Thread: Ford 347 Total Timing
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11-14-2010 06:21 AM #1
Ford 347 Total Timing
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.Roger
Enjoy the little things in life, and you may look back one day and realize that they were really the BIG things.
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11-14-2010 07:27 AM #2
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!!!!Yesterday is history, tomorrow is a mystery, Live for Today!
Carroll Shelby
Learning must be difficult for those who already know it all!!!!
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11-14-2010 08:03 AM #3
Originally Posted by pat mccarthyOriginally Posted by jerry clayton
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.Last edited by rspears; 11-14-2010 at 08:13 AM.
Roger
Enjoy the little things in life, and you may look back one day and realize that they were really the BIG things.
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11-14-2010 07:28 AM #4
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 muchIrish Diplomacy ..the ability to tell someone to go to Hell ,,So that they will look forward to to the trip
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11-14-2010 07:58 AM #5
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 ???
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11-14-2010 08:19 AM #6
Ford racing recomends 34 to 36 for their 347 crate engines.
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11-14-2010 08:42 AM #7
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--------
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11-14-2010 11:30 AM #8
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11-14-2010 12:10 PM #9
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
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11-14-2010 01:07 PM #10
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.Roger
Enjoy the little things in life, and you may look back one day and realize that they were really the BIG things.
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11-14-2010 03:05 PM #11
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
Welcome to CHR. I think that you need to hook up your vacuum advance. At part throttle when cruising you have less air and fuel in each cylinder, and the air-fuel mixture is not as densely packed...
MSD 8360 distributor vacuum advance