Is 40 too much?

trularin · #1 (**permalink**) 07-12-2009, 06:53 AM

After a rather long ( time wise ) period I have finally gotten a new CAM installed. The heads were refurbed and most of the valve train was replaced.

So I broke it in at 2200-2700 RPM for 40 minutes ( running the bloody fan all the time ) and then backed everything off to idle.

Anyway, I set the timing to 40 at full advance. Seems to idle and run okay. I cranked it a few times and it starts fine.

Is 40 too much? I normally like 36 to 38, but she seemed to want more as I was setting the timing.

Anyone want to throw in some advice or comments?

blykins · #2 (**permalink**) 07-12-2009, 06:58 AM

How did you know it was wanting more? Could you tell seat of the pants difference?

ERA Chas · #3 (**permalink**) 07-12-2009, 08:08 AM

If this is a 351, it's best at 28 -32. I've seen Windsors make 700HP at 30 deg.
The way it is it will be very sensitive to race gas and may not hot start.

zrayr · #4 (**permalink**) 07-12-2009, 08:49 AM

Stock 289 Hi-Po engines with a stock Ford dual point distributor (no vacuum advance) have 40 degrees BTDC timing at full advance w/ 12 degrees BTDC at idle.

That said, gasoline was formulated different back then. But I can still use those specs when running my Hi-Po 289 (stock 10:1 compression ) without the Vintage Paxton installed.

With the Paxton however I either have to dial back the full advance setting to 32 degrees, OR use a octane booster. Either method eliminates detonation (pinging).

Z. Ray