Found out some interesting news about our stock cranks..

I talked to paul at pauls high performance today and he said the cranks in our cars are forged, He has car making 800rwhp with the stock crank. I was under the impression that we just have cast cranks. He just upgrades to oliver h-beam and jp or diamond pistons. He said especially on blower cars you really do not want to step up to a stroker kit. Due to the cylinder wall thickness. Just some info. I found out as I was going to get a stroker kit for the car. This will save me quite a bit of money if I only have to replace the rods and pistons.

Any one esle do just the rod and piston change and running so serious #'s?

Tom

A stroker kit shouldn't affect wall thickness. Boring causes wall thickness to decrease. I hadn't heard that our cranks were forged but it is possible I suppose. I'm going to stay N/A so I really haven't looked into it.

Hmmm, I think that goes against the conventional wisdom about our cranks.

bigray327 said:

Hmmm, I think that goes against the conventional wisdom about our cranks.

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Why? I never heard of anyone breaking a crank, forged or cast. Vibration or seriously high rpm can break a crankshaft. Like 9000+ rpm.

2mchtoy said:

I talked to paul at pauls high performance today and he said the cranks in our cars are forged, He has car making 800rwhp with the stock crank. I was under the impression that we just have cast cranks. He just upgrades to oliver h-beam and jp or diamond pistons. He said especially on blower cars you really do not want to step up to a stroker kit. Due to the cylinder wall thickness. Just some info. I found out as I was going to get a stroker kit for the car. This will save me quite a bit of money if I only have to replace the rods and pistons.

Any one esle do just the rod and piston change and running so serious #'s?

Tom

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Gt500 is forged and the GT is cast. Yes there are a lot of people that use the stock crank and just replace the rod and piston in the GT , but if you are going to make any serios power then the forged crank is wise thing to do while you are in there . And as far as the stroker goes just dont do the overbore and you will be fine if you are worried about cylinder wall thickness . JMO

Paul's full of shit on this one!

However I did pull apart a stock '05 3-valve motor that had a CAST 8 bolt flange crank in it. It even has pretty little knife edge counter weights, but I can asure you it is cast.

With that said I have not heard of anyone braking a cast or forged crank, other than a few that broke the snout off the end.

When I had my built 2v I had heard about people swapping over to an 05 Gt crank. So I do think that these cranks can hold a good bit of power compared to older versions.

who has broken the snout?? where they supercharged? excessive belt tension??

DirtyDogOfTheDesert said:

Paul's full of shit on this one!

However I did pull apart a stock '05 3-valve motor that had a CAST 8 bolt flange crank in it. It even has pretty little knife edge counter weights, but I can asure you it is cast.

With that said I have not heard of anyone braking a cast or forged crank, other than a few that broke the snout off the end.

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i have heard of a guy on one of the other forums breaking the crank. It broke off right behind the balancer and the timing chain cover. this was on a fi car, but i don't recall if it was a centri or a ts. i do remember he was putting down around 500rwhp.

I know of 1 guy in particular that broke the snout off, on his '03 cobra (forged crank) running a big 3.4 whipple. Not sure exactly what power he was making, but I remember it was big.
I have also heard of a few broken snouts on the 6.8 V-10 cranks running Kenne Bells back when they still made a kit for the V-10 (earlier 2-v stuff). And ALL V-10 cranks are forged.

unfortunately i can't give any details about the guy who broke the snout, except that it was a gt with a stock rotating assembly...and that he was at or over 500rwhp.

Well, I guess that burts my bubble. I was just going to change the rods and pistons and call it a day. But I want the ability to run 700rwph. I thought I was going to save some money. Guess not. I guess I won't be takeing the motor out so soon now. Bummer

2mchtoy said:

Well, I guess that burts my bubble. I was just going to change the rods and pistons and call it a day. But I want the ability to run 700rwph. I thought I was going to save some money. Guess not. I guess I won't be takeing the motor out so soon now. Bummer

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First: Paul is off his rocker. I'm surprised he would say something like that as knowledgeble as he is.

Second: The GT engines come from the factory with a cast crank. There are a few differences between our cranks and the earlier versions. The counterweights are "knife-edged" a bit to reduce windage. However, they still lack the center counterweights that the forged cranks have. This is their only design flaw IF you are shooting for upper rpms. The cast factory crank will live at 700 hp unless your rpm the hell out of it. They do not like rpm ranges over 7000 on a regular basis. The lack of center counterweights will cause the crank to flex and start a serious harmonic vibration that leads to spider webbing and, eventually, failure. I have seen two cast cranks broken in the middle. Two....due to rpm. I broke one of them at 7600 rpm. Broken crank snouts, on the other hand, are usually due to side loading from a centrifugal supercharger. Which leads me to..........

Third: You have a ProCharger. The side slinger mounting is notoriously hard on front bearings and snouts. Peter Del Pino didn't break the snout off his cast crank until he crested the 900 rwhp mark. This will be something that you will need to consider due to your choice of power adder regardless of which crank you decide to use. I've seen forged Cobra cranks and even high dollar aftermarket forged cranks have the snout broken. Stock stroke or stroker. That is mainly due to the radius design of the front snout and how much torsional force is being applied to the snout.

Fourth: Call ProCharger and discuss what kind of power you are interested in making and inquire as to how much boost is necessary with your head unit to achieve that power level. You might need to step up to a different unit that you can drive at a slower speed and still make the power.

Adam used the stock crank in his wifes car...about 600+ rwhp.

Paul is full of shit period, seems like everyone in Michigan is full of shit (maybe with the exception of Livernois and still waiting to hear the truth of the alledged 451 hp engine that ended up not being 451 hp....hmmmmm). Ford hardly ever sponsorsed anyone worth a damn they throw their support to these flakes that work there or their family members, and the businesses are all rip-off's period.

GERMANSHEPERD said:

Paul is full of shit period, seems like everyone in Michigan is full of shit (maybe with the exception of Livernois and still waiting to hear the truth of the alledged 451 hp engine that ended up not being 451 hp....hmmmmm). Ford hardly ever sponsorsed anyone worth a damn they throw their support to these flakes that work there or their family members, and the businesses are all rip-off's period.

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HEY! I'm from Michigan! AND i'm not full of shit, just half full of shit. I've honestly never heard a bad thing about Livernois.

KIMMER said:

HEY! I'm from Michigan! AND i'm not full of shit, just half full of shit. I've honestly never heard a bad thing about Livernois.

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me neither

So what is the consensus on the power holding rating of the stock crank?

Most power I want to make is whatever I can get from 15psi on 91 pump gas. I would like to keep it a 281ci with about 9-9.3 compression.

That car is 99% street and wont see more than 6500rpms.

If I can keep the stock crank, how much work is involved in changing out the rods and pistons? Thanks.

Stock crank will be fine. Engine has to come out to R&R the rods/pistons.

You will need to hone the cylinder walls before changing to forged pistons for sure.