I enjoyed the explanations along with the demo! My own personal experience I had this done years ago and very much was the common knowledge at the time too regarding all in rpm and total advance amount etc. This was a top 2 or 3 mod for my stock engine at the time. It's been 25 plus years but as I recall we also put a limiter plate on the vacuum advance that had notches for incremental changes.
Love the vid. I opened my shop in 1972. Replaced many springs and weights. I installed electronic ignition on my 69 AMX. This allowed the next owner to over rev and destroy engine.
You get a thumbs up after only 4 min. First time on your channel. Can tell you know what you are doing and love the frank discussion about the bench racing myths!!
Hi, I too enjoyed your channel. It's funny my experience with a 71 pontiac points distributor and 72 points is that they both have 18 mechanical advance and come in by 3000 and both were in excellent shape so I've always ran 18 initial and 18 mechanical for 36. Guess I got lucky? Was expecting it to be a little harder . I however just use a timing light to check for timing creep and as well as any additional timing past 3000.
Please don't forget to do the follow up video concerning how you max that advance at 2800. How you do that? Do you add weight to the weights? Or change the geometry of the weight assembly? Though my days of modifying cars are over, it will be nice to know the tricks I could have done to my cars back in 1968. If only I had known.
Just set total advance! Honestly I'd set the timing to 36 mechanical, sounds like the vacuume advance will take care of the idle. Seems to me that's not a bad setup for low octane fuel. And you'll not knock getting off idle. What a cool machine.
The GM weight system always hangs up it rarely ever has smooth operation. The Excel dual point distributors took the GM points and the Ford full mechanical advance weight system and combine them into the ultimate old school distributor with ease of adjustability and always delivered top performance.
It is spelled "Accell" and they used the cap and rotor from the 1955-56 Delco distributors. Best thing about them is they had a bearing above the points made the dist shaft nice and stable. They used a high rpm - type point cam that was much better than standard GM part. Never knew the advance weight system was ford-type just knew they were different and better. Worst thing about the GM distributor was the point gap and dwell changed as the vacuum advance operated. Worst thing about the Accell is that is has no vacuum advance and a lot of street engines get better mileage with VA.
If you adjust the ISO on your camera to be much longer then the orange triangle blinking will go away or be much reduced. At the same time when you adjust your ISO to be longer you must also adjust the aperture to reduce the brightness. But many cameras only do this automatically and don't allow for manual adjustment. In your case for this video the automatic adjustment has reduced the ISO time to be so short that it frequently misses the orange blink. So: If you put a filter, (sunglasses) in front of your camera then it will automatically adjust the exposure time(ISO) per frame to be longer because it is compensating for the darker image. And it will automatically adjust the effective aperture to reduce the brightness to a good level. And literally a sunglass lens will work but a filter made specifically for the camera will be better. Try a sunglass lens first before spending the money on a filter. Also, the filter is often easier than fiddling with the buttons to navigate to the menu where ISO is adjusted manually (if your camera even has such a menu feature.) If the video image on your camera has your lights on your instrument panel blinking then sunglasses will help that too.
Excellent video mate. However, I was hoping you would follow up the video on the effects of quicker advance by replacing the little springs to lighter ones on points distributors.
Watching that distributor spin at 6000 rpms had me anticipating disaster. Have you ever had the counterweights come off the posts while being tested? Just my safety background, I would have made a lexan shield that folds down covering the top of the distributor for my piece of mind.
The downside of electronic is mainly what happens when they break. It is easy and cheap to carry an extra set of points but an extra electronic module takes a bit most space and $$. I speak from experience here since I broke down a few hundred miles from home in the middle of nowhere and fortunately there was someone to help and there was an auto parts store 30 or 40 miles away that had a spare. After that I always carried a spare module.
I too like points, but many people today do not want to mess with them. I run points in most of my personal cars. I have been running M&H Breaker less in my 67 Corvette to test it’s reliability. If I were not using it as a test bed, I’d run points in it.
if you buy a quality electronic module, or just convert to hei the parts are readily available everywhere, and regularly last 50,000 to 75,000 miles before failing, but if the module fails in the hei, they are on the shelf at autozone, oreilleys, advance in their performance section. 4 pin hei modules are extremely reliable, easily last 3-4 times as long as a set of points. your arguement does not hold water sir.
@@b.c4066 My car at the time was a 72 datsun 240z with a 280zx motor. No HEI - just Nissan electronics. Even with a quality unit with a high MTBF they can always have a defect leaving straneded. Other than that go down to Plush Oregon and head east or do something similar say in Montana, Western Nebraska, Utah, Wyoming, etc. There are a number of places in the US, Canada, and the world where you need extra gas, 2 extra tires, blankets, and food before you start heading somewhere. You are imagining there is an auto parts store somewhere nearby. I blew a tire going across Wyoming in a dually and was fortunate enough to only be 60mi from a town with a tire shop. There were only 2 things in town - the tire shop and the hotel/bar/restaurant. The next town was over a 100mi away. No auto parts.
The only things that electronic conversions remove/do are 1) you don't need to fiddle with the point gap and/or alignment, 2) you won't lose performance as the point block wears, 3) you eliminate the possibility of a rounded point drive cam, & 4) you have a more consistent spark signal. Everything else is transferred along unless those things are addressed individually.
Great Video, I was wondering at 13:12 of the video you indicated that the advance was 16 degrees at 2800, But when i look at the scale, it looks like 8 degrees. Earlier in the video you said that each big line was 10 degrees, but the scale would indicate 5 degrees. Why is this different. Thank you
Oh hey one more comment, for those of us who want to know how much total mechanical timing they have without having to rev it up to 4000-5000 in the driveway, I heard you can warm your car up to temp. Then turn off, remove springs from dist. Fire the car and then observe max total timing. A quick way to see if your total mechanical at 3000 rpm or so equals what it would be way up at 5000+? Is this an accurate test at idle with no springs?
I would not recommend removing the springs altogether. I would put the lightest springs possible in and they would reveal the total mechanical advance. The springs serve to keep the weights in place and this is the reason I would not run it with the springs removed.
@@gasandspark This Is a "JEWEL" for me, always wondered how this is determined, NOW how do you limit the advance, is there a trick for THAT, Thanks for offering your video👍
What distributor machine are you using? I am trying to modify a old Allen for working on VW distributors. They had a weak lamp, I am trying to use a inductive timing light to produce a brighter lighter to see the arrow.
I really like learning something new about any engine, this isn't something I've seen before even though I've read about it. As you mentioned, the only reason for fitting an electronic trigger is majority of people have zero idea how to set points or are too lazy to re-set points at required service intervals (although when I was teaching there were plenty of students who had never seen a car or motorcycle with points as they were pretty much phased out by mid 80's on bikes and most cars some years earlier) Was that a Hall Effect or optical trigger? From what I've read about Pontiac's, going over 6,500 rpm is quite likely to break things plus they can't flow enough air to pull high rpm under load (I still have a pair of 1965 Catalina 389 heads in garage)
the only reason to fit an electronic trigger is to bring a degree of reliability, and less maintenance costs to the vehicle, plus better cold starts, better high rpm power. there is a reason gm stopped using points around 1973. magnetic and or hall effect triggers are simply superior in every way. and if you can fit one into an old muscle car without changing the looks or originality of the car it is simply ignorant not to do so. no offense intended, but by your logic we should all go back to racing flat head fords, and inline 6 cylinders with single 1 bbl carburetors. a very common thing to do in the late 70's and throughout the 80's on older gm cars was to ditch the points distributor, ballast resistor wiring, and install an hei. now days even the large cap hei is inferior, but for most stock engines that never see 6500 rpm they do work well. points are a thing of the past, to use them now days is ignorant, lazy, and expensive. retrofit an electronic trigger and be done with it.
and i should say, I'm not trying to be a jerk. one of the biggest issues with points in a performance automobile is bounce, they simply do not consistently perform when pushed past 4000 rpm. an electronic pickup that does not rely on a cam lobe to open and close the circuit is simply superior in every way there is no mechanical contact therefore nothing to wear, plus the voltage delivered is a full 12 volts, not cut back with a ballast resistor (dodge), or resistance wiring (gm). back in the day companies like accel sold modified points, as well as better cams that alleviated some of the issues, and when used in a dual points setup they worked. then came 1974, gm had hei, chrysler went to electronic ignition, and it was better than anything prior to it. the reason being is with federal emissions mandates there was a clause that said the emissions equipment most not fail, or need maintenance for 7 years or 75,000 miles. it basically forced the big 3 to develop the technology that would last. the hei was amazing for the era. it just flat works. far superior in every way. it works so well that here in 2022 companies make ford, chrysler, even vw beetle distributors with hei cap and electronics. the design was that good! if aesthetics matter you can get a small cap hei that still uses an external coil, still has vacuum and mechanical advance and to all but the most trained eye looks original and passes the casual glance. so unless you are doing a museum type restoration for a show car where every inch of it is scrutinized for originality keeping points is just lazy!
@@b.c4066 The problem with original 4 lead GM HEI was the unit inside distributor was very prone to failure as it overheated, (but they were cheap so carrying a spare not a big deal) I've seen double spring points and I've also seen points return springs overheated and lose pretty much any 'spring' they had. Honda engineered the spring rate to create points bounce so prevent over revving (they still went about 1,000 rpm into red) The GM unit is often used as a replacement DIY for OEM motorcycle systems which can get incredibly expensive (usually on 1980's bike that still had mechanical advance) or as an upgrade from points. Honda managed to piss off the big 3 as they had small cars that could exceed the 1973
I once fitted points to a 70s 360 Chrysler and the bushes were so worn it would only run on 4 cylinders with the proper gap set. The bushing wear exceeded the points setting?
Is there a reason one of the springs looks beefier than the other. I think I need new springs, mine look like their ready to break, very week. It's a 1970 Chevy 350 small block.
The springs are what set how quickly the curve comes in. Ideally you want the curve “all in” by 2800-3000 rpm. Lighter springs allow it to come in earlier and heavier springs make it come in later. Heavy and light springs can be used together to get the desired curve. It’s rare that I end up with 2 springs of the same type when dialing in a curve.
If you go to my website at gasandspark.com I list my current prices. Currently I charge $250 for labor to rebuild / recurve a distributor. Triggering components; points, pertronix or M&H wireless and vacuum cans are extra.
This may be a dumb question, why do you want all your mechanical advance in by 2800-3000 rpm (in a GM product)? I'm not arguing, I just like to why that is conventional wisdom?
Hi Rust Bucket. Good question. It’s because a lean mixture, which is present at idle or light load) requires less time to burn. As you add throttle, thereby richening the mixture, you need more time to burn. More time to burn = more advance. Too much advance will create detonation that will damage an engine. The balance between bringing in mechanical advance to burn the rich mixture and not having too much advance to create detonation seems to be the 2800-3000 rpm mark.
I was watching your video.. you need to relook at your advancement at idle speed . Your statements on advancement at idle or a give rpm is not correct.. you need to go back and reset to 0
