4.2 stoker ????????????

S

SVT_BIRDSC

Registered User
Anyone kno anything about supersixmotorsports.com and their stoker motors are they real and is it worth the money
 
I bought my engine from them. Very Knowledgeable and great service. He can do your heads too. Give Tom a call,, he likes to talk. :)
 
I haven't seen anyone with a stroker motor running a M90 blower. They mostly are running centrifugal blowers. The 4.2 crank isn't forged, it's cast. That's got most people too concerned to try. The main issue being the stress placed on the crank with a roots blower vs a centrifugal. People have broken SC cranks, so there hasn't been a hurry to try a 4.2. I know a couple folks that did try a truck crank (the source for the 4.2 units) broke them. I don't know if it was ever blamed specifically on the blower though as I thought there were tuning issues.
 
I have met Tom from Supersix many times, great bunch of guysa t that shop. I also wouldn't worry about the strength of the 4.2 crank, Matt white95v6 runs 600HP and still has the 4.2 crank holding up just fine. Its turbo'd but still thats a lot of power and TQ for the crank to handle so I think it can handle the roots blower. Matt runs 9's.
 
I also know Tom personally and have seen their 4.2 n/a Mustang run a 12.08. I don't believe that he recommends using a Rootes blower on that package. I'm planning on using his 3.8 long rod package on my next race motor.
 
HP doesn't break cranks, torque (or RPM) does. Think of torque as being a direct measurement of the stress on the crank per ignition event. Forced induction is a torque multiplier. Positive displacement superchargers (roots and lysholm) increase torque across the RPM range. A centrifugial supercharger doesn't increase low rpm torque, which is where torque is usually at its highest. Neither does a turbo.

The problem is the market has it all backwards, you turbo a big engine and super a small engine. Anything else is unbalanced and either prone to failure or unstreetable.

Jason
 
I also spoke to Tom, and . . . . .

I'm also interested in his 4.3 long rod stroker. I called and talked to him a couple of times about my application in an SC, and he seemed very knowledgable and familiar with our cars. Since I will not be out to be the fastest SC on the planet, I think his engine would be great with say, an MPX, or an AR. I asked Tom about theeir new block ("99-2004), whether it was compatible with the SC peripherals (AC/accessories, power steering, etc) and he says it is. Overall I think it'll make a great package. My car has 187k on iit right now, and when it hits about 210-220k, I hope to have the bucks to buy his 4.3. One thing about the pricce bothered me though. You can buy the short block for $3500 and the long block is $7300, so that means his heads are $3800, kind of high, is it not for the heads? :eek:

'95 SC auto, 187k, still strong, APTEN chip, 76/75mm TB/MAF, 5% pulley, SCP exhaust w/Kooks coated shorties.
 
dklitzke said:
I'm also interested in his 4.3 long rod stroker. I called and talked to him a couple of times about my application in an SC, and he seemed very knowledgable and familiar with our cars. Since I will not be out to be the fastest SC on the planet, I think his engine would be great with say, an MPX, or an AR. I asked Tom about theeir new block ("99-2004), whether it was compatible with the SC peripherals (AC/accessories, power steering, etc) and he says it is. Overall I think it'll make a great package. My car has 187k on iit right now, and when it hits about 210-220k, I hope to have the bucks to buy his 4.3. One thing about the pricce bothered me though. You can buy the short block for $3500 and the long block is $7300, so that means his heads are $3800, kind of high, is it not for the heads? :eek:

'95 SC auto, 187k, still strong, APTEN chip, 76/75mm TB/MAF, 5% pulley, SCP exhaust w/Kooks coated shorties.
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Your pricing is off for some reason. Their prices are listed on their website and heads should be about a grand.
 
The main problem with a nodular iron crank is strenght. They are a good peice however they cannot withstand the extra forces the SC setup produces. I'll put it in layman terms best I can.

Consider the SC crank pulley as an extension of the crank. Then think of where the crank is attatched (frontmost main bearing cap). Then think of the belt attached at the outermost set of ribs...

Consider a N/A 3.8 setup with a centrifigal where there is no second set of ribs and the SC runs off the same set as does the rest of the accesories.

At 5,000 RPM's there is allot going on where the belt meets the crank pulley. The further away from that main bearing cap the stronger the material of the crank needs to be so it can withstand certain loads and forces occuring at that location. The closer to that main cap the forces are occuring the less strenght needed to withstand them.

Thats why the SC came with a steel crank as oppossed to a nodular iron one..The extra strenght was needed due to placement of that outer belt..

Sure there are many other factors on why youde want ro need a steel crank in certain applications however power was the least of the many reasons a steel crank was used in that application.

You can use a nodular iron crank however your engines life expectancty will be greatly reduced
 
No, this is not why the SC needed a stronger crank. It needed a stronger crank because of the torque produced by the engine (thanks to the supercharger). Not because it needed more strength to drive the supercharger.

Jason

DamonSlowpokeBaumann said:
The main problem with a nodular iron crank is strenght. They are a good peice however they cannot withstand the extra forces the SC setup produces. I'll put it in layman terms best I can.

Consider the SC crank pulley as an extension of the crank. Then think of where the crank is attatched (frontmost main bearing cap). Then think of the belt attached at the outermost set of ribs...

Consider a N/A 3.8 setup with a centrifigal where there is no second set of ribs and the SC runs off the same set as does the rest of the accesories.

At 5,000 RPM's there is allot going on where the belt meets the crank pulley. The further away from that main bearing cap the stronger the material of the crank needs to be so it can withstand certain loads and forces occuring at that location. The closer to that main cap the forces are occuring the less strenght needed to withstand them.

Thats why the SC came with a steel crank as oppossed to a nodular iron one..The extra strenght was needed due to placement of that outer belt..

Sure there are many other factors on why youde want ro need a steel crank in certain applications however power was the least of the many reasons a steel crank was used in that application.

You can use a nodular iron crank however your engines life expectancty will be greatly reduced
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greenwood_60 said:
No, this is not why the SC needed a stronger crank. It needed a stronger crank because of the torque produced by the engine (thanks to the supercharger). Not because it needed more strength to drive the supercharger.

Jason
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Actually you are wrong.........................

The majority of the stress placed on the crankshaft is at the snout, because of supercharger load. With this load and increased torque provided by the M90 the crank tends to fail just after the 1st Main bearing.
 
Let's just say this, the #1 cause of crankshaft failure is going to be detonation or some other failure of the rods, pistons. The next cause will be failure due to wear and tear, worn journals, lack of lube.

A well tuned, and tightly controlled 4.2 crank will likely be good for a lot of hp. But if you need fudge factor room, the SC crank will give you a little more safety room if things go wrong for a moment.

It's kinda like the stock pistons vs forged pistons. The stockers are damn strong and probably could make quite a bit of power. But once you start going over 400hp at the rear wheels, do you really want a piston to fail by turning into a hundred pieces destroying the engine as they make their way out? I'd prefer the failure mode of a forged piston.
 
Lets say I have alot of experience with nodular iron cranks and the stresses roots type blower setups put on the snout because of teh desighn of teh system. I know this because when I was a poor college student it was cheaper to use factory shortblocks then buy aftermarket. Making close to equal power my stock shortblock held up wonderfully with nitrous and not so wonderfully with my B&M roots blower.

It had nothing to do with detonation although detonation will surely leed to a sooner failure. Never threw a rod or spun a bearing causing a crank failure. I have however twisted nodular iron cranks and not just one...

Not only does the pulley itself from weight alone cause extra stress but where the weight is..Further away from the crank...Then add the stress of the tension on the serpentine belt further away ...Its cumulative...

A perfect tune will not make up for inadequate engineering strenght of parts. Believe me Ford would never have spent the extras $$$ on a steel crank unless they had to. But you can always run an iron crank if ya like..Make some good power and prove me wrong.
 
Try instant psi and high compression. Thats why you can run a centerfugal verses a roots on a cast crank. It builds slowly. Our little engines start out with low compression but hit the gas and instant something like 14:1 under max boost. Im no expert but I did stay at a holliday in last night:D
 
I bet you were not running nitrous at 1500 rpms. I bet you were not dropping the clutch with the NOS button already down. TORQUE BREAKS CRANKS. You can run NOS, turbo, or centrifugal SC with a cast crank, just look at the torque curve of those setups.

The stress put on the crank by the pulley/belt is negligible. Do a little bit or research in to the stress put on the crank durring the ignition stroke, and the stresses put on the crank at high RPM. You would need a accessory belt made from carbon nanotubes to take those kind of forces.

I understand how you could come to your conclusion. If you only pay attention to the HP levels of the engine, your conclusion would sound reasonable. I am sorry, I don't mean to call you out on this, but you are wrong.

Yes, detonation can/will also break cranks, pistons, bearings, rods, etc., but a forged crank is not how you protect your engine from detonation, and that is not how Ford protected the engine from detonation. Ford did take measures to protect the engine from detonation, a forged crank was NOT one of them.

Don't run a positive displacement blower on a cast crank, 3.8 or 4.2. We all know the cast crank SC's were recalled for cranks, why would you want to make the same mistake? Even worse, the longer stroke means more leverage on the crank. Less torque will break the 4.2 crank, period (cast vs. cast or forged vs. forged). You want more displacement, over bore it (I don't know how far you can over bore this engine). There are many better ways to get the power you want. Don't use the cast crank.

Jason

DamonSlowpokeBaumann said:
Lets say I have alot of experience with nodular iron cranks and the stresses roots type blower setups put on the snout because of the design of the system. I know this because when I was a poor college student it was cheaper to use factory shortblocks then buy aftermarket. Making close to equal power my stock shortblock held up wonderfully with nitrous and not so wonderfully with my B&M roots blower.

It had nothing to do with detonation although detonation will surely leed to a sooner failure. Never threw a rod or spun a bearing causing a crank failure. I have however twisted nodular iron cranks and not just one...

Not only does the pulley itself from weight alone cause extra stress but where the weight is..Further away from the crank...Then add the stress of the tension on the serpentine belt further away ...Its cumulative...

A perfect tune will not make up for inadequate engineering strenght of parts. Believe me Ford would never have spent the extras $$$ on a steel crank unless they had to. But you can always run an iron crank if ya like..Make some good power and prove me wrong.
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The stress put on the crank by the pulley/belt is negligible.
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That is so not true. There are many forces that cause a crank to fail obviously. In the case of a LOW POWER SC motor a nodular iron crankshaft will not hold up nearly as well compared to that of a Steel crank. The MODE of failure is not from RPM or Torque alone. Sure they are a necesity as it would take a heck of alot of stress to crack a non spinning motor.......

If we dummy this up even further..

Consider the crank as a see-saw with the pivit point being the main cap. Only thing is this seesaw does not rock its stationary. Consider the left side of the seesaw the enigine side while the right side wil be the balancer /pulley side.

Now for those of us who have played on Seesaws as children understand how even if we are at an equal weight, where we position ourselves on the see saw will give us a weight advantage...Maybe we didnt know why then but we figuired it out. If one of use were heavier...We would have to sit closer to that pivit point to equalize the weight.

Now being our seesaw is stationary at the pivit point what do you supposse happens as we move weight away from that pivit point on the right side. More force is being applied downward....Add more weight even more force. Keep on adding weight and it will eventually break. When it breaks is dependant on the strenght of the seesaws material. Adding weight a foot away from the now stationary pivit point on the right side will cause the failure to occur much later then if you had it 30 feet away...

NOW....Instead of a pivit point we have a bearing. Picture the same scenario but with the seesaw now spinning..Spinning with that extra weight. The further away that weight is once in motion the more stress put on that seesaw at the pivit point. More the weight closer to "pivit point" and there is less stress being created at that point. Also any imbalance after that point toward the right of the pivit point or flex of the actual material will make it only that much worse.

The mode of failure for an SC using a noduilar iron crank would be at or around that virtual "pivit point" which is why ford went with a steel crank. Nodular iron cranks made by Ford have withstood much higher then SC generated hp and torque abuse in the past at sim RPM's...Sure detonation. RPM, Torque all are factory is destroying any engine let alone just a crank..But add those everyday stresses which are unavoidable to the scenario of our pulley setup and THAT i sthe reason why Ford went with a steel crank

Not that I'm an engineer or anything :rolleyes:

May of been a silly and way out there analogy but it ssomething my nephew can even relate to
 
Hmmmm....If it is true about the 4.2, then why dont you do it and tell us when it breaks. There has only been one person that had done it and completed it to my knowledge. He parted out the car after he got it together. Dont think he ever drove it very far. If the 4.2 crank was strong engouh for the snout load of the SC, dont you think Dalke would have a group purchase of rotating assys? Think about it, the top guys running SCs are running 232cid (or .030 over). There is a reason they will find a used SC crank rather then going to the cheaper, new, balanced version of the 4.2 crank.

Chris
 
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