Setting the timing?

[skokie]

I was reading my how to rebuild Chevy small block book. I came across the part that says how to set the timing. It said that you need to point the oil pump shaft to #5,then back the timing back to 8 degrees BTDC & then line the rotor to #5. Now I am a little confused. Why would you do it this way? I have to be missing something.

Also the reason I checked into this was that when I removed the old balancer the keyway slot and the timing mark was at 0 but when I put in the new balancer the timing mark is 8-9 degrees past the timing mark which I believe is throwing off my timing a bit since when I have timing set at 12 for the HEI it runs like crap until I get the mark at what would be abut 14-16.

Any thought
Thanks in advance.

[cory321]

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[68gmsee]

Re: the timing mark on the harmonic balancer: There was a thread about this not too long ago. Might want to do a search.

Not sure what the book is trying to tell you but, when I do it, I set the engine at tdc with the #1 at the compression stroke first by doing this.

I take all of the sparks plug out. This makes it easier to rotate the engine with my 1/2 wrench on the crankshaft stud. I insure that as the #1 piston is coming up I am getting compression. I usually just use my finger in the hole. Then I insert a screwdriver into the spark plug hole so I can determine when it reaches the top and just before it starts to go back down. Your harmonic balancer mark should be at TDC at this point. If it's not, but a white paint mark on there.

Then I insert an extra long screwdriver in the distributor hole and rotate the oil pump so that when I insert the distributor (it rotates as you slide it in) it lines up with the rotor pointing to the #1 positon. I usually mark it some way so I can tell where the #1 pos is when I take the cap off.

It usually takes me a few tries to get it right, but it works for me.

Last, if your mark is off on the harmonic balncer, only thing you can do is to move the dis until it runs good for you... May have to play with it some.

[Long Roof]

I concur with all that 68gmsee said. If you have the valve cover off you can also tell if the #1 is on comp by looking at the valves, they will both be closed.

[Alex Hayley]

I have a somewhat similar problem. The timing mark on the balancer is nowhere near the timing tab. It is under the waterpump at TDC. I can only assume that the balancer outer ring slipped or the balancer is the incorrect one for the engine. To ensure I understand the instructions, if I follow the directions as 68gmsee described, once at TDC on the #1 piston, could I simply mark the balancer at the 0 mark on the timing tab and time my engine from there?

[68gmsee]

Originally Posted by Alex Hayley

To ensure I understand the instructions, if I follow the directions as 68gmsee described, once at TDC on the #1 piston, could I simply mark the balancer at the 0 mark on the timing tab and time my engine from there?

That should do it. Once you have the #1 piston at its maximum upwards motion on the compression stroke, you should also be at TDC on the harmonic balancer/timing chain cover indicator.

skokie: Make an indicator out of coat hanger wire and bolt it to the intake manifold or other area. Bend it to point to the #1 piston and then remove the cap. If you're still off when it's at TDC, check to see how much the dis rotates as you slide it down, and then try to move the oil pump shart slightly more in the direction you need so that the rotor points to the #1 position. As I mentioned, it always takes me a couple of tries or more.

[skokie]

Thanks for the info. If I go by the vacuum guage at 12 degrees I am pulling 17 but when I go to 14-16 the vacuum reads almost 19 and it runs a lot better. Probably off a bit on the oil pump shaft.