Revisiting my post a couple of days ago about how my 289 runs fantastic as long as I don't try to wind it out in first or second. As far as winding it out in third...I'll refer you do yesterday's post by DaveOxide, and just say, I pretty much learned that lesson a long time ago. /forums/images/icons/wink.gif It revs freely in N as well, under no load.
Anyway I digress. [color:blue]A clue! A clue!</font color=blue>
Is that a blue paw print on the distributor cap???
289. 10.0:1 Comp XE262H Cam. Stock distributor with Petronix. Big cap. Ford Racing plug wires. Ford Motorsport 40KV Coil.
Last night I tried taking off the "restrictive" hypo air cleaner. Didn't make a bit of difference.
Next I took another look at the engine. Hmmm Distiributor might be a little loose. Better check my timing.
I unhooked my vacuum advance and started it (idle dropped to about 500 RPM with no vacuum advance). Timing light shows about 9 degrees before TDC. About what I thought. I reved it up and I'd say total timing jumped to around 24 degrees at maybe 3000 (complete guess. My cheapy, $35, Walmart Special, inductive timing light doesn't have a tach). Then, advancing the throttle farther I got a possible clue. While the timing held steady, the pulses from the timing light became sporadic. I couldn't really hear a miss, but the either it was missing, or the timing light won't work properly above 4000 rpm or so.
Next up I checked total timing with the vacuum advance hooked up. It was more...say 6 to 10 degrees more. I'm just guestimating based on the 12 degree mark on the balancer, so I can't be really precise.
So, I took it for a drive with the vacuum port plugged (Holley 4160...vacuum port on the passenger side, front, near the primary sight glass). Maybe it reved a little further...Say to 5000 (instead of 4800) before it just wouldn't rev any more.
I guess I'm thinking the spark is beginning to drop out above 4000RPM, and the condition worsens above that. I'm also wondering if I'm even getting a true reading of engine RPM off of my tach at high rpm. I mean, doesn't the tach "count" ignition pulses? If I'm loosing 10% of my pulses at 5000 RPM, wouldn't the tach read 4500, regardless of engine speed?
Also, on the Petronix. I know there's been plenty of posts on the way it should be hooked up. It's been 4 years since I hooked mine up and I'd guess I probably went with whatever was easiest. Could improper hook up allow it to work, but cause it to get futzy at higher rpm? Or, do cheapy timing lights just not work at that high of revs, meaning [color:blue] my clue</font color=blue> is actually just a [color:red] red herring </font color=red>?