raeser1300
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Do i need to change rotor in my -99 gen1 motor when installing gen2 crank
Gen2 crank in gen1
- Thread starter raeser1300
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erikjennes
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You need the gen 1 rotor. The PC3 USB needs to setup on a dyno and you need to file a tooth of the idler gear otherwise it wont fit.
For the rest you are ok
Also you need gen 2 crank bearings. Rod bearings are the same.
Don;t forget to put a 1mm or 0.040" spacer plate under the cylinder block.
For the rest you are ok
Also you need gen 2 crank bearings. Rod bearings are the same.
Don;t forget to put a 1mm or 0.040" spacer plate under the cylinder block.
A spacer will get you by, but your playing with fire going about it this way. The extra stroke with the longer rods causes for more extreme rod angles that add unwanted stress to them. I know of several guys that have done this and have resulted in windowing engines due to broken rods.
For roughly the cost of that spacer, you can find a used set of gen2 pistons and rods for anywhere from free-$75. That way you'll have stock gen 2 geometry which will keep your engine happy, reliable, and together.
Is the bore the same size? The crank rods and pistons just a drop in deal to the gen 1 cases?
Yep. The only thing that changes is the rod is shorter to make up for the longer crank, and the wrist pin is slightly higher I think too.
But if the bore size wasn't the same, it wouldn't be a popular upgrade for the gen 2 guys to run a gen 1 block on higher power applications. The gen 2 blocks trnd to crack sometimes, where then gen1 won't. Direct swp.
But if the bore size wasn't the same, it wouldn't be a popular upgrade for the gen 2 guys to run a gen 1 block on higher power applications. The gen 2 blocks trnd to crack sometimes, where then gen1 won't. Direct swp.
Never built a busa motor so didn't know and figures I would ask. Thanks for the info
No prob, other notes worth mentioning is then you would use all gen 2 bearings.
Exactly.
And I don't think a .040 spacer would be enough. Figure if using gen1 rods pistons to keep proper piston to valve clearance. If you up your stroke 2mm you would need to up your spacer to .080 to keep it in spec.
And I don't think a .040 spacer would be enough. Figure if using gen1 rods pistons to keep proper piston to valve clearance. If you up your stroke 2mm you would need to up your spacer to .080 to keep it in spec.
Busashot
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The rods are the same length from Gen I to Gen II. The difference is from the smaller wrist pin and the pin location is moved higher by about 1mm. So I also wondered about the .040 being sufficient especially if the head has been milled or angle milled. I personally don't think the rod angles are that bad to cause the problems you have seen but could be wrong.
Because of the smaller wrist pin I heard some have had issues with reliability in that area.
I have the APE 1441 kit from APE for the Gen I but not yet installed. I wonder if I should exchange the CP pistons for Gen 2 CP pistons with steel wrist pins and run Gen 2 Carrillo rods.
Because of the smaller wrist pin I heard some have had issues with reliability in that area.
I have the APE 1441 kit from APE for the Gen I but not yet installed. I wonder if I should exchange the CP pistons for Gen 2 CP pistons with steel wrist pins and run Gen 2 Carrillo rods.
I guess what really comes down too is how much power your making/how hard you ride. Most of my experience/intel comes from boosted applications over the years. However the ones that failed were even on the low boost stage one bikes. But I've seen a few na apps window blocks too.
Your right. Same rod length, wrist pin is smaller, but moved up 2mm in the piston.
Your right. Same rod length, wrist pin is smaller, but moved up 2mm in the piston.
Busashot
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Hmmm good info for sure. Thanks 4 sharingthis is 1 mod that I considered doing but the risk/reward factor swayed me to reconsider and find HP elsewhere
I wouldn't let this scare you one bit. There has been a lot more successful 1441s than the few that have had issues. Most issues are usually from abuse, poor maintenance, bad install, bad tune or inferior parts to keep price down. Seen it with the most mildest of combinations out there in the car and bike world.
I may go the route of both aftermarket Gen 2 pistons and rods to be closest to manufacturer tolerances for the longevity and reliability I am usually accustomed to seeking. The bonus with the Gen 2 stuff is the piston and rods are a little lighter than Gen 1. This is a bonus towards reliability as far as bearing wear as well as revving characteristics
I was talking to a friend about the gen2 crank in gen1 cases and he said he won't ever do it because the gen1 cases weren't built to handle the stress of the longer stroke. How much more stress does the longer stroke put on the cases?
The cases have nothing to do with it. The gen1 and 2 cases are similar on the inside. To say the cases aren't strong, I would argue the point of the countless 400hp street bikes. Or the 550-600 pro street bikes that make a few hundred pass's a year. What about the 6-700hp lsr guys??? All using stock cases.
Another factor is the bigger the stroke, the more counter weight is added. While stock cranks aren't perfectly balanced, the point of the counterweight on the crank is to offset the throw of the crank.
We had a discussion on suzukihayabusa.org about rod bolts. One of the guys (a very smart engineer) broke down the forces at play on cranks and rods. A very interesting topic, however he have a number something like 150G's is what the piston and rod experience when the piston is at the top of the stroke and the crank yanks it down. If might of been more, but that gives you an idea.
So when you move the stroke out further away from centerline, on the power stroke the rod angle changes faster. So instead of pushing straight down on the rod for longer, it starts pushing off to the side. That's usually when they break.
Another factor is the bigger the stroke, the more counter weight is added. While stock cranks aren't perfectly balanced, the point of the counterweight on the crank is to offset the throw of the crank.
We had a discussion on suzukihayabusa.org about rod bolts. One of the guys (a very smart engineer) broke down the forces at play on cranks and rods. A very interesting topic, however he have a number something like 150G's is what the piston and rod experience when the piston is at the top of the stroke and the crank yanks it down. If might of been more, but that gives you an idea.
So when you move the stroke out further away from centerline, on the power stroke the rod angle changes faster. So instead of pushing straight down on the rod for longer, it starts pushing off to the side. That's usually when they break.
Thanks for all the info. I know the gen2 jugs are weaker but I have only seen people have problems with those at high boost. I'm glad you could clear that up for me man. So if you used the gen2 rotating assembly in a gen1 motor you wouldn't have to use the spacer right because the wrist pin is moved up on the gen2 piston?
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