Dumb Question(s).......

[Tusc]

Ok, I've searched the archives but have not found answers to these two yet.

1 - I know that until '00 the pistons were forged, but what parts comprise the bottom end on the V10? Forged crank/rods? How many bolts are on the main caps? Staight/splayed? Basic caps vs billet? What kind of bearings did D-C use?

2 - The C5 uses a "power shaft" inside a tunnel to reach the T56, how is it designed with the Viper?

And one more question that's not quite AS ignorant as the other two...

The wrist-pins... on a V10, which deals with somewhat less stress than a V8 given equal RPM capabilities... why do the wrist-pins in the Viper's V10 tend to be the weak point? Is there something I am missing about the geometry involved?

I ask because, to me, the V10 sounds like an engine that is designed to handle more than its 450hp rating. 450 is a lot of hp, but the mental image I am getting of it is that D-C put out an "LS6" that only makes 305hp. A better way to say it might be that the V10 isn't struggling to handle 450hp but is more taking it in stride. Am I making any sense here? I had a long night....

 

[KenH]

The crank and rods are both forged. The crank has 6 4-bolt main caps which are cross bolted (not sure if they are splayed or at right angles). The bottom end of the Viper is plenty strong with the cast pistons in the later years being the weakest point. Most high output vipers I am aware of are using stock bottom ends for the most part with perhaps a piston change for high boost applications. 1000HP that some cars are approaching on a basically stock bottom end should tell you something about the strength of the assembly.

I have not heard of the wrist pins being a weak point in the Viper.

I think that most would agree that the Viper engine was intentionally overbuilt to be able to take the rigors of roadracing in stride.

--- Ken

 

[JonB]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by KenH:
The crank and rods are both forged. The crank has 6 4-bolt main caps which are cross bolted (not sure if they are splayed or at right angles). The bottom end of the Viper is plenty strong with the cast pistons in the later years being the weakest point. Most high output vipers I am aware of are using stock bottom ends for the most part with perhaps a piston change for high boost applications. 1000HP that some cars are approaching on a basically stock bottom end should tell you something about the strength of the assembly.

I have not heard of the wrist pins being a weak point in the Viper.

I think that most would agree that the Viper engine was intentionally overbuilt to be able to take the rigors of roadracing in stride.

--- Ken

<HR></BLOCKQUOTE>

WHAT KEN SAID !

 

[lleone]

So what was(ere) the dumb question(s)?

;-)

 

[Doug Supercharged Vipers]

No bad questions here.

The engine is a 90 degree V-type lightweight engine. The block is sand cast aluminum alloy with pressed-in dry cast iron liners and cross-bolted iron main caps, 6 Main bearing caps w/4bolts per cap. No. 3 bearing is the thrust bearing. The pistons are forged aluminum (up to 1999, 2000 and up are cast aluminum).
The piston pins are press fit into the rods. The connecting rods are forged steel shot peened. The crankshaft is forged steel, #5 counterweight is notched for the DIS pickup. The camshaft is nodular iron supported by six journals directly in the aluminum block, the thrust plate controls end play...the cam chain is a dual roller.

All model years are good in nature. Only exception would be the 2000 and up cast piston cars are less tolerable to extreme bolt-on modifications, suffice to say, the 2000 are still very durable engines.

Regards,
Doug

 

[KenH]

Per Doug's comments. I have always wondered why the Viper engine does not use CAM bearings, but instead runs it right in the journals in the block. I am assuming there must be some advantage, but I've always wondered what it was and how wear (if it occurs) is handled. Can anyone shed light on this?

--- Ken

 

[Tusc]

...ditto what Ken just said...

And here's Q #3 - what kind of ignition/distributor does the Viper run? In the many pics I have seen under different Viper hoods all I see are the long plenums and runners. Does Viper use something akin in nature to an Opti-spark? Does it run a cam sensor? As far as tuning and engine management, I have heard that there is no knock sensor - is this true? How do you guys tune? How can you reprogram the PCM? Do you have handy programs like LS1 Edit, LT1 Edit, Autotap, or Tunercat? Is the PCM reprogrammable or do you have to burn a chip for it?


Ok, so those are about 20 questions. All of a sudden they're just bouncing around my skull.

 

[KenH]

Distributor? A Viper doesn't need no stinkin' distributor!

The system is distributorless. It is a Direct Ignition System (DIS). About the only thing you can see is a dual coil pack at the rear of the engine which is mostly hidden under the windshield cowling. There are a total of 5 coils and each one fires two cylinders which means that you get a spark on the exhaust cycle as well as on the intake. It uses both crank and cam position sensors and everything is under control of the PCM including things like spark advance.

I don't think there is a knock sensor and you won't find any aftermarket chips for the PCM. That's one of the weakest areas of Viper modification. The only performance PCM was a unit offered by Dodge which is no longer available and rumored not to have been very effective anyway. What little PCM tuning that is going on is mostly through external boxes such as the Roe VEC1 unit. Some of the high-end tuners may be doing something directly with the PCM, but I'm not sure.

Here's a link to an interesting thread on this topic: http://vca1.viperclub.org/ubb/Forum2/HTML/000914.html

--- Ken