Hot Rods SBC Distributor and the "One tooth off" myth???

Some of you may have been following my saga of replacing the intake manifold gaskets on my SBC...it's been stubborn from day one, and the distributor is now joining in the fun.

I've never successfully installed a distributor into this engine, someone else has always had to step in and save the day. It just never lines up right...and even that other person just "stabbed it up and down until it fit."

Long story short...I got it in, the engine starts (kind of rough- for some reason, when I squirt a bit of starting fluid in there, the starter LABORS to turn over) but when I try to set total timing it's WAY off the charts. If I advance it closer to the 35* mark it starts popping like mad, when I retard it, it runs equally rough.

Years ago, I had it so that the advance canister hit the intake, allowing me a maximum of about 21 BTDC at 3500RPM...I solved that by renaming my distributor terminals and spinning it 45* the opposite direction.

My brain isn't working anymore. This truck has defeated me.... It ran well enough that I figured it was right...can I do the same thing again- re-number my distributor in hopes of not having to take it out again?

Thanks.

 

yes you can move the wires over. put the timing mark on top dead center and see where the rotor points. if it was running, and is pointing to #6 rotate it around 180 degrees. it should now be pointing to number one. move the #1 wire to align with the rotor, rotate distributor if needed. put all wires in place and time.

 

Sure, the distributor doesn't care what terminal is #1, so long as the firing order is correct.

But, it will always gnaw at you, causing worry on those long sleepless nights - corroding at the depths of your very soul eventually.

That, and the timing light won't work at the factory designated wire, stuff like that. It makes troubleshooting problematic for future H.AM.B.ers too. "What wizardry is THIS?" etc.

 

How loose is your chain? (like the song...) Timing chain... Grab your fan (engine not running) and turn it clockwise 'til t stops against compression, then counter clockwise.
Excessive looseness will culminate in 'late' timing...

 

I have an old slot screwdriver, a big one, that I scratched a line on the end of the handle, in line with the blade. I use this screwdriver to align the oil pump shaft when I'm getting ready to drop a distributor into a chevy engine. The line lets me know which way the slot in the shaft is facing, so I can put it where the tang in the distributor will just drop in. There is some lead angle on the distributor gear, so it takes some trial and error to figure out just where the pump shaft needs to be, relative to the distributor tang. But the tang on the distributor is aligned to the rotor, so it's consistent, and least.

I'll take the time to get it right, even if it means pulling the distributor out 3 or 4 times to get everything set up just so.

Seems that when I need to move the distributor, it needs less than 45 degrees, so the moving the plug wires trick won't work, anyways.

 

TB33anda3rd,
I'm lost...if it's pointing to #6 at TDC...are you telling me to rotate the engine over, 180* or the distributor body?

I'm also going to double check that my wires are in the correct order.

Truck,
If I can make it run right, I won't care. It'll be unique, that way...however, I WILL either label or disclose that info when I sell it (who am I kidding, I won't be that lucky).

 

Also in reference to original problem, put the timing light away for a day or two and set the ignition timing using a vacuum gauge connected to a source of (constant) manifold vacuum. This works slick. You may want to check and see where it's at later with a light, but just try it. It's very common for vibration dampers to slip as they get older and renders the timing marks useless. Not saying your SBC has this problem but it's common with Fords.

Here's how: With engine warmed up and idling at factory spec rotate distributor for maximum vacuum indication (advance timing) at idle RPM, and then back off (retard timing) 1" Hg from highest reading and tighten distributor hold down.

Check carb idle mixture settings same way.

 

Squirrel,
I've had this thing in and out 70 times, with it only falling into place this one time, that's why I went with it. It's funny, I have the exact same setup on a giant screwdriver I have, complete with Sharpie line on the handle showing orientation of the blade. When I look at the bottom of my distributor, the slot is ALMOST in line with the rotor...it looks like it may only be 5* off. Is this normal? I've been trying to line it up about 5-10* off (tried both directions) from where I marked for the rotor to point. No luck.

 

yes rotate the engine, or align number 6 to the rotor.
that distributor makes one revolution for every two of the crank. so every time the timing mark comes up it will be pointing at 1 or 6.

 

might be time to let it sleep over night and think about the error of it's ways...

I wonder if there is too little chamfer on the tang or the slot, or the gear?

 

I've been sleeping on it...this intake manifold gasket replacement has taken me over 2 weeks now. I DO think something is wrong inside the engine, maybe the pump driveshaft isn't right, but NO distributor has ever just fallen into place on this engine. I did this countless times on my old Y blocks and it always went in right on the first try...maybe I SHOULD have kept that tired old Y block...
Thanks to all..this is restoring my hope...I was ready to tow the fucker somewhere 4 hours ago.

 

It's a SBC, they almost always move the oil pump shaft a little when the dist comes out. I've used a long screw driver or an oil pump primer, you just need to get it close and then adjust it when it's running. Sounds like you might just need to start fresh and put it back on TDC, use a rag in the #1 hole, tap starter until it pops out, then use crank bolt to line up the marks on the balancer. Drop dist in where you want #1 to be, don't forget if your using a vacuum advance dist you might have limited room.

 

It often doesn't drop clear down on the oil pump shaft until you bump the engine over. Then if it isn't on the money timing wise you drop back and do it again. Once in a blue moon I get it right the first try.
Usually I get #1 up on TDC, then set the distributor in where I want it to be and with a remote starter button bump the engine over a tad so the distributor drops in place. Then I bring it back up on number 1 with the timing marks lined up on the damper and tab and lock it down where I think the timing should be to fire it up.

 

Here is how I put in the distributor ;
1. TDC compression on # 1
2. Slot in oil pump drive fore and aft . ( long screwdriver and light )
3. Lower the distributor into the hole ( rotor installed ) with the rotor turned about 30 degrees CCW from the straight fwd position. When it drops in the rotor will turn the 30 degrees should be pointed straight fwd.
4. Put your cap on.
5. Rotate your distributer so that the vacuum advance is in factory position - around the 7-8 o'clock position.
6. Now the plug wire terminal that is in the front is plug wire # 1 because it is over ( or very close to ) your rotor position.
7. Install plug wires, coil wire and 12 v wire
8. Snug rotation clip - just tight enough you can turn it
9. Start engine and adj

I have done it this way for many years - it's worked for me.
There are some other ways but this is the easy way.

 

Jim's and the above method are good. You have to account for the spiral cut on the dist. gear for it to drop in straight.

 

Why do we think we need to be at TDC when we install the distributor? If you know the initial timing you want why not set it there? Let's assume the average SBC and an initial setting of 8 deg. Come up on compression, stop at 8 deg BTDC, stab the distributor in with the leading corner of the rotor at the lead of the cap tang. Lock it in and start it up. There's a loss to this technique, you won't get the gratuitous backfire and flame show trying to start it on TDC. Deyo, I guess I can feel your pain as sometimes the easiest jobs can give you that unwanted rectal exam. And of course it's always on your own shit, do it for someone else and you look like a genius. As was said above, yes, there's nearly a 30 deg difference from where the tooth hits the cam gear and the spiral as it goes into the oil pump. Even at that, you'll still have the housing within a couple degrees of ready to run. Good luck, have a beer, coffee, smoke, cocktail, whatever you like. Hit it with a fresh goal that YOU win, not that mechanical shit.

 

Since I've left everyone on the edge of their seat I wanted to check back in...I finally got the chance to get back out there and mess with it and by lining up the zeros the rotor was pointing at #6, since it was NOWHERE near where #1 would have been. Then I put the cap back on, pointed the closest post at the mark I made where the rotor was pointing (just like I thought, about 15-20* or so) then grabbed the #6 wire and went right around, 5,7,2,1,8,4,3.

It's now at 35* BTDC at 3500 RPM. Road test is later on.

Thanks to all.

 

You guys Crack me up! Your all working way to hard just to plant a dist and lining up the marks to T.D.C. on the balancer is pointless. The reason you got Lucky on your Old Y block is because the Oil pump drive shaft is 6 sided and the receiver hole in the Dist. is chanpfered to help guide the shaft in.
I've been Laughing all the way through the above posts. Thank you all.
The Wizzard

 

I have always found tdc, and dropped the distributor in where I wanted it. Maybe once did the stars align and it dropped in perfectly, usually its sticking up because of the oil shaft. I then just hit the key or starter switch, spin the engine until it drops in.

 

Wow, Here's an actual motor mechanic.
The Wizzard

 

I've never had enough balls to hit the key. But turning it over with a bar and socket has worked every time

 

+1 on not worrying about the distributor dropping into the oil pump drive when I'm stabbing the distributor. I usually drop the distributor in with the rotor pointed where I want it, put the distributor hold down on and tighten the bolt until you feel it start to get tight, spin the engine over until the rotor is back where you started, finish snugging the hold bolt down, crank the engine and set the timing.
I always put the plug wires in the cap the way they came from the factory. Makes things a lot easier working on the engine later. Point style distributors and HEIs are indexed differently.

 

I use my old chevy distributor with the gear off, that I use to prime the pump to turn the oil pump shaft just like quoted above

I just changed dual points and while both were accell the new one needed the pump to be in a different location to get the rotor pointing in the correct direction

 

Stude is right. The dist rotor does not have to be in the eleven o`clock position to operate correctly. Just do what he said then pop the cap and note what position the rotor is pointing at when the motor is at tdc That is your number one cylinder in the firing order, then arrange your wires accordingly. Now hand rotate the motor to 7 degrees advance on the dampener. put your timing lite on it and with the key on rotate the dist housing in a counterclockwise direction. when the lite fires, you will have set the timing in what is called static timing. lock the dist down. If the motor is right( timing chain, etc. ) it will fire right up. I will say that I hate putting a used motor in anything without tearing it down. In my experience you have a 25% chance of it being right. Treat the motor as if it was new. That is fire it up and run it for 20 minutes at about 2000 rpm to lube the cam and lifters because if it has set for awhile the internals will dry. Everyone has to learn. Good luck

 

now pull it back out and spin the engine and start all over...
na J/K but practice does help (or repetition ) once you get the hang of it
you'll look back and have a good laugh...

 

Most of the above info is useful to get your distributer installed into your engine. I typically try to get the oil pump shaft aligned with the distributer using a large screw driver as described above. However, on more than a few occasions I have held pressure down on the distributer and had someone bump the starter over until the distributer drops in fully. On most 'street' applications I just use the terminal which is pointed toward cyl #1 as cyl#1. regardless of how the factory placed the wires originally. On a restoration, however, I use the factory designated terminal.

But, if you still find that your timing is way out to lunch if set by a timing light you may have other issues. There have been a few posts above touching on this. One being that the balancer certainly could have spun some on the rubber/crank snub.

The other which is common with SBC is an early balancer and a later front cover/timing tab or vice versus. This can put you showing up to 60* out as the tab on the timing cover is in a very different location compared to where it should be for the balancer used.

In this case I always set the timing using a vacuum guage and tach much as posted by Truck64 in post #7. this will usually get you the most advance reasonably possible, but you often need to make adjustments and back it down a little if hard starting, or pre-ignition/pinging under load/accelerating.

Physically getting the distributer in and seated just gets you to a point where you can start making you adjustments to set the timing.

There are other ways as well, you could locate true TDC using dial indicators or the piston stop method, then set your distributer statically from there and make adjustments either with a vacuum guage, or by ear/feel when driving. The latter is better done by more experienced mechanics ,who are a bit more familiar with how a particular engine responds with more or less timing etc...

 

If you install the timing gear dots at "6 and 12", all you have to do is turn the engine over one revolution to get the dots at "12 and 12", and back to number one being at tdc after the compression stroke. It's not a real tough job.

 

I don't get it. If your dist. is off alittle and there is not enough room to turn it to adjust it. Why not pull it out and rotate it to where it needs??? Couple plug wires, cap, and loosen one bolt. Not a big deal. Also, I have worked as a mechanic for years, and when I have done an intake job and the car runs. I always MARK the rotor to the dist. I mean realy mark it down close to where the shaft is on the body. If you put it right back to where it was, you wont even need to time it. Some of you will say you will always need to check the timing, but on some of the newer crap (96-2000s) if the dist. is off even one degree it will throw a check engine light. Doing it this way for years and VERY seldome have I had to correct it.

 

Everyone has their preferred method of doing anything. you should be able to take all this advice and develop yours. mine has developed from doing things like this for over 35 years. Be careful of the keyboard mechanics.

 

Quote; "old sparks,,,. Be careful of the keyboard mechanics." That right there is some good advice.
The Wizzard