Bob & CSCameron,
I'm running 20w-50 VR1 Valvoline. I may try something thinner, but wanted to see how the motor ran first. I chose the thick stuff for a bit of safety margin. I may go thinner next oil change.
As far as runs here's what we did, not perfect, but a first cut:
4th Gear, 20-60 MPH, 6.7s timed run. With 4:89's this should yield a run from ~1000 RPM to 3000 RPM. The plan was to get 300 RPM/s for consistency. This is the typical rate of acceleration we run on street cars. I found that the truck is not capable of 300 RPM/s... It's hard to look at data and teach at the same time! Ooops!
Our runs timed out prior to reaching 3000 RPM, but I don't think that's too big a deal. The power curve at that point was pretty flat. We'll adjust things tomorrow.
Peak torque was typically about 1500 RPM, peak power 2600 RPM (timed out, but pretty flat curve).
As far as the governor, when we started it was not doing any governing at speeds I saw! The engine would rev to 3400 RPM and I suspect higher. I adjusted it to stop the party at a tick over 3000 RPM. I want to play with it a bit tomorrow if I have time. Seems to work OK now, but when I drive into it in 4th I can drive through it. It does not do this in the lower gears. Not sure what's up here, may be the test method. I've adjusted it according to the Carter manual and it works fine if tested according to that, but they don't have a test for 4th at top speed with light load.
Once I get everything sorted and consistent I'll try and post the curves. I'm not sure how much "tuning" there is to be done. I'm going to try some timing sweeps and maybe pull the air cleaner. The AFR is pretty damn good for a carb that we haven't touched and still has some safety wire on it. It's in the 12's at max torque and leans out a bit to the 13's at max hp. I don't have any jets so my tuning will be limited. I guess I could monkey with float level... I will say I have not seen it run leaner that 14, even at light loads. Maybe there's some MPG to be had
. Then again I don't think it ever runs at light loads...
Like I said, if anyone has some ideas post 'em!
Andy
Home
.
