Video není dostupné.
Omlouváme se.
MSD HEI 8365 Locked out timing experiment
Vložit
- čas přidán 6. 08. 2024
- I ran this test twice...one with the module in place and the second, without a module. I wasn't exactly sure why the timing retarded when running a module but I thought it had to do with dwell time. Someone else mentioned it was a latency issue between the module and pickup so after further testing, I came to the conclusion this is the reason. To test my dwell theory, I locked out an old points-type distributor and tested it and found the dwell did not cause the timing to retard. It was rock solid in all RPM ranges.
Anyway, when you remove the springs and weights (from an HEI) and leave the module in, the timing will retard as RPM increases. To be able to run a distributor without a module you will need an ignition system that is capable of firing off a magnetic pickup.
Great visualization!
Variable reluctance triggers like that one are sensitive to the resistance they are feeding into. Low resistance in combination with the inductance of the pickup coil causes a phase shift, as you can see.
We recently tried the locked distributor vs a curved one on a 604 crate motor on the dyno and found the locked was stonger out of the gate but power fell off quicker up top vs the curve . 28@ 4000 and 33@6000 . Vs 34 locked . The curve works great in a circle track car and can help with traction off the corners . I like your homemade machine it’s neat .
Nice, real-world testing out on the race track. I'm all about experimenting with different setups. I've always wanted to run the same test on the drag strip and on the circle track to see if there was any difference...not only ignition testing but fuel, intake manifolds and header sizing. I've done all this on my race car but never found a circle track guy who wanted to experiment...seems most of the guys around here do what everyone else is doing. Just curious, did you leave the module in when you locked out the distributor? If so, I'm wondering how much the timing was retarding as the RPM increased. Like you said though, traction off the corners can make the difference in passing or getting passed so you might be set up optimally with the way you have it set up now.
It was a pro billet being controlled by a 6AL . I was watching the dyno guy he was running the timing light and was about 1 degree per thousand . He was setting it at 34 at idle and was showing 31 @4 000. I just wanted to try it on the dyno to see if there actually was a difference and there is . Lol we have a lot of big cheques on the wall showing a curve works on the track versus locked . Another thing is a circle track engine runs a lot hotter then a drag car so that will effect the timing as well . I have a sun 504 that I did the distributor on and used a MSD box to run it so it is more accurate from the machine to the car .
@@nathandean6639 Great info, thanks for your input. I recently acquired a Sun 680. It needs a lot of work but it does turn on and spin..not sure if anything else works. As soon as it warms up a bit I'll tear into it.
Maybe you already were in it if u made your own distributer machine , check out the racing fuel systems forums . There is a new one and old one the new one is more active but lots of great information on the old one , they have a ignition section and lots of discussion on timing and how to mod weights and what not . The best thing since sliced bead haha . I am subscribed and keep the videos coming.
The first discrepancy is the RPM difference between each test. 1000-4000 rpm vs 500-3000 rpm
The timing still “retarded” in the 2nd test; it was much less but still moved, which is partially due to the lower rpm range.
Rotor phasing needs to be adjusted to narrow the timing movement throughout the rpm range. Back to 4000+ rpm…
Another area, in the engine causing erratic timing I’d the camshaft “walking” in the block. Setting a tight camshaft end play helps stabilize timing.
Thank you for your input. Looking back, I should have ran both tests up to 5000 rpm and been more consistent but wasn't thinking. I agree that cam walk can play a part in timing discrepancies as well as a worn timing chain...definitely things to consider when checking timing on engine with a lot of miles. Trying to catch this stuff on video is difficult because of the camera frame rate so I'm glad that it turns out as well as it does.
I am curious as to what your goal with this is. Very interesting experiment good to know that it can be done though
No goal really. I've always wanted a distributor machine but it seems people who have them think they're still worth their weight in gold so I finally decided to build my own. You can do all this same stuff in the car but my race car is super loud and there's too much stuff to watch...this makes things simple. Plus, I have so many experiments I've been wanting to try for years.
@@BruceCoggins ok that makes sense and yeah they think those machines are made from gold. I've been wanting a flow bench for adjusting carbs and tweaking them but those are outrageous too
This is a super cool video. Thank you sooooo much. 😎 😎 😎 😎 😎
Thank you. I plan on making a lot more videos as soon as the weather warms up. It has been way too cold in the garage even with a heater.
If I lockout my MSD distributor and set my timing mark to TDC, and drop the distributor in lined up with the #1 plug wire, how do I set it for 40deg. I do have a starter saver wired in???
Before you drop the distributor in, turn the engine over to the 40 degree mark and then drop in the distributor and line the rotor up to the number one terminal. This is assuming you have a balancer that is marked. Next, start the engine and verify the timing and adjust as necessary.
Crank triggers. The most accurate timing devices are locked out.
Correct and they are the best way to go for any serious racer. Phasing is an important part that most people don't check. I have a video or two on phasing. I plan on making more videos when the weather gets a little warmer...it's been a long cold winter, lol.
Bruce, new subscriber here. How ddid you build your distributor test stand? What motor did you use to spin that distributor shaft?
Thank you for subscribing. I got the idea of building this thing online ...there's a guy who built one and posted how he built it...I used his instructions but modified them to make it my own. Search for homemade distributor machine. For the motor, it's just a standard blower motor. It just needs to spin clockwise...I can reverse the wires and turn it counter clockwise for BOP distributors too. I have a variable speed switch and an on/off toggle switch. I cut an old extension cord and put some clamps on the ends so I can hook it up to a regular car battery. Let me know if you have any other questions.
@@BruceCoggins Thank you so much!! I am trying to start a garage that specializes in pre-WWI race cars. Also any exotics that are equipped with a distributor and/or magneto. I have been sourcing equipment so that I will be able to cast, fabricate, turn down , mill any part that is needed. There are just no stores that stock parts for 100 year old plus cars...
Awesome, good luck. Let me know if I can help you out with anything.
@@BruceCoggins Thank you so much my friend!!
what did you use to turn the distributor?
I used a blower motor...Murray PM102...and wired in a DC motor speed controller.
What are the advantages and disadvantages of having locked out timing. Isn't there a risk of engine damage if the engines rpm increases and only is allowed only a certain amount of timing and wouldn't engine performance suffer if there was no timing advance as engine rpm increases. I guess I don't understand why you would not want any timing advancement as engine rpm increases
for drag cars, or circle track cars where rpm is usually kept at 3000 or above. there is simply no point in having timing jump all over the place. it just slows the car down, and can have a dramatic effect on air fuel ratios. for a street car that has to idle in traffic, start from -40 to 110, run on piss aka pump gas, get lugged up hills in the wrong gear, and in general be driven by knuckle heads, subjected to torture the engine is not designed to handle.. ignition timing that changes is a good thing. but for performance in a racing engine many times it is not whats best. especially for a carbureted car that leaves the line at 2500 rpm full throttle and runs for 8-9-10-11-12 seconds then gets shut down. also usually use racing gas with a much more consistent knock resistence.
I was out of town -at the race track, of course, LOL- when this question came up and I couldn't answer it right away...B.C., wow you nailed it. This is another reason I started doing these videos. I wanted to find like-minded people to join the discussions, help teach, and basically share some knowledge. Thank you for your input again...you answered this question a lot more coherently than I could have hahahaha
Thank you for your question. Looks like B.C. pretty much nailed the answer and I completely agree with him but to add to this a little bit, a drag car operates a full throttle so there really isn't any need to have an advance curve.
So, you asked if there would be engine damage if the engine RPM increased and the timing didn't adjust for it. Most guys only check initial timing and call it a day and trust that the centrifugal and vacuum advance will do what it needs to do. This is perfectly fine for a street car but for a race engine, we focus on the total timing. Even with a functioning centrifugal advance, once you set the total timing, theoretically, that's as far as it is going to advance so basically at that point the engine doesn't know if the distributor is locked out or not once you get up in RPM. All you need to do is figure out how much timing the engine needs for optimal performance. There a several ways to do this. The fastest way is to put the engine on a dyno or put the vehicle on a chassis dyno but you can also play with timing and fuel at the race track. Once you find the happy number (total timing), whether the distributor is locked out or not, you tighten the distributor down and hit the track.
Speaking of dynos...most guys go to the dyno just looking for HP and TQ numbers so they can brag on forums and try to out do the next guy. I have used a chassing dyno a few times but I use it to tune...I don't care what the number HP is...my goal is to make sure I'm not running too lean or too rich and I play with the timing, again, to make sure I'm not too far advanced or too retarded. I just want to find a base that works so when I go out of town to race, I have an actual starting point.
Hope this helps and thank you for your question.
One thing that kinda neat to do and can benefit from phasing a distributor on a carbeureated engine...
If you have a GM HEI big cap distributor with a four pin ignition module, swap the four pin for a seven. Install a wide band O2 and a standalone ecu like a Megasquirt. You will also need a stepper solenoid, an iac-idle air control valve, both four or six wire, and a mas.
Megasquirt I think has an onboard mass.
The seven pin ignition module will connect to the Squirt via three wires. One from the hall is use by the squirt for cam position. A second wire for bypass and the third to alter timing.
The O2 is for afr as is the mas. The squirt takes the O2 and mas to determine how much if any to open the iac.
Set your carb to run slightly rich. The iac is used as a controlled air leak by the squirt providing more air as needed to maintain afr.
Phasing the distributor and having the timing set by the squirt gives you computer controlled ignition.
Letting the squirt act as an air regulator, you now have a static carburetion device acting dynamically.
The stepper solenoid is to let the squirt actuate the mechanical choke. So a temp sensor would be needed.
its called inductive delay. and depending on which computer and ignition box (6a,6al, 7al etc) the delay changes even more. and if using an efi system you have even more (or less) inductive delay. with efi systems they tell you to check base timing, verify it matches what the ecu is commanding, then rev to 3500 (very important if using cdi box with multiple spark at lower rpm) and check timing again. then adjust inductive delay accordingly. this is nothing new. electronics do not respond at the speed of light, and once it has to trigger the coil 6500 revolutions per minute times 8 cylinders it has a delay. to further your experiment. try using different coils with altered primary and secondary resistance. its an eye opener for sure. now days its tough to beat a coil near plug setup, even if using a carburetor. holley makes a cnp setup that can be fired off of a crank trigger and cam sync, or one of their dual syn distributors. then even with a carb if you have a single cylinder that is prone to rattling you can alter its ignition timing at different vacuum and rpm points. a coil that only has to fire one cylinder and can dwell for up to 5 milliseconds before being saturated is far superior to an msd box, and coil that can only dwell 2 milliseconds and has to fire 8 cylinders. even if your hei is in perfect condition it is not uncommon to see as much as a 15-20% misfire rate once above 5000 rpm. even if you can get that misfire rate down to 10-15% it is a lot of free power. distributors were/are amazing electromechanical devices, but time has marched on and a big reason modern ls, coyote, hemi engines make the power they do is coil on or near plug technology, and the ability to control them much better. you can keep the carb and enjoy a lot of these benefits by switching to a well thought out cnp/cop setup .biggest benefit is you can stop tuning to the most detonation prone cylinder. run 7 at 36* and that pesky number 8 can have -30-32 (just an example not hard numbers) but once you understand that, and learn to use the system, it only makes sense to use multi port fuel injection and again adjust individual cylinder fuel trims for max power, max knock desistence. computers are a good thing, but the learning curve is steep at first.
add cam twist, cast crank flex. and all this gets even more distorted. which is why oems have went to stiffer cranks, 58x,36-1 crank triggers with cam syncs. usually on the front of the cam, not the back where twist and flex is worse.
go to a 14, or 16 volt system.. and everything changes yet again. thats one of the biggest reasons modern cars use pulse width modulated alternators. they need consistent voltage. doesnt so much matter if its 13.4 or 14 volts. just that it stay as consistent as possible. computers, computers, computers.
Thank you for your input...very informative. I've been aware of -inductive delay- for many years but even today, after all these years of people running locked out HEIs, there are still some who are not aware that it happens or they think its caused by other things like a loose timing chain for instance. You are a wealth of information and have given me some more things I can experiment with...the idea of trying this same test with different coils with various primary and secondary resistance seems interesting. Again, thank you for your input and I appreciate you sharing your knowledge with us. It's never too late to learn.
@@BruceCoggins and another thing, how do you know each tooth of the distributor reluctor is spaced evenly? There are usually variance of +/- a degree or two in production hei distributors, not sure on the msd stuff. You can also get backlash in the cam to timing gear interface causing timing fluctuations. When you consider all the tolerance stack, delay it's an amazing piece of engineering, a single part, so simple to the eye. Yet very complicated in its design. Oh and here's another one.. test 4 different msd hei modules without moving the distributor and I bet you get timing differences between each module. Neat stuff ain't it sir? 😁
@@BruceCoggins and yet another test, reverse the polarity of the reluctor and watch the timing change, reverse the coil polarity, or use the wrong hei coil. (Yes the carb vs large cap efi hei coils are different) and you'll get timing differences.
you went 4000rpm with the module
you wend 3500 without it, why?
what is the function of the moral? 🤔
I simply failed to pay attention to the RPM...what I was showing is how timing will retard if you lock out the mechanical advance but leave the module in place. Just doing some rudimentary testing...nothing scientific.
@@BruceCoggins Ok, thanks. What is the function of the module?
I just assumed her was good, am I losing 6 degrees of mechanical advance as I rev up to 6000rpm?
The ignition control module is required to fire the coil however aftermarket ignition boxes do the same thing but are more versatile so you can toss the module and fire the ignition directly from the magnetic pickup. A module is the electronic equivalent to points...a little more sophisticated but essentially the same thing. They have built in dwell to give the coil time to charge up in simple terms. I assume you have locked out your timing and still run a module which is why your timing retards as RPM increases which is due to latency between the module and the pickup.
@@BruceCoggins Thanks, clear explanation,
@@BruceCoggins with out the built in latency what is the RPM limit for the coil? and does it go down in voltage at high rpm? would a ignition box stay accurate to 550p rpm, that's often peak power for street engines.