And we're back online. I decided to replace my oil pump while I had the beast apart. I had 10 PSI per 1000 RPM at operating temps with rotella 15w-40, so I was hoping a pump rebuild would get me back into a factory oil weight. I had a bunch of challanges getting the beast to work properly with the new oil pump, and long story short, I was putting the bypass plunger in backwards like a total idiot. Now that I've got that figured out, I'm running shell 5w-30 at 18 PSI idle at operating temps. I'll probably drop down to 5w-20 next oil change and see what that does.
I also have an obnoxious howl off my accessories, and I've replaced the alternator (needed to anyway) and the water pump (probably needed to) and it still howls. It must be a goofy V-belt
But anyway. I drove a good bit last night and today, and with the new jets (#58 mains), the lighter weight oil, and a direct drive flex fan, she's faster and stronger than ever! At first I had a really bad stumble at 700-1000 RPM, but only when I was cruising at those RPMs. It would blast out of the lul if I gave it more fuel, so I know it wasn't the accel pump or power valve, must've been a fuel delivery problem. Regardless, by the time I got home last night, that was all gone, and she gets off the line nice and strong, and doesn't bog at low RPMs. Also, with the current jetting, I smell regular exhaust fumes while I'm driving, not the fuel smell of running too rich. Even after doing a bunch of pretty good wheeling last night, I never smelt fuel once (except for when I flooded the carb up a steep hill). At this point, I believe my main jets are dialed in. Also, when I rebuilt the front end of the motor, I set the base timing at 13* advance, and that seemed to make a pretty big difference.
as I sit now...
I have a pretty darn good centrifugal advance curve (I don't think I can find the springs to make it any better, but I'll look)
I have a base timing of 13* (adjusted for an altitude of 5000 ft.)
I have my main jets as dialed as I can get without a lean rich indicator (which I've been considering buying or making)
I have my power valve dialed (but set 1.5 inHg lower than recommended for wheeling) and my accel pump dialed, and basically the whole carb dialed in (for a DD anyway, not race dialed)
I'm running cold while wheeling (event the very slow crawl high RPM stuff) and on the road.
I'm running great oil pressure on a factory oil grade. That will only get better once I use 5w-20.
This leaves two more things I need to focus on. The first is the vac advance tuning. The second is proper spark plug wire routing and organization, and proper ignition system grounding. Right now my wire are very close to eachother, and are draped over the valve covers. JeepHammer suggests that the wires be routed at least .5" (I think its .5" anyway) from eachother and from anything metal. Also, they shouldn't cross up as much as mine do. This can seriously debilitate your spark.
I will begin this last phase of my golden tune hopefully tonight or tomorrow, but first I need a vacuum pump. I saw that Matt had one in his I6 vid. It looked like the mighty vac one I've seen around. I'll look into getting one of those units. I'll have to wait until my next paycheck to get plug wires.
On second thought, To tune the vac advance, you turn it up a little and dive at PTC, then punch the throttle down sharp and feel for hesitation, I can do this without a vacuum pump (I've found out they are about $50). The vac pump just allows you to check how much advance is added to the curve for a given vacuum reading. Its basically so you can chart your curve, and I don't need that really. If I can figure out a way to make one for cheap, I'll get my curve put up.
Meanwhile. I will top her off today, and drive her around for a few days while I play with the vac advance, and report my gas mileage.
Without going into great detail, the article states that there is no motor oil currently available that protects your motor well on startup (they are all too thick/viscus). The first number (the one before the "w" on multigrade oil) represents how viscus the oil is cold (0 being the lest viscus). The second number represents how viscus the oil is at operating temp (again the lower the number the lower the viscosity). Since all oils are too thick on startup, the lower the viscostiy on startup, the better it protects and faster it reaches operating viscosity (hence 5w-20 since 0w-20 is racing only oil as far as i've found). Also, there is a sweet spot between pressure and flow that motors love, and that is usually 10 PSI per 1000 RPM. So since I'm at 18 PSI hot idle right now with 5w-30, when I change my oil next, 5w-20 should put me closer to 12 PSI. Thats where I'll get the best cold protection for the motor, and the sweet spot for pressure and flow. According to the article at least. And full synthetic is less viscus cold too.
Im not preaching anything, just sharing my reasoning
Only thing I'll argue about is the 10psi per 1000rpm thing. That was taken out of the mopar bible back in the 70's as a guideline for safe oil pressures for racing conditions.
Out of curiosity, what do you suggest. I unfortunately have no real backing in anything other than what other people say works, so I'm open to anybody's opinions on the matter. I've always run what my truck says to run, and it has pushed 40 PSI for 160,000 flawless miles, but that's all I know.