Any drag racers out there?

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238
Location
Monterey Park, CA
quote:
Originally posted by Jason Troxell: I thought the 70wt was for alcohol engines which see extreme fuel dilution. [I dont know]
Alcohol fuel engines use 60w. You must realize these top fuel 500ci engines don't have water passages to make them stronger, and produce 6000hp/8400rpm and running 54psi boost. They are started only at the line after being towed there. Leo
 
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308
Location
SF/Bay Area, CA
I've always wanted to understand drag racing engine builder's experiences with using products like SYNERGYN RACING OIL SAE 70. I'm not so much interested in any particular brand as I am with the need for a 70 weight motor oil. Any comments?
 
Messages
238
Location
Monterey Park, CA
I am and run 15w40 Royal Purple. I do know lighter oils in a high hp/tq revving engine can cause spun bearings due to oil shear hence the need for heavier wt single wt oils. BTW the 70w oil is used in top-fuel engines, and I believe those don't even use any coolant. So only the oil is protecting the engine. Here is me at SuperChevy a couple weeks ago with a 12.10 dial in.  - [ May 16, 2003, 12:46 PM: Message edited by: pedaltothemetal ]
 
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308
Location
SF/Bay Area, CA
Dear pedal, This will probably sound like a dumb question. Have the top fuel engine builders found that their engines will not last in the short time frame they're designed to run if they use a "lighter" oil such as an SAE 50 or 40? I've often thought that since they are constantly working to extract fractions of a second out a car that a lighter oil with less viscosity and thus less drag (no pun intended!) on the engine would be an advantage. Do they need the higher vis oil due to larger internal clearances? Thanks for your insights.
 
Messages
238
Location
Monterey Park, CA
I don't know about top fuel. Those cars don't even have a transmission. The multiclutches connected directly to the drive shaft are slipped down the whole pass. So at the start they are using very little of their maximum power they can. So I doubt they need to go to a lighter wt oil to save power. The 70wt oil also performs like a 25w70, and I know the top fuel engines need this viscosity with high film strength to lubricate very hot metals since they don't have water jackets. You surely don't want metal to metal and seizure so the engines blows up. Although dragracers DO use 10 or 20wt single viscosity oils to qualify if they feel a need to. Even if these race oils are single wt they perform like a 0w10 or 5w20. But they do go back to their normal wt racing. Leo
 
The fuel cars(nitro) change oil between each run,as the nitro dilutes the oil very badly.The only weight I know that is used is 70 wt,and as for make it depends on who is sponsoring which car.Force has his Castrol specially mixed,The CSK car uses a special blend of Havoline 70 wt synthetic,Pedregon(Cruz) has Quaker State decals on the side,but I don't know who is making his oil,I'm sure it's a Shell product. I don't run a fuel car,but in my Dodge race car(NHRA Super Street class),I use Quaker State 10w40 right off the shelf at Wally Mart. [ May 19, 2003, 05:19 PM: Message edited by: Chris 2421 ]
 
Messages
238
Location
Monterey Park, CA
Fuel dilution sure makes sense! You can smell the nitro as soon as they start up. Must be running real real rich to avoid detonation with that 54psi boost! This goes for alcohol cars to as Jason Troxell mentioned cause you can smell the alcohol richness too. Leo
 
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22,188
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Colorado Springs
Reliability doesn't really matter on those cars, I mean they install a new short block for every run! Have you ever looked at the size of the ports on the cylinder heads for those suckers [Eek!] **** that's some flow!
 
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