John Mihovetz [ ACCUFAB ] Modifying my crankshaft

[Waldo]

I would think that anything less then 20lbs of boost will be fine and anything over 20 a person at somepoint will have problems.

I'm sure the OEM Ford crank shaft and balancer are more then enough to handle the stress when presented within it's design perimators However , i am no longer within those and am no longer useing the OEM balancer.

Lorenzo,

How many pounds of boost were you running before you began to have issues with your crankshaft and balancer?

I'm currently running 19 pounds of boost with my 4.0 liter Whipple. Does anybody know of any crank and/or balancer failures with that combination?

Best Regards,
Waldo

 

[Rockstar]

24.5 LBS of Boost with the Whipple 4.0 and I have ran the piss out of it, 925 RWHP. No problems.

 

[Fast Freddy]

^^^^ - how many miles?

 

[B.M.F.]

Lorenzo,

How many pounds of boost were you running before you began to have issues with your crankshaft and balancer?

I'm currently running 19 pounds of boost with my 4.0 liter Whipple. Does anybody know of any crank and/or balancer failures with that combination?

Best Regards,
Waldo

Alot of it would depend on how you drive your car aswell. I don't feel there will be as many GT failures as there would be/is in the GT500 crowd as Gt's don't get drag raced alot, not many get street drivin and beat like a dog in comparision to the Gt500 crowd. I feel that 92% of the people with whipples on the Gt's will not have a problem. There are ton's and i mean tons of Gt500's making 750-850+rwhp with no failures, Drag racing and the extreme stress of acceleration are very hard on parts and that is where alot of these problems arise from. So i think for the most part there is not much to worry about. But there will be that one or two cars here and there in the future that make big power that may run into a issue.

 

[Lorenzo]

Waldo I am useing the 19 Lb pully and actually i was unaware of the underlying problem with the key way on the crank.
Now even more interesting was the assumption by John that my engine had been run hard, On the contrary believe it or not i have been very easy on my car, I dont drag race, track, or even do burnouts I have plenty of other things to do that with,honestly i just cruise around on the streets close to home and have only had it over 100 MPH once in the 3500 miles i have put on it.
I have made one big mistake with it in the last 1500 miles and that was the use of AvGas. I have learned after the fact that the fuel i was useing contained Lead. It was evident internally when John dissasembled the motor, also John noticed that my key way for the balancer was in the early stages of failure. I think that was one of the reasons he thought it had run hard. Long story short, I am testimony that the small key way in harmony with added boost can become an issue regardless of how it is driven.

Best Regards,

 

[BlackICE]

I would be interested in seeing photos of what this impending failure looks like. Not that it will really change anything as you have to pull your engine to fix it.

 

[Lorenzo]

OK hold on here. Everyone knows how things can get out of hand on an open forum so to speek. it's one thing to talk about things over a cup of coffee and another to read it in print.
As said before, when left within it's original design im sure everything would be just fine. I had my motor apart for another silly reason and just took the opertunity to upgrade this also.
Who knows, maybe i would have never had an issue, IMHO the OEM keyway does look very small. Now that Bill {Shadowman} and John {ACCUFAB} have performed their magic on my Gal,
I will not have anything to worry about. Bill has went above and beyond the call of duty for me on this project and i couldn't be more pleased with the results. John's motor massaging skills are second to none. My hats off to them both.

 

[Waldo]

Waldo I am useing the 19 Lb pully...Long story short, I am testimony that the small key way in harmony with added boost can become an issue regardless of how it is driven.

Lorenzo,

Thanks for the response. I'm not concerned that the sky is falling, but I am interested in any preventive measures I should consider since I've installed the big Whipple. An ounce of "in-car" prevention now will be less expensive than pulling the engine to install a new crankshaft later.

I would especially welcome any advice from the gents from SVT.

Best Regards,
Waldo

 

[Fast Freddy]

Alot of it would depend on how you drive your car aswell. I don't feel there will be as many GT failures as there would be/is in the GT500 crowd as Gt's don't get drag raced alot, not many get street drivin and beat like a dog in comparision to the Gt500 crowd. I feel that 92% of the people with whipples on the Gt's will not have a problem. There are ton's and i mean tons of Gt500's making 750-850+rwhp with no failures, Drag racing and the extreme stress of acceleration are very hard on parts and that is where alot of these problems arise from. So i think for the most part there is not much to worry about. But there will be that one or two cars here and there in the future that make big power that may run into a issue.

does the GT-500 have the same crank as the GT with the same keyway setup?

 

[B.M.F.]

does the GT-500 have the same crank as the GT with the same keyway setup?

Yup just GT crank does not have provision to drive oil pump.

 

[BlackICE]

Maybe us Whipple owners should upgrade to a TT given all the FUD with the crankshafts. :lol

 

[Hennessey Performance]

John knows his stuff.

 

[Fast Freddy]

Yup just GT crank does not have provision to drive oil pump.

seeing how the Shelby GT-500 has the same keywayed crank as the GT i would like to know how many GT-500's have had problems with the keyway on their crankshafts? there have been way more GT-500's made than GT's. some of these GT's went straight from the factory to Carrol Shelby and got the BIGGER Whipple superchargers installed with a warranty. also alot of GT-500's have had whipples and kenne bell superchargers put on them as well by other tuners than just Shelby. i have never heard of a GT-500 with this problem? has anybody here heard if any of the thousands of GT-500's on the road with whipples and kenne bells have damaged their crankshafts?

last but not least what is the difference in design, weight and fit of the crank balancer on the GT-500 versus the GT?

 

[Fast Freddy]

My understanding is that our crank wasn’t specifically designed for our motor, meaning it was designed beforehand. The weak link lies in the tiny keyway at the end of the crank. Not a huge cause of concern for gen I Whipples or the stock SC but as the rotors grow heavier on the Gen II and III’s they put too much strain on that keyway. If that goes you strip the end of the crank and the flywheel takes off.

Also, regardless of the TT or SC our cranks are not bolted in the middle. Long-term that might reveal itself as a problem.

I’ll double check the above with Shadowman but I believe ACCUFAB can modify our cranks or we can purchase a new one from him that specifically addresses all of the concerns.

how many rotors does the stock GT supercharger have and how many rotors do the various generations of Whipples and Kenne Bell superchargers have? i have seen 2, 3, and 4 lobe designs......

also would a lightweight flywheel help? i have a aftermarket lightweight flywheel in my viper made for racing.......

 

[Fast Freddy]

The issue with the crank is simple. It is fine in the application it was designed for. Adding a Whipple is outside of that design parameter. Now, that does not mean to call Whipple and complain either. Its simple physics and some good old common sense. The keyway is very small, the factory bolt is torque to yield and that combination just is not made for repeated abuse.

For sure, all of the Whipple applications will have crankshaft issues at some time in the future depending on how much it is driven and how hard its driven.

For example on this particular engine, this engine had 3500 miles and I'd suspect relatively hard miles. The keyway was already damaged to the point that we removed the crank and fixed it. I have pictures to display this. I have fixed several of these over the last year. It can go so far that the end of the crank can break off and who knows where the 20 lb balancer will go. The costs to fix at that point is pretty high.

The best fix available is a billet crank. We designed one that also added material to the front of the crank, bigger threads and a larger face for the cam gears to fit against.

Best regards,

John Mihovetz

seeing how the GT-500 has the same keywayed crank design as the GT how many GT-500's have you seen or heard with this problem? there are way more GT-500's on the road with whipples and Kenne Bells than GT's......

also if the weight of the Whipple's heavier rotors are the culprit here wouldn't a lighter balancer and flywheel counteract this weight issue? i am just trying to come up with a solution here that does not require removal of the engine and a rebuild with a new or modified crank that would allow the use of a gen one or gen two 3.3L whipple with boost pressures of 20 psi or less.....

 

[2112]

also if the weight of the Whipple's heavier rotors are the culprit here wouldn't a lighter balancer and flywheel counteract this weight issue?...

If not the flywheel, maybe a better/lighter damper?

 

[Waldo]

...i am just trying to come up with a solution here that does not require removal of the engine and a rebuild with a new or modified crank that would allow the use of a ... 4.0 litre... whipple with boost pressures of ...19... psi or less.....

+1

 

[2112]

+2

 

[BlackICE]

Just bolt on the Gen 3 and smile. If you don't feel comfortable using the Gen 3 with a stock crank, then send it to me.

 

[HHGT]

It would be really appreciated if someone from Ford Engineering stepped in here and put a lot of owners minds at ease....

Someone want to start a poll as to how many Whiplles and which Generation?