idle when hot
Dr. Detroit
Joined: Mar 2012
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From: New Braunfels Texas
Race Director
Joined: Mar 2017
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From: Virginia
Can you take a picture inside your distributor showing your springs? Sometimes the weights are put in backwards, and that leads to other problems.
I'm guessing English isn't your first language? That's fine, we are still here to help. When you say the springs are "tighten", does that mean they are too stiff? The spring wire is too thick, and it will not release the weights to advance at a reasonable RPM?
Sometimes distributors need to be rebuilt, or replaced (I did to one that was nearly stuck). Pictures help!
Feel free to post in French, too, if that helps get your point across. Sometimes specific terms don't quite translate.
I'm guessing English isn't your first language? That's fine, we are still here to help. When you say the springs are "tighten", does that mean they are too stiff? The spring wire is too thick, and it will not release the weights to advance at a reasonable RPM?
Sometimes distributors need to be rebuilt, or replaced (I did to one that was nearly stuck). Pictures help!
Feel free to post in French, too, if that helps get your point across. Sometimes specific terms don't quite translate.
Burning Brakes
Joined: Dec 2021
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From: Paris
Race Director
Joined: May 2006
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Use the two gold springs from the 928G and you probably should look at the advance stop bushing which requires distributor removal. If the bushing is missing or cracked replace it with the bushing in the 928g kit. Do not use the weights in the 928g kit.
Thread Starter
Instructor
Joined: May 2023
Posts: 104
Likes: 10
From: Paris
Can you take a picture inside your distributor showing your springs? Sometimes the weights are put in backwards, and that leads to other problems.
I'm guessing English isn't your first language? That's fine, we are still here to help. When you say the springs are "tighten", does that mean they are too stiff? The spring wire is too thick, and it will not release the weights to advance at a reasonable RPM?
Sometimes distributors need to be rebuilt, or replaced (I did to one that was nearly stuck). Pictures help!
Feel free to post in French, too, if that helps get your point across. Sometimes specific terms don't quite translate.
I'm guessing English isn't your first language? That's fine, we are still here to help. When you say the springs are "tighten", does that mean they are too stiff? The spring wire is too thick, and it will not release the weights to advance at a reasonable RPM?
Sometimes distributors need to be rebuilt, or replaced (I did to one that was nearly stuck). Pictures help!
Feel free to post in French, too, if that helps get your point across. Sometimes specific terms don't quite translate.
this is the pic of my distributor.
Last edited by Abel88; May 26, 2023 at 06:10 AM.
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From: Paris
Thread Starter
Instructor
Joined: May 2023
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From: Paris
Melting Slicks
Joined: Dec 2014
Posts: 2,786
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From: Central UT
Hi Abel, congrats on having an L71 - fun cars! When they're set up correctly. A couple of thoughts may help:
- Here is a link to the tri power setup on our '68 L71. It will be the same as yours. The early parts of the thread may or may not be of value to you. But inside this thread you'll see some of what Scott (Rescue Rogers) was referring to. You can't just adjust the idle screw very much on a tri power without having to adjust the outboard carbs linkage or you'll have even more idle issues. You'll find it in the thread. https://www.corvetteforum.com/forums...ix-thread.html
- You need a dial back timing light so you can really tell what you have for initial timing and 'all in' timing at around 3600 rpm. This will have a big impact on how the car runs and also cooling. I know you're in Europe, but I'm certain you can get one like this if you don't have one:
- Do you still have the original TI distributor that came on the car or has someone over the years swapped it out. It sounds like you may be having some distributor issues contributing to you timing issues? At the end of this thread I provide some information on getting my TI distributor rebuilt and tested. https://www.corvetteforum.com/forums/c3-general/4497305-68-the-beast-updates-and-progress-while-i-m-in-there-2. Edit: I missed that you're running an MSD. So am I right now, but will put our rebuilt TI back on over the winter. The MSD should work just fine if set up correctly. I'll have to look, but I think I set mine up for around 10-12 initial and 36 all in; but I'll check because I could be remembering incorrectly.
- If your L71 still has original lifters, how long has it been since they've been adjusted? Stock they came with solid lifters and need to be adjusted periodically. If they aren't adjusted correctly, this will impact your ability to tune it properly.
- Ours runs cool on 100+ F degree days in traffic. But.........I rebuilt the water pump, put in a new direct fit DeWitts radiator, new seals, 180 stat, new fan clutch, new hoses/belts, took off the heat riser and cut off the blades inside and reinstalled (you can't tell), etc. It will go anywhere now, but it was a combination of things: cooling system, timing, tuning, rebuilt carbs, understanding how tri power really works and getting it set up, etc.
Last edited by Hopper12; May 25, 2023 at 04:30 PM.
Thread Starter
Instructor
Joined: May 2023
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From: Paris
Hi Abel, congrats on having an L71 - fun cars! When they're set up correctly. A couple of thoughts may help:
- Here is a link to the tri power setup on our '68 L71. It will be the same as yours. The early parts of the thread may or may not be of value to you. But inside this thread you'll see some of what Scott (Rescue Rogers) was referring to. You can't just adjust the idle screw very much on a tri power without having to adjust the outboard carbs linkage or you'll have even more idle issues. You'll find it in the thread. https://www.corvetteforum.com/forums...ix-thread.html
- You need a dial back timing light so you can really tell what you have for initial timing and 'all in' timing at around 3600 rpm. This will have a big impact on how the car runs and also cooling. I know you're in Europe, but I'm certain you can get one like this if you don't have one: https://www.amazon.com/INNOVA-5568-P...NsaWNrPXRydWU=
- Do you still have the original TI distributor that came on the car or has someone over the years swapped it out. It sounds like you may be having some distributor issues contributing to you timing issues? At the end of this thread I provide some information on getting my TI distributor rebuilt and tested. https://www.corvetteforum.com/forums/c3-general/4497305-68-the-beast-updates-and-progress-while-i-m-in-there-2. Edit: I missed that you're running an MSD. So am I right now, but will put our rebuilt TI back on over the winter. The MSD should work just fine if set up correctly. I'll have to look, but I think I set mine up for around 10-12 initial and 36 all in; but I'll check because I could be remembering incorrectly.
- If your L71 still has original lifters, how long has it been since they've been adjusted? Stock they came with solid lifters and need to be adjusted periodically. If they aren't adjusted correctly, this will impact your ability to tune it properly.
- Ours runs cool on 100+ F degree days in traffic. But.........I rebuilt the water pump, put in a new direct fit DeWitts radiator, new seals, 180 stat, new fan clutch, new hoses/belts, took off the heat riser and cut off the blades inside and reinstalled (you can't tell), etc. It will go anywhere now, but it was a combination of things: cooling system, timing, tuning, rebuilt carbs, understanding how tri power really works and getting it set up, etc.
we've just adjusted the lifters so it should be OK. I receive my springs early next week. Re-timing ....good to know all in timing should be reached @ 3600rpm....so far I read 2500 - 3000. but 3600 would make sense as the red line on a L71 is higher.
and thanks also for the names shared in case I need my carb to be rebuild.....even if from France it's a bit less easy !
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Paul....I must say I'm impressed by the content you've shared. that will definitely help to better assess and set my carb & Distributor (indeed TI / K66 option which may need to be rebuild)
we've just adjusted the lifters so it should be OK. I receive my springs early next week. Re-timing ....good to know all in timing should be reached @ 3600rpm....so far I read 2500 - 3000. but 3600 would make sense as the red line on a L71 is higher.
and thanks also for the names shared in case I need my carb to be rebuild.....even if from France it's a bit less easy !
we've just adjusted the lifters so it should be OK. I receive my springs early next week. Re-timing ....good to know all in timing should be reached @ 3600rpm....so far I read 2500 - 3000. but 3600 would make sense as the red line on a L71 is higher.
and thanks also for the names shared in case I need my carb to be rebuild.....even if from France it's a bit less easy !
Thread Starter
Instructor
Joined: May 2023
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From: Paris
Sorry to disagree with that 3.6 k number, 3k is maximum. Email Lars Grimsrud at v8fastcars@msn.com for his latest document on distributor set up. You can Google his name, ex-GM engineer.
Dr. Detroit
Joined: Mar 2012
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From: New Braunfels Texas
It will run fine with the 3600rpm setup......but not optimal......would be a bit more ping resistant.....
Jebby
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https://www.corvetteforum.com/forums...-bigblock.html
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From: Paris
Here is a link to a very old version of the Lars Grimsrud article, email him for current document.
https://www.corvetteforum.com/forums...-bigblock.html
https://www.corvetteforum.com/forums...-bigblock.html
Melting Slicks
Joined: Dec 2014
Posts: 2,786
Likes: 2,328
From: Central UT
Sorry to disagree with that 3.6 k number, 3k is maximum. Email Lars Grimsrud at v8fastcars@msn.com for his latest document on distributor set up. You can Google his name, ex-GM engineer.
I also agree with the 3000rpm number.....it is no matter that the engine revs higher.....in fact, with the longer overlap of the L-71 camshaft, it could come in a little sooner.......like 2800......
It will run fine with the 3600rpm setup......but not optimal......would be a bit more ping resistant.....
Jebby
It will run fine with the 3600rpm setup......but not optimal......would be a bit more ping resistant.....
Jebby
