What might cause a vibration or miss in a 259 / 289 v-08 in a pickup that has been rebuilt with all parts new except the camshaft. The vibration can be felt in both the cab and steering wheel. A new second 259 engine was put in the pickup with a new clutch and flywheel but the vibration was still in the truck?
1. The engine mounts can cause this type problem if they are
installed without the steel Sleeves on the bolts, because the bolts can
be
over tightened which will squash the rubber portion of the mounts and
the vibration will be transferred to the frame. Also check external
parts like the exhaust pipe or clutch linkage rubbing on the
frame.
2. Loosen (or remove) the fan belt and run the
engine to see if the vibration goes away with the water pump and
generator / alternator not rotating.
3. A bad distributor
or
carburetor can cause a vibration.
4. Check the spark plug wire
routing: When you route the wires on the left side, do not run #5 and
#7 together or a spark may be induced in #7 when #5 fires. That can
cause the incoming charge in #7 to ignite early. The 259 and 289 v-8's
both have a firing order of 1-8-4-3-6-5-7-2 with the cylinders numbered
from the front of the engine left side (drivers side) 1, 3, 5, 7 and
right side 2. 4. 6. 8. As you can see the firing order will fire #5
then #7 and that is the reason for the special routing of the #5 and #7
ignition wires.
5. Make sure the valves are not too tight.
Set the intake to .025 and the exhaust to .027, I do not prefer setting
them with the engine idling.
6. Slightly retarded cam or ignition
timing will not induce a vibration, although advanced ignition timing
might. After the valves are adjusted the compression should be checked
to be sure all cylinders are reasonably equal and then check the timing
to insure it is set to IGN with the engine warm and at idle: 500 RPM or
so.
7. Check the vibration dampener on the front of the crankshaft to make sure it is not installed backwards. The holes are offset to prevent this, but they aren't offset so much that a person couldn't distort the rubber cushions and install it backwards. The engine mounts on trucks hold the engines more firmly than passenger cars, so use dodge pickup truck mounts they can be adapted to the Studebakers and give the truck a little smoother feel.
8. Don't forget to check the front axle conecting rods for wear. Slao don't forget to check the tires for balance. This item is because the vibration can be felt in the steering wheel.