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SBC Dist. will not line up? will it ever end?

4K views 28 replies 12 participants last post by  68NovaSS 
#1 ·
I have a 96 Chevy express van and I completely built a all new 383 for it. I have had a ton of issues but got it running. I then had a intake leak and pulled it apart tp replace the gaskets and re seal it and not my dist. will not line up? I have the vortec engine and the dist. had to be learned and set to 0deg. It was set with a snap on scantool and the dist was not cocked either way when set. Now I replaced the intake gaskets and now I put the dist. back in and it will not set to 0deg without turning the dist. clockwise as far as it will go (until the cap hits the manifold) I marked the dist prior to removing it and ti went right back in but it is way off. What gives? I had a similar issue when I first assembled the engine because it is a summit dist. (aluminum housing vs the factory plastic one) and the gear was assembled 180deg out and the dist. would not set. I replaced the dist. and it set with no issue but now I am all out of wack? Any thoughts? Thanks Guys!!
 
#2 ·
chucksrt said:
I have a 96 Chevy express van and I completely built a all new 383 for it. I have had a ton of issues but got it running. I then had a intake leak and pulled it apart tp replace the gaskets and re seal it and not my dist. will not line up? I have the vortec engine and the dist. had to be learned and set to 0deg. It was set with a snap on scantool and the dist was not cocked either way when set. Now I replaced the intake gaskets and now I put the dist. back in and it will not set to 0deg without turning the dist. clockwise as far as it will go (until the cap hits the manifold) I marked the dist prior to removing it and ti went right back in but it is way off. What gives? I had a similar issue when I first assembled the engine because it is a summit dist. (aluminum housing vs the factory plastic one) and the gear was assembled 180deg out and the dist. would not set. I replaced the dist. and it set with no issue but now I am all out of wack? Any thoughts? Thanks Guys!!
I'm not sure what you are saying as far as the gear was assembled 180* out. It just sounds like you need to turn the motor with a socket and the distributor should almost fall in. Your oil pump rod may need turned a little to line up with the distributor.
 
#3 ·
The dist gear has an odd number of teeth and if the gear is installed 180 deg out then the timing will never line up on this vortec engine (you don't have much rotation on this dist.). I pulled the dist. and advanced it 1 tooth and it reads it is out 24 deg; I skip it back a tooth and the same thing just opposite. The oil pump does hold it from going all of the way down but if I just tap the ignition it generally falls right in.
 
#4 ·
I'm with S-10, totally confused...what do you mean an odd number of teeth??? If it didn't have the same tooth pattern as the dist it would never mesh. Also, 180 out is referring to the position of the rotor when the dist is installed, meaning it is turned too far away from the #1 plug tower, it has nothing to do with the "number of teeth" anywhere. Did you rotate the motor at all while the dist was out, even a little bit? You can't use a long screw driver to rotate the oil pump shaft? And the oil pump will stop the dist from dropping in if the oil pump slot is not lined up.
 
#5 ·
Get number one to TDC compression stroke and look down the hole for the distributor, you will see the shaft that drives the oil pump.
Set the slot in that shaft as per this picture.



You also have to set the rotor 45 degrees anticlockwise to it´s number one firing position, it rotates clockwise going in as the helical gears mesh.
 
#6 ·
68NovaSS said:
I'm with S-10, totally confused...what do you mean an odd number of teeth??? If it didn't have the same tooth pattern as the dist it would never mesh. Also, 180 out is referring to the position of the rotor when the dist is installed, meaning it is turned too far away from the #1 plug tower, it has nothing to do with the "number of teeth" anywhere. Did you rotate the motor at all while the dist was out, even a little bit? You can't use a long screw driver to rotate the oil pump shaft? And the oil pump will stop the dist from dropping in if the oil pump slot is not lined up.

It does have the same tooth pattern. Which means that if you look at the dist from the bottom and the pin that holds it in place goes through the middle of it, there would be one side of the gear where the pin is would have a single tooth right over the pin and on the other side the teeth would be on either side of the pin. So if the gear is on the dist. backwards/180 deg out (like the first dist. I received from summit) you will have a very hard time getting the timing where you need it. Iirc the dist. gear has 13 teeth.
 
#7 ·
That's so far out in left field! There is no way to install the distributor gear
"backwards/180 degrees", upside down or any other way. Figure it out, if you have two teeth on one gear, the gear meshing with it has one gear tooth between those two...but here is another on the other side waiting to mesh on the next rotation. You are waaaay over thinking this! You need to move the oil pump slot to wherever it needs to be to have the rotor pointing at #1 tower on the cap when it rotates down, and the distributor shaft drops into the slot, period. Is this a joke thread?? :thumbup:
 
#8 ·
dont know if this will help or not but i put the dis. in for a buddy on his 327 build. he showed me a trick that worked dang good. get tdc#1 then point the #1 on the dis straight at the #1 piston. that dis. fell rite in place like it should and was done that easy. any of you guys ever tried this. it did drop rite in.it was a first for me.
 
#10 ·
Lets go over this AGAIN.

With the # 1 piston,at TOP DEAD CENTER,on the compression stroke,point the distributer rotor to the right of the # 1 firing position(rotor),(as youre looking down)look at the bottom of the dist.there will be a boob sticking out,line the oil pump slot up with this boob ,install distributer,when installed,the rotor will turn,and point at the #1 plug wire (of course,) this is after you put the dist cap on,im assumiing you marked the dist,to show where #1 is,if you didnt,look at the dist cap,see where #1 wire is,point rotor to the right .
 
#12 ·
68NovaSS said:
That's so far out in left field! There is no way to install the distributor gear
"backwards/180 degrees", upside down or any other way. Figure it out, if you have two teeth on one gear, the gear meshing with it has one gear tooth between those two...but here is another on the other side waiting to mesh on the next rotation. You are waaaay over thinking this! You need to move the oil pump slot to wherever it needs to be to have the rotor pointing at #1 tower on the cap when it rotates down, and the distributor shaft drops into the slot, period. Is this a joke thread?? :thumbup:
How many teeth are on the dist gear? Is it an even # or odd #? If it is an odd # then the gear can be installed 180 out! Unless the pin was drillied offset then it wouldn't line ou if it was put on 180 out. I have set the dist. to TDC and the oil pump was lined up! I don't know what happened? I know if the pump is out of alignment that the dist. will not drop down all of the way. I ste everything as mentioned and I can not get it to set correctly in time (the dist is cocked til it hits the manifold to get the timing set. If I move the dist 1 tooth either way it then goes way out of time. -24/+24deg out. I had the dist set I evne set a mark and it all lined right up but now I can not get the dist to line back up with my marks. I understand all of the pics and info on the oil pump but if I set the dist in and for some reason the dist doesn't line up I can just crank the engine until it pulls the dist. in to place.
 
#19 ·
Custom10 said:
I am still scratching my head 180 ways from sunday. Trying a compass next till I get it right :rolleyes:
Can´t fathom that either, if the gear had to be located in a specific way it´d be marked.
(They ought to mark it "this way up" for people like me !!

I thought the important part is the distributor fires number one at the right time, distributor orientation secondary.
 
#23 ·
chucksrt said:
The vortec dist has very little side to side movement. Moving it a tooth in either direction just causes it to be way too far out to get into time.
If the theory you're going by mattered, then just use #6 to time it. Put a TDC mark 180 degrees from the line now on the damper.

But the whole thing revolves around setting the distributor in and having the oil pump drive shaft indexed correctly. In some non stock installations, there may be a lack of clearance that will make setting the timing a chore- but there's almost always enough adjustability to allow setting it right w/o clearancing the firewall or grinding, etc.

The rotor turns about 2" CW as the distributor engages the cam gear and is seated (on a large cap HEI, less on a small cap HEI), so set the rotor that far CCW to allow the gears to turn the rotor into position. The oil pump shaft can be easily turned w/a long screwdriver to allow the shaft of the distributor and the pump shaft to engage correctly.

Be sure the distributor isn't bottoming out by temporarily removing the gasket between the distributor and intake and setting the distributor into position. Then lift up on the top plate to be sure there's still a small amount of clearance. If there isn't clearance, use nylon spacers made for setting the distributor height. The shim kits are sold through Summit and Jegs, etc. from Moroso, Mr. Gasket, Jegs brand, and others as well. The kits typically contain 0.030", 0.060", and 0.090" (or 0.100", depending on brand) shims. Don't just stack fiber washers, they'll become oil logged and crush down and you'll lose the clearance if the clamp is tightened.
 
#26 ·
Rotate the number 1 cylinder to Top Dead Center (TDC) of the compression stroke. The engine front cover has 2 alignment tabs and the crankshaft balancer has 2 alignment marks (spaced 90 degrees apart) which are used for positioning number 1 piston at Top Dead Center (TDC) . With the piston on the compression stroke and at top dead center, the crankshaft balancer alignment mark (1) must align with the engine front cover tab (2) and the crankshaft balancer alignment mark (4) must align with the engine front cover tab (3).

1. Rotate the crankshaft balancer clockwise until the alignment marks on the crankshaft balancer are aligned with the tabs on the engine front cover and the number 1 piston is at top dead center of the compression stroke.





2. Align white paint mark on the bottom stem of the distributor, and the pre-drilled indent hole in the bottom of the gear (3). NOTE: The OBD II ignition system distributor driven gear and rotor may be installed in multiple positions. In order to avoid mistakes, mark the distributor on the following components in order to ensure the same mounting position upon reassembly:

o The distributor driven gear
o The distributor shaft
o The rotor holes



Installing the driven gear 180 degrees out of alignment, or locating the rotor in the wrong holes, will cause a no-start condition. Premature engine wear or damage may result.

3. With the gear in this position, the rotor segment should be positioned as shown for a V6 engine (1) or V8 engine (2).

o The alignment will not be exact.
o If the driven gear is installed incorrectly, the dimple will be approximately 180 degrees opposite of the rotor segment when the gear is installed in the distributor.

4. Using a long screw driver, align the oil pump drive shaft to the drive tab of the distributor.
5. Guide the distributor into the engine. Ensure that the spark plug towers are perpendicular to the centerline of the engine.

graphic
6. Once the distributor is fully seated, the rotor segment should be aligned with the pointer cast into the distributor base.




o This pointer may have a 6 cast into it, indicating that the distributor is to be used on a 6 cylinder engine or a 8 cast into it, indicating that the distributor is to be used on a 8 cylinder engine.
o If the rotor segment does not come within a few degrees of the pointer, the gear mesh between the distributor and the camshaft may be off a tooth or more.
o If this is the case, repeat the procedure again in order to achieve proper alignment.
 
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