The morning was spent talking about various subjects while waiting for
everyone to arrive. Geoff entertained question after question about
development, calibration, testing, temperature, materials, and a host of
other subjects. He showed us many interesting
things he had in his shop. One among many interesting tidbits was an
LT-5 ladder, which Geoff is showing us on the right here.
The crosspieces are steel, mounted in an aluminum frame that forms the bottom
part of the block. This design was precipitated at the insistence of GM.
Geoff told us that the first try at this design had the problem that the
steel crosspieces would work themselves loose in the softer Aluminum so that
they would actually slide laterally. This was fixed by extending the steel
sections so that the bolts holding the two pieces of the block together
pass through them as well as the Aluminum.
The discussion filled up the morning quite nicely, with Geoff periodically disappearing into the back room to bring out another interesting artifact or drawing to discuss or to demonstrate a point. Some issues were settled, some were not, but progress was made on all fronts.
By lunchtime everyone had arrived, including Jordi who drove his ZR-1 up from
Spain.
This yellow beast was quite a noisemaker since the catalytic converters
and the mufflers were oddly missing. You can see Corey here taking his turn
at seeing
the lack of pieces for himself. We had lunch at a pub down the street from
the shop, and after some more discussion turned our attention to the Yellow
LT-5 that Geoff had prepared to be assembled before our very eyes.
The plan was to get the heads and cams on (Daniel had deftly installed the pistons while we chatted the morning away) but things did not turn out so smoothly. The oil pump decided to be stubborn and didn't want to turn, and the actuation system for the butterflies in the secondary intake ports needed a bit more work than expected. So after another few hours of conversation, we left Geoff to take care of some other things he needed to do, and Daniel working on getting the heads prepared for assembly the next day.
All arrived Friday morning ready to get to it. The
assembly process went along pretty
smoothly from here, with only a few glitches along the way, which Geoff
and Daniel took
in stride and worked out. By lunch time both heads were on and the cams were
in and set to factory timing. That is how it is shown here, the T-shaped tools
are essential to setting the factory timing. The crank is set to top dead
center on cylinder number 1 and the T-shaped pins are put in holes that are
machined in the cams. The chain sprockets can then be tightened on to the
cams. This sets the factory timing within about a degree.
We all thought was
quite ingenious in its simplicity, designed to speed things along on the
assembly line. It was decided that this was a great stopping
point and the re-timing of the cams would be a suitable project for after
lunch, since we wanted a slightly different timing from factory.
With that we headed off to lunch at the same pub as the previous day, as the discussions continued non-stop.
The afternoon was spent timing the cams. Quite a job. If you're interested
in the process, check out the assembly page.
We set the cams to 110o intake and exhaust. This process took
basically all afternoon, setting up all four cams. Geoff showed great
patience and made sure everyone understood what he was doing, how one should
go about doing it, and giving insight into why it was done that way. As the
cams were timed, the cam covers were put on bolted down. Finally, all the
yellow parts were put on for the photo shown here. A good days work
considering all that we learned about the engine, the design and the process
of building it.
Geoff had some more to do that evening (man, does this guy work hard) so after a bit more talking (had a lot of that this weekend if you didn't notice), we left him in peace for the evening and went off to get some grub.
This was electronics morning. Geoff showed us what the chip was, and how it
was programmed, including the inch thick printout of the calibration data.
(this not include the 3 inches of program printout). The whole setup is shown
here. Including, the ECM specially made for testing, the panel that allows
only the most rudimentary adjustments to be made while the vehicle is running,
th chip in its small blue case, and finally the all-important PROM burner
used to modify the chip or make new ones. Keep in mind that this is 1987
technology, it's much more modern today, as Geoff demonstrated to us on his
laptop.
This ended the educational portion of the weekend, and the visitors all ran off to do a little touring, since we were in England after all.