I have recently been trying to figure out the timing on my 351M. Awhile back, I had Pony Carbureter's rebuild the carb on my truck. The instruction sheet I got with the carb says the following:
All Ford engines will run better, deliver more power and give better fuel economy with the timing advanced BEYOND factory specifications. In addition, premium unleaded fuel is recommended - especially in 6 cylinder engines. After you have read the procedure, your engine will perform the best when the engine will either just barely "ping" on full acceleration or not quite "ping". (pinging indicates timing advanced too far.)

The basic procedure is advance the timing until the engine idles fastest, then go out and drive it. If it pings, back it off just a hair and drive it again. repeat until it just barely pings or doesn't ping at all.

Has anyone else ever heard of this before or tried it? I tried it on my mustang (68 302) and didn't really notice anything. When I took the mustang in to the Ford dealership for a tune-up, the guy told me he backed off the timing because it was advanced too far. I'm wondering if I should go with stock specs or go with it advanced more.

When I asked about this a few days ago, some guys responded saying they had to use less advance, like 6 or 8 degrees for the 351 (stock is 14). Anyone have any strong opinions on this theory??

 

I got nailed to the wall last time I answered this in detail on this forum so I'll just say this. I've got a 351M that I put into my '72. I couldn't get it to quit pinging at anything above idle so I kept retarding the timing until it quit, once I got it set to quit pinging I simply left and have never checked it with a light to see where it is. Hope this helps. If you want more specific details on exactly how I accomplished this e'mail me at trailridr(No Email Addresses In Posts!)

Trail Rider

 

I don't have much experience with the 351M, but have been working with Windsor engines for the last 12 years in my Mustangs. The W engines tend to like between 12 and 14 degrees advance in most cases. This does make the engine a bit more responsive, and you may see a slight increase in gas mileage. The stock setting on these engines is supposed to be 10, but I have seen some as low a 7 from the factory. Anything above 14 and you do risk running into detonation (pinging), which can cause piston and valve damage in very short order. The procedure you outlined sounds about right, but I always use a timing light to be sure.

Be careful that the harmonic balancer has not shifted though. The rubber isolator on the stock piece does tend to break down over time, and that can result in the outer ring with the timing marks to shift, giving a false timing reading. If it comes to that it is time to replace the balancer anyways.

Of course, if you want the most out of your engine nothing beats a tuning session on a chassis dyno. I am always amazed at how much extra oomph my dyno tuner can get out of engines with timing changes and a bit of carb tweaking. Best $100 I spend on my engines!

Cheers,
Ian

 

It is common practice for most to set their timing to the "stock" spec and forget it. In reality you need to fine tune it depending on your individual engine condition. I have the Initial timing specs for 1967 Trucks on my web site. Take a look at footnote 1. They do call it "initial timing" for a reason.

<a href="http://www.hometown.aol.com/tbeeee/Timing.html">http://www.hometown.aol.com/tbeeee/Timing.html</a>


The same principle applies to the 351 timing which was the original topic here.


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