Initial advance for 62 327-340

[Hal E.]

What was the initial advance on this engine which is mechanical advance only? With the poor quality of today's gas....what it realistic today? I am having some run-on and idling issues with today's gas (premium)probably due to the ethanol or MBTE content.

Thanks for any advice.

[Joe L.]

Re: Initial advance for 62 327-340

What was the initial advance on this engine which is mechanical advance only? With the poor quality of today's gas....what it realistic today? I am having some run-on and idling issues with today's gas (premium)probably due to the ethanol or MBTE content.

Thanks for any advice.

Hal------


I don't have the 1962 spec, but the 1963 spec was 10 degrees BTDC.

How much should you run with today's fuel? Simple. Run as much as you can without experiencing significant pinging.

[Mike T.]

Re: Initial advance for 62 327-340

Hal, I'm pretty sure the spec for the '62 340 was the same 10 degrees initial. As Joe already mentioned, it's a matter of experimentation to see what will work for you. I've got a friend with a '62 340 in the Houston area and he's been playing around with the timing on his car from that 10 degree setting on up to 20 initial degrees and so far, the 20 has produced some pinging and the next test will be at 15/16 degrees to see how that works out. The factory setting works fine, no problems at all but he's just trying to find out if it will tolerate a bit more. He does have a Sun 500 machine and has verified his total is within range but I can't remember exactly what those figures were supposed to be. He's got 93 octane gas in his area while we only have 91 here in Northern California.
Mike T.

[Timothy B.]

Re: Initial advance for 62 327-340

Hal,

If the 62 has a 24* centrifugl advance which you need to check the inital can be set 14*BTDC and maybe 16* if your sure the stop bushing is in place.

[Duke W.]

Re: Initial advance for 62 327-340

The '62 and '63 340 HP engines' maximum centrifugal is 24 deg. @ 4600, which is pretty lazy, and with only ten degrees initial, you only have 34 at very high revs, which is a little short of the optimum 36-40 range for peak power.

My suggestion is to run the initial timing as high as possible without significant detonation.

Back in the sixties, when I took my SWC to the drag strip I put 103 RON Chevron Supreme in the tank and advanced the initial timing to about 18, and I had the '64-'65 springs installed, so all the advance was in at 2350. The actual initial was probably no more than 16 because the timing tab reads low with the big balancer (discussions and measurements are in the archives), so my actual maximum was probably never more than 40.

With the jacked up timing, high octane gas, and exhaust cut outs open it did pretty well - about 102 MPH through the traps, but the ETs were just low-mid-14s due to the CR trans and 3.08 axle. They didn't have 60' clocks back then, but I'm sure the 60' times were about 2.5 seconds. Any attempt at a clutch drop just lite the hard 6.70-15 Michelin X tires, so I had to just "drive" is out of the hole like quick street start.

One advantage was I only had to shift once before reaching the lights at 6500 in second gear.

Duke

[Stuart F.]

Re: Initial advance for 62 327-340

Duke;

You are a brave man, my friend! I NEVER came off the line (street or strip) with my 63 L-76, and that is with a 3:36 final!!!! Every time I tried to do a sort of hole shot (on the street), it would bog down badly and I'd hardly get a chirp from the tires. I usually had to clutch it again and hit it with some more revs just to get it going. It protested a lot until it got cleared out, and I knew I was abusing it so I avoided those situations at all costs. If someone wanted to play, it had to be by my baby's rules; 30 mph up. That's when the baby rules! Many a fuelie with 4:11's or 4:56's found that out, to say nothing about the other commandos with their "for strip" geared muscle cars.

As you said; you only had to shift once. You might have just as well been using a Powerglide slush box.

Stu Fox

[William C.]

Re: Initial advance for 62 327-340

If you are having problems with engine run-on after turning the key off, more initial timing will allos you to maintain the proper idle speed with less throttle opening, and reduce the run-on. Less initial timing will simply make it worse, especially true on a distributor like the '62 340 without a vacuum advance.

[Duke W.]

Re: Initial advance for 62 327-340

Duke;

You are a brave man, my friend! I NEVER came off the line (street or strip) with my 63 L-76, and that is with a 3:36 final!!!! Every time I tried to do a sort of hole shot (on the street), it would bog down badly and I'd hardly get a chirp from the tires. I usually had to clutch it again and hit it with some more revs just to get it going. It protested a lot until it got cleared out, and I knew I was abusing it so I avoided those situations at all costs. If someone wanted to play, it had to be by my baby's rules; 30 mph up. That's when the baby rules! Many a fuelie with 4:11's or 4:56's found that out, to say nothing about the other commandos with their "for strip" geared muscle cars.

As you said; you only had to shift once. You might have just as well been using a Powerglide slush box.

Stu Fox

I only went to a drag strip two or three times. I knew the car was not set up for drag racing, but I was curious what it would do. The clutch drops probably contributed to the snapped axle drive pinion in 1966.

After that I stuck with hot lapping Kent and sucking guys into races from a 40 MPH rolling start. If there was enough open road in front of me, there was no way I could loose because most muscle cars of the era would run out of revs when I had one more gear left.

Duke

[Stuart F.]

Re: Initial advance for 62 327-340

Yes, it's funny how many hot dogs suckered for the rolling start - 30 mph (w/3:36) or as you found at 40 mph (w/3:08). They were so sure of their dragging machines that they thought their 13 second quarter miler could beat anything. Used to love the helpless look on their face when they were wound out in fourth and we were still shifting. There were some Wisconsin State boys had that same look when their Dodge pursuits were peaked out and, well that's a whole other story.

Stu Fox