[RZRBound]

6 miles with the aero stage 3 and there she went. About 3/8" wobble in the primary clutch and vibrating like hell. Was at 7# 6400 running torco mixed to 97 octane. Thought I was being safe. Well, none the less, which direction from here? I'm definitely going billet crank and might as well go low compression forged pistons and I guess good rods. Is this something the average guy can do? What products do you all recommend? Thanks in advance. This definetly sucks the big one :rm_thumbdown:

 

[sandjunkie]

Sorry to hear about your bad luck.

 

[RZRBound]

Thanks. Wasnt planning on this. I wonder if a pinned and weld crank would hold up OK or not and leave the rest alone? If its a major tear down, may just stick with replacing with all the good stuff. Guess it depends on the severity of the replacement.

 

[bioaction2]

Definitely go billet my friend. I tried the pinned crank with the stage 3 and the next week link is the connecting rods.

 

[RZRBound]

That was my first thought. Guess I should stick with it. Might as well do a complete kit with crank, rods, and pistons. Damn the money is pilling up! This thing is worse than the drag car. How much of a pain is it to do this? Also, what happened to that purty avatar bio? haha

 

[Guest]

Sorry to hear that...
I have a K&T turbo and low compression pistons on the way and you aren't giving me the warm and fuzzy..
Hopefully you just have bad luck..but then again so do i...damn!:rofl3:

 

[milosusa]

Sorry to hear that, but I been there too. Hopefully your twisted crank did not do to much damage to case and magneto, like did on mine.:rm_thumbdown:
milos .

 

[Mr331]

Sorry to hear that. Is there a billet stock replacement crank or are they all strokers?

 

[bioaction2]

It's a complete tear down gears and all. Is it hard? No but clean everything good and re torque everything to spec and be thorough

 

[Guest]

Not trying to hijack but a question I have..is crank failure common at 6500 RPMs on such low boost? I thought the failures were at higher RPMs or higher boost or a combo of both?? I want a reliable motor on modest boost...so I am adding some forged 8:1 pistons..I only want to run 10-12 psi or so and I don't want a grenaded mess on my hands...do I need to do more..crank? Rods? From reading here I thought I had the bases covered...

 

[allcool]

Sorry to hear of your crank failure.

I have lots of experience with cranks of all kinds. I myself personally have trued, welded and pinned dozens of multi cyl cranks. Pinning and welding will only help to prevent twisting a crank out of phase.
Pinning and welding does nothing to prevent a bent crank.

If anyone personally experienced in crank rebuilding is telling you a pinned and welded crank will not bend as easy, they are trying to sell you. Unless they are really not a crank expert and just don't know. Some well intentioned, maybe were sold a bill of goods while trying to find a economical solution to this problem.

Think about it. Drilling thru the rod pin to press in a couple of dowel pins, then welding up their ends will help keep crank from spinning/twisting webs to crank pin. No way a pinned and welded crank adds torsional rigidity strength to the oem crank webs, rod pin, or crank snout.

IMO don't waste your money on pinning and welding, thinking it will prevent crank bending, a major cause of RZR crank failure.

Many here have had good luck with the oem crank for stage 1 boosted applications. Others have not.

Just have to decide if a bent crank/broken rod that might take out the rest of the motor when it goes, is worth your $avings compared to going for the billet crank to begin with.

Run a stock crank and know its life is limited for most higher power boosted motors. Or get the solution, a billet Crankworks crank. It will probably be cheaper in the long run. It will hold up to bending forces that will turn the stock crank into a pretzel.

Don't get me wrong, truing a oem crank to .000" run-out, than welding and pinning is a good thing.
It just wont accomplish what most here are looking for.



IMHO, Crankworks billet crank is really a bargain, for what you get...

Billet rods on needle bearings for more RPM's
Replaceable front plain bearing sleeve made from A2 tool steel
Heat treated to 65 HRc Isotropic finish for a friction free surface
Crank is completely rebuildable
0.5 lbs lighter than stock
1 piece center pin (added strength, less flex)
More uniform oiling passages

go billet, you can always get more money...crank up the boost...

 

[sld386]

6 miles with the aero stage 3 and there she went. About 3/8" wobble in the primary clutch and vibrating like hell. Was at 7# 6400 running torco mixed to 97 octane. Thought I was being safe. Well, none the less, which direction from here? I'm definitely going billet crank and might as well go low compression forged pistons and I guess good rods. Is this something the average guy can do? What products do you all recommend? Thanks in advance. This definetly sucks the big one :rm_thumbdown:

Ouch that hurts to hear that happened sorry you had bad luck sounds like my luck. Kevin

 

[milosusa]

Sorry to hear of your crank failure.

I have lots of experience with cranks of all kinds. I myself personally have trued, welded and pinned dozens of multi cyl cranks. Pinning and welding will only help to prevent twisting a crank out of phase.
Pinning and welding does nothing to prevent a bent crank.

If anyone personally experienced in crank rebuilding is telling you a pinned and welded crank will not bend as easy, they are trying to sell you. Unless they are really not a crank expert and just don't know. Some well intentioned, maybe were sold a bill of goods while trying to find a economical solution to this problem.

Think about it. Drilling thru the rod pin to press in a couple of dowel pins, then welding up their ends will help keep crank from spinning/twisting webs to crank pin. No way a pinned and welded crank adds torsional rigidity strength to the oem crank webs, rod pin, or crank snout.

IMO don't waste your money on pinning and welding, thinking it will prevent crank bending, a major cause of RZR crank failure.

Many here have had good luck with the oem crank for stage 1 boosted applications. Others have not.

Just have to decide if a bent crank/broken rod that might take out the rest of the motor when it goes, is worth your $avings compared to going for the billet crank to begin with.

Run a stock crank and know its life is limited for most higher power boosted motors. Or get the solution, a billet Crankworks crank. It will probably be cheaper in the long run. It will hold up to bending forces that will turn the stock crank into a pretzel.

Don't get me wrong, truing a oem crank to .000" run-out, than welding and pinning is a good thing.
It just wont accomplish what most here are looking for.



IMHO, Crankworks billet crank is really a bargain, for what you get...

Billet rods on needle bearings for more RPM's
Replaceable front plain bearing sleeve made from A2 tool steel
Heat treated to 65 HRc Isotropic finish for a friction free surface
Crank is completely rebuildable
0.5 lbs lighter than stock
1 piece center pin (added strength, less flex)
More uniform oiling passages

go billet, you can always get more money...crank up the boost...

Just curious, have many actually a bend cranks do you saw on RZR ? They twist, but I really don't believe they will bend so easily. I really think OEM crank is a pretty good, if you prevent twisting, look even on billet they are worry about that and weld the pin. Sure billet crank is superior to pinned crank, but depend how far you want to go, if you want to just run up to 7500 RPM with boost up to pump gas tolerance I think billet is way overpriced for it. IMHO
milos

 

[bioaction2]

I bent and twisted my first crank, twisted my second one and my third was pinned and welded so the next week link was the rod and that really tore up things when it went. So Im getting a new engine now and Im going with a Billet this time.

 

[GIFF-TURBO]

I bent and twisted my first crank, twisted my second one and my third was pinned and welded so the next week link was the rod and that really tore up things when it went. So Im getting a new engine now and Im going with a Billet this time.

7800rpm and boosting 14psi is no problem for the Billet crank

 

[Banshee84]

Just don't be in a hurry to get a crankworks crank. I think they make like one per week or maybe one a month. :rofl3:

 

[cwspfx]

Just don't be in a hurry to get a crankworks crank. I think they make like one per week or maybe one a month. :rofl3:

X2

 

[bioaction2]

K&T just got a few in as of my call from them a few days ago.

 

[uae]

Sorry to hear that. Is there a billet stock replacement crank or are they all strokers?

Yes i got one from K&T and it is from Crankworks.
we kick the sh&& out of it with 0 problem
we are running the rev @ 8000

 

[uae]

Sorry to hear of your crank failure.

I have lots of experience with cranks of all kinds. I myself personally have trued, welded and pinned dozens of multi cyl cranks. Pinning and welding will only help to prevent twisting a crank out of phase.
Pinning and welding does nothing to prevent a bent crank.

If anyone personally experienced in crank rebuilding is telling you a pinned and welded crank will not bend as easy, they are trying to sell you. Unless they are really not a crank expert and just don't know. Some well intentioned, maybe were sold a bill of goods while trying to find a economical solution to this problem.

Think about it. Drilling thru the rod pin to press in a couple of dowel pins, then welding up their ends will help keep crank from spinning/twisting webs to crank pin. No way a pinned and welded crank adds torsional rigidity strength to the oem crank webs, rod pin, or crank snout.

IMO don't waste your money on pinning and welding, thinking it will prevent crank bending, a major cause of RZR crank failure.

Many here have had good luck with the oem crank for stage 1 boosted applications. Others have not.

Just have to decide if a bent crank/broken rod that might take out the rest of the motor when it goes, is worth your $avings compared to going for the billet crank to begin with.

Run a stock crank and know its life is limited for most higher power boosted motors. Or get the solution, a billet Crankworks crank. It will probably be cheaper in the long run. It will hold up to bending forces that will turn the stock crank into a pretzel.

Don't get me wrong, truing a oem crank to .000" run-out, than welding and pinning is a good thing.
It just wont accomplish what most here are looking for.



IMHO, Crankworks billet crank is really a bargain, for what you get...

Billet rods on needle bearings for more RPM's
Replaceable front plain bearing sleeve made from A2 tool steel
Heat treated to 65 HRc Isotropic finish for a friction free surface
Crank is completely rebuildable
0.5 lbs lighter than stock
1 piece center pin (added strength, less flex)
More uniform oiling passages

go billet, you can always get more money...crank up the boost...

Just curious, have many actually a bend cranks do you saw on RZR ? They twist, but I really don't believe they will bend so easily. I really think OEM crank is a pretty good, if you prevent twisting, look even on billet they are worry about that and weld the pin. Sure billet crank is superior to pinned crank, but depend how far you want to go, if you want to just run up to 7500 RPM with boost up to pump gas tolerance I think billet is way overpriced for it. IMHO
milos

I have seen two, one on stock motor and the other one was on a turbo with 8 PSI only and the rev limiter was stock.