Top Fuel smoke

Author
Discussion

protemporum

Original Poster:

68 posts

218 months

Thursday 19th October 2006
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Hello, i've been lurking around here for a couple of weeks now,and i've enjoyed what i have read.
Since the start of transmission i have been watching and enjoying the NHRA coverage on Five.
I have a question: A good percentage of the Fuel cars lay down "top-end" smoke, when they clear the lights and lift-off. When i attended the drags on a regular basis, this sort of smoke was an indication of burnt cylinder heads/piston/ring-land, is this still true, or is there another explanation?
Potemporum.

anonymous-user

62 months

Thursday 19th October 2006
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Assuming it's not down to damage, it can be a result of running wider ring gaps, meaning when the motor's not under load, oil isn't under as much pressure, causing it to make its way through the combustion chambers etc.

This is a known technique for saving pistons in nostalgia fuelers across the pond, albeit they're turning 11k rpm through the lights in some cases (32" tyres etc).

There maybe other reasons for the smoke however...

Flying toilet

3,621 posts

219 months

Thursday 19th October 2006
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Yeah, them Force boys run them lean!

protemporum

Original Poster:

68 posts

218 months

Friday 20th October 2006
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Hello,
thankyou for your promt reply's. 11,000 r.p.m.! nitro-besty, i was there the day Dennis Priddle ran 6.04 at Santa Pod with the front engined, ex-Donovan "Skyjacker" (i think that's what Donovan named all his cars) So what sort of r.p.m. was Dennis winding that 417 too!
Protemporum.

aeropilot

36,658 posts

235 months

Friday 20th October 2006
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nitro-besty said:

This is a known technique for saving pistons in nostalgia fuelers across the pond


Saw lots of evidence of this 2 weeks ago at the California Hot Rod Reunion at Bakersfield........

The nightime Cacklefest just has to be experienced...........although might just have to take a respirator along when I go back over there for it next year....thumbup

anonymous-user

62 months

Sunday 22nd October 2006
quotequote all
protemporum said:
Hello,
thankyou for your promt reply's. 11,000 r.p.m.! nitro-besty, i was there the day Dennis Priddle ran 6.04 at Santa Pod with the front engined, ex-Donovan "Skyjacker" (i think that's what Donovan named all his cars) So what sort of r.p.m. was Dennis winding that 417 too!
Protemporum.

The thing to note with the modern nostalgia fueler technology, is that it's based around small capacity motors and control tyres (i.e. 32-33" tall). From memory, Harris' 265mph pass was using 398ci. In the days of Priddle and co, tyres weren't controlled, so there wasn't a need to rev the nuts of motors. Because of that, and the fact the knowledge and technology back then was fairly simple, something around 6k rpm or so would be the average.

The same should be true of my toy next year. Although I have piddly tyres, so will be short in terms of terminal speeds lol.