Distributor experts....
Burning Brakes
Joined: Dec 2007
Posts: 952
Likes: 0
make sure you have the #5 and #7 wires separated from each other as much as possible, including in the wire holders. These cylinders fire consecutively and since they are adjoining cylinders you can get crosstalk between the wires from the voltage causing them to misfire.
This image is really from a C2 but it should be the same for your '68. See how the #5 and #7 wires are at opposite ends of the wire holders? This is the reason why
This image is really from a C2 but it should be the same for your '68. See how the #5 and #7 wires are at opposite ends of the wire holders? This is the reason why
If the insulation value is high enough, you can ty-wrap them together. That's BS
Thread Starter
Le Mans Master
Joined: Sep 2000
Posts: 9,078
Likes: 7
From: DFW TX
Cruise-In VII Veteran
St. Jude Donor '07
Well today a fellow forum member came over and tried his distributor. Same problem, same issue with the vibration. His distributor ran better at idle (I think it was a Crane conversion), but broke up at 1900 rpm.
We check compression at #7 and it was 165. My next guess would be the rockers are over-tightened and they are pumping up as the engine rev's. One thing I noticed when changing out the valve covers the rockers were all tight. Not the norm for most cold engines.
I think at this point I can rule the following:
Fuel issues
Ignition issues
Timing issues
Vacuum leaks
Still need to check:
Compression check all cylinders
Pull valve covers and look for rocker issues or a wiped lope.
We check compression at #7 and it was 165. My next guess would be the rockers are over-tightened and they are pumping up as the engine rev's. One thing I noticed when changing out the valve covers the rockers were all tight. Not the norm for most cold engines.
I think at this point I can rule the following:
Fuel issues
Ignition issues
Timing issues
Vacuum leaks
Still need to check:
Compression check all cylinders
Pull valve covers and look for rocker issues or a wiped lope.
