Thread: Ford 347 Total Timing

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My SBF 347 stroker is running 10.3/1 compression with a Comp Cam w/valve timing @ .050 intake 4btdc/40abdc; exhaust 51bbdc/-1atdc installed @ 108.o intake centerline and duration @ .050 intake 224, exhaust 230, lobe separation 112.0. On the chassis dyno we were getting a bit of high rpm "flutter" and the total timing was 28degrees. Bumped it to 36 degrees and smoothed out. My tuner was hesitant to go as high as 36 degrees, and the plugs after that run had the heat mark well around the bend toward the base of the electrode which seemed to point to the timing being about right. On some SBF forums I have seen total timing as high as 40 degrees, but they also had a bit more cam. Any thoughts on where my total timing should land based on my specs?? Just back checking my tuner's thoughts this morning.

Usually on the small blocks I've had 32 to 36 was where they made the best power.... On the track with race gas or alcohol gone higher, but not on the street with that dubious stuff we get at a gas station!!!!

was damper check at TDC with the head off ? if so 1 to 2 you could be off ez as for timming it takes what it needs so 36 is not much

You probably just need a colder heat range plug---

Since the ignition fires with the valves closed, ignition timing and valve timing are not related!!!!

You didn't use race gas in it for the dyno ???

Originally Posted by Dave Severson

Usually on the small blocks I've had 32 to 36 was where they made the best power.... On the track with race gas or alcohol gone higher, but not on the street with that dubious stuff we get at a gas station!!!!

Originally Posted by pat mccarthy

was damper check at TDC with the head off ? if so 1 to 2 you could be off ez as for timming it takes what it needs so 36 is not much

Originally Posted by jerry clayton

You probably just need a colder heat range plug---

Since the ignition fires with the valves closed, ignition timing and valve timing are not related!!!!

You didn't use race gas in it for the dyno ???

Dave,
Thanks for the input - thought I was OK at 36 but just wondered. Had seen on some Mustang forums kids talking about 40 degrees, but running pump gas, even what they call 91 octane, is a bit questionable today.

Pat,
Yes, the damper was verified at the machine shop and TDC "0" marked with red paint to keep me straight.

Jerry,
Good point on the heat range. No, we did the dyno runs on the same gas it will run on the street, 91 octane pump gas. May not be right, but that's what we did.

Ford racing recomends 34 to 36 for their 347 crate engines.

Roger

Yep you did the gas gig good (triple ggg)

We go to tune cars and about 1 out of ten will have put race gas in and then you can't get the fuel flow out of the injectors you need or sometimes they have leaded race gas and cats--------

Originally Posted by jerry clayton

Roger

Yep you did the gas gig good (triple ggg)

We go to tune cars and about 1 out of ten will have put race gas in and then you can't get the fuel flow out of the injectors you need or sometimes they have leaded race gas and cats--------

Sometimes even a blind pig finds the pearl in the slop....

Roger, on a side note, how quiet (or noisy) is your stroker........I'm referring to clicking like valve adjustment noise? My 331 is noisy as h***, less when warmed up, but still there. With open headers I didn't notice it but as soon as I installed the quiet exhaust I can hear it pretty good. Just curious what another one is like.

Don

Originally Posted by Itoldyouso

Roger, on a side note, how quiet (or noisy) is your stroker........I'm referring to clicking like valve adjustment noise? My 331 is noisy as h***, less when warmed up, but still there. With open headers I didn't notice it but as soon as I installed the quiet exhaust I can hear it pretty good. Just curious what another one is like.

Don

Don, I've noticed the same thing! Nothing worrisome, but a definite "click" like the old solid lifters but with rollers. My lakes headers are significantly quieter now with a combo of SS wool and dense fiberglass packing but are still right at the leading edge of the door, creating a medium loud rumble at cruise (2000rpm) and I can hear the "click" of the engine over the exhaust. I imagine if I ran it through some Hushpowers or MagnaFlow's it would be even more noticable.

That's comforting, Roger. I have spoken to Scat and they say some strokers are noisy and some aren't. Something to do with the short pistons rocking at the end of their stroke. I figure I'll just uncap the headers and not worry about it.........oil pressure and all looks fine. Or, I may just lie and tell people I have a solid lifter cam in there and it is set up on the loose side.

I've reset the roller rockers 3 times and if I go any tighter the engine runs badly. It pulls like gangbusters, so it must be running ok. Bet you love the 347 a lot.

Don

Yeah, Don, the 347 pulls like crazy - torque curve is nearly flat from 2100 to 4500, then falls off slightly to cross the HP line at 5500. With a light car (have not weighed it yet) it is a blast to drive - more power than I have ever owned before, bar none. My 5th gear OD (0.64) lugs down quite a bit below 60mph, but then in 5th it really wants to cruise at about 80mph or so