Bill is the man on Ignition :mrgreen:
Right back atcha!
IMHO, the first thing to fix is ignition, not jetting, air correctors or emulsion tubes. You can fiddle with fuel pressure, jets, correctors and there is some excellent work one can do on well (emulsion) tubes, but when something as simple as a secondary arm touching the manifold adaptor, or a manifold vaccum or ported vac line to the distributor, or worse, grit and shEat in the fuel system can lean out a carb under wide open throttle, you can be constantly moving back and forth. The gas leal by propane method can help set base idle, and the base idle still has the secondary barrel activated in the US Holley Weber 5200. The West Germans tuned the 2.8 2-bbl carb to suit the 104 hp 170 engine, and the way it is now is lilely to be very close.
The game changer is IMHO, the ignItion and plug heats. They change idle, transition and tip in.
When 15, I helped and Ex Ford Ford Service techncian Alan Ireland, and he said do air fuel last. Fix the ignition detail first.
I guess I have seen many of the works that are done under the sun, and a lot of intial air fuel stuff is vanity and a chasing after wind.
I'm saying don't do any other major work on the jetting first. Don't be that guy, and don't be "Putting the Cart Before the Horse "
Circumstances alter cases
Phil Irving, Australian WWII engineering techncian reponsible for the Vincent V twin Motor Bike engine, the Formula One Repco Brahbam RB620 2.5 Liter V8, and Holden Grey Repco Power head and the later Red engine PI 12 port Heron and then modified Hero Yella Terra Repco Six cylinder Cylinder head developer.
https://en.wikipedia.org/wiki/Phil_Irving.
In Tunning for Speed he goes through the Weber and every other dag gam carb ever made till 1960 with eleborate jetting process,
always after the recomended Ignition ramps are put into place first.
Check
161henry's 3 page work ethic (epic?) work with the Triple YFA Carter 300 big six powered Rat Rod.
First thing to work on is the basics
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161henry":2rofjcde said:
Well sometimes it’s the simple things. Keep in mind I realize I need to recurve the DS2. And I have some metering rod work to do. But, I have the manual ford fuel pump with the fuel filter on it. I also installed an inline filter because the tank I used had sat a long time. I cleaned it the best I could. I noticed a leak at the inline filter so I popped it out and it was full of rusty red stuff. I replaced it and the AFR looks a lot better. I’ll look into the filter on the pump next. I ordered a fuel pressure gauge yesterday and I have a 35 gph pump in the garage if I need it. I’m guessing part of the reason I’m going lean at first is because my homemade intake has to much volume? And it takes a bit to get enough air pulling through the cards to draw fuel?? If I would have taken a stock intake and welded two pipes and flanges on it that would have been better for low end torque? Let me know if my thinking is sound or not.
Thanks
Warren
viewtopic.php?f=2&t=78286&start=100
161henry":2rofjcde said:
Last night I had some time and I installed the lightest advance springs the kit had. I used the weights that came with the HEI distributor and now I have 20 degrees advance just off idle with max of about 32 degrees. Before when I’d step on the gas you could feel the engine lag. When the timing finally came in it felt like a set of secondaries opened up on a property tuned engine. I still have metering rod work to do but it’s a ton better than it was. Why would a recurve kit come with weights that are smaller and lighter than stock?
And this is how it goes. If you want to undo all the work you do focusing on jetting the carb, I'll tell you how to profile the emulsion tubes to fatten or lean out the air fuel ratio anywhere you like.
But the cold running verses warm running "feel" and the subtle variances in air fuel ratio are due to ignition.
Once you fix the ignition, you then will have to rework your air fuel ratios to suit.
Go back to
cr_bobcat's ignition mapping of the distributor advance back in 2016 or so.
Jetting is based on having a good ignition advance curve, and the right plug heat range.
