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Advice on timing on this street cruiser with a heavy foot

Jc cooper

Second gear fun!
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What initial mechanical and vacuum advance timing with FBO distributor and control box , on a 67 440 hp engine , 915 heads , flat top JE’s , maybe 10to one , and a custom grind bullet solid flat tapper 502 lift , 237 int 241 ext duration timing all in at 3800 rpm , would you guys suggest!
 
What's your timing now and how's it run?

I say throw all the timing at it that it will take. If it's pinging back it off.
 
I’m not sure how typical it is but the stock 440 in my 67 (actually a 68 440) won’t take more than about 33 - 34 degree total timing max without pinging. I used an FBO advance limiter to cut centrifugal back to 17/18 degrees and set base timing at 16 degrees and it runs strong. I have vacuum advance hooked up to manifold vacuum mostly because with auto & factory AC I try to keep as strong an idle as possible and as much timing in as I can to keep the coolant temps down.
 
I’m not sure how typical it is but the stock 440 in my 67 (actually a 68 440) won’t take more than about 33 - 34 degree total timing max without pinging. I used an FBO advance limiter to cut centrifugal back to 17/18 degrees and set base timing at 16 degrees and it runs strong. I have vacuum advance hooked up to manifold vacuum mostly because with auto & factory AC I try to keep as strong an idle as possible and as much timing in as I can to keep the coolant temps down.
What's your cranking pressure/compression ratio? Cranking pressure tells a lot.....
 
I’ve never run a compression test on it - too afraid to. Stock pistons, cam, intake, etc. but the inside of the engine looks like hell with carbon, scratches in the walls, piston edges chipped (probably from detonation/pinging). But it’s a testimony to how tough these engines are as it doesn’t smoke, uses no oil and pulls strong.
 
No expert on when all timing should be in but 3800rpm seems late.
 
Those 915 heads might make the compression higher than 10 to 1

34 degrees with the distributor vacuum hose disconnected.
 
Those 915 heads might make the compression higher than 10 to 1

34 degrees with the distributor vacuum hose disconnected.
I have a 440 with closed chambered heads that is 10.3-1.......with comp gaskets.....
 
92 octane pump premium on the street? 16 at idle, 32 total with vac adv plugged, then hook up vac adv to full time vac and try it going up a hill and listen for ping.
 
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