Viper with bottom end failures (thrown rods)??

[MES]

I was just reading here and here
about the Ford Lightning's throwing rods. They are bumping up the boost and/or running nitrous then throwing rods. I was thinking I've never heard of a Viper with a thrown rod or bottom end problem, other than spun bearing or melted pistons. Has anyone ever heard of a Viper motor that let go, and threw a rod? If so what were the circumstances that caused it? Just wondering with all the new supercharger kits what the engine can it actually handle. There are several here with cars making 800 rwhp on a stock bottom motor, so what's the limit? Anybody?

 

[Mike H]

its been very common with vipers that road race all the time...It happened to me.

 

[TOOOFST]

Along with the motor life,compared to stock.

 

[bad viper]

Seems that thisw is also a problem with stroker motors.

 

[Tom F&L GoR]

Textbook engineering says that "load" on the bottom end is mostly due to inertia forces of yanking the con rod and piston assembly up and down. Therefore, engine speed (road race guys with higher rev limiter boxes?) and strokers (more weight and/or piston travel) will be "worse" for the bottom end, much more so than generating more power.

 

[treynor]

I believe with road-raced Vipers, the main failure mode for the bottom end is oil starvation; however, I stand ready to be corrected. The only power-related Viper bottom end problems I've heard of involved large doses of NOS damaging the stock wrist-pin bearing.

 

[GTS Dean]

It would be interesting to find out what the post-mortem on Mumdog's Silver Bullet was. The week before it grenaded at the Motorsport Ranch Finals, he was layin' down the whup-a$$ at TWS. At lunch (TWS), he said he was running pretty much the whole "south 40" back section in 3rd gear on the rev limiter. Bob W., Rob Foster and myself looked at each other in bewidlerment as we considered his comments. You can look at the end results in two ways: 1) his style led to second-fasted overall times for Viper Days at TWS behind BobW. 2) His motor held together for one or two sessions at the MS Ranch finals where he set lap times that were unassailable the rest of the weekend. Bob's motor went another year, mine's still running and Mumford has a new car.

Oh well.....

 

[Paul Hawker]

Believe the major culprit to oil starvation is the stock oil pan. In long sweepers with high G Loads the oil can be sloshed away from the pickup tube. This in turn starves the engine for lubrication and oil cooling. Since the oil pressure gage is damped this oil starvation is unnoticed by the driver.
Simple and inexpensive solution is to replace pan with windage tray equipped pan, which will reduce this sloshing, and provide and additional measure of protection.

I believe it is Mumford's intent to drive thru the corners at such a high rate of speed, that the oil does not have time to slosh.

 

[JonB]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Paul Hawker:
Believe the major culprit to oil starvation is the stock oil pan. In long sweepers with high G Loads the oil can be sloshed away from the pickup tube. This in turn starves the engine for lubrication and oil cooling. Since the oil pressure gage is damped this oil starvation is unnoticed by the driver.
Simple and inexpensive solution is to replace pan with windage tray equipped pan, which will reduce this sloshing, and provide and additional measure of protection. <HR></BLOCKQUOTE>


BINGO, Paul !! Many examples to see this problem


Especially urgent on 1996.5,7,8,9 Gen-II Motors. Even MORE critical if you add slicks or suspension mods that equate to 1.0+ Gs in turns. (Or ACR!)

Commercial:
And we also have a trap-door-baffle kit for 96-99 or 2000+ that can help as well.... but the best fix is to add the Hi capacity pan and windage set, billet 'lifetime' gasket, and the trap doors. [all for $899, cheap insurance.....E-Z install!]

2000+ just need the trap doors!

 

[Mike H]

I am with 1bad.....we have been playing with just about everything. From what I have seen, heat and oil deprevation is the culprit. Now I have 3 row stack oil cooler and radiator, 3 quart Accusump, custon front ductwork to force all the air thru the radiator, (not around it) and we are now replacing bearings every 2-3 races. We see the bearings still showing wear. This year will tell if this setup and maintenace cures the problem.