Day 3 at the Dyno: Murphy: 3.5 Home: 0.5
Wednesday, was a complete writeoff. We were convinced something was installed wrong on the motor to produce all this slack in the timing system, so a complete new timing kit arrived, and the parts were exactly the same as already on the engine, and the timing belt was the same length as the Gates I already had on there. So I spent the rest of the day driving around to all the Lexus dealers in Houston looking for a tensioner and an oil pump to compare dimensions. Didn't accomplish the square root of SFA.
Day 4 at the Dyno: Murphy: 3.5 Home: 3.5
We finally evened the score with Murphy yesterday and the motor ran!
First thing, we decided not to waste any more time trying to figure out "why" the timing system had so much slack, and just go ahead and fix the problem and get on to the next stage. I had thought we could shim the tensioner with a valve lash cap, since its shaft was just under 6.00mm diameter, however when we looked at the amount of shimming needed, it was more like 1/8" to 3/16", which we couldn't get with a valve lash cap. Then Dennis came up with the idea of using a set (grub) screw because of its hardness, so he chucked up a 3/8" set screw in his lathe and bored it to 6mm, and set the depth so we'd have around 3/16" of "shim". Here's a pic of the finished product - not too pretty, but effective:
Next I put the timing belt back on the motor, then cranked the engine without plugs just to see how it was working, and voila, it stayed in time finally. So that was one big problem out of the way!
Here's a pic showing the trigger wheel back where it ought to be. notice the missing tooth is bang on 6 o'clock, and the 5th tooth after the missing one is centered on the crank sensor:
So then I put the plugs & COP's back on and we cranked it for real, but it still wouldn't start, so at that point, since it was obvious the EDIS wasn't man enough to spark the 8 coils, I decided to pull my harness and COP's and go with the Ford coilpacks, so it would be a 100% EDIS system.
That took about an hour to pull off the old ignition, and wire up the new coilpacks, so by 1 PM, we were ready to try again, and bang, right on the first bump of the starter she fired up and ran! Oil pressure was good at 65-75 psi, but as soon as we turned on the circulation water to the dyno, we blew a coolant hose. Here's a video of the first run:
Fixed the hose, and another coolant leak on the front bridge, then went for another run, but the engine was overheating, and the cooling system on the dyno didn't seem to be working. After some discussions, we decided to modify the front coolant bridge and plug the bypass port of the water inlet (behind where the thermostat would normally sit). As the dyno has its own thermostat, we were running with no 'stat in the engine, so the bypass line was wide open all the time.
This modification sorted out the overheating problem, so we went for another test run. Here's a video of the exhaust - straight pipes, baby! They sound pretty good, if a bit blubbery 'cause of the rich AFR:
Here's one of the front showing the timing belt running smoothly finally:
And with a timing light on it. Lot of good it did to have the timing light, since I decided not to put the timing cover back on, 'cause we wanted to watch the timing belt & trigger wheel!
Here's a couple of pics showing the Denso IK20 plugs after the runs. Yeah, we're a bit rich ;-)
These are 1, 3, 5, 7 from left to right:
And 2, 4, 6, 8 left to right:
Left bank apparently is running richer than the right bank, except for #5 which looks leaner than the others. Not sure what to make of that, other than perhaps we've got some left/right fuel/air distribution issues. At least the four corners don't appear to be leaner than the middle cylinders, which was my big fear about building this motor with this ghetto carb setup.
Another odd thing was happening - the plug wires (which were for a '97 Mustang) weren't seated well down in the plug wells of the Lexus motor, and were working their way up in the wells, and causing the engine to misfire. I had to use these plug wires in order to get the special connectors on them for the EDIS coilpacks, but they were just a bit too short for the deep wells of the 1UZ.
So, goals for today are:
1) Fix the plug wire problems
2) Rejet the carb to lean it out
3) Install the MegaJolt Lite Jr. controller so we'll have variable timing. (We ran yesterday with the static timing provided by the "limp" mode of the EDIS)
4) Do a couple of power pulls :scared: