Thread: timing HEI smallblock from scratch

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Okay Kiddies, its been a while since the last time I put an HEI distributor back into a small block Chev, but I think it goes like this. # 1 cylinder is at the front of the motor, on the drivers side.---remove the spark plug (actually better if all the plugs are removed), and put your finger over the plug hole. Next, bump the starter untill you feel compression coming up in that cylinder, and watch the timing mark on the harmonic balancer. Don't let the timing mark go past the 12 o'clock position (straight above centerline of crankshaft) Take your big old johnson bar and turn the engine untill the timing mark is dead nuts at 12 o'clock position. (note that it is really important to feel compression coming up in that cylinder---it is possible to get the timing mark in the correct position but have your engine 180 degrees out of phase if the piston has been coming up on the exhaust stroke, not the compression stroke)
---The rotor in the HEI distributor should be turned by hand while it is still out of the engine untill it is in the position required to fire #1 sparkplug. (That position is pointing towards the front of the car, not straight ahead, but to the first plug terminal towards the drivers side of the car from dead center when the vacuum advance pot is pointing approximately towards the center of the passenger side cylinder head ) Look at where the tang is positioned on the bottom of the distributor shaft, that engages with the slot in the oil-pump drive gear----reach down into the engine thru the distributor hole with a long screwdriver and turn the distributor drive gear untill the slot in it lines up with the position that the tang on the distributor shaft is going to be in when the rotor is pointed at #1 terminal in the distributor cap. Now, if your a praying man, a little one might be in order---lower the distributor into the hole--you will feel it when the distributor gear engages with the camshaft gear, and the stupid rotor will want to turn as you drop the distributor in farther, because it is a spiral/bevel gear.---if it turns so far that it is no longer lined up with number 1 terminal, lift the distributor out and turn it back (counterclockwise) by what you think one gear tooth would be, and put it back into the engine again. This is purely a bit of "trial and error" but it must be right, or that engine aint never going to run. now, odds are really good that the tang no longer aligns with the oil pump slot, and if that is so, the distributor will not fit down all the way into the centerhead, like its supposed to. If that happens, pull the distributor back out, reach into the motor and tweak the position of the oilpump slot, and try again. When everything lines up, the distributor will fit down tight against the gasket (gee I hope you remembered to put the gasket on first).
Install the rest of the sparkplug wires, remebering that the rotor turns clockwise, and that the firing order is stamped on the centerhead . Install the distributor hold down clamp, and tighten the clamp hold down bolt untill the distributor can just be turned by hand. If equipped with one, unplug the vacuum advance and plug the hose with a pencil or something, and start the engine. If you are lucky, and the engine fires o.k., let the car run for 5 or ten minutes to get the engine warmed up, then shut it off, hook up the timing light, and set to whatever your specs call for, Then hook up the vacuum line to the vacuum advance, and that should be it. If anyone disagrees with this method, or if I have made a mistake, or if you know a better way, please let me know, and please, make sure you've got some oil in that engine and some tranny fluid in that turbo 350 before you start this exercise.

Close, but a couple of comments:

Don't let the timing mark go past the 12 o'clock position (straight above centerline of crankshaft) Take your big old johnson bar and turn the engine untill the timing mark is dead nuts at 12 o'clock position.

Why 12 o'clock? The timing pointer is at about 1 o'clock. If you set the timing mark straight up, you'll be setting 40 - 50 degrees btdc initial static timing. That pretty much guarantees a backfire. I set the static timing at about 12 degrees btdc using a degreed balancer, a timing tape, or the marks on the timing tab.

reach down into the engine thru the distributor hole with a long screwdriver and turn the distributor drive gear untill the slot in it lines up

I think you mean oil pump drive shaft, not distributor drive gear.

Firing order on all Chevys is 1-8-4-3-6-5-7-2, clockwise.

A search of the forum would bring up quite a few threads covering this topic for those who want more info.

brian,you wont the timing mark to line up with the 0 on the timing tab. that could be on the lift or right side of the timimg cover. the timing mark comes up on the compresson or exhaust stroke, thats why you blow you finger off the plug hole. the next thing is getting the dist lined up, dont worry about where the oil pump rod is when you drop the dist in, let it go down far as it can and then have someone bump the starter over and when the dist. and oil pump rod line up the dist. will drop down all the way. when you get the dist in you wont be able to turn the rotor but you can turn the dist to line up the rotor to the plug wire. if your wires are long enough you can get your comp stroke up, drop the dist. in with the rotor anywhere you wont it and then put the # one wire where ever the rotor button is pointing. it makes no dif. where # one is in the cap as long as you run the rest of the wires in the right timing order.

Setting it at 0 usually works, but most instructions advise setting it at 12. That gets the static timing as close to where it needs to be initially. Initial timing on a Chevy is never going to be 0, so why set it there?

Originally posted by Henry Rifle
Setting it at 0 usually works, but most instructions advise setting it at 12. That gets the static timing as close to where it needs to be initially. Initial timing on a Chevy is never going to be 0, so why set it there?

you set it there as a starting point, so youll know where to set the rotor. before i put my dist. in im going to set the timing mark on the HB at 0 (or somewhere close) on my timing tab, drop the dist. in on #1 wire in the cap, put a timing light on it and set the timing, to what ever i wont it. untill you put the dist in and hook up a light i cant see how you would know where to set the dist to give you 12 degrees. you can find 12 degrees on the HB with a tape, but where is 12 degrees in the dist?

. . . where is 12 degrees in the dist?

lt1,

Nothing wrong with your method, and I'm not picking nits - but here's an answer to your question. You don't have to find 12 degrees in the distributor. If you put the rotor on the #1 contact with the balancer at 0 degrees, your static timing will be 0 BTDC. If you set the rotor on the #1 contact with the balancer at 12 degrees, your static timing will be 12 BTDC.

I set the balancer on 12, turn on the ignition and rotate the distributor until I see a spark - like Denny mentioined, or put one of those neon timing lights in the circuit. When that spark hits with the balancer on 12, I know I've got initial timing set pretty close to 12. That's a really good starting point for most motors.

This is the method suggested in "How to Hotrod Big-block Chevys," and most of the other reference books I have.

Again, nothing wrong with your method, but I've had better luck setting in a little more inital static advance.

Henry Rifle and It1s10 you are both right, when doing the initial timing, the timing mark on the harmonic balancer should be lined up somewhere between the 0 degree and 12 degree marks on the timing pointer. The trouble is, I,m in here on the computer and the timing cover is out in the garage. I went out and took a closer look after I read your reply, and the timing pointer is not at the 12 o'clock position like I had thought, more like 1:00 o'clock. And yes Henry, I did mean the oil pump driveshaft. Thanks a lot guys for your input.

henry, i really dont know to answer this but when you post i feel like youer correcting me and if i answer back im arguing with you and the truth is you can set the timing eather way, but im not basing my info. from
"how to build a big block" but experence. ive been doing this everyday for 40 yrs., been to most of the tune-up classes that comes around, and all of G.M. tune-up classes and im ASE certificated in motor repair and engine performance and ive never seen a instrustor hook a timing light to the dist for any other reason than to set the time after you start the motor im sure it does what you say it does but in the real world its not necessary.
with all- due respect of course

Comments removed. It isn't worth the hassle.

Works for me.

( As he taps one from the keg)Now that we are all around the keg,how do I determine whether my engine has the 4,5 swap on the cam.Long story short pulled the intake and dis and did not record their location,nice shiney intake now ,but how do i determine if the 4,5 swap has been done? I just dont want to blindly hook it up,I get how to time it ,top dead center and all.(As he pounds the rest of his coorslite down)

I don't know, I just know about tires, when there flat you change the mothers.

Imagine no timing light, nor timing marks or tape or even a zero marker. NOW, what I would do from there is take off the valve covers and watch for number one compression, IE no rocker or spring movement, this is given the motor was put together correctly. TO be closer than just guessing on the lobe of the cam, I would set the (hopefully the damper has some sort of mark, even one put in by a tapered punch) at about 1 o clock, drop the distributor in with the number one at about where you assumed it, pointing towards the center of driver valve cover with the stock vacuum advance pointing at the passenger center valve cover. This is just to because the vacuum advance doesnt like the other side for aesthetics, etc. Now all you gotta worry about is that when you put the cap on you do it right. Thats if you dont have much to go off of I think, if you got marks, tape, lights it just gets easier, but I always get it started before I put a light on it, and the spark method works good too, just keep your thumb away from the spark...it gives a nice 50 000 volt or so shock...WEEEE!
And...what? no stock marks, tape or idea of what degree to time to?? If you're good go by ear, startup, hot startup and seat of the pants...thats the MOST accurate method ever devised for sure, no doubt about it. Do it any way you want, the small block chevy is pretty easy to time and set the valves on...or any engine if you go with the running mate method. K I think I've said far enough thats been said before...oh did I mention the 4 beer I downed while writing this??