After a long race weekend, the Wagon deserved a little servicing. I put almost four hours of race pace on it, that must be equivalent to at least a few thousand freeway miles, so My Lil’ Red Wagon got the Platinum Service. Motor/trans/diff oils changed, catch cans emptied, steering/brakes/wheels/tires inspected, bolts checked all around (yep, I found a couple loose ones), cylinder head retorqued, spark plugs checked, valves adjusted, and a leak down test performed. The engine short block I bought from a fellow racer had one previous race weekend on it, and the top end is fresh, so I was hoping for some pretty good numbers. Using 100 psi for the test, cylinders 1 and 4 looked great at 2 and 3% leak down, while cylinders 2 and 3 tested at 5 and 6%. A little higher than expected, but certainly within limits. I’ll keep track of the numbers for several tests and look for any trends. I had one motor that actually got better for its first three weekends, before it plateaued and then slowly deteriorated. One advantage of the leak down test is being able to find out where the leak is occurring. If you hear the air hissing at the exhaust pipe, you’ve got an exhaust valve leaking. If its through the carb, the intake valve is leaking. And if you hear it through the crankcase breather line, the leak is around the piston rings. At this point, I’m hearing just a little bit at all three. (You can find this post-race service list on my Racing Checklists page). More leak down info here.
During the Saturday and Sunday afternoon races, the oil temp was running a bit warmer than I liked, so I’m working on some remedies. First, I opened up the air inlet for the oil cooler. I had placed the cooler behind the OE headlight opening thinking it might be sufficient at 4.5″ x 8.5″, or about 38 square inches. Now I’ve opened the hole up to about the size of the cooler, 5.5″ x 10″, which ends up being 30% larger. Amazing how much difference just an inch or two makes. then I added some deflectors to better channel the air into the cooler. We’ll check the difference out at a track day planned in a couple of weeks.