Broken Or Cracked Crank?
- Thread starter lawdude
- Start date
IW 10% OD
I don't think the balancer contributed to the oil pump loss
I think it was the "shock" of banging the limiter and jumping in and out of WOT. In addition the "clamp" on the crank bolt seemed to be weak from the autopsy that L&M did on it.
I don't think the balancer contributed to the oil pump loss
I think it was the "shock" of banging the limiter and jumping in and out of WOT. In addition the "clamp" on the crank bolt seemed to be weak from the autopsy that L&M did on it.
I talked to an avid road racer (corvette guy) at a shop a few months ago, and he was telling me how he had seen lots of them gernade oil pumps on the track, also due to banging on the limiter.
Oh had that too... LOL
you can see a small crack in the snout
Wow, you dont mess around. When you break something it's catastrophic! :beer:
wow something else to think about
yea, took out the short block but good. The crank, block, pistons, rods, rings, bearings were all shot, bearing were fused to the crank, needed a chisel to get them off.
Wow stk when did this all happen? Recently?
I had an experienced modular engine builder tell me that every single oil pump failure he saw come into the shop had an aftermarket balancer on when it went failed. He told me that there is no way he would ever run one on any if his car's and just recommends doing an upper pulley or going with a larger blower for customers that want more boost.
well IMO, that's a chicken/egg deal, buys with aftermarket OD balancers are more likely pushing the limits more and driving the car harder. So is it the balancer or is it the driving style? :shrug:
Also - the Cobra Jets have a IW balancer on them and are pushed very hard
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The modular cranks are internally balanced so that we don't have to deal with the added mass on the flywheel/flexplate and balancer to "counter act" the torsional vibrations that was so critical on the pushrod cars. With that being said a quality harmonic dampener is imperative on the modular cars especially when utilizing the factory oil pump gears(or leave the factory unit on) They are produced from powdered metal and are very strong with a extremely tight tolerance for a highly efficient operation. However the down fall is that they are very brittle and vibrations and rapid acceleration/deceleration back and forth will cause the oil pump gears to fracture and fail. Early harmonic dampeners(namely underdrive units) did not offer sufficient enough dampening to curb the vibrations in the engines harmonics. The gears can/should be replaced with billet gears in most high performance applications. Unfortunately tolerances can not be held to the same tight specs on the billet gears due to the thermal expansion that is greater then that of the PM gears so there is a slight drop in pumping efficiency. The next issue with the factory pump is oil will be pushed out of the front cover at ~7,800rpm. Both of these issues can be solved with upgrading to the melling oil pump.
The other issue with a harmonic dampner is not with the dampner persay but with the lack of a 2nd key-way. On a NA car a person could get by with a single key-way most of the time(still recommend double for extra piece of mind for little money) however a supercharged application I view it as a mandatory in high performance applications. A single key way is simply not sturdy enough to handle the abuse/strain the Supercharger places on the snout. This is also why I do not like the aftermarket pulleys on the Shelby, 03-04 cobras and lightning that does away with the cage support that the factory uses to help alleviate some of the strain on the front bearing/journal removing this system will increase wear. But not to the degree of cutting the life of the engine to 1/4 of the original design minimums.
The crank itself is a fantastic and extremely tough piece of equipment. There is some concern with the lack of center counter weights and inherit issues with such a long stroke in mean piston speeds but the unit is certainly up to some extreme tasks and will even survive high RPM use to about 8,200-8,500rpm but will need to be checked often in those situations at the end of the race season.
The other issue with a harmonic dampner is not with the dampner persay but with the lack of a 2nd key-way. On a NA car a person could get by with a single key-way most of the time(still recommend double for extra piece of mind for little money) however a supercharged application I view it as a mandatory in high performance applications. A single key way is simply not sturdy enough to handle the abuse/strain the Supercharger places on the snout. This is also why I do not like the aftermarket pulleys on the Shelby, 03-04 cobras and lightning that does away with the cage support that the factory uses to help alleviate some of the strain on the front bearing/journal removing this system will increase wear. But not to the degree of cutting the life of the engine to 1/4 of the original design minimums.
The crank itself is a fantastic and extremely tough piece of equipment. There is some concern with the lack of center counter weights and inherit issues with such a long stroke in mean piston speeds but the unit is certainly up to some extreme tasks and will even survive high RPM use to about 8,200-8,500rpm but will need to be checked often in those situations at the end of the race season.
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I'm new to modding, But does this apply when using a kit like
Lethal Performance 2011-2012 GT500 Boost Upgrade Kit [LP-2011GT500SCBK-L] : Lethal Performance, Performance parts for Ford Mustangs
I'm sure I'm wrong, but just wanted to make sure. The idler pulley is something entirely different I'm guessing.
it does not apply and the idler pulley is something different
^^^ great info in here.
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