Author Topic: SBC 305 HEI Distributor?  (Read 17011 times)

Offline 197

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SBC 305 HEI Distributor?
« on: May 07, 2008, 03:32:06 PM »
At school were working on a 305 which is on a elcamino. We pulled the manifold, carb, and distributor off but no one marked where the plug wires went or were the distributor was.

Today we got the new manifold and carb in, and the distributor seated all the way down, but the rotor isn't pointed at the #1 cylinder. Do we need to crank the motor over so that the rotor points at the #1? And then just put the wires on? Or is there some special trick I should know.
'73 C20 454

Offline Lt.Del

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Re: SBC 305 HEI Distributor?
« Reply #1 on: May 07, 2008, 04:19:51 PM »
I don't know who is teaching that class, but, if there are no plans to turn the bottom of the engine (crank, pistons) then someone should have known to mark where the rotor points.

You need to rais the distributor now.  Then turn the crank until the #1 piston is at the top.  Then place the distributor in place with rotor pointing to #1 plug wire.  Hopefully it is on the firing stroke, versus exhaust stroke.  The number 1 piston fires on every other rise. This could cause your distributor to be 180 degrees off and try to fire #6 instead of #1 (in other words, firing on #1 exhaust stroke)

If someone can read the valve opeining on the cylinder head w/ valve cover off, you can see if it is the firing stroke or exhaust stroke.  One valve will be open.  There are two valves per cylinder---i am not sure which valve is exhaust vs. intake.

firing order 18436572

Offline 197

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Re: SBC 305 HEI Distributor?
« Reply #2 on: May 07, 2008, 04:48:43 PM »
Can we bump it over with the starter? The rotor is at about 7:30. I think thats the only spot where it would go all the way down.

Once we get it aligned up, is there any spot on the cap where #1 spark plug wire has to go?
'73 C20 454

Offline Lt.Del

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Re: SBC 305 HEI Distributor?
« Reply #3 on: May 07, 2008, 04:59:55 PM »
you can bump it with the starter, yes.  It will go all the way down in many positions, just play with it.  The sprocket gears must mesh with the gears on the cam.  It will go down in many different positions.  Make sure the distributor cap screws fit on the body of distr (the spring clamps -4)---for HEI i believe there is a little notch where the cap will fit on the body of the distr. 

If you have a vacuum advance, ensure that doesn't hit the firewall when adjusting the timing.  Ensure there are plenty of room from the firewall.

On my HEI on my 79, the #1 plug wire on distr cap pretty much points to the #1 cylinder (roughly the 5:00 position if looking down on engine from radiator area) the silver looking vacuum advance is roughly in the 8:00 position

Offline HAULIN IT

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Re: SBC 305 HEI Distributor?
« Reply #4 on: May 07, 2008, 05:15:50 PM »
Ok, If your in auto mechanics class there should be some books/computer, ect. to help you guys with this. A few posts ago we discussed this under the TDC one, check it out. The basics are as follows, we won't get into what you should have done, I think you have figured that out by now. Crank the engine (starter is ok to do) while someone holds their finger over (or ball up a piece of paper towel & lightly push it against the plug hole) # 1 cylinder spark plug hole, it will "pop" as the piston comes up on compression, stop cranking NOW, continue to rotate in the same direction (best by hand on the crank bolt now) until you have the line on the balancer lined up on the tab with 8*-10* BFTC. Pull the distributor & find #1 wire, If you didn't move them, your all set. If not, a manual will help. I saw 78-81 305 was different than most others in one picture I looked at (I didn't know that? oh well) It should be in front of the cap behind the left corner of the carb. Start to the Right of the hold-down screw...18436572. Verify this on your cap. Now mark a line on the distributor base directly straight down from the center of #1 post on the cap. This is where the rotor needs to be pointing. You may have to try several times to get it to "drop" in the right place, sometimes you may have to get a long screwdriver to turn the oil pump drive slightly. Any other questions, just ask! Proceed on, Lorne

Offline 197

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Re: SBC 305 HEI Distributor?
« Reply #5 on: May 07, 2008, 06:28:41 PM »
Thanks for the tips. I know what I would of done but I wasn't there when they pulled the manifold and distributor off.

We wont have any time to work on it untill friday but keep the help coming.

Zach
'73 C20 454

Offline Fordeatinz71

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Re: SBC 305 HEI Distributor?
« Reply #6 on: May 07, 2008, 06:59:30 PM »
wow, i'm really saddened that the shop teacher doesn't know this.  or is this something that he's not really supervising?  anyhow, if you follow HAULIN IT's tips, you'll get 'er dialed in...
1991 Chevy Silverado K1500 ECSB, 350, 700R4 w/shift kit, 3.42's, exhaust work...
1983 GMC Sierra K1500 SWB-sold :(

Offline 197

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Re: SBC 305 HEI Distributor?
« Reply #7 on: May 07, 2008, 07:02:21 PM »
wow, i'm really saddened that the shop teacher doesn't know this.  or is this something that he's not really supervising?  anyhow, if you follow HAULIN IT's tips, you'll get 'er dialed in...

I dont think that he was watching when they pulled it. Hes helping though. Hes not the best shop teacher but the only one we got. Thats why I asked here.
'73 C20 454

Offline Fordeatinz71

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Re: SBC 305 HEI Distributor?
« Reply #8 on: May 07, 2008, 07:05:38 PM »
well, i guess it's a good thing that at least you still have an auto shop class...ya'll will get it handled.  just put your finger in hole #1 and as its turned over (slowly...) you'll feel it push your hand out when you are on the power stroke...then just put something like a straightened coat hanger or a long, skinny screwdriver down the hole on top of the piston and turn until it's all the way at the top...then drop the distributor in with the rotor aimed at 1...then you should be golden...
1991 Chevy Silverado K1500 ECSB, 350, 700R4 w/shift kit, 3.42's, exhaust work...
1983 GMC Sierra K1500 SWB-sold :(

Offline camdenoilchange

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Re: SBC 305 HEI Distributor?
« Reply #9 on: May 07, 2008, 10:15:56 PM »
wow, if your shop teacher can't set a distributor your in trouble. did he get tired of teaching PE and switched to automotive? anyways, good tips listed above. good luck to you!

Offline 197

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Re: SBC 305 HEI Distributor?
« Reply #10 on: May 08, 2008, 07:10:37 AM »
hes more of a lazy "Mopar" man. lol

The tips are awsome. but when we get the rotor to point to the #1 cyl then where to we start putting the wires on?
'73 C20 454

Offline Lt.Del

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Re: SBC 305 HEI Distributor?
« Reply #11 on: May 08, 2008, 08:40:57 AM »
starting at #1, go ahead place the rest of the wires on the cap, clockwise, firing order 18436572

surely he can tell you what cylinder is what....right side (looking from radiator side at engine) is odd, 1,3,5,7 - left is even 2,4,6,8

Offline HAULIN IT

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Re: SBC 305 HEI Distributor?
« Reply #12 on: May 08, 2008, 08:43:23 AM »
This should make it a little clearer I hope. 78-81 305

Offline 197

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Re: SBC 305 HEI Distributor?
« Reply #13 on: May 08, 2008, 02:32:13 PM »
Thanks for the diagram!
'73 C20 454

Offline Fordeatinz71

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Re: SBC 305 HEI Distributor?
« Reply #14 on: May 08, 2008, 06:10:58 PM »
hes more of a lazy "Mopar" man. lol

The tips are awsome. but when we get the rotor to point to the #1 cyl then where to we start putting the wires on?

ahh, Mostly Obsolete Parts Assembled by Retards...lol...Miles Of Parts All over Road...

the diagram is nice, but you can start your number 1 anywhere.  you don't have to have it at a certain place.  that was just where the factory put it.  it will start firing #1 and so forth whereever you wanna start it...
1991 Chevy Silverado K1500 ECSB, 350, 700R4 w/shift kit, 3.42's, exhaust work...
1983 GMC Sierra K1500 SWB-sold :(