hey welcome to Gold scratch so the topic of this video is uh Distributors distributor Advance curves vacuum advance centrifugal Advance original or uh initial Advance how that all works how you make it better why it's important and so we're going to get to all that as usual I got my typical chart to show you so before I do that just a couple things uh first of all for the tip of the day we're going to explain this at the end there's a lowly lock washer or some people call them spring washers so if my point is I guess my punchline is if you have any of these in your bolt bin 38 of an inch or bigger soon as this video is over and after you like And subscribe go throw them all away because they're just going to get you in trouble and I'm going to explain why at the end of this video so couple other housekeeping points you know I have to share with my subscribers and viewers sometimes in life you get lucky and so 2015 I bought my Z28 Camaro back and it had an l78 396 not the right engine in it and so I wanted to sell it so I opened a YouTube channel just so that I could demonstrate that it ran and subsequently I started injes again and I used it for that same reason to demonstrate I have a test have a run stand I never asked anybody to like And subscribe I never thought about doing that and if you watch any of my old videos you'll see that I don't do any of that so uh few years later of course with inspiration starting with my son Michael who inspired me to make better videos and and grow the channel uh then Mike Kimble came along he started off being a customer he took an interest in what I'm doing uh he's brought me uh along a long way technically we have better equipment to do it with now he works on content for me all the time does a lot of research and homework for me so thanks to Mike pushing me to be better Alec Vendrick my good friend who is holding the camera today who's actually shoots most of my recent videos mik Kimble lives half an hour away from here and my good wife maryan of course who supports me and everything else and she's my backup uh she's my backup cameraman or camera lady so thank you for everybody and mostly all the people who are watching this video today I want to share with you sometime in the next 12 hours or so I'm going to pass 10,000 subscribers so year ago I had six or 700 subscribers uh back in April we made a with help of Mike Kimble made a pretty good video that got it moving and it's been growing exponentially ever since and once again we got 10,000 subscribers we're growing at one and a half to 2,000 subscribers a month so you can do the math where we're going to be in a year from now thank you very much for everybody who likes and subscribes share it with your friends give me your comments and uh helping to uh help me to grow the channel and we'll keep working on making interesting helpful videos as I mentioned before experience is expensive uh you can get it for free by watching gold scratch speaking the comments and the last video or recent video talked about the Pontiac engine uh it's at the machine shop right now say hello to Walt and Albert they just sent me a video they've a little video to me they've got the block almost ready just putting the plugs back in they discovered one of the oil galy plugs had a hole 16 of an inch hole drilled in it and I didn't understand that through that question out lots of good comments from Pontiac lots of Pontiac experts and and lots of interest in it who gave me the answer to that question thank you very much the next video was Steve Shotz uh 60h 327 350 build so we shared with you how we were proposing to do that lots of good comments on that and I just want to respond to one of them Steve's looking at his options right now but a lot of the comments said yeah you should build a 383 or 400 or whatever so going back to my corporate days one of the models was no more or less than you need Steve wants 400 horsepower I can easily give him that with a 350 if it's a 383 it'll be 450 if it's a 400 it'll be 500 so it's not what he asked for so that's why we're sticking to that plan and we'll see what Steve decides to do so back to the video at hand today so Distributors this just an old uh hii style distributor I took it apart just to demonstrate something so every distributor has an advanced curve so if you look at my little graph here that I have uh on this line it's RPM of the engine 1 00 2,000 3,000 4,000 and on the vertical line it's number of degrees of ignition Advanced so uh where it maxes out is at 34 degrees so uh we're going to show you two ways of getting there and what are the benefits of each and so the original block line what I've done as I mentioned before uh some of the smartest guys in the world design these cars originally we're using an the spec sheet out of this manual for an l79 327 350 horse engine that was used in Corvettes novas and chevels in the from 1964 to 68 or so and that was one of my favorite engines it's basically the fuel injection engine but with a hydraulic cam instead of a flat or instead of a solid lifter cam so we're using the actual numbers we're going to put a uh screenshot up of all the specs so you can look at them in your own good time of how this works so if you follow the block line starting the block Line This is the I just took the numbers from this manual from page 14 of the specifications of this manual for this engine so the l79 if you bought a Corvette from GM and drove it off the showroom floor at four degrees of initial Advance there's a th000 RPM so that's you set that you actually set it at 950 I think there's two points on the graph uh so they are ti they here at 14 degrees it had 1400 sorry at 1400 RPM it had 14 degrees of Advance at 1800 RPM it had 20 degrees of advance and at 30 4700 RPM and had 30 degrees advance so it followed this BL line I plotted all these points and it takes until 4700 RPM to get full advance now those cars ran pretty good right off the showroom floor but you know back in the day we thought we could outspark these guys so what do we do we took the Distributors apart and here's the distributor apart so here's how uh mechanical Advance first of all so there was a little Springs couple little springs on here that holds us back but as you're Distributors is turning the faster it goes the more these weights want to flight shoot out and as they do they get the rotor of your distributor ahead of the shaft of your distributor basically and that's how you get Advance going on okay and the amount that they can advance is limited by if I take this guy off here the size of that little slot that's in there so so what do we do back in the day we took them all apart we actually welded that little slot up with some bronze Weld and then we took a round file and we filed it round and we thought we had improved it we put it back in and checked the timing and did that until we got it right might have the distributor out two or three times before we were happy with it and here's what we ended up doing here's a modified curve of your mechanical events so one of the things we did by welding that little slot we shortened the amount of mechanical events so or certific events so in the original l79 it had 30 degrees total of centrifugal advance so we shortened it up so only have 22 degrees of of uh mechanical advance so because of that we got to start off at 12 degrees of initial evance so we had more initial advance in the engine when it at when it's at idle okay and then that the other thing we did was uh the other way you can modify the courses and you can buy kits nowadays with stronger Springs or different color springs things that modify the the not only the that modifies the rate of travel and the length of the slot modifies the amount of travel or the amount of advance so what we were able to do then was shorten it up so all the advance was in by 3,000 RPM and typically in a modern high performance distributor that's kind of what they are nowadays and if you ever watch my uh videos on the dinos we set in the timing typically what we're doing we rev the engine up to at least 3,000 RPM and I set the timing at that point knowing that it's not going to gain any more than that somebody's going to say ah it might back off a little bit when the timing change yeah but that's not relevant right now we're trying to get it the full events by 3,000 RPM so the red line shows you starting more initial faster mechanical faster acceleration of your certificate events and then and flatlining out so so on a street car there's a two or three different versions as I said there's three kinds of Advance there's initial Advance mechanical Advance or also called centrifugal advance for the reason I just showed you uh and then there's vacuum advance so a race car uses no stal Advance no vacuum advance a circle track car typically locks the advance in if they want 34 at 34 degrees it stays there all the time and never moves and so why would they do that well uh race car usually takes takes the green flag about four or 5,000 RPM and all the advances in by then so they don't really they don't really care what happens back here the one negative thing is it's hard to start an engine with 34 degrees of Advance especially if it's hot and how they do that is they put the ignition and the start on separate switches you get the engine cranking over on the starter because as long as the ignition is not firing it'll turn over easily and then they turn the ignition on and that's how they get it started so uh that's how they deal with that drag racers sometimes use a little bit of initial Advance uh just to make the car easier to start so that's how that works and so uh the advantage is uh quicker curve start with more initial events get to that full Advance earlier so you have from 3,000 RPM on up the engine can use all the advance that whatever maximum Advance is going to be so uh why do you have Advance at all so 34 degrees before adop at Center it takes time for that flame to propagate uh in your ignition when the spark fires you don't have an explosion at least you better not have an explosion you have combustion combustion is just rapid burning the rapid burning jumps from one molecule to the other and so it takes time for that to happen so the idea is if the spark Fires at 34 degrees before top dead center somewhere just after top dead center the maximum force is achieved and the Piston's on the way back down obviously you don't want to have it trying to push the piston in the wrong way wrong direction so that's that the next issue that I was reluctant to get into too but I can't avoid it talking about this and when I thought about doing a video about this uh last night I thought oh maybe I'll check on the internet and see if anybody else has done one well that's an understatement there's lots of videos about Advance vacuum advance and one of them is uh whether the vacuum events should be ported or manifold uh vacuum events and I don't want to get into the debate uh and I'm going to avoid it by I'm going back to my smart guys if you bought your Corvette or Nova or chevel with a 327 350 horse engine and drove it off show floor vacuum advance was hooked up to your manifold advance and I think I'll go with those guys they were pretty smart so um cover another point off whe you need vacuum advance at all some guys modify their Distributors if you're if you're going to run a distributor on Street you need vacuum advance and here's why vacuum advance in the whole debate about whether ported so back to this I'm jumping around a little bit I apologize so ported is this this is ported vacuum advance so if you hook your distributor there's your vacuum advance device on your distributor just an old grungy distributor sorry about that okay and suction is created because you have manifold vacuum that advances your distributor so if you hook it to here that's ported if you hook it here to manifold so manifold means that's the vacuum that you're seeing in your manifold so if your engine's got 15 inches of vacuum or 20 inches that's what it's going to see so let me cover off that question first whether you need vacuum at all why do you need it because you're engine needs a lot more Advance at idle than it needs when it's under load and the reason that is when you're at idle your throttle plates are almost closed okay if you look at the bottom of the engine bottom of the carburetor your throttle plates are almost closed you have huge uh vacuum and so your volumetric efficiency in the engine is terrible it's almost zero the molecules of your combustible mixture are very are not dense at all and the less dense they are the more time it takes for that combustion to take place so you need to give it a lot more heads up warning and you do that by having lots of vacuum so so I'm assuming here that we've hooked the vacuum line up to manifold vacuum and I'm following the red line here the modified curve so manifold vacuum adds the GM specification I took right out of this manual at 15 in of vacuum is 15° okay and at 8 in of vacuum is zero by the way so at 15 inches of vacuum as you are accelerating up to 2,000 RPM as long as you're not on the throttle hard you're not loading the engine yet you're just cruising okay so that manifold vacuum uh 15 degrees will add on to your 12 and give you 27 degrees or so uh of total events by here and it'll continue to increase as as it goes up because you're the total Advance increases because your accelerate your certific Advance is increasing also okay let's create a scenario you're at 2,000 RPM you're cruising along your throttle plates are almost closed and you stomp on the throttle when you stomp on the throttle that vacuum goes to zero and the vacuum advance Falls falls out completely your Advanced curve drops down to this line and your centrifical Advance takes over and finishes the job so if you had it hooked to here which is called Port vacuum would be the opposite the the vacuum advance would continue because if you have it hooked here at idle you got zero advance but as you accelerate and open those throttle plates it's measuring the vacuum above the throttle plates and as air flow goes by them the vacuum increases vacuum goes up here's my point on the argument about which one is best my view is neither types of vacuum events is a performance issue vacuum advance is intended to manage your engine when it's not underload not when it's underload you put put your Throttle Down the vacuum goes to zero centrifical Advance takes over and you do not want more than 34° if you have any kind of a mechanism that's increasing as you accelerate you're going to have more than 34 degrees so my final position is I'll go with the smart guys that's how they designed it that's how they hooked it up as I said before whenever you think you're going to outsmart these guys the one the smartest engineers in the world design these things if you're going to outsmart them you better be on do your own homor because uh they knew what they were doing I'll stick with them that's manifold vacuum go to zero takes over you do not want more than 34 degrees or anything else you don't want your vacuum events to be a part of it it's only there to manage your engine when you're not trying to make Power that's my point so hope you found that part interesting please like And subscribe and we're going to get back to the tip of the day so lock washers so why am I so being so nasty to lock washers well I've got lots of experience with them my very early corporate days in a big steel mill one of the things I was responsible for was maintenance of overhead graines we had over 200 grains from 10 tons to 400 tons and when somebody said go get me a 2in bolt they didn't mean 2 inches long they meant two inches around that's the kind of bolts we're dealing with with so Fasteners was a really expensive item and a big item and important item from reliability point of view uh Fastener failures in Industry are the single major cause of equipment failure in all types of Industry heavy industry lack of lubrication is second and there's a lot of reasons for them not just because of lock washers Fasteners are important and I took an interest in Fasteners more than 50 years years ago for that reason my knowledge and experience with cars was helpful and so here's where we're at if you take any lock washer 38 of an inch or larger and torque it this spe you will destroy the lock washer they may be cute and they got that little curly little thing and it makes you feel really good when you use them they call also called Spring washer but if you if you're going to torque a joint any joint to specification you do not want to have a lock washer there now if it's full that's 5/16 or smaller and or you're not torquing it into you're not torquing it or you're you're tightening it against plastic or aluminum or something there might be a case for lock washers and you can use them if you really do want to use them uh you can buy grade eight lock washers and I recommend you do that um one of the verifications for this point is I actually asked this question to one of the major manufacturers of Fasteners who we bought them you know by large volumes back in the day why do you even sell them and his answer was this is a Salesman for them because they're a gimmick people like to buy them so we want to they want to buy them we'll sell them to them that was what I was told now that may not make sense to you but here's one way you can check this out for yourself go to your car or your engine and try to find a lock washer that came from the oems you'll have a hard time finding any because they never used any these guys were pretty smart and they knew they they didn't do anything to help you and if you're going to torque a joint or tighten a joint to a specification you do not want to have lock rusher in there so all they're going to do is get you in trouble and once again if you take a lock rusher of any size in tcet thep you'll totally destroy it what it'll do it'll soften The Joint you want your joints you look at the way a main bearing cap is tightened or connecting rod or cylinder head those joints are infinitely stiff and anything in there that's soft like this that's going to soften that joint is going to it's going to destroy the Integrity of your connection so leave that with you okay on the point of distributor curves so uh back in the day we thought we were making improvements uh actually later I actually had access to a distributor machine that's a lot easier than putting your distributor in and out but if you're live in the local area we're in London Canada London Ontario Canada there's a fella here performance unlimited Barry is the owner and Barry has a distributor machine and he is an expert at curving Distributors he can custom curve Distributors and the red line that I've showed here is just kind of uh General application ation of the thought process that I was explaining uh what bar you may do may be different you may have a specific curve that you want have in mind uh so this isn't necessarily the only way to modify it this is just one example but if you're interested in doing that you bring you to sh DeBerry tell them what your application car how much the car weighs and gear ratios and all that and he can actually design a custom curve for you good guy and uh that's one way to get it you can also buy Distributors I think with custom Curves in them so I just haded to leave that thought with you kind of missed out on the first run and once again thank you for watching
