monk302
Founding Member
I have never seen what a clutch can do if it explodes without a scattershield in place. Anyone have a picture of the damage it can produce?
When is it necessary to use a scattershield?
- Thread starter wickedmach1
- Start date
BobV
20+ Year Stangneter 
Here's a nice example of a clutch explosion
For drag racing, scattershields are normally required for anything running faster than 12.00 seconds in the 1/4. As a general guideline, I'd use one on anything over 350hp or 6000 rpm, although it's not a bad idea at lower performance levels as well. NASCAR certainly requires them for most of it's professional classes, and even NASA "recommend"s them for hobby classes. The NASCAR bigboys are running titanium bells, and there were several explosions in the past couple years. I remember one (Derrick Cope(?)) that even got some TV time showing the damage to the transmission.
Scattershields are generally approved to a "SFI 6.1" specification. The test generally involves cutting a flywheel apart while it's turning 7000 rpm - if the housing contains it, it passes. The SFI certification is for 5 years on 6.1, and 2 years on 6.2 & 6.3. The most common APPROVED scattershield material is steel, while the hi-$$$ (ie NASCAR) guys use titanium (~$3000). The are also aluminum scattershields - they are hydroformed from aluminum PLATE, NOT CAST, and typically run over $1000. There are NO Ford manufactured bellhousings which are SFI approved. SFI approval does NOT require membership in their organization either.
Nodular iron bellhousings were used on some trucks for their added torsional rigidity. They reduce flex in hi-torque applications resulting in longer clutch and transmission life. They were NOT designed for clutch containment.
Nodular or ductile iron is still a cast material. It's similar to regular cast iron, but has increased silicon content. It is about 30% stronger, but still fractures when impacted, unlike the 1/4" hydroformed steel in a typical scattershield, which deforms and deflects when impacted.
The link provided earlier give a basic overview of STEEL properties for various grades, but does not address nodular IRON. Iron and steel and NOT the same - kinda like glass and plexiglass - iron can be stronger (depending on what grade of materials we're comparing), but shatters on impact as it has limited elasticity. Here's a nodular iron link which gives a basic overview of nodular iron properties.
For drag racing, scattershields are normally required for anything running faster than 12.00 seconds in the 1/4. As a general guideline, I'd use one on anything over 350hp or 6000 rpm, although it's not a bad idea at lower performance levels as well. NASCAR certainly requires them for most of it's professional classes, and even NASA "recommend"s them for hobby classes. The NASCAR bigboys are running titanium bells, and there were several explosions in the past couple years. I remember one (Derrick Cope(?)) that even got some TV time showing the damage to the transmission.
Scattershields are generally approved to a "SFI 6.1" specification. The test generally involves cutting a flywheel apart while it's turning 7000 rpm - if the housing contains it, it passes. The SFI certification is for 5 years on 6.1, and 2 years on 6.2 & 6.3. The most common APPROVED scattershield material is steel, while the hi-$$$ (ie NASCAR) guys use titanium (~$3000). The are also aluminum scattershields - they are hydroformed from aluminum PLATE, NOT CAST, and typically run over $1000. There are NO Ford manufactured bellhousings which are SFI approved. SFI approval does NOT require membership in their organization either.
Nodular iron bellhousings were used on some trucks for their added torsional rigidity. They reduce flex in hi-torque applications resulting in longer clutch and transmission life. They were NOT designed for clutch containment.
Nodular or ductile iron is still a cast material. It's similar to regular cast iron, but has increased silicon content. It is about 30% stronger, but still fractures when impacted, unlike the 1/4" hydroformed steel in a typical scattershield, which deforms and deflects when impacted.
The link provided earlier give a basic overview of STEEL properties for various grades, but does not address nodular IRON. Iron and steel and NOT the same - kinda like glass and plexiglass - iron can be stronger (depending on what grade of materials we're comparing), but shatters on impact as it has limited elasticity. Here's a nodular iron link which gives a basic overview of nodular iron properties.
BobV
20+ Year Stangneter
One day someone is going follow one of your very uninformed and idiotic suggestions and wind up dead.
Just because automakers spend millions of $$$ on R&D still doesn't make a part worth a popcorn fart (see the recent recall on the Ford GT for faulty control arms). Jump on out of the 60's, fella.
Just because automakers spend millions of $$$ on R&D still doesn't make a part worth a popcorn fart (see the recent recall on the Ford GT for faulty control arms). Jump on out of the 60's, fella.
Thats just to silly!!!!
HistoricMustang
Active Member
I say, I say, do as you wish. Buy parts from someone who pays the manufacturer everytime one is made or from old Joe making parts in his garage after a wild weekend with a bottle of "Night Train Express".
I trust Ford Blue in a very big way!
HistoricMustang
www.historicmustang.com
I trust Ford Blue in a very big way!
HistoricMustang
www.historicmustang.com
Route666
Active Member
Thanks for the link Historic, but it shows alloy steels having better tensile and elastic limits than carbon steels.
BobV, have the SFI people tested standard bellhousings? I think that would be a cheaper way to go if they pass the test.
But surely if a scattershield passes containing an exploded flywheel at 7000rpm then stock ones should be able to contain more. Why they then decided to make redundant and less safe scattershields is beyond me.
Do you see why this sounds ludicrous Historic?
BobV, have the SFI people tested standard bellhousings? I think that would be a cheaper way to go if they pass the test.
But surely if a scattershield passes containing an exploded flywheel at 7000rpm then stock ones should be able to contain more. Why they then decided to make redundant and less safe scattershields is beyond me.
Do you see why this sounds ludicrous Historic?
HistoricMustang
Active Member
Route666
Active Member
Don't you think that's what mindset Ford had when they designed every single car they have sold?
I don't think AM companies can sell stuff based on backwards need.
Example: "Hey come get a bellhousing that's LESS safe than the one already in your car! You'll only have to pay us a few hundred for it, what a deal!!"
They use safety and performance to advertise their wares. I don't think they'd still be around in this day and age if they were lying. False advertising and liability are serious issues especially for companies making safety equipment...
I don't think AM companies can sell stuff based on backwards need.
Example: "Hey come get a bellhousing that's LESS safe than the one already in your car! You'll only have to pay us a few hundred for it, what a deal!!"
They use safety and performance to advertise their wares. I don't think they'd still be around in this day and age if they were lying. False advertising and liability are serious issues especially for companies making safety equipment...
