SrtBrad
Michel Productions
We hardly ever hear about the Viper cars with spun rods. Reason being for the most part is the weight difference between the car and truck.
and i think i like men
and i think i like men
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These trucks that sit with low, low miles are asking for all kinds of issues.
Interesting observations there, BradWe hardly ever hear about the Viper cars with spun rods. Reason being for the most part is the weight difference between the car and truck.
and i think i like men
We hardly ever hear about the Viper cars with spun rods. Reason being for the most part is the weight difference between the car and truck.
and i think i like men
There has been quite a few on the Viper Alley site with spun rod bearings with the Gen3 motor also. So it's not the weight difference.
Interesting observations there, Brad
There has been quite a few on the Viper Alley site with spun rod bearings with the Gen3 motor also. So it's not the weight difference.
Yes I partially agree but not as frequent as the trucks due to the weight difference. If you factor in performance mods and FI then that's also a whole different story. The Viper motor was engineered for the car's weight primarily. Are you saying that weight is not a factor at all? What kinds of conditions and mods were a factor in the cars that spun rods that you talk of? I might be wrong on the weight issue as I don't have actual numbers and charts to back up my understanding but was explained by a reputable Viper shop that weight is a contributing factor to some spun rods.
More weight=heavier load...I don't think the weight is the main problem for the trucks, but I'm sure it's a contributing factor.
I'm sure the issue isn't with the weight of our trucks. After talking with alot Viper race tech's and Todd at Arrow racing and Sean at Roe Racing and after I spun a rod bearing this summer. All have said the most commond reason is under heavey load and high rpm the #3 / #5 crank bearings get starved for oil due to the poor oiling system and inherent problem the Gen3 motor has with the lack of lubricating at high rpm. There is a fix for this problem, like mods for the crank journals and oil pump housing and spring. No one has ever mentioned weight.
More weight=heavier load...I don't think the weight is the main problem for the trucks, but I'm sure it's a contributing factor.
My understanding is the stock gearrotor pumps can cavitate at 5300-5500 RPM under hard acceleration. with either of the 2 oil pump designs.
Other issues.
1. Due to our intake manifold designs #3 tends to run lean causing premature detonation thus pounding the bearings producing excessive heat and resulting in a spun bearing or worse.
2. Our engines due to the long crankshaft design tend to warp in the middle under extreme torque causing the sandwiching of the middle bearings (#3 and #5) causing oil starvation issues which can also result in a spun bearing or worse.
3. Ring land clearance is so thin that detonation can cause fractures causing small pieces to break off and getting stuck in the piston wall or bearing area causing a spun bearing or worse.
4. Having a reading on later 05 and 06 models with more than 1.0 volts on the knock sensor will produce undesirable hammering on the rods which over time will most likely spin either #3 or #5 rods first. I recommend making sure that the knock sensor voltage reads no more than 0.5 volts. At 1.2 volts the knocks sensor retards the timing by 2 degrees.
5. Having too much timing causing most issues listed above will also result a spun bearing at the least.
Ok lets think about this. Yes I agree the oiling system is of a poor design for high rpm and heavy load driving practices. If the oiling system is poor then technically all the bearings would be vulnerable to spinning. Why is it that most cases of spun rods are #3? My opinion is that the flex of the crank starves our #3 bearings resulting in spun rods. The more weight equates to more load which in turn has more flex on our cranks which equals more chance of spun bearings on out trucks over the cars. What's your opinion? There are other factors involved as well including running lean due to intake issues just to mention another contributing factor.
Gear / rotor pumps do not "Cavitate" indepenently. If they suck an "air bubble", they can have a difficult time recovering.
The thread re; Gen III oiling on the Viper Club of America is excellent. The simple, primary issue is Cavitation. (Sucking an air bubble). Either under hard acceleration like SrtBrad stated or high cornering load (G-force). Our trucks are less likely due to deeper oil pan sump and overall less G-Forces. Keeping the oil level at the top end minimum or even just a bit over would be beneficial. I have personally went into a right hand bend with a slight downhill grade at well over a hundred and started braking mid corner. I sloshed enough oil that it came out my valve cover oil cap. Not only did it make a mess, I discovered that my cap o-ring was bad. It is amazing how much the oil moves around and defies gravity in these types of conditions.
Advanced Timing can cause "Pinging". Which is easy to hear and caused by ignition that just too early. Usually does not damage a piston.
Detonation is a monster. Super sonic sound wave caused by fuel mixture self igniting (Usually at the edge of a piston or a sharp edge like a valve relief cut out on piston top). These edges can glow red hot and promote detonation. Our combustion chamber design is not efficient (compare to a narrow angle 4 valve, aluminum, modern motorcycle engine) or flat. Poor quenching of the fuel mixture. You really want to squeeze the fuel mixture towards the center where the plug is (ours is off center).
The best remedie is keep the combustion chamber thermally stable (all aluminum engines like @200F) and give it as cool a charge as possible. An A/F ratio Under 12.6-1 NA is good insurance, I have commented plenty on using an AEM wideband to keep an eye on this. Torries SAFE tunes are smart!!
I would not say the design is "poor". But it looks like you can run into a limitation. Especially if you have a Viper car. Thier pan is shallower than ours.
The bearings themselves don't "spin" in the rod big end. However, if they loose the hydro dynamic barrier (from a passing air bubble), now they will get scored against the crank journal and melt away.
I do have a hard time with the crank shaft literally "flexing" in the block to an extent it overcomes the oil's "hydro dynamic barrier" under the flow and pressure from the pump. The blocks are so very ridged in design and have alot of "webbing" cast into them. The cranks themselves are Forged. I would love to see a block diagram of the engines oiling system to see some possible compromise in the oil feeds to the crank and rod journals.
If I had to take a stab at what happened to SrtDub's engine..... He had dreaded Detonation and or Cavitation. Most likely an lean tune combined with limitations mentioned by SrtBrad in the intake (Starved #3 cylinder) caused a lean condition. SrtDub did state that the pistons on cylinders 3+4 were tight on the rods. This would indicate damage from detonation which can collapse the ring lands and stick a piston in the hole. Now the rod's ability to move has been compromised. Maybe to the extent of bending a wrist pin....Boom!! It will happen in an instant with no real warning.
Any chance of a low oil level in the engine?!? Are you running a "Catch Can" to keep hot oil fumes out of the intake!?
Picturs of pistons SrtDub!?!? You did state no FI on the engine correct!?!
Thanks
Cheers!
Gear / rotor pumps do not "Cavitate" indepenently. If they suck an "air bubble", they can have a difficult time recovering.
The thread re; Gen III oiling on the Viper Club of America is excellent. The simple, primary issue is Cavitation. (Sucking an air bubble). Either under hard acceleration like SrtBrad stated or high cornering load (G-force). Our trucks are less likely due to deeper oil pan sump and overall less G-Forces. Keeping the oil level at the top end minimum or even just a bit over would be beneficial. I have personally went into a right hand bend with a slight downhill grade at well over a hundred and started braking mid corner. I sloshed enough oil that it came out my valve cover oil cap. Not only did it make a mess, I discovered that my cap o-ring was bad. It is amazing how much the oil moves around and defies gravity in these types of conditions.
Advanced Timing can cause "Pinging". Which is easy to hear and caused by ignition that just too early. Usually does not damage a piston.
Detonation is a monster. Super sonic sound wave caused by fuel mixture self igniting (Usually at the edge of a piston or a sharp edge like a valve relief cut out on piston top). These edges can glow red hot and promote detonation. Our combustion chamber design is not efficient (compare to a narrow angle 4 valve, aluminum, modern motorcycle engine) or flat. Poor quenching of the fuel mixture. You really want to squeeze the fuel mixture towards the center where the plug is (ours is off center).
The best remedie is keep the combustion chamber thermally stable (all aluminum engines like @200F) and give it as cool a charge as possible. An A/F ratio Under 12.6-1 NA is good insurance, I have commented plenty on using an AEM wideband to keep an eye on this. Torries SAFE tunes are smart!!
I would not say the design is "poor". But it looks like you can run into a limitation. Especially if you have a Viper car. Thier pan is shallower than ours.
The bearings themselves don't "spin" in the rod big end. However, if they loose the hydro dynamic barrier (from a passing air bubble), now they will get scored against the crank journal and melt away.
I do have a hard time with the crank shaft literally "flexing" in the block to an extent it overcomes the oil's "hydro dynamic barrier" under the flow and pressure from the pump. The blocks are so very ridged in design and have alot of "webbing" cast into them. The cranks themselves are Forged. I would love to see a block diagram of the engines oiling system to see some possible compromise in the oil feeds to the crank and rod journals.
If I had to take a stab at what happened to SrtDub's engine..... He had dreaded Detonation and or Cavitation. Most likely an lean tune combined with limitations mentioned by SrtBrad in the intake (Starved #3 cylinder) caused a lean condition. SrtDub did state that the pistons on cylinders 3+4 were tight on the rods. This would indicate damage from detonation which can collapse the ring lands and stick a piston in the hole. Now the rod's ability to move has been compromised. Maybe to the extent of bending a wrist pin....Boom!! It will happen in an instant with no real warning.
Any chance of a low oil level in the engine?!? Are you running a "Catch Can" to keep hot oil fumes out of the intake!?
Picturs of pistons SrtDub!?!? You did state no FI on the engine correct!?!
Thanks
Cheers!