Topic: Lancia Butt race recap and troubleshooting
Here's what happened to us at Buttonwillow - it was a bit of a saga:
Arrived Friday AM and pretty much worked on it nonstop with lots of help from Chris Overzet and Spank.
Saturday 10:30AM - We are finally done with tech after fixing the kill switch wiring and some other stuff and ready to race. Driver #1 suits up and hits the track for one lap, comes in, everything looks ok, goes back out for 2 laps, coolant expansion tank cap (borrowed from Supertroopers...no worries, not your fault guys, and thanks for the generosity!) blows off in a giant cloud of steam on 2nd lap. Driver #1 pits with car overheating. Temps reached 300+ degrees on the head. What a wonderful and not-at-all-auspicious start for the Lemons Lancia!
Saturday noon - Borrow replacement expansion tank cap (from random team's Ford truck tow vehicle, again many thanks!) while other team member drives to parts store for new one, we get more water in it and bleed the air out again, Driver #1 does one lap and comes back in to report that everything seems ok, temps hanging out around 195, goes back out for 5 more laps and pits.
Saturday sometime in the afternoon - Driver #2 gets in car and does 5 laps of terror because mirror situation is terrible. We decide to stop driving to avoid crashing into someone. Another trip to parts store and rigged up an alternate bracket that allows us to affix mirror in much better position.
Saturday evening - install drivers and passenger side mirrors, change engine oil and transmission oil. Overall feel pretty great about the car actually running and hoping we are going to run well on Sunday with everyone getting at least 1 hour driving the car.
Sunday 9AM - Driver #3 drives for 45 minutes and comes in reporting the car doing ok, temps hanging out around 195, 10AM Driver #4 drives for ~30 minutes and comes in reporting the car doing ok, temps around 200, 10:45 Driver #5 (forgets to turn fan switch on!) drives for ~60 minutes and comes in reporting the car was fine for 45 minutes then started losing power. Temps were around 210-220. Eventually it lost all power and stalled. Got it restarted and had to crawl back on the dirt back to the pits. It would run and stumble but had no power. We start troubleshooting ignition issues and look inside distributor and check the plugs, finding nothing strange.
Sunday noon - Driver #1 goes out for 1 lap and pits reporting stumbling/hesitation/misfire (after right turns?) still there. We then take apart the carburetor to clean jets and examine float and fuel bowl for debris or anything strange, finding nothing. 1PM Driver #1 goes back out and does 3 laps then pits reporting same problem occurs, but not until 3rd lap. We play with fuel tank pickup thinking that would fix it. Driver #1 goes back out and pits again. I can hear hissing/sucking sound at carburetor, suspect air leak in there somewhere (maybe, but maybe not). We try cutting frayed bit off of fuel line at carburetor intake port (possible air leak). Doesn't help. Driver goes out and pits again reporting same problem. We keep messing with fuel cell thinking perhaps it's a pickup issue, reposition pickup tube a couple times, and put 6 gallons more gas in. Eventually Driver #2 (me) goes out and milks it around the track for 30 minutes until race ends noting that fuel starvation occurs after every hard right turn. I can minimize the fuel starvation by going through right turns at part throttle and pumping the gas pedal following those turns getting full fuel flow and full power to eventually return. Temps hanging out around 220 throughout the afternoon. It was a hot day so we're unsure if that temp is excessive or not.
Our diagnosis is that carburetor is fubar and we need a new one. Possibly temperature related? Maybe the automatic choke (water temp driven, but the water lines are capped off) is getting triggered or stuck once a certain temp is reached...but then why only following right turns? Some sort of air leak in one of the seals in the carb is one more leading theory. Maybe the fuel bowl empties on those right turns and it takes a little while to refill? Maybe there's a fuel boil thing going on and the right turns cause it by putting something hot in closer position to the fuel line somewhere? Or perhaps it's a vapor lock situation in the fuel cell or fuel lines?
Thoughts? For next race I'm leaning toward upgrading to slightly bigger and simpler carburetor and adding a high quality fuel pickup (Holley Hydramat?) and checking the fuel cell vent as well as all fittings on the fuel lines. Other than that I can't figure out why we get fuel starvation after right turns. Any ideas for how to fix this would be appreciated!
Captain of McDads/AFART Racing -1977 Lancia Scorpion (IOE Winner Sears Pointless 2021... wait, really?? YES, REALLY!!).
Captain of 42 Hours of MeLons (2013-14) - Vattenmelon Vagn 1984 Volvo 240, B-Class Winner: Arse-Freeze 2014