08 forged bottom end ??
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Dyno Dave
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No, it does not. It uses the piston/rod assemblies from the 6.1L Hemi.
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Cast piston and cracked cap powdered metal forged rod.
MQQNVPR
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Cast does NOT mean junk! And forged does not always mean wonderful!! Most NASCAR teams are now using cast aluminum pistons, albiet a hypereutectic aluminum. I believe the 6.1L Hemi pistons are eutectic alloy, like the previous cast pistons which were 30% stronger than the original forged Viper pistons. They have been fully tested to meet all the demands required and expected. If you're going to any type of forced induction upgrading everything inside should be considered.
The floating pins from the 6.1L Hemi are also a pretty good upgrade vs. previous pressed pins.
The floating pins from the 6.1L Hemi are also a pretty good upgrade vs. previous pressed pins.
No one is questioning the fact that the eutectic alloys arent strong. Hell, they are great pistons really. the problem is, that they are brittle- very brittle. they hold their "shape" better than forged, where a forged piston will deflect and then return when stressed. The eutectic alloy will not deflect- to a point, but then it CRACKS when it does. Not good if you have any detonation which is the equivalent of hitting the piston with a hammer.
I have seen more than one eutectic piston literally crack to peices just from trying to disassemble it off of the rod. The pin, press fit in gen 2/3, "pops" when it comes loose from the rod in a hydraulic press, and that harmonic alone while pressing against the piston with the press at times can shatter the pistons.
The biggest problem however comes from its design, not just its material. The "cast" pistons have very high ring placement, making the ring lands and rings themselves very easy targets for detonation damage.
I have seen more than one eutectic piston literally crack to peices just from trying to disassemble it off of the rod. The pin, press fit in gen 2/3, "pops" when it comes loose from the rod in a hydraulic press, and that harmonic alone while pressing against the piston with the press at times can shatter the pistons.
The biggest problem however comes from its design, not just its material. The "cast" pistons have very high ring placement, making the ring lands and rings themselves very easy targets for detonation damage.
MQQNVPR
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The ring placement has nothing to do wtih cast vs. forged. The rings have been moving up on all engines -- even the Vipers' -- for the past XX years to reduce crevice volume; i.e., unburned hydrocarbons. the MUCH tigher fit to the bores of a cast piston greatly reduces same said crevice volume and reduces cold slap == VERY common with forged pistons.
You'll see anodized top lands and top ring groves because they're moving up into the heat zones.
If you want to send me a PM we can continue there.
You'll see anodized top lands and top ring groves because they're moving up into the heat zones.
If you want to send me a PM we can continue there.
bigmike32172
Viper Owner
I'm thinking every high performance motor should have a forged bottom end.
I mean really, the additional cost at the plant per engine would amount to an extra $200 bucks or so by the time they buy the parts in bulk.
I just look at it as taking the time and effort to build a multi million dollar house with a weak foundation
I mean really, the additional cost at the plant per engine would amount to an extra $200 bucks or so by the time they buy the parts in bulk.
I just look at it as taking the time and effort to build a multi million dollar house with a weak foundation
Disturbed
Viper Owner
Forged = boost/NO2.
hypereutectic = N/A.
hypereutectic = N/A.
Why not just continue it here? This is all on-topic...
I never said the ring placement has anything to do with cast or forged in general, but it certainly does in regards to the Viper, which is what we are talking about. In the Viper engine, the top rings are placed much higher on the euctectic pistons than it is on their forged, earlier counterparts. This, along with the fact of them being hypereutectic in the first place contributes to Forced Induction engine failures.
I am well aware the rings didnt move just because they were eutectic, but they did move going from one piston type to the other, thats the point. The reasoning behind it, a coincidental common goal to reduce HC's if you will, was never my point.
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Forged = boost/NO2 = stronger and more flexible, a bit heavier, less emissions friendly
hypereutectic = N/A = weaker and less flexible, usually lighter and more emissions friendly
Each of the above piston types has their advantages and disadvantages.
I'd prefer strength and durability (forged) with our pistons and I think most of us would as well. Unfortunately, emissions comes into play here with new cars and that can change things from Vipers for sale to no Vipers for sale or too costly.
hypereutectic = N/A = weaker and less flexible, usually lighter and more emissions friendly
Each of the above piston types has their advantages and disadvantages.
I'd prefer strength and durability (forged) with our pistons and I think most of us would as well. Unfortunately, emissions comes into play here with new cars and that can change things from Vipers for sale to no Vipers for sale or too costly.
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