Pontiac V-8s are notorious for low oil pressure at idle, but it isn't necessarily a problem. With the engine at normal operating temperature, the old standard of 10 psi per 1,000 rpm still holds true, which would put you safely in the black. We've seen plenty of seasoned Pontiac mills allow the gauge to drop almost to zero at idle in Drive when coolant temperatures are hovering around 200 degrees, and many of them performed flawlessly. Pontiac engine builders often take steps to improve the situation, typically by keeping critical tolerances on the low side (for street engines) and upgrading oil pumps.
Evidently, the Pontiac engineers weren't too concerned with oil pressure at idle in their V-8 engines, as the factory spec provided is given at 2,600 rpm, at which point they feel you should see 30-40 psi in standard V-8s and 55-60 psi in performance V-8s.
Trick TriggerPlease educate us on the advantages and disadvantages of the crank trigger used in the "672hp Pontiac 350" article (July '02). I assume it provides a more accurate timing of the spark since it would eliminate timing-chain stretch. How is it connected to the distributor? Is it a good street item? It certainly looks trick.Conrad A. Carter Jr., P.E.via e-mail
Your assumption about the increased accuracy of the crank trigger is correct, and this is the main reason racers prefer these units. Normally, once the crank trigger is installed, the distributor is locked out, meaning the advance mechanisms are disabled and fixed in one position. Drag racers often set the distributor for maximum advance and leave it there, but for the street, this isn't really a feasible approach.
There are a few ways to use the MSD crank trigger. The first involves simply mounting the trigger unit and plugging it into a typical MSD ignition box, such as a 6AL. However, this arrangement provides no timing curve. The next option is to use MSD's Timing Computer (PN 8980), which has a preprogrammed, nonadjustable timing curve. To use this, you would lock out the distributor's advance mechanisms and set the distributor for the desired total timing. The control unit will then retard the initial timing by 20 degrees during cranking, and hold it there until the engine exceeds 1,000 rpm. From there, the control gradually advances the timing and reaches the total mechanical setting (at the distributor) by 3,000 rpm.
MSD also offers a Programmable Timing Computer (PN 8981), which allows some tuning through rotary switches for idle timing, including the points at which the advance curve begins and ends. There is also a Multi-Function Ignition Controller (PN 8979) that is digitally programmed either with a hand-held control module or a laptop computer. This offers broad tunability but is also the most complex option.
How Hot Is Too Hot?My 455 Buick had not been driven for 16 years. I installed a new radiator, clutch fan, 160-degree thermostat, and fan shroud, and I used a 50/50 coolant mix with the original recovery bottle. The engine ran at 205 degrees F on a 95-degree F day. It doesn't seem to boil over, but does this constitute an overheating problem, or am I worrying about nothing?Scott HolmanPittsburg, CA
First off, your 455 is not overheating. Although most of us consider anything over 200 degrees F on the gauge to be too hot, OE manufacturers don't recognize an overheating condition until the coolant hits about 230 degrees F. This is pushing it, and would probably require the presence of electric cooling fans to keep the heat from getting out of hand while idling in traffic. The primary reason carmakers allow operating temperatures to approach these levels seems to be to reap the benefits of the cleaner exhaust emissions that result.