71 spark knocks
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Joined: Sep 2000
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71 spark knocks
I have a 71 with a 351W I installed, I think I've ended up with a wierd engine. I started out with a Windsor out of a 77 LTD, it went to bad so I installed a long block from a local supplier, I told them I wanted an early 70's engine but I'm not sure what I've got. The block is a wf code I think and the heads are wf code or vise versa. The heads have the sqaure water jackets. I can't seem to get this engine to run good without spark knocking. If I time it with a light it will hardly run at all. New elder. carb. elect. ignition. Good steady vacuum, help.
Senior User
Joined: Oct 2000
Posts: 125
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From: Spokane, Wa.
71 spark knocks
Hey CW,
What specs are you using to set your timing ? It's just a hunch but you probably need to retard the timing a few degrees ( 2~3 ) if you're running regular grade fuel. Older engines were built for higher octane fuel, when the stepped the octane level down to 87 it started causing detonation ( pinging, spark knock ) and manufacturers either retarded the timing a few degrees or installed knock sensors which 'listen' for pinging and retard the timing to compensate when it happens and advance it when it goes away. Were your heads rebuilt ? If you don't know you should ask and ask if the hardened valve seats were put in to accomodate unleaded fuel.
Hope this is of some help ( and I haven't stepped on anyone's toes )
-Scott
What specs are you using to set your timing ? It's just a hunch but you probably need to retard the timing a few degrees ( 2~3 ) if you're running regular grade fuel. Older engines were built for higher octane fuel, when the stepped the octane level down to 87 it started causing detonation ( pinging, spark knock ) and manufacturers either retarded the timing a few degrees or installed knock sensors which 'listen' for pinging and retard the timing to compensate when it happens and advance it when it goes away. Were your heads rebuilt ? If you don't know you should ask and ask if the hardened valve seats were put in to accomodate unleaded fuel.
Hope this is of some help ( and I haven't stepped on anyone's toes )
-Scott
Cargo Master
Joined: Jul 1999
Posts: 2,484
Likes: 7
From: New Egypt, New Jersey
71 spark knocks
Scott, All of us "toes" belong to the same foot here, Ken Payne being the "big toe". 
Anyway, I had always thought it was the other way around. I thought that the older engines (early or mid 70's and older) ran better on any octane than the newer ones. My '79 351M will "ping" like crazy if I use a low octane fuel (less than 93). I'd like to try to what you sugguested. The "good stuff" is so much more expensive, not that the low octane is cheap anymore. I think when the removed the lead, they added gold! 
Kenny
Anyway, I had always thought it was the other way around. I thought that the older engines (early or mid 70's and older) ran better on any octane than the newer ones. My '79 351M will "ping" like crazy if I use a low octane fuel (less than 93). I'd like to try to what you sugguested. The "good stuff" is so much more expensive, not that the low octane is cheap anymore. I think when the removed the lead, they added gold! Kenny
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
71 spark knocks
[font size="1" color="#FF0000"]LAST EDITED ON 01-Oct-00 AT 03:42 PM (EST)[/font][p]Kenny, you should be able to run 87 or whatever the lowest octain is. If it is pinging just back the timing up untill it stops.
My 2 from a toenail.
John
jowilker@nc.freei.net
66 F100s
In the still cool hours of the night, you can hear chevys rusting away.
My 2 from a toenail.
John
jowilker@nc.freei.net
66 F100s
In the still cool hours of the night, you can hear chevys rusting away.
Senior User
Joined: Oct 2000
Posts: 125
Likes: 0
From: Spokane, Wa.
71 spark knocks
Isn't that what I just said ? =Þ
In my *gasp* car ( an '88 Merkur Scorpio ) I had advanced the timing a few degrees to get a little more low end power but as a consequence, had commited to using 92 octane gas. =)
-Scott
In my *gasp* car ( an '88 Merkur Scorpio ) I had advanced the timing a few degrees to get a little more low end power but as a consequence, had commited to using 92 octane gas. =)
-Scott
