Pre ignition knock

Bascomanny

Bascomanny

New member
Pre ignition knock

I have a completely rebuilt engine, everything new. It sounds great but when I put a load on it, it starts pinging, like a desel engine. I have changed the distributor, the timing, put high octane fuel. I still have the knock. Does anyone have a suggestion. Please help. Thank you
 
Is the head a standard Model A ? If so, then the ignition timing must be wrong and much to advanced.

How did you time the ignition ?

Marc
 
Do you think the noise is pre-ignition or detonation[ spark knock] ? They are 2 different animals.
What cylinder head are you using ?
What are you using to set the ignition timing ?
Where do you keep the spark lever ?
Do you retard the spark when it starts making this noise ?

I'm wondering if there is something else wrong with it.
 
Do you think the noise is pre-ignition or detonation[ spark knock] ? They are 2 different animals.
Click to expand...

Patrick, can you explain the difference.
Tnx, Ken
 
Pre-ignition is like when Leaded Gas went away & Yo' Car would "DIESEL" & you couldn't get the dang thing stopped!
I had a '68 Datsun P.U, with a 2800 Mustang V-6 & C-4 automatic. Ran out of gas, poured in a gallon of Coleman Fuel to get to the station, PINGED, RATTLED, beyond belief. Couldn't get it SHUT OFF! As a last resort, plugged the tail pipe with a red shop rag & a screwdriver & held it there.
Almost finished mowing my lawn, once, & PFFFFT!--Did you know that a BRIGGS would run on ENERGINE CLEANING FLUID???
Bill W.
 
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In the 60's I ran out of gas and only had some Coleman lantern fuel in the trunk. I used a quart to make it to the gas station, and as Bill said that engine sounded like a popcorn machine on steroids.

My 28 Phaeton had a very bad pinging problem with the slightest push of the gas pedal. This was on a completely stock engine, and with proper timing. I finally learned that it was caused by just and crud packed into the rear of the cooling chamber, which caused a hot spot on the cylinder. This was a good lesson to remove the head on an unknown engine and make sure it's clean inside. The engine had newer green paint and looked clean on the outside, so I pulled the pan to check for sludge and checked the bearings for play. It was good, so I just assumed the cooling system was also clean. BIG mistake!
 
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