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Rob

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Back from Katech, Again. Second Time a Charm?
For the last three months there hasn't been any Blue Bullet blogging because the car was at Katech a lot longer than expected. Last summer, after they pulled the motor out of the car and tore it down, Katech decided to set the rebuild aside while they embarked upon a program which researched improvement of oil consumption of their "Street Attack LS7" engine packages. To do this they built an in-house test engine and tried different cylinder wall preparations, different pistons, different piston-to-bore dimensions and different oil ring tensions to see what affect those changes might have on oil use. Compared to how they have done Street Attack LS7s in the past, They settled these four updates for my engine:

1) Pistons made of 4032 forged aluminum rather than 2618 forged aluminum.
2) Different cylinder wall finish
3) Revised piston-to-bore clearance
4) Higher oil ring tension

In late September, they emailed me saying the engine would be done at the end of October, so I got on the Southwest Airlines site and booked a one-way ticket to Detroit Metro. On 30 October, I caught a Jet to Detroit and got a room in Clinton Township, right near Katech. The next day, I went over to Pontiac to do lunch with Tom Read, the media contact at GM Global Propulsion Systems to discuss some future writing work I may do on the 8L90 eight-speed automatic transmission. After that, it was over to Katech to pick up my long lost Blue Bullet. Then, I returned my Hertz car and retired to my hotel with a take out burger and fries from Mickey Ds. Munching on a Quarterpounder, I sat at the desk reading tomorrow's weather forecast on my laptop.

On the Road, Again

The trip back to California would start the next day with a run south to Cape Girardeau, Missouri to take care of some business relating to the 2019 National Corvette Caravan. Cape. G is on the Mississippi in the southeast corner of the state. I would drive southwest from Clinton Twp. to Indianapolis to pick up Southwest Caravan Section Captain, Tony Megowan. He and I would continue on to Cape Girardeau where, the following morning, we'd meet with members of Corvettes of Southeastern Missouri and the staff of the Cape Girardeau Convention and Visitors Bureau. Those folks are planning an event on the sixth and last night of the trip for Caravaners in four Sections: our Southwest along with the Pacific Central, Oklahoma/Texas Pan Handle and Kansas/Missouri.

It rained for almost the entire drive down to Cape G. Fortunately, "real" winter weather had yet to arrive in the upper mid-west, so while we got wet, there was no snow or freezing temperatures. The Blue Bullet is a '12 ZO6 w. the ZO7 performance package which normally has the car on Michelin Cup tires, which are ultra-performance, "almost race tires" with limited rain grooves, reduced tread depth and a soft tread compound. Because Caravans and their pre-run trips can require driving in bad weather, about a year ago, Michelin supplied the Southwest Caravan Organizing Team with a set of Michelin Pilot Super Sport tires to put on my car. PSSes have full-tread-depth with a tread configuration much better suited for wet weather driving. We'll, also, use Pilot Super Sports for the Caravan next year.

The following day, after our morning meeting, we began "PreRun4", a recon trip over five days worth of the seven-day route the Southwest Section would take in 2019, but going in the opposite direction. From Cape G., we headed back north to Kansas City, Missouri for a meeting the next day with people at the National Airline History Museum. The Southwest and Pacific Central Sections will come to the Museum for a catered, sit-down dinner on the fifth night of the Caravan. Following that will be a presentation about the Museum's Lockheed Super Constellation, a long-haul, airliner which first flew in 1956 and was the state-of-the art at the end of the propeller-driven era when air travel was a more unique experience than it is, today.


On Sunday morning, 4 November, we scouted a large large parking area near our hotel to use for Caravan Departure. After that, we bid farewell to K.C. and were rolling west on I-70 headed for Colby, Kansas to try out a hotel the Southwest Section will use on Night Four of the Caravan and to inspect a departure point at a nearby Walmart parking lot.

Mountain Snows

On Monday, the plan was to drive to Grand Junction, Colorado to both try out one of the hotels and look for a departure point. This part of PreRun4 was an adventure as we crossed the Rocky Mountains on Interstate 70 in a snow storm. The weather around the Eisenhower/Johnson Tunnel and Vail Pass was forecast to be: snow showers with up to half-an-inch accumulation and temperatures in the low-30s. I knew, once we got as far west as Aspen, the snow would stop and the weather for the rest of that day's run would be ok. I, also, knew the Blue Bullet, with its Pilot Super Sports, would be fine driving through snow showers as long as we traveled at a safe speed and the snow turned to slush once it stuck. Since it was not supposed to go below 30°, I didn't think ice would be a problem because the road stays warmer than the air. Not wanting to use two days to detour south into New Mexico and Arizona, I decided before we left Colby Monday morning to trust the "weather guessers" and stick to the Caravan route, going right up I-70 through whatever show showers we found.

The forecast was spot on. As we approached the Eisenhower/Johnson Tunnel, it began to snow and when we came out on the west end of the tunnel, there was definitely a show shower, but it was slushy on the ground and there was no ice. We drove through the snow shower to Vail where we got gas. As we continued west, snowfall lessened and once we got to Aspen, it stopped.

In Grand Junction, after 1951 miles, I checked the oil for the first time. I added 1.5-qts of Mobil 1 5W30, the oil Katech put in the engine. The engine had averaged 1300 miles per quart which didn't make me very happy as it was actually worse oil use than the same trip almost a year before after the original Katech build, but...there would be better news when I checked the oil, again, at the end of the trip.

On Wednesday, 7 Nov., after the "PreRun4 snow adventure" the previous day, we crossed the high desert of eastern Utah on I-70. I've been over this route three times since 2016 on Caravan pre runs and, prior to that, almost a dozen times, but I can never get enough of the exceptionally beautiful, 105-mile stretch of highway between Green River and Salina Utah. Caravaners are going to love this part of the trip, not only for the fantastic eye candy but, also, for the 80-mph speed limit the State of Utah has on most of I-70 from the Utah/Colorado line to where it ends at I-15 about 25 miles north of Beaver, Utah and then continuing on I-15 most of the way to St. George.

We overnighted in Henderson NV and on the last day on the trip we drove to Tony's place in Ventura, where I dropped him and then I made run north on US 101 to Goleta. After 2866-mile trip home was over, I checked the oil. The oil level was the same as it was after I added oil in Grand Junction two days before so, on the final 915-miles the engine used no oil and its average oil use for the trip was a little under a quart every 2000 miles–definitely an improvement.

More Testing Needed
At this point, the oil consumption of my rebuilt Katech Street Attack LS7 is better than before. Interestingly enough, according to data the Katech people supplied me back on 31 OCT when I picked-up the car, the engine is, also, making a little more power, surprising since the changes made to improve oil consumption sometimes cause slight friction increases which costs a little power. On Katech's engine dynamometer, the Blue Bullet's Street Attack LS7 made 614-hp@6900-rpm SAE corrected, about 15-hp more than the same engine produced after the original build up.

I have another about 1000 street miles to put on the car before I can establish a good number for oil use going forward.

For the last three months there hasn't been any Blue Bullet blogging because the car was at Katech a lot longer than expected. Last summer, after they pulled the motor out of the car and tore it down, Katech decided to set the rebuild aside while they embarked upon a program which researched improvement of oil consumption of their "Street Attack LS7" engine packages. To do this they built an in-house test engine and tried different cylinder wall preparations, different pistons, different piston-to-bore dimensions and different oil ring tensions to see what affect those changes might have on oil use. Compared to how they have done Street Attack LS7s in the past, They settled these four updates for my engine:
 

LLC5

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Joined
Sep 28, 2004
Messages
2,299
Location
Wa.
Corvette
98 black 6spd convert.
Those 4 updates would lead most people to believe that the aftermarket tune had little to do with the missing cylinder bore cross hatch and oil consumption in the first engine.
 

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