Re: TR, would you hold my hand?
I don't know about all that hand holding stuff....
I'm pretty much a homo-phob and proud of it!
Helping tune your vehicle is about as far as I'm willing to go!! [img]images/icons/tongue.gif[/img]
*Timing set to 8* BTDC @ 1600 rpm w/vac advance isolated.*
*93 octane gas.*
1,600 RPM is a little high for an idle, don't you think?
With manual trans, you should be doing about 700 RPM for a curb idle.
Somewhere between 8 and 12 degrees BTDC is where I'd start and sneak up on all the timing I could before detonation.
Have you tried it with cheaper gas? No need to buy that expensive stuff if you can do just as well with 89 octane...
*turns roughly 2600 @ 55mph*
*cruise at 2500-3200(50-85mph) *
Sounds like you aren't doing too bad on the final drive ratios.
You aren't working the engine to death, although I'd limit my extended runs above 3,000 RPM with stock cast iron connecting rods...
You should be safe to 4,000 to 4,500 with cast iron rods as long as you don't shock load the engine while you are up there. (IE: Don't rev it up and side step the clutch to do burnouts!)
*Not much more throttle dropped it to below 5"(2.5-4").*
Sounds like you need a 5 or 5.5 power valve opening also.
Doesn't the 2100 have a two stage power valve? I'm not too familiar with farm truck carbs, but I seem to remember doing one a few years back that had a two stage power valve....
*also, do you know offhand if holley jets are compatible with the motorcraft? I have yet to dig for the jets in the carb. *
The Motorcraft carbs that Holley built, the jets interchange, so will power valves, but I have NO IDEA what the Motorcraft part numbers mean when it comes to size...
*how reliable is an autometer ratio gauge?*
What is a 'Ratio Gauge'?
Do you mean a fuel ratio gauge, like an O2 sensor connected to a display head in the passenger compartment, or do you mean a vacuum gauge?
If I'm getting this correctly, you have the rich/ lean indicator, and you are wondering why you can't make it go into the rich area...
Here is a way, turn your idle mixture screws out some, but make sure you remember how much so you can put them back.
Also, you can jet the carb up, or close the choke blades most of the way while the engine is warm.
Both should affect the fuel/air mixture to the rich side...
*I could not get it to read into the rich zone, even with repetitive goosings of the accelerator pump.*
The O2 sensor doesn't respond fast enough to read that very short time the accelerator pump shot lasts, and besides, with the throttle blades opening at the same time, you may never get much past balanced fuel/air ratio.
You have to remember, you are dealing with a carb that is set up to be very conservative, and to run on an engine that has to pass emissions standards. It's not like you have a racing only Holley right out of the box (IE: Jetted rich as hell).
It's going to be pretty close to 14.7 no matter what you do right now...
If you want to mess with the accelerator pump shot, (larger pump, larger discharge nozzles, longer discharge time, ect) you may see some rich side swings...
Sounds like your carb is pretty close to correct now, no detonation, no over lean, no over rich...
*Now for an unexpected twist: I am completely anosmic. I cannot smell the difference between gasoline and 90W gear oil. I don't have the ability to just smell if the carb is rich, and so lack that baseline for tuning.*
That sucks man! One of the greatest joys in life is the smell of burning rubber and sweet gas!
No matter what you have been told by the 'Old Mechanic Squad', you don't tune with your nose, you watch the plugs, and listen for detonation or lean misfire.
*question #3: I cannot hear detonation in this new engine even with the advance turned way up.(I haven't tried to make it ping, but with all the fiddling haven't found it.) I have, however, found many misses in the tuning of system. should I assume that these misses are detonation, due either to a lean mix or timing advance?*
There are a lot of reasons for misfires and dead misses...
Lean fuel mixture is one of them, so is improper rotor phasing when you turn the timing way up.
There is a long laundry list of things that cause misses....
cap, rotor, coil, coil wire, plug wires, pickup coil, spark plug(s), module (especially if you have the stock one), and about a dozen or so wiring connectors that like to turn to green crap when no one is looking...
We can also include...
Rotor phasing, spark scatter, cross fire, multi-fire, ground fire, false triggers, ect...
All you can do is go back over the basics and use quality parts.
All in all I'd say you don't have too much of a problem.
You may want to richen up a little on the bottom end, and I'd give it about 12 degrees of initial timing (vacuum advance unhooked and carb line plugged).
I'd look into maybe being happy with the fact it runs pretty well (I know a crap load of 258 guys that would kill to run 85 MPH even down a mountain!) and only needs minor tuning.
Throw me some pretty close pictures of your engine bay, ignition system and carb, and I'll see if anything catches my eye...