Advancing base timing on '87 stock 5.0

Topic: Advancing base timing on '87 stock 5.0 (Read 1151 times) previous topic - next topic

Advancing base timing on '87 stock 5.0

September 11, 2017, 01:46:44 AM

My stock 5.0 is running fine but wanting more response I decided to advance the base timing by twisting the distributor clockwise. Fuel tank was full of mostly premium for this, about 1/3 leftover regular, with Gumput injector cleaner that claimed to boost octane conveniently thrown in.

I don't have a timing light and thought I could still see a mark indicating 15°. Tested it out in the hills around me and had to back it off after hearing knock. Then back it off more. And more. And back to base.

I noticed the throttle response was a lot better when advanced and seemed to have more torque to power it through my AOD that shifts early, until of course I gave it more throttle. I thought these were supposed to be fine with advancing the timing, sometimes without even running premium? Or is that just for the Mustang which has different pistons?

Advancing base timing on '87 stock 5.0

Reply #1 – September 11, 2017, 02:37:21 AM

I haven't personally advanced the timing on a SO 5.0, but I owned an 86 Mustang GT that is essentially an SO motor with flat top pistons and a more aggressive cam. I ran about 14* BTDC and never experienced any knock.

Honestly, the likelihood of you getting the timing dialed in without a light is slim-to-none. It's worth it to pick up a 30 dollar timing light. Doesn't need to be anything fancy.

Advancing base timing on '87 stock 5.0

Reply #2 – September 11, 2017, 05:11:02 PM

I have run 14-16º on a few of my cars. When we were doing the ethonal change over, i noticed a drop in mpg and advanced it a bit to try to get a bit more mpg and power back. It did help, its not something id go after unless i was already doing a tune up or messing with stuff anyways.

Btw, i haven't tried higher octane gas at all, ethonal actually slightly increases how much timing and compression you can run. Every car/gas blend is a bit different. It will also change with altitude, so you don't want to be on the edge of pinging.

Advancing base timing on '87 stock 5.0

Reply #3 – September 12, 2017, 09:46:05 AM

Get a Timing light and do it quick since you have already messed with it. That detonation you heard and possibly the detonation you cant hear right now is murder on rod bearings.