Big-time drag racing question
Thread Starter
Melting Slicks
Joined: Apr 2004
Posts: 2,083
Likes: 2
From: Montreal Qc.
Big-time drag racing question
Watching some Funny-Car and Top-Fuel thing on TV right now, and it reminded me I always wanted to know something about the high-level big-dollar guys.
At the end of every run you see a bunch of mechanics frantically pulling the motor apart, V/Cs off, etc. I always wondered just how much of a "rebuild" they do between runs. Do they tear the whole thing down to nothing and put it all back together again, or do they just remove a few parts, check for damage, etc.?
Just wondering cause they always show the first few seconds of the tear-down and i don't know what goes on after that.
TIA for your replies
At the end of every run you see a bunch of mechanics frantically pulling the motor apart, V/Cs off, etc. I always wondered just how much of a "rebuild" they do between runs. Do they tear the whole thing down to nothing and put it all back together again, or do they just remove a few parts, check for damage, etc.?
Just wondering cause they always show the first few seconds of the tear-down and i don't know what goes on after that.
TIA for your replies
Team Owner
Joined: Nov 1999
Posts: 32,782
Likes: 11
From: Former NCM Drag Racing coordinator, National director Corvette Challenge Spring Hill, Tennessee: Whiting, New Jersey
Cruise-In VI Veteran
Cruise-In VII Veteran
Watching some Funny-Car and Top-Fuel thing on TV right now, and it reminded me I always wanted to know something about the high-level big-dollar guys.
At the end of every run you see a bunch of mechanics frantically pulling the motor apart, V/Cs off, etc. I always wondered just how much of a "rebuild" they do between runs. Do they tear the whole thing down to nothing and put it all back together again, or do they just remove a few parts, check for damage, etc.?
Just wondering cause they always show the first few seconds of the tear-down and i don't know what goes on after that.
TIA for your replies
At the end of every run you see a bunch of mechanics frantically pulling the motor apart, V/Cs off, etc. I always wondered just how much of a "rebuild" they do between runs. Do they tear the whole thing down to nothing and put it all back together again, or do they just remove a few parts, check for damage, etc.?
Just wondering cause they always show the first few seconds of the tear-down and i don't know what goes on after that.
TIA for your replies
this will help:
http://www.hotrod.com/techarticles/e...ild/index.html
Thread Starter
Melting Slicks
Joined: Apr 2004
Posts: 2,083
Likes: 2
From: Montreal Qc.
It is a complete engine rebuild between ever round and the also rebuild the clutch.
this will help:
http://www.hotrod.com/techarticles/e...ild/index.html
this will help:
http://www.hotrod.com/techarticles/e...ild/index.html
Thanks for the great link and the quick reply!
Le Mans Master
Joined: May 2002
Posts: 5,446
Likes: 1
From: 10.70 @ 124mph, Stock Bottom End @ 3620lbs, ECS Racing Team Member. The 1st NMCA LSX Index Rumble World Champion. 2011,12,13 Champion
The engine and trans get a make over. 
It is a complete rebuild in 90 minutes. Other areas are inspected too.
It is a complete rebuild in 90 minutes. Other areas are inspected too.
Instructor
Joined: Mar 2006
Posts: 216
Likes: 0
From: Palo Alto California
I remember my high school auto class took a free field trip to the top fuel drag races, and I have never considered seriously drag racing my car since 
. It seemed like everyone and their mom had a 6 second car.
Here is a fun facts list that we also had on the wall.
I like this one - The engines twist the crank (torsionally) so far (20 degrees in the big end of the track) that sometimes cam lobes are ground offset from front to rear to re-phase the valve timing somewhere closer to synchronization with the pistons.
No wonder they need a rebuild.
. It seemed like everyone and their mom had a 6 second car.Here is a fun facts list that we also had on the wall.
I like this one - The engines twist the crank (torsionally) so far (20 degrees in the big end of the track) that sometimes cam lobes are ground offset from front to rear to re-phase the valve timing somewhere closer to synchronization with the pistons.
No wonder they need a rebuild.
Last edited by TUNED87vette; Jul 18, 2007 at 05:02 PM.
Race Director
Joined: Jan 2003
Posts: 15,177
Likes: 90
From: State of Confusion
Good-link, John!
..... as-recently-as 20 years-ago, a savvy, low-bucks tuner didn't necessarily have-to yank the heads and change the rods/pistons after every run:
I recall Dick & Kim Lahaie dropping the oil pan, and removing the rod-caps, to 'read' the bearings for damage and as a means of changing the tune-up for the next run, and if all looked-well, the caps & oil pan went-back onto the bottom of the block, then they decided how to tune the motor for the next session.....
(Lahaie spent a rainy-day in Reading, trying to explain 'reading' the bearings to me, but I was too-naive..... my-loss )
in those days, rounds were every 2+ hours apart (now teams have 75 minutes ), and if they detected something-wrong, they still had ample time to make whole-sale parts-changes.
By '88, when some teams began running loads of pop in-excess of 90%, I believe even Lahaie began swapping rods & pistons every run to ensure quality-parts were on-hand:
when Jim Head and "AA"-Dale Armstrong (Kenny Bernstein ) began running direct-drive, and Gene Snow dropped his gear-ratio into the 2.6-range, the stress on the bottom-end became so-great that it HAD-to-be done.
It's a shame the NHRA no-longer holds 'Le Grande Nationale Molson' @ Sanair, or you could see for-yourself:
I attended the '89 race at Saint-Hyacinthe, and it's international-flavor made it a unique affair.....
Team Owner
Joined: Nov 1999
Posts: 32,782
Likes: 11
From: Former NCM Drag Racing coordinator, National director Corvette Challenge Spring Hill, Tennessee: Whiting, New Jersey
Cruise-In VI Veteran
Cruise-In VII Veteran
I remember one friday night there I broke my rear on the line , it locked up and they had no tow truck to get me off the track. They ran the rest of the night with my car on the line and raced around me. I had to waite till they were done to bring my trailer on the track, unlock the rear and load it up. We worked all that night installing a new rear for the next day. Man I loved it up there.
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Race Director
Joined: Jan 2003
Posts: 15,177
Likes: 90
From: State of Confusion
fans were 'negotiating' prices of souvies, and a some good-looking females got 'complimentary' T-shirts, a few sizes too-small, of-course.
I remember having a hard-time trying to purchase a soft-drink at the track, but beer and bottled water were plentiful, and vendors strolled the pits with small freezers, containing ice cream and fruit, unlike anything I'd seen in the States.