Re: Locked timing on a street/strip car
[Re: 70Drop]
#2546454
09/05/18 11:44 PM
09/05/18 11:44 PM
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Joined: Oct 2007
Posts: 4,209 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,209
New York
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Fixed timing is best, because every engine needs the exact same spark under all conditions.
Boffin Emeritus
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Re: Locked timing on a street/strip car
[Re: polyspheric]
#2546458
09/05/18 11:49 PM
09/05/18 11:49 PM
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Joined: Dec 2004
Posts: 10,555 Rittman Ohio
fourgearsavoy
I Live Here
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I Live Here
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Posts: 10,555
Rittman Ohio
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I just don't understand why you would need to lock it out on a street/strip car I mean will it gain any performance? I set my base at 23 and total at 34 all in by 1800 RPM and it runs perfect with my combo. Gus
64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60
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Re: Locked timing on a street/strip car
[Re: 70Drop]
#2546487
09/06/18 12:41 AM
09/06/18 12:41 AM
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Joined: Jan 2005
Posts: 4,243 Charlotte, North Carolina
sgcuda
master
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master
Joined: Jan 2005
Posts: 4,243
Charlotte, North Carolina
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There is a need for a timing curve, especially street cars. It wouldn't be a good idea to lock it out. There are points in time when the engine could use less than maximum high speed timing.
[image][/image]
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Re: Locked timing on a street/strip car
[Re: 70Drop]
#2546499
09/06/18 01:03 AM
09/06/18 01:03 AM
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Joined: Dec 2005
Posts: 11,639 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 11,639
Fulton County, PA
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24 base with 36 total. Big cam, not much manifold vacuum. What RPM are you able to get the thing to idle at? In gear? Drilled throttle blades or the throttle opened way up? If its all in by 1500 or 1800, why bother with idle problems?
I can lock it out, set the throttle blades where they're supposed to be in relation to the transfer slots, make it idle at 800 in gear with a big flat tappet or roller, great throttle response, runs great. Timing is rock steady at any speed rather than chasing the base around at idle with light springs. What am I doing wrong?
If the results don't match the theory, change the theory.
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Re: Locked timing on a street/strip car
[Re: 70Drop]
#2546521
09/06/18 01:43 AM
09/06/18 01:43 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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The car idles fine. That's not an issue. The reason I'm thinking about it is 1) I like simplicity on my cars 2) Locked timing will allow me to run a crank trigger. I love the precision of crank triggers. I cringe when I see timing flutter at WOT. Every car I've had has done a little bit of that. Even just a degree or two bothers me! If you shimmed the dist shaft you wouldnt see any flutter
Last edited by MR_P_BODY; 09/06/18 01:46 AM.
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Re: Locked timing on a street/strip car
[Re: MR_P_BODY]
#2546527
09/06/18 02:31 AM
09/06/18 02:31 AM
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Joined: Jan 2005
Posts: 223 California
70Drop
OP
enthusiast
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OP
enthusiast
Joined: Jan 2005
Posts: 223
California
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The car idles fine. That's not an issue. The reason I'm thinking about it is 1) I like simplicity on my cars 2) Locked timing will allow me to run a crank trigger. I love the precision of crank triggers. I cringe when I see timing flutter at WOT. Every car I've had has done a little bit of that. Even just a degree or two bothers me! If you shimmed the dist shaft you wouldnt see any flutter I have a collar on the shaft that fits tight up against the drive gear. Is that the play you're talking about controlling? I've never shimmed a shaft before
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Re: Locked timing on a street/strip car
[Re: CMcAllister]
#2546543
09/06/18 05:06 AM
09/06/18 05:06 AM
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Joined: Jan 2003
Posts: 27,421 Balt. Md
383man
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,421
Balt. Md
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24 base with 36 total. Big cam, not much manifold vacuum. What RPM are you able to get the thing to idle at? In gear? Drilled throttle blades or the throttle opened way up? If its all in by 1500 or 1800, why bother with idle problems?
I can lock it out, set the throttle blades where they're supposed to be in relation to the transfer slots, make it idle at 800 in gear with a big flat tappet or roller, great throttle response, runs great. Timing is rock steady at any speed rather than chasing the base around at idle with light springs. What am I doing wrong? I don't see anything wrong. I use light springs in my dist that has full advance all in by 1800 rpm. Basically I set my total at 36 as that's what my car seems to like best and let the initial fall where it does. Which on my car its got around 24 degrees at idle in park. It runs great like that and has no ping at all on 92 pump. I see some guys run locked out timing on their cars but I never have. But to be honest when you think about it the setup we run and guys like Gus which his sounds about like mine is not all that far from being locked out. Course we don't have to much timing when cranking the eng but once its running and we hit the gas we are almost at total timing right after hitting the gas pedal some. I like the ight springs all in by 1800 to 2000 rpm as it works nicely on my street driven car. Ron
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Re: Locked timing on a street/strip car
[Re: 70Drop]
#2546568
09/06/18 09:28 AM
09/06/18 09:28 AM
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Joined: Jan 2003
Posts: 8,030 Tulsa OK
Bad340fish
master
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master
Joined: Jan 2003
Posts: 8,030
Tulsa OK
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I ran locked timing on my 11:1 360 on the street for years with zero trouble.
68 Barracuda Formula S 340
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Re: Locked timing on a street/strip car
[Re: CMcAllister]
#2546595
09/06/18 10:38 AM
09/06/18 10:38 AM
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Joined: Jan 2003
Posts: 13,380 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,380
Marion, South Carolina [><]
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24 base with 36 total. Big cam, not much manifold vacuum. What RPM are you able to get the thing to idle at? In gear? Drilled throttle blades or the throttle opened way up? If its all in by 1500 or 1800, why bother with idle problems?
I can lock it out, set the throttle blades where they're supposed to be in relation to the transfer slots, make it idle at 800 in gear with a big flat tappet or roller, great throttle response, runs great. Timing is rock steady at any speed rather than chasing the base around at idle with light springs. What am I doing wrong? Like Dwayne said, you're not doing anything wrong. Locking it out works better as the engine gets wilder. Nothing wrong at all doing it on a street driven car. For a mild engine it may not have as much benefit. No need for a start retard either...don't use it. Crank triggers are so nice when setting the timing, the mark is rock steady.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: Locked timing on a street/strip car
[Re: fourgearsavoy]
#2546600
09/06/18 10:55 AM
09/06/18 10:55 AM
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Joined: Dec 2013
Posts: 4,694 Wichita
GY3
master
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master
Joined: Dec 2013
Posts: 4,694
Wichita
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I just don't understand why you would need to lock it out on a street/strip car I mean will it gain any performance? I set my base at 23 and total at 34 all in by 1800 RPM and it runs perfect with my combo. Gus Pretty much the same here.
'63 Dodge 330 11.19 @ 121 mph Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs. 10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.
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Re: Locked timing on a street/strip car
[Re: GY3]
#2546608
09/06/18 11:15 AM
09/06/18 11:15 AM
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Joined: Jan 2003
Posts: 13,380 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,380
Marion, South Carolina [><]
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I just don't understand why you would need to lock it out on a street/strip car I mean will it gain any performance? I set my base at 23 and total at 34 all in by 1800 RPM and it runs perfect with my combo. Gus Pretty much the same here. So how much time do you think your engine spends under 1800 rpm on the street? Other than idling. I don't see the need for the advance.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: Locked timing on a street/strip car
[Re: 70Drop]
#2546609
09/06/18 11:16 AM
09/06/18 11:16 AM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
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master
Joined: Sep 2014
Posts: 4,457
Washington
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The car idles fine. That's not an issue. The reason I'm thinking about it is 1) I like simplicity on my cars 2) Locked timing will allow me to run a crank trigger. I love the precision of crank triggers. I cringe when I see timing flutter at WOT. Every car I've had has done a little bit of that. Even just a degree or two bothers me! If you shimmed the dist shaft you wouldnt see any flutter I have a collar on the shaft that fits tight up against the drive gear. Is that the play you're talking about controlling? I've never shimmed a shaft before I think Mr Pbody is talking about shimming the distributor itself. Some of the stuff I've seen had .080-.090 slop in the distributor. On the dyno with a customer supplied MSD that was wacky. It had .100 clearance. Shimmed it to where it had about .010 and it was golden.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: Locked timing on a street/strip car
[Re: 70Drop]
#2546625
09/06/18 12:13 PM
09/06/18 12:13 PM
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Joined: Jan 2003
Posts: 14,506 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
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So. Burlington, Vt.
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So, you’ve got your big lumpy cam and the accompanying super low vacuum, low gears, and a high stall converter. You keep bumping up the initial timing and discover the vacuum goes up, throttle response gets better, idle circuit in the carb becomes more responsive. You bump up the initial more, and get more of the same improvements.
As Chip said, if the combo is “wild” enough, you keep bumping up the initial, and limiting the sweep to keep the total where you want it....... and eventually you find there is no sweep anymore.
That’s how I came to it over 30 years ago........by making adjustments, driving the car and seeing if it ran/drove better or not. More initial did everything better....... so I kept sneaking up on it....... more driving, more evaluating....... until there was essentially no “curve” left. For the last curve I was at 30 initial/36 total, all in by 2200. I locked out another distributor, swapped it out...... and it was marginally better, so I left it like that.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Locked timing on a street/strip car
[Re: an8sec70cuda]
#2546628
09/06/18 12:21 PM
09/06/18 12:21 PM
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Joined: Dec 2013
Posts: 4,694 Wichita
GY3
master
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master
Joined: Dec 2013
Posts: 4,694
Wichita
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I just don't understand why you would need to lock it out on a street/strip car I mean will it gain any performance? I set my base at 23 and total at 34 all in by 1800 RPM and it runs perfect with my combo. Gus Pretty much the same here. So how much time do you think your engine spends under 1800 rpm on the street? Other than idling. I don't see the need for the advance. Very little. The reason mine is setup this way is to make sure it starts easy. 99% of the time it is at full advance.
'63 Dodge 330 11.19 @ 121 mph Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs. 10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.
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