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Discussion Starter · #1 · (Edited)
My enegine rattles or knocks around 3000rpm, stops if I lifts my foot of the throttle, starts when I push it. Thought it could be ignition but my experiments did not reduce the sound..

Here is a video, not easy to hear the knock but it is there, like from 32-39 seconds out..

I hear you knockin`but you. - YouTube
 

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What the initial timing?
Is the vacuum advance ported or off the manifold?
What is the approximate compression ratio?
What is the octane rating of the gas in the tank now?
 

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sound like motor is at early stages of developing a rod knock..maybe...??

what is the oil pressure reading.....
 

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Discussion Starter · #7 ·
Some testing today, initial timing was close to 16, reduced it to 14 and picked up some low-end grunt. Still knocking.

Hooked off vacum (from manifoil) to eliminate a misadjusted can; this seems to reduce/eliminate(?) the knocking, though I will have to double/triple-check this later, need to calm down first. Starts to hear rattles everywhere after some hours:confused:

Reduced the can from 12 to 8-9 degrees after a fine adjustment with ignitionlamp. Now can goes off as soon as I`m near the throttle.

I really need to check this out now, from my recidens in south part of Norway I am moving to the south-part of France in about a month. The plan is to drive the old Ford along with my friends truck, some 1400 miles where the enegine will be working around 3000 rpms most of the time.
I need to know that the enegine can take the distanse before I go for it.

A part of my check-up plan for the enegine is to pull the oil-pan, clean it and replace the oil-pickup, new oil and filter. Then I also can inspect the rod-bearings. After doing this I will know a bit more about the odds I have on making it all the way to Cannilac in Limousin, France :cool:
 

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Discussion Starter · #9 ·
Initial timing is not the culprit, you need to check your timing at 3000 RPM.

Forgot to mention this but the weights openes 20+ degrees and ends up just under 35.

Compression is calculated to 9.5 and the gas over here should be no problem, will take a run with octane-booster anyway.

Will I be able to go all the way to France at 60mph to avoid knocking?:(
 

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If your vacuum advance is connected directly to manifold vacuum, you are probably getting too much advance too early. If it knocks at partial throttle but goes away at wide open throttle, that is likely your issue. Connect the vacuum advance to the port on the carburetor (make sure it's the correct one for your carb).

I don't know what engine or year you have, or what kind of ignition system you are using, but the 66 and 69 shop manuals I have specify 6 degrees of initial timing at idle for almost all of the engines. You may want to reduce some of your initial timing to get the best performance without knocking with the gas you are using. In case you didn't know, initial timing is set with the vacuum advance disconnected.
 

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I used to bump timing to 10/12* initial back in the 60's.

I also had an engine that had very loose main clearance and would knock like yours is doing. I had rebuilt a 289 and the block when returned from shop looked very clean so I assembled it. I did not thoroughly wash it or clean it as it looked like it had been tanked after machining!!! lol!! Motor ran good and was quiet for a few miles Until machining debris was pushed into mains with use and that cut the bearings and crank fairly quickly and when disassembled I had .004 or .005 clearance, damn it all. I then went to car wash with face shield and rain coat and VERY thoroughly washed every engine block after that, NO more problems or surprises.
 
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