Final adjustments and closing project
It has been some weeks since last update of my Corvette blog. I have done about 160 km (100 miles) by now since motor was back in car. I have also been two weeks in US on vacation. The final tune and last parts bought took some days to get - so two weeks vacation in US was the right thing to do ;-)
As part of transmission overhaul I also installed an external gear oil cooler which was installed "after" the internal gear oil cooler in radiator. In one of my testruns I blew one of the cooler hoses and sprayed a couple of litres of transmission oil on the street. End of that story was going home by rescue car and dumped the external cooler. Bought another external gear oil cooler with termostat and fan. The new external cooler bypass the internal gear oil cooler.
After the first start of engine (including a couple of start/stop to get enough transmission fluid into the transmission and checking for any leaks of fluid) I ran the engine in garage for about 20 minutes in 2000 rpm. This procedure is part of seating the piston rings properly. After that I drove the car carefully and accelerated and deaccelerated (by engine breaking) about 10 times also as part of seating the pistons rings. Now I am driving the car normally - using the gears but not "abusing" the engine - for breaking in. Changed oil once (using standard 10-30W mineral oil) and oil filter twice. Next oil and filter change is after break in period. Then I will be using Mobil 1 fully synthetic oil.
Summarize last "adjustments":
- Got a new tune from PCM4less by e-mail and burned it myself by using tools from moates.net (cost burning tools about 100 USD).
- New green Bosch 42lbs/hr injectors from FIC (used his tool to calculate injector size based on crank HP).
- New gear oil cooler (Derale Performance 13720) with termostat and fan.
- Replaced in-tank fuel pump with new.
- Bypass throttle body coolant.
The external gear oil cooler replace complete the internal gear oil cooler in the radiator. The cooler is "big" and does not fit in an Corvette C4 engine bay. I have deleted the A/C system including removing the A/C condenser. That makes enough space for installing the new cooler in air intake for cooling air to radiator. The fan requires switched 12v power to operate (5 amp max). I have also deleted the AIS (air injection system) including air pump. I got the switched 12v power to the fan from the power to air pump. The power supply is 10 amp max (10 amp fuse).
Also part of testruns is engine logging by Datamaster. I got a new tune from PCM4less and both my wideband lamda and the histogram in Datamaster reported that the AFR in first tune from Alvin was somewhat lean. I have been e-mailing with Alvin at PCM4less and also John at FIC. Alvin also recommended buying some chips and HW for burning chips from moates.net. And so I did. From FIC I got new Bosch green 42 lbs/hr injectors (see picture below) and I got a new tune from Alvin by e-mail. Before getting the last tune by e-mail I used his new order sheet and answered a lot of question about my build.
Yesterday I did another Datamaster logging and the fuel trim is spot on. The engine is idling OK, the AFR in crusing and some throttle (still kind of careful because of breaking ing engine - does not rev engine above 4K rpm) is OK. The DM log is sent to Alvin for last verification. The plan now is to do a couple of longer trips to complete the break in of motor.