L79 timing question
Race Director
Joined: Mar 2009
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From: Canada's capital
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Thread Starter
Burning Brakes
Joined: Jan 2007
Posts: 960
Likes: 25
From: Middlesboro KY
Not common at all, get a new one, or like I said try any old Chevy dizzy that you know works, or go to a corner garage and see if they have an old one. Too bad you're so far away, I've got 2 or 3 lying around. Try your local corvette club. Paragon will take care of you. that's the first stop.
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
Look at it this way. You bought a replacement distributor for an L 79. The timing curve on what they sent you in no way resembles the timing curve on an L 79. Did they send you new initial timing specs or other info to indicate the distributor they sent you was something other than a direct replacement?
Thread Starter
Burning Brakes
Joined: Jan 2007
Posts: 960
Likes: 25
From: Middlesboro KY
Look at it this way. You bought a replacement distributor for an L 79. The timing curve on what they sent you in no way resembles the timing curve on an L 79. Did they send you new initial timing specs or other info to indicate the distributor they sent you was something other than a direct replacement?
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
you need more mechanical advance in the new dist and not necessarily in that soon
you can change your curve with lighter springs or go heavier springs and more initial
then hook up the vac can to see if the mill likes it
im guessing you needed more initial with the mallory too
maybe that curve needed toyed with
power time the mill vac. disconnected ..try 36-38 total all in at 4000 or slghtly under
then see where your initial sits at idle as others have suggested
if it does total out at 5k as others have posted, i think you could use 15 deg initial and the vac can, maybe.....jmo.....
initial timing is what gives best low speed throttle response
Last edited by midyearvette; Aug 15, 2011 at 06:47 PM.
Race Director
Joined: Apr 2005
Posts: 11,290
Likes: 2,148
From: Bowling Green, Kentucky
Look at it this way. You bought a replacement distributor for an L 79. The timing curve on what they sent you in no way resembles the timing curve on an L 79. Did they send you new initial timing specs or other info to indicate the distributor they sent you was something other than a direct replacement?
I would not expect either distributor to be an exact drop-in for my car. I would expect the need to check and modify for my specific car. But I would expect something closer to the factory curve than what Brumbach got. Let's see how it goes.
Larry
Thread Starter
Burning Brakes
Joined: Jan 2007
Posts: 960
Likes: 25
From: Middlesboro KY
vac advance wont help that condition, think about what you are saying, at low rpm with any throttle opening, vacuum will drop
you need more mechanical advance in the new dist and not necessarily in that soon
you can change your curve with lighter springs or go heavier springs and more initial
then hook up the vac can to see if the mill likes it
im guessing you needed more initial with the mallory too
maybe that curve needed toyed with
power time the mill vac. disconnected ..try 36-38 total all in at 4000 or slghtly under
then see where your initial sits at idle as others have suggested
if it does total out at 5k as others have posted, i think you could use 15 deg initial and the vac can, maybe.....jmo.....
initial timing is what gives best low speed throttle response
you need more mechanical advance in the new dist and not necessarily in that soon
you can change your curve with lighter springs or go heavier springs and more initial
then hook up the vac can to see if the mill likes it
im guessing you needed more initial with the mallory too
maybe that curve needed toyed with
power time the mill vac. disconnected ..try 36-38 total all in at 4000 or slghtly under
then see where your initial sits at idle as others have suggested
if it does total out at 5k as others have posted, i think you could use 15 deg initial and the vac can, maybe.....jmo.....
initial timing is what gives best low speed throttle response
Last edited by Brumbach; Aug 15, 2011 at 07:09 PM.
Thread Starter
Burning Brakes
Joined: Jan 2007
Posts: 960
Likes: 25
From: Middlesboro KY
Paragon offers TWO distributors for these cars: one is for 1962-74 without SHP and the other is 1963-74 with SHP. Both exclude FI and TI. This covers a lot of territory.
I would not expect either distributor to be an exact drop-in for my car. I would expect the need to check and modify for my specific car. But I would expect something closer to the factory curve than what Brumbach got. Let's see how it goes.
Larry
I would not expect either distributor to be an exact drop-in for my car. I would expect the need to check and modify for my specific car. But I would expect something closer to the factory curve than what Brumbach got. Let's see how it goes.
Larry
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Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
its the shaft
Paragon offers TWO distributors for these cars: one is for 1962-74 without SHP and the other is 1963-74 with SHP. Both exclude FI and TI. This covers a lot of territory.
I would not expect either distributor to be an exact drop-in for my car. I would expect the need to check and modify for my specific car. But I would expect something closer to the factory curve than what Brumbach got. Let's see how it goes.
Larry
I would not expect either distributor to be an exact drop-in for my car. I would expect the need to check and modify for my specific car. But I would expect something closer to the factory curve than what Brumbach got. Let's see how it goes.
Larry
midyearvette had to re-curve it , all new shafts or distributors HP or reg need to be reset, to get proper timing
You need a new combo of springs and initial timing to set it up
Tell them Frank
JACK
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
I said it wrong. At low speeds, I had to drive in low gear with the mallory. Not the situation with the new distributor. I can drive in 4th gear @ 25 mph. Real smooth too. Not sure how much vac is operating or advance at the lower speeds. You obviously do. I can only describe the difference in the two distributors relative to driveability. With the new distributor, 24 degrees is the best I can achieve without changing the initial timing above 10 degrees. (with vac disconnected). I agree, I need more initial advance, 12 more degrees (for a total of 22 degree) to get the 36 degrees. That's where it's setting now. No problems but would like to get to spec someday. I don't want to back to the mallory (mechanical advance only).
from what i am reading, you are saying the advance of the new dist. is only 14 degrees??......36 minus 22=14
i would think you should have at least 20-22 mech. (crank)???
something is stuck or the dist needs replaced for you to acheive what you want and i agree, the curve doesn't need to be right on to spec, but a lot closer than you have
where did you set initial for the mallory??
Thread Starter
Burning Brakes
Joined: Jan 2007
Posts: 960
Likes: 25
From: Middlesboro KY
there is something amiss on the curve of the new dist.
from what i am reading, you are saying the advance of the new dist. is only 14 degrees??......36 minus 22=14
i would think you should have at least 20-22 mech. (crank)???
something is stuck or the dist needs replaced for you to acheive what you want and i agree, the curve doesn't need to be right on to spec, but a lot closer than you have
where did you set initial for the mallory??
from what i am reading, you are saying the advance of the new dist. is only 14 degrees??......36 minus 22=14
i would think you should have at least 20-22 mech. (crank)???
something is stuck or the dist needs replaced for you to acheive what you want and i agree, the curve doesn't need to be right on to spec, but a lot closer than you have
where did you set initial for the mallory??
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
Race Director
Joined: Apr 2005
Posts: 11,290
Likes: 2,148
From: Bowling Green, Kentucky
Larry
Thread Starter
Burning Brakes
Joined: Jan 2007
Posts: 960
Likes: 25
From: Middlesboro KY
Well, I still talking with Paragon. Apparently, the vendor is no longer making the reproduction unit. I was hoping they would send out another to replace this one. They did speak to the vendor and he stated that the one I have is a condensed variant that covers a number of vettes. I would've expected that since this one is for SHP 327 it would at least be close to the original spec. I asked Paragon about their rebuild components, specifically the inner shaft with the football for the SHP and would it possibly correct the problem. The tech said it would be identical to the one in the reproduction unit. They wanted to talk with another source and get back to me. I'm beginning to wonder if I wouldn't be better off asking for a refund and pursuing an aftermarket unit. Any look-alike, point-tach drive units that'll perform near to the required spec?
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
.....he stated that the one I have is a condensed variant that covers a number of vettes. I would've expected that since this one is for SHP 327 it would at least be close to the original spec. Any look-alike, point-tach drive units that'll perform near to the required spec?
Personally, I would send it back as I said WAY back in this thread. What I see wrong with what you have is too fast advance rate in the centrifugal advance, not enought total centrifugal advance and too much vacuum advance. In other words, like I said early on, this thing is not what I think you need and is nowhere close to stock. Keeping in mind that "stock" can be improved upon.
Thread Starter
Burning Brakes
Joined: Jan 2007
Posts: 960
Likes: 25
From: Middlesboro KY
The only Vette's that have a curve like what is in your distrubutor are ones that are set up for straightt line acceleration.
Personally, I would send it back as I said WAY back in this thread. What I see wrong with what you have is too fast advance rate in the centrifugal advance, not enought total centrifugal advance and too much vacuum advance. In other words, like I said early on, this thing is not what I think you need and is nowhere close to stock. Keeping in mind that "stock" can be improved upon.
Personally, I would send it back as I said WAY back in this thread. What I see wrong with what you have is too fast advance rate in the centrifugal advance, not enought total centrifugal advance and too much vacuum advance. In other words, like I said early on, this thing is not what I think you need and is nowhere close to stock. Keeping in mind that "stock" can be improved upon.
Race Director
Joined: Apr 2005
Posts: 11,290
Likes: 2,148
From: Bowling Green, Kentucky
Well, I still talking with Paragon. Apparently, the vendor is no longer making the reproduction unit. I was hoping they would send out another to replace this one. They did speak to the vendor and he stated that the one I have is a condensed variant that covers a number of vettes. I would've expected that since this one is for SHP 327 it would at least be close to the original spec. I asked Paragon about their rebuild components, specifically the inner shaft with the football for the SHP and would it possibly correct the problem. The tech said it would be identical to the one in the reproduction unit. They wanted to talk with another source and get back to me. I'm beginning to wonder if I wouldn't be better off asking for a refund and pursuing an aftermarket unit. Any look-alike, point-tach drive units that'll perform near to the required spec?
At this point you can:
1. Keep what you have. Work with it and revise it to better suit your car. Jackfit did this a month or so ago and was successful.
2. Send it out to some else who can do this for you. More $$ but a good end result.
3. Return the unit. Buy and refurbish a good used Corvette distributor. They are available on Ebay, at Carlisle, Corvette Forum Parts for Sale, etc. etc.
4. Return the unit. Buy another aftermarket distributor (Accel, Mallory, etc) and and work with it to make it right for your car.
5. Wait on something from Paragon.
If it were me personally, I would keep it and work with it to make it right. Or I would box it up and sent it to www.tispecialty.com for rework. The final product should/will last a lifetime.
Good luck.
Larry
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
I agree
I recognize that you paid $400 for this distributor and want it to fit and work correctly. And for that price it should.
At this point you can:
1. Keep what you have. Work with it and revise it to better suit your car. Jackfit did this a month or so ago and was successful.
2. Send it out to some else who can do this for you. More $$ but a good end result.
3. Return the unit. Buy and refurbish a good used Corvette distributor. They are available on Ebay, at Carlisle, Corvette Forum Parts for Sale, etc. etc.
4. Return the unit. Buy another aftermarket distributor (Accel, Mallory, etc) and and work with it to make it right for your car.
5. Wait on something from Paragon.
If it were me personally, I would keep it and work with it to make it right. Or I would box it up and sent it to www.tispecialty.com for rework. The final product should/will last a lifetime.
Good luck.
Larry
At this point you can:
1. Keep what you have. Work with it and revise it to better suit your car. Jackfit did this a month or so ago and was successful.
2. Send it out to some else who can do this for you. More $$ but a good end result.
3. Return the unit. Buy and refurbish a good used Corvette distributor. They are available on Ebay, at Carlisle, Corvette Forum Parts for Sale, etc. etc.
4. Return the unit. Buy another aftermarket distributor (Accel, Mallory, etc) and and work with it to make it right for your car.
5. Wait on something from Paragon.
If it were me personally, I would keep it and work with it to make it right. Or I would box it up and sent it to www.tispecialty.com for rework. The final product should/will last a lifetime.
Good luck.
Larry
Jack
Last edited by Jackfit; Aug 17, 2011 at 08:19 PM. Reason: misspelled L-79
Melting Slicks
Joined: Jul 2004
Posts: 2,869
Likes: 196
From: Maryland
I agree. I was hoping this one was defective and they would replace it. Since that's not an option, I'll give them a little time find a solution before I ask for a refund. Do you have any recommendation for a new distributor? I'm not interested in new technology. I prefer good old points and of course need the tach drive. Meanwhile, I can return to old faithful Mallory (w/o vac).
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
I agree. I was hoping this one was defective and they would replace it. Since that's not an option, I'll give them a little time find a solution before I ask for a refund. Do you have any recommendation for a new distributor? I'm not interested in new technology. I prefer good old points and of course need the tach drive. Meanwhile, I can return to old faithful Mallory (w/o vac).
take the car for a ride and check for pinging, if so back it off in 2 deg increments
shoot for 38 deg total.....