I am having issues setting the timing on a 66 corvette 327/350hp. The setting is suppose to be 10 degree BTDC. When I turn the distributor clockwise I can on get to 4 degrees BTDC and then it starts hitting the vacumm advance on the distributor. Any ideas? Thanks in advance ya'll are great.

 

You may have to remove the dist. and move it one tooth to get the extra clearance. You might also check the little grommet in the points plate that limits the vacuum advance. Mine disintegrated over time and I couldn't get the timing to stay stable because of this overlooked little tiny grommet.

 

I don't want to sound stupid but what do you mean more the ign wire one position in the direction that I need room? Sorry for being a little slow.

 

I will give it a try. Thanks

 

I've done that before and it works but it's been years, but you should really remove the dist. and move it one tooth over so you get the advance in the middle of the range. Just make sure the rotor faces the exact same as it was. The housing can face any direction as long as the rotor is lined up with the firing cylinder.

 

You may need to remove the distributor and reverse the drive gear so that the dimple on the gear aligns with the rotor..When properly indexed this will allow enough room for the distributor to turn for proper timing.

 

Please correct me but to advance the timing don't you rotate the distributor counter clockwise (opposite the direction of the rotor)? This moves the VAC away from the coil, no interference, so getting to 10 BTDC should be doable. .

 

On any car you advance the timing in the direction that the hose nipple on the vacuum advance can points....remember that and you can't go wrong...

 

IF you have a factory or OEM camshaft

 

Nope. The housing has a defined orientation on a Corvette so the tach drive cable aligns with its hole in the firewall without kinking and the VAC is centered in its opening in the upper distributor shield. From the OP's description, he needs to pull the distributor, remove the drive gear, and replace it turned 180* from where it is now in order to get the VAC off the intake runner.

 

Sorry John, I was speaking about distributors in general. Obviously Corvettes ones have to face approx. in the position required for those two requirements.

 

There is only ONE WAY to index the wires on cap. It's in your CSM. Do it any different way and you will NEVER, EVER get the correct timing with the OE manifold and coil bracket. As stated pull the dist. and verify that the dimple is pointing the same direction at the rotor tip or tap out the pin part way and rotate it 180 deg. so it is.

Before pulling the dist. set the balancer notch at 8-10 on the timing tab, number one nearly at TDC of the compression stroke. Note the indexing of the rotor tip as it clears the gear (it will rotate CCW). It should be along engine centerline. To reinstall start with the rotor tip pointing approximately along engine centerline and drop in. The rotor tip will rotate about 20 deg. CW as the gear ingages.

If it won't seat all the way, you'll have to remove the dist. and tweak the oil pump drive slot. A paint mixing stick is a good tool to use.

Once seated connect an ohmmeter to the coil negative terminal and a convenient ground. Rotate the dist. until you get continuity. This is called "static timing" the engine, and it should be near 8-10.

In the final position at 8-10 initial the plane of the cap window should be approximately normal to engine centerline and the VAC should be about halfway between the coil bracket and manifold interference points. If not, there's something wrong with the installation or the cam gear is not properly indexed to the cam. This has been observed with some aftermarket cams and the dimple in the dist. gear must be indexed 180 deg. out from the rotor tip.

Start the engine and check with a timing light and tie down the dist.

Duke