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| A different Distributor Springs question https://slantsix.org/forum/viewtopic.php?t=45756 |
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| Author: | MattyBrown [ Thu Jul 28, 2011 5:47 pm ] |
| Post subject: | A different Distributor Springs question |
Hi guys. First let me say I'm sorry I haven't been around much. I've been super busy, running around from here to there constantly... and luckily my Valiant is getting me to those places! It's been great (knock on wood). A few months ago I was talking about doing a distributor recurve at my leisure (I can do this because I have an extra, identical distributor). I've never done it before but I was given links to posts and an article about getting it done. Should be no problem, I'm good at following directions. Multiple people recommended I go with BigSlant6fan's spring kit. I contacted him and he told me the price and his PayPal address and all that. But one thing he said confused me: "You will also need to fill in the advance slots some with weld or brazing." Can anyone tell me what he is referring to? I was under the impression that I was simply going to be replacing the worn factory springs with springs of a different specification. Why is there welding involved? Can someone who's done this before explain it to me? The more you "dumb it down" the better! THANKS!!!!! -Matt |
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| Author: | ceej [ Thu Jul 28, 2011 5:58 pm ] |
| Post subject: | |
What he's talking about is the governer. It is under the advance plate, and limits how far the weights can swing out. It's important to know which governer is in the distributor your working on. They may look identical from the outside, yet be very different on the inside. To remove the governer, there is a clip inside the shaft that must be removed. If you look straight down on the top of the shaft with the rotor removed, there is a chunk of felt inside. Remove that, and you will see the clip. CJ |
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| Author: | olafla [ Thu Jul 28, 2011 7:13 pm ] |
| Post subject: | |
Hi MattyBrown, there is plenty info with pictures in the Recurve Threads in the engine FAQ, and my recent thread I modified my distributor for easy recurve tests may also interest you. I am playing around with the distributor springs right now, and my '77 distributor has a number 9 governor, giving 9 distributor degrees advance, which means it will let the weights swing out to give 9x2=18 degrees additional engine ignition advance. With the standard 12° static initial advance for '77, the total will be 30°, which is more or less spot on for the SL6. On earlier engines, the factory static ignition advance was often set very low, and the distributors often came with a number 11 or 15 governor, multiply by 2 to get the total additional advance. Knowing that the SL6 likes a lot of initial advance, but a total advance limited to about 20-32°, you have to limit the travel of the weights to be able to use an initial advance higher than original setting for your year engine, if you have a governor that allows for a lot of additional advance. Bracing or welding the governor slot is one method. Another is of course to get a governor from a newer engine. The governors used in SB V8s are the same, I don't know if the BB V8s use the same too. The number is stamped onto them. Olaf. Oops, small printing error above: a total advance limited to about 20-32°, should be 28-32°! |
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| Author: | MattyBrown [ Thu Jul 28, 2011 7:13 pm ] |
| Post subject: | |
Thanks Ceej and Olaf. So, do you know if BigSlant6Fan sells the same distributor kit to everyone regardless or does it have to be different depending on distributor type and governor? He didn't ask me about the governor when I enquired about the kit. I did tell him the year and all specs for my car. -Matt |
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| Author: | DusterIdiot [ Thu Jul 28, 2011 7:37 pm ] |
| Post subject: | But why??? |
Quote: The governors used in SB V8s are the same, I don't know if the BB V8s use the same too.
Yes to a certain extent, there are some unique slanted slots in the BB points distributors...but why bother, you pull a 17R out of a 1975 400-4v distributor and it pretty much condemns you to a 34 degree advance if it goes "all in"...if you use one, you'll need a 9R governor to pattern and a welder to fill the slots in...-D.Idiot |
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| Author: | emsvitil [ Thu Jul 28, 2011 8:04 pm ] |
| Post subject: | |
No welding needed. Just wrap some wire around the end of the slot to shorten it. |
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| Author: | olafla [ Thu Jul 28, 2011 8:27 pm ] |
| Post subject: | |
bigslant6fan's kits are for all SL6 distributors, you also get a chart showing the advance at certain revs against a combination of springs. The question is relevant, though, but only if you use the springs with the original unmodified, long slot governor, then the spring rates may change as they stretch more than intended. But then again, that situation would leave the purpose of recurving rather irrelevant! Olaf. |
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| Author: | MattyBrown [ Thu Jul 28, 2011 9:09 pm ] |
| Post subject: | |
I guess my problem here is that I'm completely ignorant of the math and science involved in calculating a good curve. The things I read on the forums about it all ends up as mumbo-jumbo in my head. I was really hoping to just rejuvenate my distributor more than alter it or make it custom. I'd be perfectly happy with something close to stock. I was hoping I could just order a simple kit, follow some directions, throw it in my car and be done with it. I guess it's not that simple, eh? -Matt |
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| Author: | Aggressive Ted [ Thu Jul 28, 2011 10:10 pm ] |
| Post subject: | Distributor Recurve |
Matty, It can be very simple...you can do just that. When you get yours apart tell us what is stamped on the governor. Like 7R, 9R or 15 R....etc..That determines how long the slots are and how much the weights can move and will determine which springs to use. I run a 1974 SL6 15R governor and have the mechanical severely limited by using a big stiff secondary spring from a 440 distributor. So you don't need to do any welding or shortening the slots if you don't want to......it is just another way of limiting mechanical throw. Map the curve your running now with Joe's spread sheet in the recurve section of the Engine FAQ. Then when you make changes you can map that curve. It is very handy to use as a guide or comparison, before and after. If you limit the throw like I have, there are many different vacuum advance cans you can use to modify your curve even more. For example I cruise between 2000 and 2600 rpm most of the time. Those rpms on my boxy 3500 lb 74 Swinger is 50 to 65 mph. It would be good to know your rear end ratio and what rpm and vacuum you see at cruise. |
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| Author: | MattyBrown [ Sat Jul 30, 2011 11:07 pm ] |
| Post subject: | |
Ted, thanks for the info. I will post some info when I start disassembling the distributor. The only other problem I face is that I don't have certain tools that would be beneficial in this situation. I don't have a vacuum gauge or tachometer in my car so I can't really tell what those figures would be. Also, I'm currently running with EGR blocked off. How big of a factor is that? Thanks! -Matt |
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| Author: | Aggressive Ted [ Sun Jul 31, 2011 11:24 am ] |
| Post subject: | |
I run with my EGR blocked off too. It is the first thing I do on all my SL6 motors. One less variable........note the pictures of my motor by clicking on the red link below my name. You need the tools to get consistent results and optimum tune. It also goes muck quicker too. You can do it by feel, but it takes much longer and you will still wonder what it is doing and when. |
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| Author: | olafla [ Mon Aug 01, 2011 8:41 pm ] |
| Post subject: | |
MattyBrown, before removing the distributor, turn the engine by hand to find the top dead center; remove the #1 spark plug and use a coat hanger wire or similar to register that the piston is on it's way up to the top dead center (TDC), when the ignition mark is coming up to zero. Also make a note of which direction the hose fitting on the vacuum pod points, and which way the rotor points, before removing the distributor from the engine. It makes reinstalling the distributor much easier, when you know you have a fixed point to go back to. The drive gear makes the distributor shaft turn app. 30° when lifted out/inserted. If you have a camera, take a photo before/after every step you do, and make notes! It is great fun to learn by doing, just go ahead, you'll get all the help you need here in the forum. It is also wise to check if there is much slack in the timing chain. When at TDC, distributor cap off, you can turn the crank back and forth by hand, and see how much slack (in degrees) you have as the zero mark moves relative to the timing advance marks on the tab, before the distributor rotor start moving. Olaf. |
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| Author: | wjajr [ Tue Aug 02, 2011 5:27 am ] |
| Post subject: | |
MattyBrown; one other detail to keep from chasing your tail after reassembly of the distributor. As you remove the slotted governor from the distributor housing, the part that was held onto the shaft by that cussed “C†shaped wire and the rotor button slides onto, be sure to make a note as to which way the rotor button was orientated in the distributor. Better yet, mark it somehow with a scratch, magic marker, dot of paint etc. If you reassemble that part 180 degrees turned from when it was removed, your timing will be 180 degrees out when distributor is placed back into engine. The car will not start, you will pull your hair out trying to figure what went wrong because you will swear every step documented was followed correctly. I bet I took my governor out ten times while recurving it. Nine times in a row it went back together just as it came apart, once it did not. That started a chain of events the wasted time & money until this dope figured out what happened… Bill |
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