[T3] Clemmie's Invasion MPG, Joys & Troubles

[Phil Hof]

Well, there are mixed results from the Invasion, overall good but with some issues.  Clementine got me home safe and sound, but I had to nurse her home.  Successes include drivability, mileage, and FUN!  Negatives include overheating, brake lights, and grouchy second gear.  Specifics:

She drove well and accelerated nicely, especially on the hills and through Sedona.  What a beautiful and satisfying drive in our cars!  That’s what the Type 3 was made for:  moderate speeds, dips and rises, and plenty of curves.  A blast!

Mileage on the 1000 mile trip averaged 32.1 on 91 octane premium (10% ethanol).  This is excellent and reminiscent of when she was brand new.  To recap:  rebuilt motor, 1776, slightly increased compression (have to check the build sheet but I think the low 8s range), and larger Mercedes injectors.  I also fitted an LM-2 A/F gauge and have been tuning the MPS over the last couple of months, mainly leaning it out for better drivability.  Readings are in the low 13s on cruise, occasional 14s on very light load and throttle, and high 10s/low 11s for a split second when stabbing the pedal, moving into the 12s under max load.  I think I have it just right.  The MPG says it’s plenty lean, and the gauge says it isn’t overly lean.  Around town I have been getting low to mid-20s.

One interesting characteristic I noted was the effect of altitude.  On a carb car, the less dense air will enrichen the mixture, lowering power.  But the D-jet MPS has an aneroid that leans it out as you climb.  I found it was a little aggressive, pushing cruise slightly above 14 at the 7000 ft level, especially in the heat.  Theoretically 14.7 is best but without a closed loop system, I won’t go that lean.  If I were to drive a lot at high altitude I might want to richen it up a tad, but since I live around 1000 ft and local passes are only about 4000, I’ll leave it as-is.

Now for her problems.  I had installed an oil temp gauge, and I doubt it is accurate.  I will pick up a cheap IR thermometer tomorrow and check it out over the next few weeks.  On the highway near home, she ran an indicated 240 once fully warmed up.  This is only a bit high, and she didn’t "feel” hot, either driving, or with a hand on the oil filler or hovering over the motor.  Maybe this sensor and gauge are not quite matched?  I didn’t worry.

But on the drive through the 100 degree desert, she ran about 260-275 even though I kept her only at about 60 mph.  Speed and temp correlated, so I took it easy.  So far no problem.

On the way home, temps were 118 in the Palm Springs area, and the oil temp rose.  I kept her to 50 mph up to that point, and she stayed at 275-280.  Then came the long slow climb up through Beaumont Pass and indicated oil temps climbed to 280-290, so I slowed to 50 mph.  That slowed the rise in temps but when was pushed up the grade I heard pinging/detonation, and slowed and then stopped at the close-by rest stop.  Now she felt hot so I rested for about 45 mins.  I promised her a full checkout and whatever she needed once she got me home. Oil cooler, avgas, whatever… just get me home dear and you get your way!  She came through at 50mph and the cooler (still 100) temps were good for stable temps in the 270-280 range, and she made it home without any more stops.  Whew!

Back a couple of days to the timing story… once in Prescott I checked the timing and had to reset it… thoughtlessly I didn’t check the dwell/point gap, I just reset the idle timing.  Later it had slipped again the other direction, and I again reset the timing.  I figured my distributor may be worn and made a note to check things when I get home.  Spin forward to this morning at home, and my point gap was about half what it should be.  Doh!  I reset the points and timing, and will fire her up tomorrow.  That may have been the source of the pinging and hard-working, driving up temps.  I’ll be checking on her regularly for this over the next months.  Just in case, I’ll get my spare (unknown condition) distributor rebuild like new and put that in when done, just to eliminate timing asa source of heat.

Okay… other issues I need to tend to.  I don’t now when, but I lost both brake lights.  Fuses and bulbs good, so i figured brake light switches.  Nope, they have continuity when the pedal is pressed.  I’ll check more thoroughly for resistance or voltage drop.  Oddly, when checking voltage at the 3-tab connector in the frunk, I get 12V on the hot wire; on the return wire I get the proper 0V until pressed, but only 1-2 volts when pressed!  Maybe the switches are corroded and can’t pass current well?  I am using DOT5 but it is over 5 years old and I’ll be flushing it as part of this spa treatment.  I have a couple of spare FTE switches in case.

Lastly, when really hot, I found I got a very bad grind when trying to shift from 1st to 2nd.  It happened about 1/3 of the time: I got a premonition when putting it in first… something not feeling right, and that correlated with the grinding upshift.  To save syncros and gears, I would shift from 1st to 3rd when that happened.  Now home, I checked the tranny oil, and the darn thing was overfilled by almost a cup!  I have been negligent and haven’t checked it for years (my excuse is that it doesn’t leak and I only drive about 1000 miles a year), so it’s never been checked since rebuilt and refilled by the shop.  I expected it to be low, but no-sir-ee!  I have now drained it and will refill tomorrow.  No chunks, just the expected few brass particles and iron filings stuck to the drain plug magnet.  I’ll check the coupler, bushing, and shift plate adjustments to try to find out why it would grind, and if it still does.  Weird.

Oil change and valve adjustment round out the post-driver tune-up.  Valves were good, just one tight and one loose.  Oil was not smelling burnt, and was not awfully dark.  In fact, it didn’t smell at ALL, so I suspect I boiled off additives that give it the usual new oil stink, so it’s good it’s changed.  30wt Valvoline VR1, about 3-1/2 quarts including that put into a new filter cartridge.

More tomorrow, but all-told, I am happy with her.  She drove in record heat and climbs, no hard failures to strand me, and she got me home.  Now I’m keeping my end of the bargain and cleaning her up, inside and out.

Great to see many of the folks here and on the Samba.  I wish it were another day or two so I could get to know you better.  I won’t drive her to Alabama in two years, but I may fly there to visit friends in Decatur and attend for the day.  Looking forward to it!

Thanks for listening!
-Phil
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