More punch off the line
Thread Starter
Racer
Joined: Jul 2003
Posts: 282
Likes: 52
From: Lima Oh
More punch off the line
I have a 72 LT1 that is straight stock. It runs great at all speeds, but from a dead stop, I can't get the tires to spin. With a revved engine and full throttle, it hesitates for a second and then kicks in. Thoughts?
(tried a search first, but could not come up with the right description of the issue to find anything)
Ken
(tried a search first, but could not come up with the right description of the issue to find anything)
Ken
Advanced
Joined: Jun 2012
Posts: 85
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From: verona va
I have a 72 454 auto, and just pulled the 3.08 out and put in a 3.70 rear. Big difference.I was beside the wife a few days ago at a stop light, she was going to work and I was just driving...
, the light turned green, I mashed it to the floor and sat there and spun....
first time I really did that. Needless to say I was very happy.
I told her the next morning when she came home that it was ok to talk about it, the awsome power of the vette.....she doesn't think its as funny as I do. I am still happy!
, the light turned green, I mashed it to the floor and sat there and spun.... first time I really did that. Needless to say I was very happy. I told her the next morning when she came home that it was ok to talk about it, the awsome power of the vette.....she doesn't think its as funny as I do. I am still happy!
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From: Corsicana, Tx
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I'd be looking at re-working the timing curve with a lot more initial to start with...then double ck carb accelerator pump shot next.
A close ratio with 3.70's isn't going to be a monster...but it should light up stock sized tires easily.
JIM
A close ratio with 3.70's isn't going to be a monster...but it should light up stock sized tires easily.
JIM
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
Sounds like a clutch problem or maybe the "operator" is nervous about putting the 'pedal to the metal'. If you have a low dollar clutch/pressure plate in the car, you may be getting some clutch slippage.
Thread Starter
Racer
Joined: Jul 2003
Posts: 282
Likes: 52
From: Lima Oh
I have a 64 with a 365 hp 4.10 rear and have no problem spinning the tires. Also had a c5 six speed that had no problem chirping those big run flats.
I just did a google search and two items popped up that could be the cause. Dirty fuel filter or a "dead spot" on the carb caused by a stuck float. I'll try the fuel filter first, but I have a pristine correct dated carb sitting in the garage that that I could swap out also.
Last edited by Ken99; Aug 12, 2012 at 10:55 PM. Reason: Added more cooments
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Thread Starter
Racer
Joined: Jul 2003
Posts: 282
Likes: 52
From: Lima Oh
Ken
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
This is me tuning AGVI's Vette with my sledgehammer (I was trying to make the sidemarker work, but I missed). Send me airfare to Ohio, and I can tune your car the same way:
So, what carb do you have..? I do carbs better than sidemarkers.
Lars
So, what carb do you have..? I do carbs better than sidemarkers.
Lars
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
Hey! I'll contribute! But, we must have videos of "critical" aspects of that trip... 
P.S. Since the problem is not the clutch or the 'operator', it's most likely to be carb and/or fuel system related. Timing can certainly have a major impact on power output; but if the carb/fuel system was working properly, even poor timing shouldn't keep you from lighting the tires.
P.S. Since the problem is not the clutch or the 'operator', it's most likely to be carb and/or fuel system related. Timing can certainly have a major impact on power output; but if the carb/fuel system was working properly, even poor timing shouldn't keep you from lighting the tires.
Last edited by 7T1vette; Aug 12, 2012 at 11:48 PM.
Racer
Joined: Jan 2007
Posts: 427
Likes: 1
Lots of factors here..., gear ratio, RPM, cam specs, shift points and on and on and on.
I had a 1969 Camaro with a 250 HP Turbo Fire with a three speed standard that at the time I felt was not setting any 'land speed' records runs on the local 1/4 mile outlaw strip down at the reservoir. (makings of a classic song me thinks)
I talked myself into thinking that I definitaly needed a brand 'new' engine with a "Turbo" cam, 'dual plane' Offy, Carter CFB, Black Jack Headers and the likes.
After 2500 dollars in 1982 and a cam that sounded like a 'dead plug' running on eight I am certain I gained 30 horsepower.
Man I wished I remembered a lot more in 'High school Physics' class than just the 'coefficient of friction' - dragging a brick on sand paper with a fish scale... I should have taken a 'tip' from the kid down the road to drop the tire circumference to make a "Redneck" gear change and feel the RPM's as they came in
A gear change at best or maybe just going "Redneck" will determine when you can drop the clutch, hammer the throttle and will a shift change from 1st to 2nd will burn off the newly found tires?
Just a suggestion with out dropping many dollars... Dano,
I had a 1969 Camaro with a 250 HP Turbo Fire with a three speed standard that at the time I felt was not setting any 'land speed' records runs on the local 1/4 mile outlaw strip down at the reservoir. (makings of a classic song me thinks)
I talked myself into thinking that I definitaly needed a brand 'new' engine with a "Turbo" cam, 'dual plane' Offy, Carter CFB, Black Jack Headers and the likes.
After 2500 dollars in 1982 and a cam that sounded like a 'dead plug' running on eight I am certain I gained 30 horsepower.
Man I wished I remembered a lot more in 'High school Physics' class than just the 'coefficient of friction' - dragging a brick on sand paper with a fish scale... I should have taken a 'tip' from the kid down the road to drop the tire circumference to make a "Redneck" gear change and feel the RPM's as they came in
A gear change at best or maybe just going "Redneck" will determine when you can drop the clutch, hammer the throttle and will a shift change from 1st to 2nd will burn off the newly found tires?
Just a suggestion with out dropping many dollars... Dano,
Racer
Joined: Jul 2009
Posts: 344
Likes: 5
From: oak harbor wa
sounds good to me
don't know what gears exactly but there LOWLowe
Last edited by lowes-yellow77; Aug 13, 2012 at 02:43 AM. Reason: info
Burning Brakes
Joined: Jan 2007
Posts: 1,057
Likes: 4
From: Concord Calif
You may have a problem or maybe not. I mean that engine at 2500 or so makes no real power at all. If you must spin the tires try getting the r's up where the engine makes power, 4000 at lease for the engine you have.
Thread Starter
Racer
Joined: Jul 2003
Posts: 282
Likes: 52
From: Lima Oh
Ok, here is the plan so far:
1. Determine actual rear end ratio
2. Check fuel filter
3. Check timing
4. Check carb functioning
5. Redline the engine before dumping clutch!
6. If all else fails, fly Lars to Ohio with his sledge hammer
Anything else I should add?
I know I'm not moving when I'm spinning the tires, but every once in a while it's cool to do!
1. Determine actual rear end ratio
2. Check fuel filter
3. Check timing
4. Check carb functioning
5. Redline the engine before dumping clutch!
6. If all else fails, fly Lars to Ohio with his sledge hammer
Anything else I should add?
I know I'm not moving when I'm spinning the tires, but every once in a while it's cool to do!
Last edited by Ken99; Aug 13, 2012 at 02:02 PM. Reason: added comment
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Well, I'd agree with most of that. I would not agree to "redlining the engine before dumping the clutch"; maybe get it up to 3000-3500 rpm (in the power band of the engine), then dump the clutch and hit the throttle to WOT at the same time.
Team Owner
Joined: Sep 2006
Posts: 31,280
Likes: 4,372
From: Westminster Maryland
Hi Ken,
I agree with 7T1's thoughts about "red-lining it before dumping the clutch".
I'd think some drive-train venders got some big smiles on their faces. when they read that.
Regards
Alan
I agree with 7T1's thoughts about "red-lining it before dumping the clutch".
I'd think some drive-train venders got some big smiles on their faces. when they read that.
Regards
Alan