[Darth Menace]

Originally Posted by nytrainer

Darth,
GTO4ever brings up a good point. As I mentioned I do not know the specs for your engine so any numbers I used in my examples were just that...examples. My 68 350 HO factory initial spec is 9 BTDC. If you're not sure of the specs throw the question out there. Vehicle weight, tire size, rear axle ratio, fuel quality, carb. settings, automatic trans. etc.. will be considered when fine tuning your timing. Many run the same combo as you so you can get a better idea where you want to be if you ask.

Ahh, this stuff is harsh. It seems as though a person has to have this set up before he can set this up, but then he can't tune that before the next thing is tuned. Seems to be going in a circle for me For now though, getting the timing in the general area so it doesn't stall out on me is a good start to it all. From what I've observed with the P/O he seem to have let things slide when it came to this car so getting it properly running is a step in the right direction.

Should I go check the timing at idle for interest sake?

[nytrainer]

Darth,
All those parameters (weight, gas, axle, etc) are considered when curving the distributor so don't worry about that at this point. I'd check the initial because by just setting the "all in" to 36 your initial may be too high. Don't want to get into a detonation problem. If spec is supposed to be 6 BTDC you don't want to advance it too much. BTW my engine's spec calls for 29-33 "all in" so best to make sure you are in specs. Now that you know HOW to do it just get the spec and dial her in.

[Darth Menace]

Originally Posted by nytrainer

Darth,
All those parameters (weight, gas, axle, etc) are considered when curving the distributor so don't worry about that at this point. I'd check the initial because by just setting the "all in" to 36 your initial may be too high. Don't want to get into a detonation problem. If spec is supposed to be 6 BTDC you don't want to advance it too much. BTW my engine's spec calls for 29-33 "all in" so best to make sure you are in specs. Now that you know HOW to do it just get the spec and dial her in.

hmmm I just went and tried. The way I set the all out timing was set my light to 36, rev and then adjust until it's at 0. I just went and tried to check the timing for the idle timing and i don't know how to check it hahah. It is not anywhere near the numbers. It will read at the 0 on the numbers when I have the timing light set to 30. Not sure if I am doing that right there.

On another note...this snorkle thing for the air breather...where should it be pointed? Directly at the fan or to one side? I moved this and it made a huge difference on the idle

[nytrainer]

Originally Posted by Darth Menace

hmmm I just went and tried. The way I set the all out timing was set my light to 36, rev and then adjust until it's at 0. I just went and tried to check the timing for the idle timing and i don't know how to check it hahah. It is not anywhere near the numbers. It will read at the 0 on the numbers when I have the timing light set to 30. Not sure if I am doing that right there.

On another note...this snorkle thing for the air breather...where should it be pointed? Directly at the fan or to one side? I moved this and it made a huge difference on the idle

Ummm, alright lets see. I am stating the obvious here but you do have the light connected to #1 cylinder?
When you saw the "all in" timing was 36 (still unsure what the spec should be for your engine) you had the engine at a sustained 2500-3000 rpm with vacuum advance hose disconnected and plugged? To check timing at idle simply (with vacuum advance disconnected and hose plugged) point the timing light and adjust the timimg light until the mark on the balancer is at zero. Then look at the reading on the timing light.
Usually when you are setting the initial timing you move the distributor. You then check what the total is afterwards (as described prior). Not really a great idea to be fiddling with the distributor while the engine is running at 2500-3000 rpm. When you adjust initial timing higher or lower the total timing will follow it (either up or down the same amount). You can't adjust one without affecting the other so do all your adjustments at idle. To try and clarify that lets say you have 12 initial and 34 total as observed (random example). If you decrease the initial to 9 (3 less) your total will now be 3 less (now 31) or increase initial 2 degrees then total will increase 2 also.
My replies are wordy I know but I am trying to make sure you get it.

[rohrt]

Sounds like you forgot to pull the vacuum advance line back off when checking the idle timing.

You really need to get a tach too. I had stalling issues with one car and found I just had the idle set to low. My loud exhaust was throwing me off.

Pull the vacuum line to the can again and plug it.
Take a reading of the idle advance timing for us.
Take another readin with the vacuum can connected. Then we can see how much advance your can is set at.

If you did have it connected when you took the idle reading then we know your connected to manifold souce.

I wouldn't be all that concerned with factory specs. My tempest won't hardly run with the factory spec of 6 deg BTDC initial. I have set for 14-18 and it runs 200% better. Different gas today, carb and unknown part all bets are off IMO.

I saw in one of your post on the first page that you said you took the air cleaner off and the idle was much better? And I see you just mentioned moving it a bit and changing the idle.

Is the flapper stuck closed in the snorkle? Possible vacuum leak in the line to the diaphram on the snorkle? Maybe try flipping the lid upside down and running it old school as a test I'm not expert but I think it should point to the driver side like you shown in post 13. From factory there was a metal line that ran from the valve cover to the air cleaner in place of that breather cap that is there now.

I can't for the life of me think why moving the cleaner would change the idle unless the air clean is touching something on the car it shouldn't be.

[PontGuy]

Originally Posted by rohrt

I wouldn't be all that concerned with factory specs. My tempest won't hardly run with the factory spec of 6 deg BTDC initial. I have set for 14-18 and it runs 200% better. Different gas today, carb and unknown part all bets are off IMO.

And you can add the fact that different distributors came with different curves depending on application (and they have often been swapped out too.) That's why I like to start out backwards and set the all-in first. 34-36 deg is almost always close to right for a performance 400. Then see where that puts the base timing. Once you know where the base timing is then you shouldn't have to check the all-in again unless you mess around with the distributor internals.

Just make sure that you get it right- agree with all the comments about remembering to remove the vacuum hose, make double-sure you are connected to #1 cylinder (front right) etc. And be safe! I shut down, make adjustments, and re-check. Yes tightening can throw it off. Just have to fiddle with it.

Oh and yes, agree that moving the air cleaner should not affect the idle. Another thing that could cause this is if the bottom base plate is tightening down on the carb linkage somewhere. This is a common with Q-jets and some aftermarket air cleaners where the base can hit the top of the accelerator pump lever. So you need to figure this out too.

I am 6'3 so I didn't fit in the Viper well at all. And I don't think it could be very comfortable for anyone. The seat is set a weird angle too, to make room for the trans tunnel. But if I could have gotten my friend's Viper for only 30K it would be sitting in my garage now.

[PontGuy]

Originally Posted by nytrainer

Darth,
I'd check the initial because by just setting the "all in" to 36 your initial may be too high. Don't want to get into a detonation problem.

Yes you don't want detonation, but you don't want to give up power either. So once you have it dialed in close and know what the base is you will need to test drive and adjust. If it pings/detonates anywhere, then back off. If it hesitates, then advance. I would not go past 38 all-in no matter what. With the compression numbers that you got and assuming it has at least a mild performance cam, and assuming a typical curve in the distributor, my bet is that 34-36 will be about right.

Going further with this once you understand how your engine combo responds you can custom-curve the distributor to get the most out of it. In the past I've done this myself but worked with Suntuned to curve the distributor for the 455 I have now. But we are still a long, long way from optimizing to that level on your car, and it really is not necessary unless you like tinkering to get every last HP out (like I do.)

[Darth Menace]

Yes, the vacuum advance was pulled (not plugged), and the light was connected to the #1 cyl. Also, another thing, is some instructions say to have the e-brake on while car is in drive...I didn't...I had it in park the whole time. Totally didn't think of the drive thing, and last thing I want is to do timing myself with the car in drive and revving it up to 3000rpm. I did adjust the dist while the car was idling though, not at 2500-3000rpm.

And this is where I think I am messed. The all out timing was lined up at 0 when I had the timing light set to 36, but at idle it would line up to the 0 when my timing light was at 30. Something is amiss here with what I am doing.

I can take a video later today if you want to see what in the world I am doing. Likely easier than my typing a description.

Regardless if it's set wrong, it's good that it runs better than before. Progress is being made.

Originally Posted by nytrainer

Ummm, alright lets see. I am stating the obvious here but you do have the light connected to #1 cylinder?
When you saw the "all in" timing was 36 (still unsure what the spec should be for your engine) you had the engine at a sustained 2500-3000 rpm with vacuum advance hose disconnected and plugged? To check timing at idle simply (with vacuum advance disconnected and hose plugged) point the timing light and adjust the timimg light until the mark on the balancer is at zero. Then look at the reading on the timing light.
Usually when you are setting the initial timing you move the distributor. You then check what the total is afterwards (as described prior). Not really a great idea to be fiddling with the distributor while the engine is running at 2500-3000 rpm. When you adjust initial timing higher or lower the total timing will follow it (either up or down the same amount). You can't adjust one without affecting the other so do all your adjustments at idle. To try and clarify that lets say you have 12 initial and 34 total as observed (random example). If you decrease the initial to 9 (3 less) your total will now be 3 less (now 31) or increase initial 2 degrees then total will increase 2 also.
My replies are wordy I know but I am trying to make sure you get it.

[Darth Menace]

I am going to get a tach later today. Wanting to get this beast taken care of now that we know it's likely not in it's last legs.

Yes, the vacuum advance is set up to the manifold...there is a spot for it on my edelbrock carb, but it is plugged. No idea what the difference is, so it is on the manifold.

About the air cleaner. I just assumed my moving it should cause RPM difference, sucking in more or less air. Anyway, what I didn't mention is that the snorkle is not on super tight, so that moving was while it was still on the car...just swiveling it really. This is probably something that is my own stupidity.

Originally Posted by rohrt

You really need to get a tach too. I had stalling issues with one car and found I just had the idle set to low. My loud exhaust was throwing me off.

Pull the vacuum line to the can again and plug it.
Take a reading of the idle advance timing for us.
Take another readin with the vacuum can connected. Then we can see how much advance your can is set at.

If you did have it connected when you took the idle reading then we know your connected to manifold souce.

I wouldn't be all that concerned with factory specs. My tempest won't hardly run with the factory spec of 6 deg BTDC initial. I have set for 14-18 and it runs 200% better. Different gas today, carb and unknown part all bets are off IMO.

I saw in one of your post on the first page that you said you took the air cleaner off and the idle was much better? And I see you just mentioned moving it a bit and changing the idle.

Is the flapper stuck closed in the snorkle? Possible vacuum leak in the line to the diaphram on the snorkle? Maybe try flipping the lid upside down and running it old school as a test I'm not expert but I think it should point to the driver side like you shown in post 13. From factory there was a metal line that ran from the valve cover to the air cleaner in place of that breather cap that is there now.

I can't for the life of me think why moving the cleaner would change the idle unless the air clean is touching something on the car it shouldn't be.

[Darth Menace]

Originally Posted by PontGuy

And you can add the fact that different distributors came with different curves depending on application (and they have often been swapped out too.) That's why I like to start out backwards and set the all-in first. 34-36 deg is almost always close to right for a performance 400. Then see where that puts the base timing. Once you know where the base timing is then you shouldn't have to check the all-in again unless you mess around with the distributor internals.

Just make sure that you get it right- agree with all the comments about remembering to remove the vacuum hose, make double-sure you are connected to #1 cylinder (front right) etc. And be safe! I shut down, make adjustments, and re-check. Yes tightening can throw it off. Just have to fiddle with it.

Oh and yes, agree that moving the air cleaner should not affect the idle. Another thing that could cause this is if the bottom base plate is tightening down on the carb linkage somewhere. This is a common with Q-jets and some aftermarket air cleaners where the base can hit the top of the accelerator pump lever. So you need to figure this out too.

I am 6'3 so I didn't fit in the Viper well at all. And I don't think it could be very comfortable for anyone. The seat is set a weird angle too, to make room for the trans tunnel. But if I could have gotten my friend's Viper for only 30K it would be sitting in my garage now.

There are guys as tall/taller than with Vipers. Just get a 2 inch seat lowering kit, and adjust the seat/pedals accordingly. The Viper is built like me...for speed, not comfort .

Anyway, I will get around to the car later today with a video if that helps. I haven't been taking it as easy as I am suppose to after my surgery, so waking up in pain today sucked. I am not sure crouching underneath the dash to fix the cluster helped any either. I have to do car stuff in small chunks if I want to heal at all.

[nytrainer]

once you set the initial timing the mechanical advance (centrifical) of the distributor should increase the timing in the neighborhood of roughly 20 degrees. You are saying that your initial is 30 degrees and total equals 36 and that would lead me to believe your mechanical advance in the distributor is only providing six degrees advance. A little early in the game to say there is something wrong with the base plate in your distributor so best to have you rerun the tests and get some numbers. I definitely would not have my initial at 30 degrees.

[Darth Menace]

Originally Posted by nytrainer

once you set the initial timing the mechanical advance (centrifical) of the distributor should increase the timing in the neighborhood of roughly 20 degrees. You are saying that your initial is 30 degrees and total equals 36 and that would lead me to believe your mechanical advance in the distributor is only providing six degrees advance. A little early in the game to say there is something wrong with the base plate in your distributor so best to have you rerun the tests and get some numbers. I definitely would not have my initial at 30 degrees.

Alright, I will get this done. I will take a video which should help better explain.


That being said, I didnt have the vacuum advance plugged in any way. I just unplugged the hose at the vacuum advance and kept it sitting there. Also, it was not in Neutral or drive while I did any of thise. I don't know if either of these should have made a difference.

[nytrainer]

You are using manifold vacuum for the distributor advance then when you unplug it from the distributor you must plug the hose with something, I use a golf tee because it's tapered, otherwise the RPM's will raise and you're not setting your true initial timing. You are introducing some centrifical advance when its not at idle. so look at the instructions again and try to follow it setting your initial then you could check your all in. We can go from there.

[rohrt]

If you had 36 at 3k rpm and only 30 at idle your advance could be froze up. Pull the cap and rotor off. Twist the mechanism and see if it snaps back and that the weights move freely

[Darth Menace]

Originally Posted by rohrt

If you had 36 at 3k rpm and only 30 at idle your advance could be froze up. Pull the cap and rotor off. Twist the mechanism and see if it snaps back and that the weights move freely

will do. so does it matter if timing is set while in Park or does it have to be in either Neutral or drive?

[johnta1]

No, as long as the idle is where it should be.
(in drive the idle is usually lower than in Park)

If it is set at full advance, it would just be to check what it is at idle.
If you watch the timing mark when it is revved up, it should move nicely not in a jerky motion.
(and it should move quite a bit)

As others said, plug the vacuum line because it will make the engine idle faster usually.
(if doing it at idle)

FYI, A lot of the timing lights that have the adjustable timing knob are not very accurate.

[kyle_blake]

Probably repeating everyone else but

1 plug vac advance at distributor with proper plug fitting
2 plug vacuum port that was going to carb in #1 with proper rubber cap fitting
3 put dial gauge to zero
4 car warmed up in park
5 e brake on sure why not
6 wheels blocked too sure why not can't be over safe?
7 timing gun attached to #1 cylinder drivers side
8 point timing gun down at timing marks

white line on harmonic balancer should be lined up pointing at a certain number on the timing mark plate.8/10/12 ? if it doesn't then we use gauge to find out how much!

now if you unbolted your distributor and turned it either way you are adjusting the initial timing.

Report back on the above and then we'll take next step of finding all-in?

RPM gauge helps know where you're at for sure.

Get a pen and paper ready to write down the obvious

RPM:
INTITIAL TIMING:
ENGINE TEMP:
DATE:

[PontGuy]

Another thought. If the idle is very high then you may be getting a bunch of centrifugal advance at idle. So not measuring the true base number. The idle RPM needs to be well under 1000 RPM, ideally under 700 to get a true reading.

One possibility is that someone replaced the stock springs in the distributor with very light ones. This makes the advance come in earlier. In extreme cases very light springs can make it impossible to get a good idle.

Can you pull the cap off the distributor and take a picture so we can see the weights and springs?

Edit- just re-read all this one more time. Based on the funny readings that you are getting the distributor advance setup and timing may very well be the ultimate cause of both your power and idle problems. Do you have anyone around that can help to make sure you are doing it right? Even an experienced Chevy motorhead would be a big help because the process of setting the timing is the same.

[rohrt]

May not be a bad idea to just get a new recurve kit.

Rocky Rotella did this eval a while back that I found usefull.

http://www.arkansaspontiacs.org/tech...s/Recurve.html

[PontGuy]

Rohrt, if the readings that Darth is getting are right then thinking the same.

I learned a bunch about distributor setup back in my dirt-track racing days. Trying a bunch of different heads, cams, etc. on the same engine taught me the importance of getting distributor timing right for a given combo. And based on my experience Rocky is spot-on regarding the aftermarket kits.

Just to show what crazy timing you can have in a distributor here is a graph showing what the original curve was in my 69 points distributor which did not have the original springs/weights in it when I got it, and what it looked like after Sun-Tuned and I worked to get it right for my 455. Not shown is the first pass, which had a similar curve to the final one but was flatter so it did not get all in until 3500 RPM. My engine has a mild cam for a 455 so we were thinking that it would need a longer curve, but testing on the car proved otherwise. Admit that taking it to this extreme is not necessary for a weekend driver, but a curve like the one I started with causes all sorts of trouble.

Another thing that you can get into is accuracy of the timing mark on the balancer. Usually they are close but the one on my 455 is off by 2 deg (measured using a piston stop).

Anyway, back to Darth. I am hoping that we will be able to see if the springs/weights are original or not if he posts a pic.