351w: timing questions
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Joined: Oct 2004
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351w: timing questions
Both engines are from the 86-92 era..
First I am wondering if the plate (for 302) that attatches to the timing cover which you use to read the timing marks on the harmonic balancer is the same plate for a 351w. I happened to lose the one for the 351 and attatched one from a 302. Is it the same small tab,plate,marker or whatever name you can come up with. It is important because I am trying to prevent pre-ignition because of high compression.
Second. I have tried using and NOT using a vacume advance and setting the timing differently for each scenario. I am just looking for opinions on this.
I feel it runs better without the vacume advance right now and setting the advance at about 5-10 btdc.. assuming the timing mark is correct.. there is little to no spark knock at this setting.
With vacume advance I would need to run about 0 or less degress advance...
Question is.. what would some of you reccomend. I recall reading that some people prefer no vacume advance.. where as others say it is better.
thanks for any replies in advance
First I am wondering if the plate (for 302) that attatches to the timing cover which you use to read the timing marks on the harmonic balancer is the same plate for a 351w. I happened to lose the one for the 351 and attatched one from a 302. Is it the same small tab,plate,marker or whatever name you can come up with. It is important because I am trying to prevent pre-ignition because of high compression.
Second. I have tried using and NOT using a vacume advance and setting the timing differently for each scenario. I am just looking for opinions on this.
I feel it runs better without the vacume advance right now and setting the advance at about 5-10 btdc.. assuming the timing mark is correct.. there is little to no spark knock at this setting.
With vacume advance I would need to run about 0 or less degress advance...
Question is.. what would some of you reccomend. I recall reading that some people prefer no vacume advance.. where as others say it is better.
thanks for any replies in advance
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Joined: May 2004
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'87-351W-4bbl-F-250-4X4
I, too, disconnected & plugged the vacuum advance; I changed the springs & weights in my distributor to allow 10* initial & 20* mechanical for a total of 30* advance. The truck seems a little sluggish but does not ping or rattle; I still need to adjust the carb; I'll sweeten the mixture to see if I get some "pop" back into the engine.
I, too, disconnected & plugged the vacuum advance; I changed the springs & weights in my distributor to allow 10* initial & 20* mechanical for a total of 30* advance. The truck seems a little sluggish but does not ping or rattle; I still need to adjust the carb; I'll sweeten the mixture to see if I get some "pop" back into the engine.
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Might aswell add somthing here..
Is there any easy tell tail signs of pre-ignition by looking at the spark plug?
Right now the spark plug is burning beautifully mocha brown with no deteriation or damage. although on the very tip of the insulator there is a slightly lighter color brown.
I am using colder plugs too I read somewhere they can help lower chances of preignition.
Is there any easy tell tail signs of pre-ignition by looking at the spark plug?
Right now the spark plug is burning beautifully mocha brown with no deteriation or damage. although on the very tip of the insulator there is a slightly lighter color brown.
I am using colder plugs too I read somewhere they can help lower chances of preignition.
