73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: gim_bob on December 01, 2009, 01:04:05 am
-
Every thing went accordingly, and I am now well on my way to owning my first chevy truck... Im not gonna lie Ive got BIG plans for this one.... unfortunately, I keep getting lost in relatively minor details, one of my immediate problems with the truck, one of which i know nothing of, is working with the distributor,points cap and rotor. Cap and rotor sound simple enough, but I do not understand the points. Ive never really dealt with working on vehicles aside from changing oil and plugs and stuff, so I'm completely in the dark... any advise aside from knowing chilton?!?
-
Wow, points... The good old days. Really pretty easy, replacement is easy just don't loosen the screw all the way out and loose them. You will have to set the dwell with a meter, I haven't used mine in so long, wonder if it still works.
-
RE: advice
1) Yes, chilton's sucks snowballs. Try a factory service manual; These won't tell you everything, but they blow chiltons out of the water.
Do you get the picture that i don't like chiltons?
2) points? What year truck do you have?
-
Memory time,
IIRC there is a "cam" inside the distributor, this will open your points. Points open, it triggers the coil to fire a burst, your cap and rotor tells it where to go.
I believe I used to set my points with a feeler gauge if a tach/dwell meter wasn't handy.
If you have plans for your truck, why not look into an HEI swap? Fairly easy to do, HEI's are very common and reliable. Unless the points are a temporary thing and you plan on a new ignition system down the road.
-
Yep, donut is correct.
I'd do as he suggests as well. Go with an HEI distributor. Get one for $20 from a salvage yard, there are hundreds of them in any good salvage yard. Less maintenance.
I too used a feeler gauge when I used to work with points. When the points are open all the way...when the striker is on a cam corner, that is when you measure the distance b/w the points. A simple screw loosening makes the points adjustable. Get the space (dwell) right, then tighten the screws. I used to take a bit a sandpaper to the contact surfaces any time I played with them.
-
Back when I had a chevy with points, the cap had a window you could open and adjust the dwell while the engine was running with an allen wrench.
-
Back when I had a chevy with points, the cap had a window you could open and adjust the dwell while the engine was running with an allen wrench.
yeah, i remember those. I had a allen wrench like a screw driver and you could turn it and adjust it that way. If i remember correctly, it was like a little aluminum door you could lift up.
-
If it's a 73 or 74 it may have points but if it's a 75 later it should be hei. Tell us more
-
It's a 74. As far as switching ignition systems, i haven't considered it that much. Im trying not to get in over my head right off the bat with the truck. So if I can keep it fairly simple, I would rather do that, if I were to replace it with The hei, would i then have to reset the timing all together or no?
-
If you replace the point with HEI, which I HIGHLY recommend, just put the truck on TDC, make note of where it is, drop the HEI in and point it to the same place. Then all you need is a constant 12V switched source for the Coil. You cannot use the power to the points coil.
-
It doesn't get much cheaper than this... by the time you tune up your points system you've already spent this
http://cgi.ebay.com/ebaymotors/SBC-BBC-350-383-CHEVY-SUPER-65K-HEI-DISTRIBUTOR-6500-R_W0QQitemZ350283265953QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item518e8277a1
-
I know what tdc is, but how do i find it. Ive heard you could use a screwdriver or something to feel the piston, is that the way to go about?
-
an easy way is to just pop off the current distributor cap, but note which plug wire goes to #1 spark plug (looking down on engine from the grille, its the first plug on right). Bump the engine (or turn crank- see below) until the rotor points to roughly the direction of where #1 wire attaches to dist. cap. You can check, by removing the plug and ensuring the piston is up high, but, I wouldn't use a screw driver because it is made of metal and you may scratch the piston surface or cylinder wall surface.
Use a 5/8" socket to turn the crankshaft (at front pulley) back and forth to see that the piston is all the way up if you wish.
Remember, the piston goes to the top twice for every one firing stroke. In other words, the #1 piston will go to the top for exhaust stroke, which, the distributor rotor will point to #6 to fire (180 degrees difference) instead of #1. Many, many times people have mistakenly thought they were at TDC because #1 was up, but, it was the exhaust stroke. You hae a 50/50 chance of it being right. That's why I take the distributor cap off to see where rotor is pointing--and try to line it up with #1 plug wire before removing the old distributor. Then, once distributor is out, do not turn the crank at all.
http://www.joby.se/corvette/misc/firing_order.gif (http://www.joby.se/corvette/misc/firing_order.gif)
When you put the new distributor in, point the rotor towards where the cap will have the #1 plug wire attached, but, turn the rotor about 20 or 30 dregrees counter clockwise becasue the distributor teeth will move the rotor position slightly clockwise when installing because that is the direction of the cam/distributor gears. Put some oil on the distr. gear before doing this.
-
Thanks alot! It doesnt seem nearly as complicated now as it did, I really appreciate that!!
-
no problem. Good luck.
Also remember, you can turn the distributor in any direction....ie: you can make the back most point on distributor cap #1 if you choose, instead of it being close to front. It doesnt matter which part of distr. cap is #1, as long as the firing order remains correct--the right plug wires are in the correct order around the cap, after #1, wherever you choose to start it. (1,8,4,3,6,5,7,2) Some people make adjustments to which plug point on cap is #1 to make it easier to position the vacuum advance, if equipped so it won't hit the firewall when adjusting the timing.
It may be tricky to get the distributor down all the way...sometimes you have to play with it a bit so the gears on distr. joins the cam gear O.K., that's why you have to turn it slightly counter clockwise when dropping in and play with it. The bottom of the distributor tip has an embedded slot in it that fits down into the oil pump...the distributor actually turns the oil pump. Sometimes that isn't lined up perfecty either. Once in a while you may have to get a long screwdriver and turn the screw type slot on top of oil pump slightly and try to refit your distributor in it. Some people who work with these things a lot take an old distributor and remove the gear (take the little pin out that removes the gear), that way they can put the stripped out distributor down into position and by turning the rotor, you are actually turning the oil pump slightly...maybe a little turn is all that is needed to fit your new distributor into place if it gives you problem dropping in initially. A long screwdriver does the same thing though.
-
Like I said, I'm new to most everything, and this might be best in a new thread, but what is vacuum advance, and how does it work...
ps. I regret not taking auto-shop in high school :(
-
check out a past thread....
http://forum.73-87chevytrucks.com/smforum/index.php?topic=4772.15
I have three pics in one reply on that thread.......the middle pic shows a vacuum advance.
Check your old distributor and see if you have a silver looking round thing attached to the distributor with a vacuum line going to it. If you do, it is a vacuum advance type distributor. When your vacuum pressure increases in the intake manifold, it pulls (sucks) the advance diaphram in the round cylinder, that in turn pulls the spring activated "guts" in your distributor...activates weights and springs and stuff to advance your timing which you will need under heavy acceleration.
ps. I regret not taking auto-shop in high school
I never took shop class--i took all college prep crap. Just learned by doing. I was tearing engines apart when i was 16 just to see how they worked. www.delbridge.net/vintage You can learn so much by just working on your engine yourself..it is very rewarding and your check book appreciates it too.
-
Aint that the truth, Labor is definitely not cheap!!