Advice on timing on this street cruiser with a heavy foot

[Jc cooper]

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!

 

[khryslerkid]

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.

 

[dadsbee]

Yep.. turn it, rev it and drive it.

 

[Cranky]

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.

Problem is with us old farts, we can't hear the pinging anymore!!

 

[Cranky]

Yep.. turn it, rev it and drive it.

See above.....

 

[AR67GTX]

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.

 

[Cranky]

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.....

 

[AR67GTX]

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.

 

[Fran Blacker]

No expert on when all timing should be in but 3800rpm seems late.

 

[Cranky]

No expert on when all timing should be in but 3800rpm seems late.

Generally I like my total to be all in well before 3800.....

 

[Orig69]

Those 915 heads might make the compression higher than 10 to 1

34 degrees with the distributor vacuum hose disconnected.

 

[Cranky]

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.....

 

[Outsider]

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.