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350 HO Vortec
I recently purchased a 76 Jeep CJ7 installed with a newer Chevy 350 HO 330 HP crate motor (2,000 miles) with an Edelbrock intake manifold and 1406 carb (600?) It has an HEI Summit Racing distributor.
I drove the vehicle home from Portland to SLC this past week. Two questions;
- The vehicle was running quite rough on the way home, appearing to not be running on all cylinders, poor carburation, or lack of proper timing as I was unable to determine the obvious until I arrived home. The plug wires were placed in the wrong position by the previous owner (6 & 8 were reversed.) Have I potentially caused serious damage to the engine by running 800+ miles with this setup?
- What should be the proper timing for this engine with the current setup?
Thanks in advance!.
Bob.
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If it runs OK with the wires properly set up, probably no damage. Did it overheat?
With the vacuum advance plugged, set it at 10 degrees btdc at about 700 RPM.
As a check, if you have a timing tape or a degreed balancer, run up the RPMs until the timing stops advancing. It should be about 32 degrees.
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350 HO Vortec
Jack,
The engine held its tempurature during the trip. It appears to be running great, now.
I remember the previous owner mentioning something about a Cromally cam that is installed which pushes the timing to 11-12 degrees BTDC?
Thanks again.
Bob.
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Bob,
The spec sheet recommends no more than 32 degrees. Not that that's set in stone. He may have installed a cam that allows a little more lead. You can fiddle with the timing a few degrees each way and see what happens. Keep away from any ping. These Vortec engines don't need a lot of timing lead.
I don't worry about initial timing any more. I spin the motor up until the timing stops advancing, then lock it in at the recommended setting. Whatever it drops back to on idle is what it is.