I’ll take a cue from Dave and start a new thread with this one.  The basis for this thread originally started in the roller versus link timing chain thread.  Here’s the link to the original thread.

http://forums.y-blocksforever.com/Topic24405.aspx

The oil pump is a major source for the spark scatter phenomenon as pressure pulses from the oil pump are transmitted directly back to the distributor via the intermediate drive shaft.  I’ve either completely eliminated or at least minimized the spark scatter on various engines by either using dry sump oil systems or isolating the distributor from the oil pump itself either through crank trigger ignitions or by relocating the distributor.  Another item that helps to reduce the spark scatter is to use a heavier than stock intermediate oil drive shaft and for the Y, that would be the ARP #154-7906 intermediate oil shaft.

 

For a racing Y, a crank trigger ignition does the trick and that’s what was used on Randy Gummelt’s Y powered dragster.  But this did require a 10° retard system for starting purposes.  Here’s a picture of a 390 FE Ford engine with a relocated distributor just for the purpose of isolating the distributor from the oil pump without using a dry sump system.  This particular distributor still utilizes a full curve so starting with any kind of high compression is not an issue.

And the link to the larger picture.  390 Ford with relocated distributor 

 

The style of the oil pump is also a consideration in regards to spark scatter.  Testing with various oil pumps and oil pump pickup designs shows that the gerotor style of oil pumps with an oversized inlet tube has an inherit advantage over some of the other styles in regards to minimizing ‘ignition spark scatter’ in the upper rpm ranges.  Spark scatter is much more pronounced or prevalent when using a spur gear oil pump with minimal oil pickup tube sizing.  I’ll add that any form of cavitation at the oil pump increases the propensity for spark scatter at the distributor.

Lorena, Texas (South of Waco)

Whew, Ted!  That's an awful lot of engineering, expense, and machining!  I love the idea that you divorced the oil pump surges, but the valve train surges too.

Just a few thoughts:
(Now that we have hindsight and modern technology) it sure is easy to run a 1/2"  diameter inductive pickup off the crank or cam.  Rock-steady spark drift, but now we're talking more engine electronics.

I love how Harley-Davidson and Romeo engine have done their ignitions without using a distributor (H-D since ~1980).  When the crank pickup calls for spark, they bang a coil that fires two opposing cylinders simultaneously, one is on it's power stroke while the other is on it's exhaust stroke.  No moving parts.  Lincolns had it since '88.

Seems everything nowdays is run by electric motors.  Radiator cooling fans have two speeds, we have electric water pumps (it's about time) and electric fuel pumps.  Nothing prevents us from powering oil pumps from electric motors.  They can be mounted anywhere and they can produce oil pressure before cranking (like fuel tank pumps).

I would love to see a Y-Block with EFI.  Many more ponies would unleash just by maintaining 14.7:1 air/fuel ratio every time it runs regardless of humidity, temp, altitude, etc.  When they fitted the Jeep 4.0, it woke right up.

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

Ted, thanks for sharing the information about the gerotor vs. spur gear oil pumps and the oversize pickup tubes. I wonder what effect the oil pressure by-pass spring has on spark scatter. I would suppose that a higher value for by-pass would produce more spark scatter.



But this is all academic for me. I don't expect to be racing anytime soon, if ever.



Speaking of timing accuracy, I wonder why the ignition pickup is done off of the front of the engine instead of off of the flywheel. Seems like you could get super accurate timing if you used tits on the back of the flywheel instead of some kind of reluctor wheel thingie on the damper end. And you would avoid issues of crank twist. It would be protected from the elements instead of being front and center in a tornado of flying parts.



I suppose there's a good reason for using the front of the engine.

Best regards,



Paul Menten

Meridian, Idaho

The electronics uses high-speed counters off of a 'star-wheel' arrangement.  If the wheel were as big in diameter as a flywheel doing 4-5k RPM, the tit would pass by so fast, the electronics would miss it (or the tit would have to be real long).

Ford uses a 'star' with a space, so the Electronic Engine Controller determines where #1 spark is.  The pickup reads:
dit....dit....dit....dit.(space).dit....dit....dit....dit.(space).dit....dit....dit....dit.(space).dit-etc.  Remember, Ford fires two spark plugs simultaneously, then the next pair, the next pair, the last pair, then back to the beginning.

In addition with all the other inputs (O2, ExhaustGas, Throttle Position Sensor, knock, Temp, etc.), EEC determines spark timing and fuel injector pulse-width.  It sounds very technical, but really it's not.  Once you start working with it, just about everything can be checked with a simple volt meter.

End result is, your engine doesn't have "sweet" days because every day it reliably runs great.  I see modern engines as being EXACTLY the same as old ones (same crank, pistons, cam) except the timing and fuel delivery is refined to always hit that elusive 14.7:1 air-to-fuel ratio, which produces optimum HP.  I see fewer cars stranded on the side of the road today, than when I was a kid.  - Dave

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected