replace with the correct crank, so was wondering if casting markings or other characteristics could be used to quickly identify potential replacements. Anyone know?
The 1357 looks like a job # / repair # that a machine shop might have stamped into it. I could be wrong, but the way that each number is incomplete makes it look like it was stamped by hand.
misfitsnemesis
Well-known member
Yeah stock crank will hold like has been stated already.
Barnes
Well-known member
Holeshotmoe, were you running a solid crank pulley by any chance?
holeshotmoe
Well-known member
Confirmed it's stock...measured 44 mm main center to rod center.
*mains are all about 56.52 mm...the manual specs list 56.68 - 57 mm
*rod journals are all about 44.52...spec dimensions are 44.98 - 45 mm
I was wondering if it has been turned, perhaps resulting in the nitriding being removed and weakening it. It doesn't seem like there is much material missing from the specs, but I don't know what might be typical of normal wear vs commonly removed by machining. It had a stock crank pulley and flywheel. I did notice another marking on the piece as seen below
But again, I would like to know if one can tell from the castings what engine it originated. I'm asking because I found on the web different part numbers for several 2L turbo motors.
*mains are all about 56.52 mm...the manual specs list 56.68 - 57 mm
*rod journals are all about 44.52...spec dimensions are 44.98 - 45 mm
I was wondering if it has been turned, perhaps resulting in the nitriding being removed and weakening it. It doesn't seem like there is much material missing from the specs, but I don't know what might be typical of normal wear vs commonly removed by machining. It had a stock crank pulley and flywheel. I did notice another marking on the piece as seen below
But again, I would like to know if one can tell from the castings what engine it originated. I'm asking because I found on the web different part numbers for several 2L turbo motors.
grocery_getter
Well-known member
Machining is usually done in the multiple of 10 thousandth of about .25mm at a time. Your main journals seem like they were machined one time, and the rod journals were machined twice. If you still have the main and rod bearings, you can also look at the back of the bearing shell for an indicator of bearing size. If you see STD, it means standard size, then there is .25, .50, .75 and 1.0 for undersized choices. All in mm.
Quoting holeshotmoe:
Confirmed it's stock...measured 44 mm main center to rod center.
*mains are all about 56.52 mm...the manual specs list 56.68 - 57 mm
*rod journals are all about 44.52...spec dimensions are 44.98 - 45 mm
I was wondering if it has been turned, perhaps resulting in the nitriding being removed and weakening it. It doesn't seem like there is much material missing from the specs, but I don't know what might be typical of normal wear vs commonly removed by machining. It had a stock crank pulley and flywheel. I did notice another marking on the piece as seen below
But again, I would like to know if one can tell from the castings what engine it originated. I'm asking because I found on the web different part numbers for several 2L turbo motors.
In this picture the crankshaft guy at the machine shop has noted that both the rods and mains have been undercut by .50 mm. This type of marking is fairly common among rebuilders, although there are variations. My crankshaft had RODS - Std written above MAINS - Std on a counterweight just like yours. Std = standard size, as was mentioned above.
On cranks that are nitrided, the process is only effective on the the first .020" to .025". That means that by having a .50 mm undercut, the machine shop has removed that nitriding completely, or left only a few thousands of an inch. This is likely the reason that your crank broke.
Confirmed it's stock...measured 44 mm main center to rod center.
*mains are all about 56.52 mm...the manual specs list 56.68 - 57 mm
*rod journals are all about 44.52...spec dimensions are 44.98 - 45 mm
I was wondering if it has been turned, perhaps resulting in the nitriding being removed and weakening it. It doesn't seem like there is much material missing from the specs, but I don't know what might be typical of normal wear vs commonly removed by machining. It had a stock crank pulley and flywheel. I did notice another marking on the piece as seen below
But again, I would like to know if one can tell from the castings what engine it originated. I'm asking because I found on the web different part numbers for several 2L turbo motors.
In this picture the crankshaft guy at the machine shop has noted that both the rods and mains have been undercut by .50 mm. This type of marking is fairly common among rebuilders, although there are variations. My crankshaft had RODS - Std written above MAINS - Std on a counterweight just like yours. Std = standard size, as was mentioned above.
On cranks that are nitrided, the process is only effective on the the first .020" to .025". That means that by having a .50 mm undercut, the machine shop has removed that nitriding completely, or left only a few thousands of an inch. This is likely the reason that your crank broke.
