351M pinging like crazy!

[bubbaf250]

[beratte]

I have a 79 F-150 with a 351M with an Edelbrock intake and 4 barrell. When she gets hot she pings like crazy. Anyone have this problem with this engine? Thanks

[Franklin2]

Most likely it is overheating.

[Bill_Beyer]

>I have a 79 F-150 with
>a 351M with an Edelbrock
>intake and 4 barrell.
>When she gets hot she
>pings like crazy. Anyone
>have this problem with this
>engine? Thanks

First thing I'd check is the timing. Second thing is to make sure the EGR system is functioning properly if it's still there. These engines were designed to function with EGR so taking it off can have a detrimental effect on the performance. You may have to retard the timing more and/or go to a higher octane fuel if you've pulled the EGR off.

[bubbaf250]

>make sure the EGR system
>is functioning properly if it's
>still there. These engines were
>designed to function with EGR
>so taking it off can
>have a detrimental effect on
>the performance. You may have
>to retard the timing more
>and/or go to a higher
>octane fuel if you've pulled
>the EGR off.

Or enrich the A/F mixture to compensate for the missing EGR. The purpose of EGR is to reduce NOx emissions produced by over-lean mixtures.

Check the base timing and also the vacuum advance. Ford vac advances are adjustable with a 1/8" Allen wrench in the vacuum nipple. To reduce vac advance sensitivity, turn the screw counter-clockwise. (Some aftermarket vac advances work the opposite way, though.)

BubbaF250

1980 F250 4x4 Custom, 351M/NP435/NP208/D44HD-TTB/D60-FF/3.55s 6750 GVW, Rust & White.

[Bill_Beyer]

>Or enrich the A/F mixture to
>compensate for the missing EGR.
>The purpose of EGR is
>to reduce NOx emissions produced
>by over-lean mixtures.

Yep no question a lean mixture will cause a hot engine and increase the tendency to detonate.

[beratte]

thanks all, I'll start with checking the timing. I'm not sure if the Edelbrock intake and carb retained the EGR, I'm thinking not.

[Ultramagdan]

[font size="1" color="#FF0000"]LAST EDITED ON 27-Feb-01 AT 11:35*PM (EST)[/font][p]I had a 400 C that was bored out and did the same thing. Especially when the outside temp rose. Installed some splitfire plugs. Eliminated 99.9% of the problem. Only when it was 100+ outside, then I needed to run premium fuel. I messed with timing and had no effect. Nothing worked until the plugs were installed.

I did keep mine all stock except for the oversize pistons on a 2 barrel carb.

That's my experience with it.

98 F250LD 4X4